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The Journal of
arachnOlogy
OFFICIAL ORGAN OF THE AMERICAN ARACHNOLOGICAL SOCIETY
VOLUME 3
JANUARY 1975
NUMBER 1
,1. //
THE AMERICAN ARACHNOLOGICAL SOCIETY
President Beatrice R. Vogel Billings, Montana
Vice President Vincent D. Roth Southwest Research Station, Portal, Arizona
Secretary-Treasurer Journal Editor
Mel E. Thompson Robert W. Mitchell
Whittier Narrows Nature Center, Texas Tech University, South El Monte, California Lubbock, Texas
Charles D. Dondale Entomology Research Institute, Ottawa, Ontario
Directors Jon Reiskind University of Florida, Gainesville, Florida
Robert X. Schick
California Academy of Sciences,
San Francisco, California
The Society was founded in August, 1972, to promote the study of arachnids, to achieve closer coopera- tion and understanding between amateur and professional arachnologists, and to publish The Journal of Arachnology. Membership is open to all persons interested in the Arachnida. Annual dues, which include subscription to the Journal, are $10.00 for regular members and $5.00 for student members. Institutional subscriptions to the Journal are $10.00. Correspondence concerning membership and subscription should be sent to the Secretary-Treasurer, Mel E. Thompson, Whittier Narrows Nature Center, 1000 North Durfee, South El Monte, California 91733.
THE JOURNAL OF ARACHNOLOGY
Editorial Board
Willis J. Gertsch B. J. Kaston Martin H. Muma Anita Hoffmann-Sandoval
Portal, Arizona San Diego State College, Silver City, New Mexico Instituto Politecnico Nacional,
San Diego, California Mexico, D.F.
William B. Muchmore William A. Shear Stanley C. Williams
University of Rochester, Hampden-Sydney College, San Francisco State College,
Rochester, New York Hampden-Sydney, Virginia San Francisco, California
Norman Platnick Herbert W. Levi
American Museum of Natural History Harvard University
New York, New York Cambridge, Massachusetts
Assistant Editor J. Mark Rowland Texas Tech University, Lubbock, Texas
Editorial Assistants
James R. Reddell Paula Steed
Texas Tech University, Lubbock, Texas
The Journal is published in January, May, and August with the assistance of the Graduate School, Texas Tech University. Members should send their manuscripts and related correspondence to the Editor, Robert W. Mitchell, Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409.
INSTRUCTIONS TO AUTHORS
GENERAL COMMENTS
1) Papers are acceptable from members of the Society in the following languages: English, French, Portu- guese, and Spanish. 2) All manuscripts must be typed and must be double or triple spaced. 3) Use good bond paper but not erasable bond. 4) Leave ample right and left margins, at least 1 Wz in. on the left. 5) Do not hyphenate any words at the right margin; it is immaterial how irregular this margin is in manuscript. 6) Manuscripts need not be letter-perfect, but any corrections should be minor ones and should be neatly done. 7) One copy of the manuscript is sufficient; authors should retain a copy. 8) Manuscripts requiring substantial revision after review must be retyped.
FEATURE ARTICLES
1) Arrange parts of the manuscript in the following sequence: mailing address, title, by-line, body of text, acknowledgments, literature cited, figure legends, abstract, footnotes, running head, tables with legends, and figures. 2) Mailing Address: Include the complete address and the telephone number of that author with whom all correspondence with the editorial office should be handled. 3) Title: When using common or scientific names in the title, include in parenthesis the appropriate higher taxa necessary to identify the animal(s) to the general audience. Include footnote indication if appropriate (e.g., to acknowledge grant
(continued on inside back cover)
Muchmore, W.B. 1975. A new genus and species of chthoniid pseudoscorpion from Mexico (Pseudoscorpionida, Chthoniidae). J. Arachnol. 3:1-4.
A NEW GENUS AND SPECIES OF CHTHONIID PSEUDOSCORPION FROM MEXICO (PSEUDOSCORPIONIDA, CHTHONIIDAE)'
William B. Muchmore
Department of Biology University of Rochester Rochester, New York 14627
ABSTRACT
Mexichthonius unicus, new genus and new species, is described on basis of a specimen from Campeche, Mexico. Affinities of the new genus are discussed briefly.
INTRODUCTION
Among the numerous pseudoscorpions collected recently in southern Mexico by James R. Reddell was a single individual from Ich-Ek, Campeche, which represents an unusual new species in the Chthoniidae. Though only the one specimen is available, it is of sufficient interest to warrant describing it and erecting a new genus to distinguish it clearly from all others in the family.
Mexichthonius, new genus Mexichthonius unicus, new species.
Diagnosis (based upon female only)— With the general characters of the family Chthoniidae (see Hoff, 1949, p. 429). Carapace longer than broad, distinctly narrowed posteriorly; anterior margin with large, serrate epistome; no eyes; chaetotaxy 6-4-4-2-2=18. Palpal coxa with apex broad and truncate, bearing two setae, the lateral one short and curved medially; apex of coxa I rounded, with three small setae along medial edge; coxa II with unique row of spines, including a large, complex one laterally and a row of about seven small, simpler ones more medially; coxa IV with a prominent, rounded, asetous process at the posterior end; no intercoxal tubercle. Tergites and sternites entire; 11th stemite reduced to a very narrow, thin membrane; pleural mem- branes longitudinally striate and minutely papillate. Tergites 1 and 2 each with four setae, following ones with six; anterior genital operculum (female) with eight setae; latermost setae on sternites 5-7 much reduced in size. Chelicera about 0.7 as long as carapace; hand with four or five setae (exact number uncertain); flagellum of nine or ten pinnate setae; galea distinctly elevated. Palp generally of chthoniid facies, but femur somewhat pedi- cellate and tibia elongate ; placement of trichobothria unique in that isb and ib on dorsum of hand are arranged in tandem and some distance apart, rather than transversely paired;
‘This work was supported in part by a grant (GB 37570) from the National Science Foundation.
1
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also it is sliglitly proximad of est on fixed finger, and sb is nearer to st than to b on movable finger; marginal teeth of both chelal fingers mostly very low and irregular in shape; fixed finger with a small, internal accessory tooth at about level of third marginal tooth; movable finger with a small, rounded sensillum on external surface proximad of trichobothrium sb. Legs stout, but not unusual.
Etymology— The genus is named for Mexico, where its only representative was found.
Remarks— This genus is easily distinguished from all others in the family by the tandem, rather than transverse, placement of trichobothria isb and ib on the dorsum of the chelal hand. Superficially, the chela somewhat resembles that of Lechytia Balzan, but in the latter genus the tandem trichobothria are esb and eb (see Muchmore, 1975). Mexichthonius appears to be most closely allied to Austrochthonius Chamberlin, which has been found in South America as far north as Bolivia (see Vitali-di Castri, 1968), and to Mundochthonius Chamberlin, which is known from North America as far south as Tamaulipas, Mexico (see Muchmore, 1973). Austrochthonius the new genus shares several important characters, including: 1) coxal spines only on coxa II; 2) no intercoxal tubercle; 3) three small setae on medial edge of apex of coxa I; 4) chelal teeth contiguous and partly reduced in size; 5) placement of trichobothria of chela, except isb and ib. It is also generally similar to Mundochthonius in most of these features, but, importantly, Mundochthonius possesses an intercoxal tubercle while Mexichthonius does not. The coxal spines of Mexichthonius are quite different from those in the other two genera, consisting, on each side, of a large, complexly branched one laterally and more medially a curved row of several, smaller, finely dentate ones; in Austrochthonius there is a row of several subequal, pinnate spines on each side, while in Mundochthonius there is on each side a single, deeply incised blade or one such blade plus one or more small spinules.
Mexichthonius unicus, new species Figs. 1-7
Material— Holotype female (WM 3389.01001), taken from under a rock, 5 km. SSW Ich-Ek, Campeche, Mexico, 27 July 1973 (J. R. Reddell and J. M. Rowland).
Description of female— AH sclerotized parts very light tan. Carapace 1.2 times as long as broad, distinctly narrowed posteriorly; anterior margin with a large serrate epistome (Fig. 1); no eyes present; surface dorsally smooth, laterally finely reticulate and with scattered tiny, pointed tubercles; chaetotaxy 6-4-4-2-2=18. Coxae generally normal in proportions, but apex of palpal coxa broad and truncate, coxa I with rounded apex, and coxa IV with a prominent rounded process at posterior end and dorsal to articular socket (Fig. 2); no intercoxal tubercle. Coxal chaetotaxy 2-2-1 :mmm-2-2(l);2-4-CS:2-5-2-5; lateral seta on apex of palpal coxa short and strongly curved medially; microsetae (m) on apex of coxa I evenly spaced along medial edge; coxa II with a unique row of one large, lateral and about seven small, medial spines, the large one complexly incised and branched, the small ones with very fine, lateral spinules (Fig. 3).
Abdominal tergites and sternites entire; eleventh sternite reduced to a very narrow, thin membrane, without setae (Fig. 4); surfaces of tergites and sternites smooth; pleural membranes longitudinally striate and minutely papillate. Tergal chaetotaxy 4;4:6:6:6:6:6:6:7:4:T2T:0, sternal chaetotaxy 8:(3)6(3):(2)6(2):8:8:8:7:6:T1TT1T:0:2; genital opercula as in Fig. 5; lateralmost setae on sternites 5-7 much reduced in size.
Chehcera fairly robust, 0.7 as long as carapace; hand with four or five setae (exact number uncertain, because setae lost and bases somewhat obscure); flagellum of nine or
MUCHMORE-A NEW, PSEUDOSCORPION GENUS
3
ten pinnate setae; fixed finger with eight to nine and movable finger with nine to ten marginal teeth, evenly graded in size from tip to base; spinneret a distinct knob; serrula exterior with 15 blades.
Palp generally of chthoniid facies but with femur somewhat pedicellate and tibia slightly elongate (Fig. 6); trochanter 2.0, femur 3.65, tibia 2.0, and chela 4.05 times as long as broad; hand 1.55 times as long as deep; movable finger 1.55 times as long as hand. Surfaces of segments mostly smooth, but with sparse granulation on medial sides of trochanter, femur and tibia and on dorsal side of chelal hand. Trichobothria positioned as shown in Fig. 7; generally like other chthoniids but with isb and ib in tandem on dorsum
Figs. 1-1 -Mexichthonius unicus, new species, holotype female: 1, Anterior margin of carapace, showing epistome (setae omitted); 2, Ventral view of coxae of left palp and legs I-IV; 3, Coxal spines on right coxa II; 4, Ventral view of posterior end of abdomen, especially sternite 10, anal opercula and tergites 10 and 11 (setae omitted); 5, Genital opercula; 6, Dorsal view of right palp; 7, Lateral view of left chela.
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THE JOURNAL OF ARACHNOLOGY
of hand rather than transversely paired; it lying at level of or slightly proximad of est on fixed finger; sb closer to st than to b on movable finger. Fixed finger with three small cusped denticles just behind terminal tooth, followed by 33 low, irregular elevations of the dental margin, and with a small accessory tooth on internal surface at level of third small denticle; movable finger similarly with three small denticles followed by about 27 low, irregular elevations. Movable finger with a small sensillum on external surface near dental margin, between sb and b.
Legs generally typical, fairly robust; leg IV with entire femur 2.1 and tibia 4.3 times as long as deep. Leg IV with tactile setae on metatarsus and telotarsus.
Male— Unknown.
Measurements (mm)— Body length 1.16. Carapace length 0.42. Chelicera 0.30 by 0.17. Palpal trochanter 0.16 by 0.08; femur 0.385 by 0.105; tibia 0.22 by 0.11; chela 0.525 by 0.13; hand 0.21 by 0. 135; movable finger 0.325 long. Leg IV: entire femur 0.36 by 0.17; tibia 0.26 by 0.06; metatarsus 0. 13 by 0.045; telotarsus 0.23 by 0.03.
Etymology— The species is named iinicus because of its strikingly unique character- istics, which place it in an interesting new genus.
LITERATURE CITED
Hoff, C. C. 1941. The pseudoscorpions of Illinois. Bull. Illinois Nat. Hist. Surv. 24:409-498. Muchinore, W. B. 1973. New and little known pseudoscorpions, mainly from caves in Mexico (Arachnida, Pseudoscorpionida). Bull. Assoc. Mexican Cave Stud. 5:47-62.
Muchmore, W. B. 1975. The genus Lecliytia in the United States (Pseudoscorpionida, Chthoniidae). Southwestern Nat. 20 (in press).
Vitali-di Castri, V. 1968. Austrochthonius insidam, nouvelle espece de Pseudoscorpions de I’Archipel de Crozet (Heterosphyronida, Chthoniidae). Bull. Mus, Hist Nat., Paris. 40:141-148,
Shear, W.A. 1975. The opilionid geneidL Sabacon and Tomicomerus in America (Opiliones, Trogulidae, Ischyropsalidae). J. Arachnol. 3:5-29.
THE OPILIONID GENERA SABACON AND TOMICOMERUS IN AMERICA (OPILIONES, TROGULOIDEA, ISCHYROPSALIDAE)
William A. Shear
Department of Biology Hampden-Sydney College Hampden-Sydney, Virginia 23943
ABSTRACT
The ischyropsalid genera Sabacon and Tomicomerus in America are reviewed, and three new species of Sabacon are described from the western United States. The family name Sabaconidae Dresco is evaluated and not accepted as distinct from Ischyropsalidae. Sabacon crassipalpe (Koch), described from Siberia, probably does not occur in America. The genus Tomicomerus and its single species T. bryanti are redescribed from the single known specimen.
INTRODUCTION
The opilionid genus Sabacon was established in 1879 by Eugene Simon, for the Euro- pean species S. paradoxum. Species of the genus are easily distinguished from any others within the superfamily Troguloidea by the peculiar pedipalpi— they are usually much thickened and densely set with stiff, fine setae. The palpal tarsus is short, pyriform, and reflexed against the longer tibia. As yet the adaptive or functional significance of these palpi remains unknown.
In the same year as Simon’s publication, Koch (1879) described Nemastoma crassipalpis from eastern Siberia, but his description left no doubt that he was dealing with a species of Sabacon. In America, the first species of Sabacon to be described was S. cavicolens, which A. S. Packard (1884) placed in a new genus, Phlegmacera . In 1893, Weed described Sabacon spinosus from New England, but his correct generic placement was ignored until 1914, when Roewer synonymized Phlegmacera with Sabacon. Follow- ing these original reports, species of the genus Sabacon have proven to be widespread in the northern hemisphere in temperate climates, even extending into the subarctic. The most southerly records are from high elevations in Nepal and from caves in the south- eastern United States.
The center of speciation and diversification in Sabacon would appear to be in Asia. Suzuki (1964, 1965, 1966, etc.) and other workers in Japan have described a half-dozen or more distinct species from Japan and Korea, and more recently. Martens (1972) has described six unusual species from Nepal. In contrast, Europe probably has at the most four rather poorly differentiated species. In North America, the new species described below bring our total to six, four of which are found in the Pacific northwest.
The genus Tomicomerus has a simpler history. Banks (1898) described Phlegmacera bryanti as a new species from the Malaspina Glacier, near Mt. St. Elias, Alaska. Unfortu- nately, as is frequently the case with Banks’ opilionid work, the description did not
5
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THE JOURNAL OF ARACHNOLOGY
involve direct and detailed comparison with other related, described species. In 1899, Pavesi apparently obtained material of the same species and described it as Tomicomenis bispinosus. His description contained data which clearly set the species apart from others in Phlegmacera (Sabacon), and subsequently Banks and others recognized Pavesi’s generic name, but priority dictated the use of the combination Tomicomenis bfyanti (Banks). My first impression was that Tomicomenis would become a synonym of Sabacon, since the main diagnostic feature, false articulations in the leg femora, is to be found in two Japanese and one American species that are otherwise well accommodated in Sabacon. The materials used by the original authors have long since probably been lost, and no illustrations have ever been made. A single specimen, albeit in poor condition, is in the American Museum of Natural Histoiy. Tomicomenis is a fully distinct genus sharing characters oi Sabacon and Taraciis.
TAXONOMIC CHARACTERS
Despite a wealth of characters useful in distinguishing species from one another, it is becoming apparent that attempts to group species and genera of the superfamily Troguloidea into meaningful families presents difficulties. So long as one uses the typo- logical concept of “generic characters’ or “familial characters,” the task appears simple. However, detailed studies (Martens, 1969, 1972; Gruber, 1970) are beginning to reveal that these characters are distributed in various ways throughout species groups. Only when the known genera have been revised in detail, and most of the species surveyed, will it be possible with an assurance to group them into meaningful families. I suspect that there will be considerable debate over the eventual extent of the family Ischyropsalidae, in particular.
Martens (1972) has noted, following Suzuki and other Japanese authors, that within the genus Sabacon, the Asian species are easy to differentiate from one another on the basis of the male genitalia. The same appears to be true of the North American species. Sabacon occidentalis and S. siskiyou share many similarities, and, indeed the females are difficult to separate on the basis of qualitative characters. However, the male genitalia, particularly in the terminal parts, are distinctive. Of considerable use in males, but rather less so than the genitalia, are the palpi and chelicerae, especially the glands of the latter. The proportions of the palpi are somewhat difficult to assess because of the highly three-dimensional nature of these appendages and the consequent difficulties of arranging the palpi of several specimens for measurement so that the positions duplicate one another. The teeth found on the distal inner part of the male palpal patellae are useful, though the three western species for which males are known are quite similar in this respect. In the eastern species, S. cavicolens males have one or two such teeth, while S. mitchelli males have a large distal tooth and a row of tiny denticles.
Females not associated with males can be difficult, particularly if two similar species are sympatric, as is the case with S. occidentalis and S. siskiyou. Fortunately, it appears that these two species can be separated on the basis of the proportional lengths of the legs and the relative sizes of the postocular spines. Likewise, females of S. mitchelli are considerably smaller than those of the sympatric S. cavicolens. Females of S. astoriensis are not known. Sabacon briggsi is known only from the distinctive females, which have a pointed genital operculum and quite short legs when compared to S. occidentalis or S. siskiyou.
Immature specimens of two sympatric species are nearly impossible to separate, and
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
1
the bulk of the available material is immature. In the case of S. cavicolens, which occurs alone over a wide area, I have included immature specimens in the records (Map l)to give a more complete picture of the distribution of this species. In the west, immatures have not been included because of the strong possibility of the presence of additional unde- scribed species.
NOMENCLATORIAL PROBLEMS
1. Family Sabaconidae Dresco. Dresco (1970) removed the genus Sabacon from the family Ischyropsalidae. and placed it in the newly named, monobasic family Sabaconidae. His major reasons for doing so can be summarized in the following chart (translated from Dresco, 1970):
ISCHYROPSALIDAE SABACONIDAE
carapace margin indented; chelicerae enlarged
tergites heavily sclerotized
chelicerae of some males with a disto-apical “boss,” never such a structure near middle (of basal segment)
palpi with scattered hairs, long and thin, juvenile specimens sometimes with a tarsal claw
carapace margin even; chelicerae not enlarged
tergites not heavily sclerotized
basal segment of chelicera of males with a “boss” near middle of segment
palpi short and stout, densely set with stiff bristles never a tarsal claw
apical part of penis with spines
apical part of penis without spines
Dresco’s conclusions are based on the European species of Sabacon and his own detailed study of the genus hchyropsalis . Martens (1969), in probably the most detailed study ever made of any group of opilionids, revised the gQnm hchyropsalis , and discovered that there were far fewer species than had been previously thought, and that the taxonomic characters previously used (size, shape, and spination of chelicerae, degree of fusion of abdominal tergites, teeth of the palpal patella, etc.) were not very useful. By means of actual mating experiments. Martens found that what he called “biospecies” of hchyropsalis (reproductively isolated populations) were best marked by differences in the cheliceral glands of the males. These glands are located distoapically on the basal cheliceral segment and are evidently what Dresco (1970) refers to as “bosses.” Martens (1969) found that these glands produce a secretion on which the females feed during copulation. He then used differences in the cheliceral glands of the same degree found in his biospecies to delimit “morphospecies,” or populations which by analogy might be reasoned to be reproductively isolated. It is significant to note that Martens found the traditional species-marking characters listed above to be distributed through his biospecies and morphospecies in various ways.
Because Dresco failed to consider a full range of Sabacon species, and members of other genera related to hchyropsalis in his study, the characters used to distinguish
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THE JOURNAL OF ARACHNOLOGY
Sabaconidae as a family do not hold up. Some American Sabacon species have the carapace indented in front, as in Taracus and Ischyropsalis, and the margin continues ventrally between the chelicerae. The enlarged chelicerae of the latter genera are simply adaptations for snail-eating (There is no direct evidence about the dietary habits of Taracus. H, W. Levi, personal communication, could not induce a Colorado species of Taracus to eat snails.) and do not of and by themselves indicate a close relation- ship. Some American and Asian Sabacon males are rather heavily sclerotized, and the degree of fusion of abdominal tergites is at best a species-level character in Sabacon.
Martens (1969) has elucidated the functional significance of the cheliceral glands of Ischyropsalis species males. It might be assumed that the glands of Sabacon males have a similar function. The presence or absence, or position of the glands is not of family-level significance. Taracus species lack the glands, and are otherwise typical ischyropsalids; Sabacon mitchelli is a typical species of that genus without enlarged glands, and some of the Japanese species lack them also. The form of the palpus sets apart the species of Sabacon from all others, but as its adaptive significance is not known, it may prove to be simply a specialization of the more general type of troguloid palpus. The absence of a claw in the juvenile stages is of little importance. And finally, the form of the penis is essentially similar in both groups. There are other ischyropsalid genera {Taracus, Ceratolasma) in which the penis is much more different from that of Ischyropsalis than in Sabacon.
For these reasons, I follow Martens (1972) in not recognizing Dresco’s family name Sabaconidae, and include Sabacon with the ischyropsalids. I should add here, however, that I do not agree at this time with Gruber (1970) in pldicing Hesperonemastoma in the Ischyropsalidae, nor with Martens’ (1971) implication that Ortholasma, Cladolasma, Dendrolasma, Trilasma, Crosby cus da\(\ Ruaxphilos belong there also. I plan to discuss this matter in detail in subsequent revisions dealing with these genera.
2. The status of Sabacon crassipalpe (Koch). In 1914, Roewer synonymized the three described species of American Sabacon {cavicolens, spinosus and occidentalis) with the Siberian S. crassipalpe. He has been followed in this ever since by most American authors (but see Crosby and Bishop, 1924), despite the fact that the evidence for such a synonomy does not exist. Koch’s original description (1879) suggests little except that he was dealing with a species of Sabacon. There is nothing in the description that points to any particular species of the genus described since 1879, and as Asia undoubtedly has many as yet undetected species of Sabacon, it no longer seems justifiable to accept the tradition of American “Sabacon crassipalpe.” In 1923, Roewer, in his enormous com- pendium, Die Weberknechte der Erde, indicated that he had not seen specimens of either S. crassipalpe or S. cavicolens, and based his discussion solely on specimens of S. occidentalis sent him by Nathan Banks. Sabacon occidentalis is a distinct species and not a synonym of S. cavicolens, though S. spinosus is. Considering Koch’s description, and the fact that the types of S. crassipalpe are probably no longer in existence, 5. crassipalpe should no longer be used as a name for North American forms and probably should be considered a nomen dubium.
3. The status of Sabacon jonesi Goodnight and Goodnight. Goodnight and Goodnight (1942) described S. jonesi from a single specimen taken in Natural Well Cave, near Monte Sano, Alabama. Although they stated that the holotype was a male, I found the undis- sected animal to be an early instar juvenile, possibly second or third, as suggested in the original description by the small size, weak pigmentation and sclerotization and ex- tremely long legs. It is in fact similar to many immature specimens of 5'. cavicolens I have
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
9
examined. However, I hesitate to synonymize this name with S. cavicolens because the holotype of S. jonesi represents a far-southern record of the genus and may indeed prove to be a distinct species if and when mature material is collected. The holotype is in the American Museum of Natural History and is in poor condition.
NATURAL HISTORY
Species of the genus Sabacon almost universally seem to prefer moist, cool micro- habitats. Many records are from caves, especially in California and the southern Appala- chians, but none of the species are found there exclusively, or are modified for cave life. On the surface, specimens are usually found in areas such as moist, shaded ravines or well-developed forests where the humidity is high and temperatures are apt to be low.
Most of my personal observations have been made on S. cavicolens. The greatest success I have had in collecting this species has been at high elevations in mid-autumn. In the mountains of western North Carolina, at elevations over 5000 ft, the forest consists mostly of spruce, with Fraser fir becoming more prominent at higher elevations. Collect- ing in October on high peaks such as Richland Balsam and Waterrock Knob usually yield fair numbers of mature specimens of both sexes. Because individuals are apt to mature even later at lower elevations, after the normal collecting season in the northeastern United States is over, mature individuals of S. cavicolens are rather rare in collec- tions. Most of the animals are to be found under wet rotting logs, or clinging to the undersides of stones; I have never seen any walking about actively during the day. Move- ments tend to be sluggish, certainly not as rapid as in other opilionids of similar form. High humidity seems to be the crucial requirement, and live specimens are difficult to keep and transport. I have never had any success in getting 5”. cavicolens back from the field alive. Collection notes on preserved specimens of the western species suggest a usual association with conifers and damp, cool microhabitats also. The holotype of S. astoriensis was collected in a Berlese sample of vegetable matter, including conifer duff and dried seaweed, taken from beach dunes in Oregon.
EVOLUTIONARY RELATIONSHIPS
Sabacon cavicolens, generally distributed over the eastern part of North America, south in the mountains to North Carolina, is very closely related to S. paradoxum of Europe. The known European species are likewise very similar and appear to be closely related. The other eastern species, S. mitchelli, is known only from a few high peaks in the southern Appalachians. It is quite different from S. cavicolens: the males lack cheliceral glands and do not have the first several abdominal tergites fused. They are also considerably smaller. The origins and affinities of this species are difficult to postulate, though it could be a relatively recent (Pleistocene) derivative of an isolated pie-cavicolens populations. The penis is very similar to that of cavicolens.
The western species seem most closely related to Asian forms (see Suzuki, 1964, 1965, 1966, etc.), though S. occidentalis and S. siskiyou also resemble cavicolens in many respects. With its unique chelicerae, genitalia and false articulations in the leg femora, S'. astoriensis is much more closely related to Japanese species such as S. dentipalpe andS. makinoi. Although only a single male has been collected, it was taken from a unique (for Sabacon) habitat— dried seaweed and debris in beach dunes.
Tomicomenis bryanti is a unique animal that combines features found in “typical”
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ischyropsalids and those found in Sabacon. Cheliceral glands are apparently absent, how- ever. The palpi are armed with setae similar to those found in Sabacon, but are much more slender. The chelicerae are enlarged, but not as much as in Taracus. The femora of the legs have false articulations. What could be learned of the male genitalia from the single damaged specimen suggest Taracus rather than Sabacon. New material of this enigmatic species would be very welcome; it may represent an old stock that originated prior to the differentiation of the snail-eating genera.
A KEY TO NORTH AMERICAN TROGULOID GENERA
I present the following key without attempting to group the genera into families, since that is a question about which there is currently disagreement among taxonomists.
la. Palpi stout, heavily set with stiff bristles (Fig. 12); cuticle mostly leathery,
but well-sclerotized in males of some species; northeastern United States and southern Canada south in the mountains to North Carolina, central California north to southern Alaska Sabacon
lb. Palpi more slender, not as heavily set with stiff bristles, but with more
scattered, often glandular, hairs 2
2a(lb). Chelicerae enlarged, sometimes enormously so, the sum of the lengths of the
two segments equal to or exceeding the length of the body .3
2b. Chelicerae normal, not as described in 2a 4
3a(2a). Chelicerae set with seta-bearing tubercles; leg femora without false articula-
tions; Rocky Mountains from Alberta south to New Mexico, Coast Ranges and interior mountains of California, Oregon, Washington and British Colum- bia Taracus
3b. Chelicerae smooth except for two proximal tubercles on distal segment (Fig.
34); leg femora with false articulations; region of Mt. St. Elias, Alaska
Tomicomerus
4a(2b). Length of body about 1 mm or less; legs covered with curly, decumbent setae; scattered localities in northeastern U.S., including New York, Ohio,
Michigan, Missouri, West Virginia, North Carolina, Illinois and Indiana
Crosbycus
4b. Length of body greater than 1 mm; legs without decumbent curly setae . . .5
5a(4b). Abdominal scutum and cephalothorax not separated by suture; palpi as long as or longer than body length; southern Appalachians as far north as Virginia; Illinois, Arkansas, Mississippi, Pacific northwest from northern California to
central British Columbia Hesperonemastoma
5b. Abdominal scutum and cephalothorax clearly separated by suture; palpi not
as long as body length 6
6a(5b). Eye tubercle not extending forward over chelicerae, but with a short pro- jection; dorsum poorly sclerotized; Veracruz Ruaxphilos
6b. Eye tubercle extending forward over chelicerae; dorsum well sclerotized . . .7
7a(6b). Ornamentation of abdominal dorsum consisting of large, blunt tubercles; eye tubercle lacking dorsal or lateral projections; Oregon Ceratolasma
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
11
7b. Ornamentation of dorsum consisting of chitinous pegs and spines connected
laterally to each other, especially on posterior margins of free abdominal segments, giving appearance of “lattice-work” suspended above dorsum; eye tubercle with lateral and sometimes dorsal projections 8
8a(7b). Eye tubercle with dorsal projections similar to ornamentation of dorsum; Mex- ico Trilasma
8b. Eye tubercle without dorsal projections 9
9a(8b). Lateral projections of eye tubercle connected to each other by chitinous
crossbars, giving appearance of perforations at margin of eye tubercle;
southern California (San Diego) north to southern Oregon Ortholasma
9b. Lateral projections of eye tubercle not connected; northern California to
central British Columbia Dendrolasma
Simply because generic names appear in the above key does not mean that I think them valid, but instead, I feel each should be handled in detail, in the context of a generic revision. I might here suggest, however, that Trilasma and Dendrolasma probably ought to be considered synonyms of Ortholasma, and that Ruaxphilos, known from a single, probably immature specimen is very like juveniles of this same group of species.
TAXONOMY
Family Ischyropsalidae Simon Genus Sabacon Simon
Sabacon Simon, 1879, Arachnides due France 7:266; Roewer, 1914, Arch. Naturg
80(3):123, 1923, Weberknechte der Erde, p. 694, 1950, Senckenbergiana 3 1 :52; Com- stock, 1940, The Spider Book (revised by W. Gertsch). pp. 77-78; Bishop, 1949, Proc.
Rochester Acad. Sci. 9(3): 173.
Nemastoma (part), L. Koch, Svenska-Akad. Handl. 16(5):111 N. crassipalpis Koch only. Fhlegmacera Packard, 1884, Amer. Nat. 18(2):203; Banks, 1901, Amer. Nat.
35(416):677.
Type-species— Of Sabacon, S. paradoxus Simon 1879 (name emended to paradoxum by Roewer, 1914), by original designation; of Phlegmacera , P. cavicolens Packard 1884, by original designation and monotypy.
Diagnosis— No other opilionid genus has the enlarged, bristly pedipalps of Sabacon species (Figs. 2, 12, etc.).
Description— Carapace usually broader than long, limits of sclerotized area often poorly marked; second thoracic tergite free and usually sclerotized, bearing on the midline a pair of prominent spines. Abdominal tergites sometimes fused to each other in males (scutum parvum of European authors), but last three tergites always free; in females each abdominal tergite sometimes divided at midline, usually small and poorly sclerotized. In both sexes, abdominal cuticle often with short, black setae, these fre- quently on cones on sclerotized tergites. Eye tubercle small, usually not ornamented (There is a spine on the eye tubercle in one Nepalese species, see Martens, 1973.), set back from margin of carapace; eyes small. Ozopores in usual position, small, not promi- nent. Front margin of carapace with a distinct median notch, or broadly indented between chelicerae, extending between chelicerae to large, triangular labrum; labmm well
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sclerotized. Labium small, suboval. Sternum small, inconspicuous, sometimes not detect- able in adults, in juveniles with two stout setae. Coxal endites of pedipalps and first legs large and prominent, sclerotic portion crescentic, sometimes with small setae. Coxal endites of legs two, three and four completely suppressed, not at all evident. Genital operculum large, blunt or pointed, setose, usually covering sternal area. Sternites of abdomen prominent, usually sclerotized, setose. Spiracles small, slit-like, nearly closed by cuticular granules. Legs long and thin in males, usually shorter and much stouter propor- tionally in females, with or without false articulations in femora and tibiae; accessory spiracles in tibiae lacking. Pedipalps much enlarged, femora and patellae cylindrical, patellae of males with distal teeth, tibiae much swollen distally, tarsi without claws, pyriform, reflexed on asetose areas of tibiae; patellae, tibiae and tarsi densely set with stiff setae that are not obviously glandular. Chelicerae of females normal. Chelicerae of males of most species with swollen dorsal glands on basal articles, form of gland varies with species. Male genitalia typical of family, penis long, shaft thin, glans with dorsal and ventral plates and apical stmcture, distal parts of shaft and glans plates with various strong setae. Ovipositor moderately long, not annulated, setation variable with species, apical divisions without special sense organs.
Distribution— Northern North America, Europe, Japan, Korea, eastern Siberia, Himalaya Mts. in Nepal.
KEY TO NORTH AMERICAN SABACON SPECIES
la. Males 2
lb. Females . .6
2a(la). Femora of legs with false articulations; north coastal Oregon (females unr
known) • astoriensis
2b. Femora of legs without false articulations .3
3a{2b). Basal segment of chelicera without a knoblike gland (Fig. 1 1); high mountains
of North Carolina mitchelli
3b. Basal segment of chelicera with a knoblike gland (Fig. 1) 4
4a(3b). Tip of penis with fingerlike projections (Fig. 18); British Columbia south to
northern California .occidentalis
4b. Penis otherwise • .5
5a(4b). Cheliceral gland large, narrowed at base (Fig. 23); California, Oregon .......
Siskiyou
5b. Cheliceral gland smaller, rounded, not narrowed at base (Fig. 1); northeastern
and midwestern United States cavicolens
6a(lb). Genital operculum pointed (Fig. 33); California briggsi
6b. Genital operculum evenly rounded 7
7a(6b). Only first two abdominal segments sclerotized; high peaks in North Carolina .
mitchelli
7b. All abdominal segments with sclerotized patches ................. .8
8a(7b). Postocular spines very large and prominent (Fig. 25) siskiyou
8b. Postocular spines of normal size (Fig. 27) 9
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
13
9a(8b). Ovipositor short, sparsely setose (Fig. 8); eastern U.S .cavicolens
9b. Ovipositor longer, densely setose (Fig. 20); British Columbia south to
northern California occidentalis
Sab aeon cavicolens (Packard)
Figs. 1-8, Map 1
Phlegmacera cavicolens Packard, 1884, Amer. Nat. 18(2):203, 1888, Mem. Nat. Acad. Sci. 4(1):54, PI. XIV, Figs. 5a-g.
Sabacon crassipalpe (not of L. Koch), Roewer, 1914, Arch. Naturg. 80(3): 125, Figs. 16a-c probably refer to S. occidentalis, 1923, Weberknechte der Erde, p. 694 (in part, not S, crassipalpe (Koch) or S. occidentalis [Banks]), Fig. 869 probably refers to S. occidentalis', Comstock, 1940, The Spider Book (revised by W. Gertsch), p. 77; Bishop, 1949, Proc. Rochester Acad. Sci. 9(3); 173-1 74, pi. 1, Figs. 7-8 (records from north- western states refer to S', occidentalis).
Sabacon spinosiis Weed, 1893, Amer. Nat. 27(318);575, Fig. 1.
Phlegmacera cavicolens [sic]. Banks, 1901, Amer. Nat. 35(416):677, erratum for cavicolens.
Types— Female holotype of P. cavicolens from Bat Cave, Carter County, Kentucky (labelled only “Bat Cave”), in MCZ, examined; male holotype of S. spinosus from Hanover, New Hampshire, present location unknown.
Diagnosis— Sympatric only with S. mitchelli, a much smaller form endemic to a few high peaks in North Carolina. Sabacon mitchelli males lack the knoblike cheliceral gland found in cavicolens males. Females may be distinguished by the size difference and reduced abdominal sclerotization in mitchelli.
Description— Male from Feme Clyffe State Park, Illinois. Total length, 2.4 mm. Cara- pace 0.55 mm wide, 0.48 mm long, with row of small black setae along anterior margin, anterior margin of carapace broadly indented; lateral borders poorly sclerotized. Ozopores small but distinct, rims not sclerotized. Eye tubercle 0.33 mm wide, eyes small. Second thoracic tergite poorly sclerotized, especially near midline, with row of small black setae set on bumps, middle two (postocular spines) much larger than others. Abdominal tergites 1-5 fused, but degree of fusion variable, some specimens have fifth tergite free; abdominal scutum so formed well sclerotized but flexible, with irregularly scattered stout black setae on tubercles. Abdominal tergites 6-8 free, but setae tending to form regular posterior rows; tergite 8 frequently divided and separated from lateral portions. Coxae, coxal endites, sternum and genital operculum as described for genus. Abdominal segments with moderately sclerotized sternites. Chelicerae (Fig. 1) of moderate size, setose, basal article with dorsal glandular prominence. Palpus (Fig. 2) typical of genus, femur 0.50 mm long, 0.21 mm wide, patella 0.48 mm long, 0.32 mm wide, with prominent apicomesal tooth, tibia 0.52 mm long, 0.32 mm wide, with mesoposterior asetose area against which tarsus is reflexed, tarsus 0.44 mm long, 0.20 mm wide. Legs of moderate length with minute black setae set thickly in tracts, scattered longer setae, metatarsi with numerous false articulations, tarsi long, multiarticulate, distally densely pilose, tarsal claw single, not toothed. Femora 1-4 2.22, 3.73, 2.05, 2.35 mm long respectively, tibiae 1-4 2.13, 3.63, 1.96, 2.01 mm long respectively. Penis (Figs. 6-7) with moderately long shaft, spatulate distal region bears short, stout setae, termi- nates in long aciculate process. Coloration; carapace yellowish brown, marked brownish purple near margins, eye tubercle brown with black rings around eyes, second thoracic
14
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tergite mottled light purplish brown, abdominal scutum sclerotic yellow-brown, mottled dark purplish brown, with median rows of light yellowish white spots segmentally arranged. Venter yellow-white, lightly mottled brown. Chelicerae, legs and palpi pale tan.
Female from Waterrock Knob, North Carolina. Total length, 5.2 mm. Carapace 1.44 mm wide, 0.71 mm long. Structure much as in male. Lateral margins of carapace more poorly defined than in male, anterior midline not broadly indented. Eye tubercle 0.21 mm wide. Second thoracic tergite hardly at all sclerotized, postocular spines not con- spicuous. Abdominal tergites represented by small, suboval sclerotized plates {scutum laminatum of European authors) frequently divided into two or more irregular small sclerotized regions each {scutum dissectum of European authors). Both tergites and leathery cuticle with scattered small black setae, not on prominent tubercles. Venter of abdomen without obvious sclerotized sternites. Tip of genital operculum rounded. Chelicerae without glands on basal segments. Palpus heavier, more densely setose than in male, without patellar tooth, femur 1.21 mm long, 0.24 mm wide, patella 1.03 mm long, 0.31 mm wide, tibia 1.64 mm long, 0.50 mm wide, tarsus 0.30 mm long, 0.14 mm wide. Legs proportionally shorter and stouter than in male, femora 1-4 1.68, 2.89, 1.84, 1.82 mm long respectively, tibia 1-4 1.79, 2.90, 1.87, 1.61 mm long respectively. Ovi- positor (Fig. 8) short, wide, very sparsely setose, apical region lightly sclerotized. Colora- tion as in male, but median hght spots of abdomen fuse to form a stripe.
Records— See also Map 1. CANADA: Quebec: Laurentide Park, Camp le Relais, 3000 ft, 29 August 1956, H. Dybas, juvs. (CNHM). UNITED STATES; Vermont: Bennington Co., Mt. Equinox summit, 3500 ft, 18 October 1968, W. Shear, 99 6 kS) . Massachu- setts: Franklin Co., Totem Lookout Trail, Mahawk State Park, 22 August 1956, H. and L. Levi, juv. (MCZ). Connecticut: Litchfield Co., Twin Lakes, Salisbury, 17 August 1964, H. Levi, juv. (MCZ). New York: Tompkins Co., Ithaca, numerous records, 99 juvs.; Steuben Co., Plattsburg, 16 July 1926, 9. Bishop (1949) also records the species from Monroe, Yates and Suffolk Counties. Pennsylvania: Potter Co., 4 mi E of Coudersport, 30 August 1963, W. Shear, juv. (WAS), Coudersport, 7 August 1967, W. Shear, juv. (WAS); McKean Co., Ludlow, 21 September 1943, 9. Ohio: Hocking Co., Cantwell Cliffs State Park, 5 April 1927, M. Walker, juv. West Virginia: Mercer Co., Athens and vicinity, 20 June 1966, 2 July, 22 July 1967, juvs. (WAS), Camp Creek State Forest, 4 December 1970, W. Shear, 9 (WAS). Virginia: Alleghany Co., 3 mi NW Clifton Forge, 10 September 1948, R. Hoffman (RLH?); Giles Co., Mountain Lake, 3800 ft, 27 September 1950 (RLH?), re- ported in Hoffman (1955); Lee Co., Cave Spring Recreation Area, 2 mi N of Dry den, 2-3 September 1972, R. Hoffman, juvs. (RLH); Highlands Co., Locust Spring Camp, 11 mi N of Monterey, 18 June 1969, W. Shear, juv. (WAS); Dickinson Co., Breaks Interstate Park, Cold Spring, 25 May 1967, W. Shear, juv. (NAS). North (Carolina: Graham Co., Joyce Kilmer Memorial Forest, 20 May 1970, W. Shear, juv. (WAS); McDowell Co., Crabtree Falls on Blue Ridge Parkway, 14 July 1969, W. Shear, juv. (WAS); Haywood Co., Water- rock Knob summit, 6292 ft, 30 October 1970, 99 (WAS), Richlands Balsam summit, 6400 ft, 10 October 1971, 66 99 (WAS), 13 October 1970, W. Shear, 66 99 (WAS): Jackson Co., Western Carolina University Preserve near Cullowhee, 25 October 1969, W. Shear, 9 (WAS); Yancey Co., 4 mi SSE of Black Mountain Campground on Little Lost Cove Trail, 13 July 1969, W. Shear, juv. (WAS), Mt. Mitchell summit, 6500 ft, trail to Mt. Craig, 11 July 1969, juvs. (WAS; these specimens are early instars and some of them could be S. mitchelli), Mt. Mitchell summit, 6500 ft, 1 November 1970, 66 99 (WAS); Bishop (1949) also records the species from Grandfather Mtn. and Blowing Rock. South
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
15
Carolina: Greenville Co., Greenville, 4 October 1930, N. Davis (reported in Hoffman, 1955). Tennessee: Sevier Co., Clingmans Dome summit, 6600 ft, 10 October 1971, W. Shear, 6 99 (WAS), 2 mi NNW Newfound Gap, 13 October 1970, W. Shear, juv. (WAS), Laurel Creek, 8 October 1926, 99. Illinois: Jo Daviess Co., Apple River Canyon State
Figs, 1-9.— Anatomy of Sabacon species. Figs. 1-8. S. cavicolens: 1, Left chelicera of male, lateral view; 2, Left palpus of male, mesal view; 3, Above: outline of proximal cheliceral article of male from Mt. Equinox, Vt. Below: distal end of palpal patella of same specimen; 4, Above: outline of proximal cheliceral article of specimen from Mt. Mitchell, N. Car. Below: distal end of palpal patella of same specimen; 5, Distal end of palpal patella of male from Union Co., 111.; 6, Penis, lateral view; 7, Tip of penis, lateral view; 8, Ovipositor subdorsal view; 9, Penis of S, mitchelli, subventral view.
16
THE JOURNAL OF ARACHNOLOGY
Map 1.— Eastern United States, showing distribution of Sabacon cavicolens, including records of immature specimens. Arrow in Alabama indicates locality of S. jonesi, a possible synonym of S. cavicolens; arrow in Arkansas indicates records of immature specimens possibly not S. cavicolens.
Park, 14-16 August 1946, H. Dybas, juvs. (CNHMM); Union Co., Pine Hills, 14-20 Ocotber 1967, J. M. Nelson, dd 99 (JAB), 25 October 1969, J. Beatty, juv. (JAB); Johnson Co., Feme Clyffe State Park, 24 October 1967, dd (JAB), 6 June 1970, J. Beatty, juv. (JAB); Pope Co., Lusk Creek 3 mi E of Eddyville (R6E, T12S, Sec. 10), 14-20 May 1968, J. M. Nelson, Juvs. (JAB), Little Grand Canyon, 5.8 mi SW of Murphysboro, 3 May 1970, J. Beatty, juv. (JAB), Iowa: Clayton Co., Pikes Peak State Park, 8 June 1961, H. Levi, juv. (MCZ). Wisconsin: Kewaunee Co., N of Kewaunee, July 1949, H. Levi, juv. (MCZ); Grant Co., Wyalusing State Park, 13 July 1949, H. Levi, juv. (MCZ); Shawano Co., Neapit (?), 22 September 1949, H. Levi, d QAQZ). Minnesota: Blue Earth Co., juv. (MCZ). The following juvenile specimens are tenatively referred to S. cavicolens: Arkansas: Washington Co., Devils Den, Ice Box Cave, 18 June 1969, S. and J. Peck, juvs. (WAS), Granny Dean Cave, 9 July 1969, S. Peck, juv. (WAS). Also reported from Cheboygan Co., Michigan, by Edgar (1971), and from Kentucky , Maine and Wew Hampshire by Bishop (1949).
Notes-The coloration is often much darker than the described specimen and probably depends on the age of the animal; the legs and palpi are often dark brown and the venter of the abdomen dark purplish brown. The sclerotization of the abdomen varies within populations, especially in females. Some females have each abdominal tergite divided, with the posterior ones very lightly sclerotized. In males, the degree of fusion of the first five abdominal tergites is variable, and in any case, the separate tergites are marked by indentations in the margin of the scutum; the fifth tergite is often free. Figs. 3-5 depict some components of the variation of the secondary sexual characters of the males. In most populations, the gland knob is rather low and slopes evenly on the anterior side (Figs. 1, 3), but in North Carolina specimens, the knob is larger and more rounded (Fig.
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
17
4). There is also a tendency for the palpal tooth to have one or even two small accessory teeth behind it (Figs. 3,4, 5). In some males, the apical part of the penis is bent over at a right angle, as shown in Fig. 15 for S. occidentalis. This is probably a functional change.
A few immature specimens from Arkansas caves are given in the records section and shown on the distribution map; mature material is much needed to definitely demon- strate that this population isS. cavicolens', see the discussion of S. jonesi above.
Sabacon mitchelli Crosby and Bishop Figs. 9-13
Sabacon mitchelli Crosby and Bishop, 1924, J. Elisha Mitchell Soc. 40:23-24, Plate 2,
Fig. 17.
Types— Female holotype (AMNH) from Mt. Mitchell, Yancey Co., North Carolina, 6600 ft elevation, collected 22 October 1923 by sifting moss; examined.
Diagnosis— Much smaller than S. cavicolens, with which it is sympatric throughout its range. The female has only the first two abdominal tergites sclerotized, and these quite small; the female of cavicolens has plates (though they may be divided) on all tergites of the abdomen. Males of mitchelli bear no knob on the basal articles of the chelicerae, though the glandular function may still be present; the palpal patella has a row of small denticles extending nearly the length of the patella behind three apical teeth. Males of cavicolens have an abdominal scutum, mitchelli males do not (Fig. 10).
Description— Male from Waterrock Knob, Haywood Co., North Carolina. Total length, 1.83 mm. Carapace 0.48 mm long, 0.82 mm wide. Structure similar to S. cavicolens, except in the following respects. Carapace more heavily sclerotized, lateral margins more clearly defined. Ozopores large, prominent, with sclerotic posterior rims. Eye tubercle 0.27 mm wide. Second thoracic tergite not at all sclerotized, postocular spines somewhat enlarged but not as conspicuous as in cavicolens. Abdominal tergites (Fig. 10) poorly sclerotized, not fused to form dorsal scutum in most specimens, setae fewer and not on prominent bumps as in cavicolens. Chelicerae (Fig. 1 1) relatively larger than in cavicolens, lacking knobbed gland on basal article, but with three slit sensilla (?) not seen on other species. Palpus (Fig. 12) proportionally stouter than in cavicolens, femur 0.59 mm long, 0.16 mm wide, patella 0.58 mm long, 0.25 mm wide, with three large apicomesal teeth and series of small denticles running behind teeth nearly to base of patella, tibia 0.56 mm long, 0.24 mm wide, tarsus 0.30 mm long, 0.19 mm wide. Legs short, stout, metatarsi with but one or two false articulations, tarsi multiarticulate, but disti tarsus not com- pletely divided, legs set with fine setae and long spines. Femora 1-4, 0.95, 1.01, 0.75, 1.18 mm long respectively, tibiae 1-4 0.71, 0.87, 0.64, 1.04 mm long respectively. Penis with short, broad shaft (Fig. 9) not significantly increased in width at apical part (Fig. 13), aciculate process as in cavicolens, penial setae longer, stouter. Coloration: Dorsum light purplish brown, carapace and abdominal tergites yellowish, coloration even, no evidence of dorsal pattern. Venter, leg coxae and trochanters light brown, distal parts of legs darker brown, chelicerae and palpi medium brown.
Female holotype from Mt. Mitchell, Yancey Co., North Carolina. Total length, 2.71 mm. Carapace 0.49 mm long, 0.98 mm wide. Eye tubercle 0.25 mm wide. Structure typical. Second thoracic tergite not at all sclerotized, postocular spines small. First two abdominal tergites with small plates, others not sclerotized. Coloration as in male.
Records— Carolina: Haywood Co., Waterrock Knob summit on Blue Ridge Park- way, 6292 ft, under rocks and logs in fir forest, 13 October 1970, W. A. Shear, 3 (WAS);
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THE JOUP'haL of ARACHNOLOGY
Yancey Co., Mt. Mitchell summit, 6600 ft, under logs and rocks i 'orest of fir and mountain ash, 1 November 1970, W. A. Shear, 66 (WAS).
Notes— At each of the two places this species has been coll^'^^ed, , is syntopic with^. cavicolens. In the cases of my two collections, the mitchelli males were only later dis-
Figs, 10-15, -Anatomy of Sabacon species. Figs, 10-13. S. mitchelli: 10, Body of male, dorsal view; 11, Left chelicera of male, lateral view; 12, Left palpus of male, mesal view; 13, Penis, ventral view of tip; Figs, 14-15, S. occidentalis; 14, Left palpus of male, mesal view, setation omitted; 15, Penis, lateral view.
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
19
covered in a large collection of adult cavicolens. I have collected on several other Appala- chian summits in the region, and found only cavicolens. There is some variation. The Waterrock Knob male has broader and larger abdominal tergites than the illustrated male from Mt. Mitchell, but otherwise, they agree closely.
Sabacon occidentalis (Banks)
Figs. 14-20, Map 2
Phlegmacera occidentalis Banks, 1894, Psyche 7:51.
Sabacon crassipalpe (not of L. Koch), Roewer, 1914, Arch. Naturg. 80(3): 125, 1923, Weberknechte der Erde, p. 694, Fig. 869 (in part, not S. cavicolens [Packard] , S. spinosus Weed, or S. crassipalpe [Koch]); Comstock, 1940, The Spider Book {xevhQdi by W. Gertsch), p. 77 (not S. cavicolens [Packard]); Bishop, 1949, Proc. Rochester Acad. Sci. 9(3): 173- 174 (description based on S. cavicolens, western records only).
Type— Male and female cotypes from Olympia, Washington, in MCZ, examined. Diagnosis— The form of the penis and the less prominent postocular spines will serve to separate the present species from S. siskiyou. Sabacon astoriensis has false articulations in the leg femora, occidentalis does not. Males of S. briggsi are not known, but the females of that species have a pointed genital operculum.
Description— Male from Cape Perpetua, Lincoln Co., Oregon. Total length, 2.34 mm. Carapace 1.26 mm wide, 0.59 mm long. Stmcture much as in S. cavicolens, but much less sclerotization in carapace and abdomen, lateral margins of carapace not at all dis- tinct. Anterior margin of carapace indented, lacking row of black setae. Ozopores small, indistinct, rim not sclerotized as in mitchelli. Eye tubercle 0.36 mm wide, eyes small. Second thoracic tergite unsclerotized but marked by pigmented band, postocular spines small, unpigmented. Abdominal tergites 1-5 fused to form dorsal scutum, setae as described for cavicolens. Abdominal tergites 6-8 free. Coxae, coxal endites, sternum and genital operculum as described for genus, set with small black setae, sternum poorly sclerotized, without setae. Chelicerae (Fig. 16) relatively large, basal articles with very large, prominent glandular knob. Palpus (Fig. 14) narrow, gracile, elongate, femur 0.81 mm long, 0.17 mm wide, patella 0.82 mm long, 0.27 mm wide, with very large single black apicomesal tooth, tibia 1.08 mm long, 0.30 mm wide, tarsus 0.40 mm long, 0.25 mm wide. Legs very long and slender, femora with regular rows of stout black setae. Tibiae of legs 2 with five to eight false articulations, of legs 4 with one to three false articulations. Femora 1-4 3.56, 6.27, 4.57, 5.47 mm long respectively; tibiae 1-4 3.86 6.20, 3.98, 5.40 mm long respectively. Penis (Figs. 15, 17, 18) with long, thin shaft, broadened, spatulate apical region with numerous stout setae, tip with three fmger-like divisions (Fig. 18). Coloration: Eye tubercle black. Carapace yellow-white to brown, marked darker brown, second thoracic tergite and dorsal scutum dark brown against yellow-white ground, vaguely marked light brown central band. Venter yellow-white to tan, marked dark brown. Chelicerae white. Palpus yellow-white, shaded brown dorsally on femur and patella. Leg trochanters brown dorsally, leg segments shaded dark brown distally, giving impression of banded legs.
Females from Clatskanna, Columbia Co., Oregon. Total length, 4.32 mm. Carapace 0.90 mm long, 2.00 mm wide. Structure much as in male and in female of cavicolens, but carapace proportionally longer, eye tubercle (0.54 mm wide) set farther back from anterior margin of carapace. Second thoracic tergite poorly sclerotized, abdominal tergites all free, marked by sclerotized oval plates, sparsely set with small black
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setae. Venter typical. Chelicerae lacking gland on basal article. Palpus (Fig. 19) much heavier and stouter proportionally than in male, femur 1.08 mm long, 0.31 mm wide, patella 1.35 mm long, 0.38 mm wide, tibia 1.71 mm long, 0.60 mm wide, tarsus 0.75 mm
T\\i\4 iiihi/i'/ /
Figs. 16-22.— Anatomy of Sabacon species. Figs, 16-20: S. occidentalis. 16, Left chelicera of male, lateral view; 17, Penis, lateral view of tip; 18, Penis lateral view of tip, higher magnification; 19, Left palpus of female, mesal view, setation omitted; 20, Ovipositor, ventral view. Figs. 21-22.5'. siskiyou: 21, Penis, dorsal view; 22, Penis, dorsal view of tip.
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
21
Map 2, -Coastal northern California, Oregon and Washington. Dots, records of Sabacon occidentalis; triangles, records of S. siskiyou; squares, records of S. briggsi. Arrow shows approximate type locality of S. astoriensis. Sabacon occidentalis has also been re- corded from British Columbia.
long, 0.42 mm wide. Legs long, but shorter and stouter proportionally than in male, femora 1-4 2.77, 4.49, 2.88, 5.63 mm long respectively, tibiae 1-4 2.84, 3.41, 2.72, 3.93 mm long respectively. Ovipositor (Fig. 20) relatively long, densely setose. Coloration as in male, but generally paler, central light band of abdomen consequently not as distinct.
Records— See also Map 2. CANADA: British Columbia'. Kyquot, Vancouver Island, 1-10 September 1930, S. L. Neave, 9; 17.8 mi E of Hope, Manning Park, 23 August 1969, T. Briggs, c5 (TB). UNITED STATES: Washington'. Grays Harbor Co., 5 mi E of McCleary, 26 August 1959, W. Gertsch, V. Roth, 9; Snohomish Co., 6 mi W of Stevens Pass, near Senic, 28 August 1959, W. Gertsch, V. Roth, 9; Jefferson Co., 4.5 mi SW Hoh Rain Forest on Hwy 101, 22 June 1966, T. Horn, 6 (TB); Lewis Co., Rainbow Falls State Park, 25 August 1969, T. Briggs, 6 (TB). Oregon: Clatsop Co., 7 mi N of Nehalem, 26 August 1969, T. Briggs, 9 (TB), Saddle Mtn., 9 September 1970, R. Lem, 9 (TB). Lincoln Co., 5 mi N of Depoe Bay on Hwy 101, 4 September 1970, T. Briggs et al., (TB), Cape Perpetua on U.S. 101, 7 August 1967, T. Briggs, 66 (TB); I^ne Co., Darlington Botanical Wayside near Mercer Lake, 20 June 1966, T. Briggs, 9 (TB); Columbia Co., 5 mi S of Clatskannie, 8 August 1967, K. Horn, 9 (TB); Josephine Co., 3.9 mi E on 1-5 of Speaker Road, near Wolf Creek, 8 June 1967, T. Briggs et al., 9 (TB); Yamhill Co., McMinnville, “McNab Coll.” August (no year) dd 99 (MCZ); Coos Co., Charleston, 30 September 1959, V.
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Roth, 9; Linn Co., 1.1 mi E jet. U.S. 20 and U.S. 126, 24 June 1966, T. Briggs, 66 99 (TB); Douglas Co., 3 mi E of Reedsport, 6 August 1967, T. Briggs, 6 (TB); Curry Co., 9.5 mi S of Gold Beach, 19 June 1966, T. Briggs, et al., 66 99 (TB). California: Siskiyou Co., 18 mi N of Happy Camp, 22 August 1959, W. Gertsch, V. Roth, 9; Humboldt Co., near Orick, 18 June 1966, T. Briggs et al., 6 (TB); Del Norte Co., Del Norte Coast Redwoods State Park, 25 June 1966, T. Briggs et al., 66 (TB), 1.6 mi N of Del Norte Coast Redwoods State Park, 18 June 1966, T. Briggs et al., 66 (TB).
Notes— There appears to be little variation in the important characters of S. occidentalis, except that some specimens are darker or lighter than the described ones.
Sabacon siskiyou, new species Figs. 21-25, Map 2
Types— Male holotype and female paratype from 3 mi north of McCloud, Siskiyou Co., California, collected 2 September 1959 by W. Gertsch and V. Roth (AMNH); female paratype from 6 mi east of Camp Connell, Eldorado Co., California, collected 10 Septem- ber 1959 by W. Gertsch and V. Roth (MCZ), male paratype from Deadhorse Summit, near Pondosa, 5500 ft, Siskiyou Co., California, collected 19 September 1961 by W. Ivie and W. Gertsch (MCZ). The specific epithet refers to the type locality and is a noun in apposition.
Diagnosis— Similar in general appearance to S. occidentalis, but with considerably shorter, unbanded legs, a differently formed penis, and very large, prominent postocular spines (Fig. 25). Distinct from S. astoriensis in lacking false articulations in the leg femora.
Description— Male paratype from Deadhorse Summit. Total length, 2.49 mm. Cara- pace 0.57 mm long, 1.11 mm wide. Structure typical for genus, but usually much less sclerotization even in the darkest specimens than in cavicolens or occidentalis . Carapace fairly well defined, however. Eye tubercle 0.28 mm wide, eyes small. Ozopores small, inconspicuous, without marginal sclerotization. Second thoracic tergite weakly sclerotized,-but with large, prominent postocular spines (Fig. 25), often contiguous at the base or even partly fused. Presence of dorsal abdominal scutum difficult to ascertain due to weak sclerotization, but probably much as in occidentalis', abdominal cuticle compar- atively smooth, with only a few small, dark brown, scattered setae. Venter typical, with rather long, weak black setae contrasting with stout ones found in other species. Abdom- inal sternites not sclerotized but marked with pigment. Chelicerae (Fig. 23) miuch as in occidentalis, but gland lower, not as much enlarged at apex. Palpus (Fig. 24) somewhat stouter than in occidentalis, femur 0.64 mm long, 0.25 mm wide, patella 0.82 mm long, 0.36 mm wide, apicomesal tooth large, single, usually slightly recurved, tibia 0.80 mm long, 0.37 mm wide, tarsus 0.44 mm long, 0.36 mm wide. Legs shorter, stouter than in occidentalis, setation pattern essentially the same, but larger setae longer, thinner., Tibiae 2 with one to three false articulations, tibiae 4 with none. Femora 1-4 1.84, 3.90, 1.85, 2.57 mm long respectively, tibiae 1-4 1.80, 2.66, 1.60, 2.22 mm long respectively. Penis (Figs. 21, 22) somewhat stouter than in occidentalis, with more and stouter setae, tip unevenly spatulate. Coloration: Pattern of body as in occidentalis, but paler, yellow-white areas in occidentalis tend to be pale tan in siskiyou',\Q%^ even medium brown, not banded.
Female from Eldorado Co., California. Total length, 2.77 mm. Carapace 0.59 mm long, 1.46 mm wide. Stmeture as described in male, with the usual sexual differ- ences. Abdominal tergites fairly well marked, sometimes divided. Genital operculum
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
23
rounded at tip, ovipositor similar to that of occidentalis , only slightly less setose. Palpus with femur 0.90 mm long, 0.34 mm wide, patella 1.10 mm long, 0.48 mm wide, tibia
Figs. 23-28. -Anatomy of Sabacon species. Figs. 23-25. S. siskiyou: 23, Left chelicera of male, lateral view; 24, Left palpus of male, mesal view; 25, Anterior end of body of male, dorsal view. Figs. 26-28. S. astoriensis: 26, Left palpus of male, mesal view; 27, Anterior end of body of male, dorsal view; 28, Penis, lateral view.
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shorter and stouter than in male, femora 1-4 2.14, 2.66, 1.83, 2.46 mm long respectively, tibiae 1-4 1.85, 2.63, 1.61, 2.26 mm long respectively. Coloration as in male.
Records— California'. Siskiyou Co., Deadhorse Summit, near Pondosa, 5500 ft, 18 September 1961, W. Ivie, W. Gertsch, 3; Eldorado Co., 6 mi E of Camp Connell, 10 September 1959, W. Gertsch, V. Roth, 9; Madera Co., 2 mi S of Fish Camp, 12 Septem- ber 1959, V. Roth, W. Gertsch, 9; Yosemite National Park, Strawberry Creek, 12 Septem- ber 1959, V. Roth, W. Gertsch, 9. Oregon'. Benton Co., near Iron Mtn., 21 November 1948, I. Newell, 33.
Notes— The Oregon males are darker in coloration and somewhat better sclerotized than those from California, but are otherwise typical.
Sabacon astoriensis new species Figs. 26-30, 32, Map 2
Types— Male holotype from Peter Iredale Shipwreck Picnic Area, Fort Stevens State Park, Clatsop Co., Oregon, collected 27 November 1971 by E. M. Benedict (MCZ). The specific epithet is an adjective referring to the nearby community of Astoria.
Diagnosis— The only American species with false articulations in the leg femora.
Description— Male holotype. Total length, 2.0 mm. Carapace 0.52 mm long, 0.78 mm wide. Carapace well-sclerotized, lateral margins distinct, anterior margin with an acute indentation at midline. Ozopores large, distinct, posterior rims sclerotized. Eye tubercle 0.26 mm wide, relatively larger than in other species, set closely at anterior margin of carapace, eyes large. Second thoracic tergite moderately well-sclerotized, postocular spines small but pigmented (Fig. 27). Abdominal tergites 1-5 solidly fused to form heavily sclerotized dorsal shield, tergites 1-4 marked by pairs of black setae on low humps, tergite 5 with posterior row of black setae. Tergite 8 divided in midline, lateral portions of tergite 8 also separate from dorsal portions. Posterior part of abdominal dorsum with scattered black setae (Fig. 29). Coxae, endites and genital operculum typical, sternum completely suppressed. Abdominal sternites sclerotized, with rows of black setae. Chelicerae (Ffg. 30) with low glands on basal segments resembling those of cavicolens, distal segment enlarged dorsobasally with depressed lateral area bearing small denticles on rim. Palpus (Fig. 26) slender, gracile, not as heavily setose as in some other species, femur 0.60 mm long, 0.20 mm wide, patella 0.58 mm long, 0.21 mm wide, with stout patellar tooth, tibia 0.59 mm long, 0.22 mm wide, tarsus 0.25 mm long, 0.18 mm wide. Legs short, stout, sparsely setose. Femora 1 and 3 with one to three false articulations, femur 2 with nine to ten false articulations, femur 4 with four to five false articulations, tibiae 2 and 4 with one to four false articulations. Femora 1-4 1.11, 1.63, 0.95, 1.63 mm long respectively, tibiae 1-4 1.05, 1.55, 0.84, 1.21 mm long respectively. Penis (Figs. 28,32) with broadly expanded tip gradually tapering to flagelliform termination (Fig. 32), penial setation weak. Coloration: Sclerotized parts dark brown, intersegmental cuticle white. Legs, palpi and chelicerae brown, darker distally, legs not banded.
Female unknown.
Known only from the type locality.
Notes— This peculiar species is related to one or two of the Japanese forms, as sug- gested by the penis and the false articulations in the leg femora. The modification of the distal cheliceral article is unique. Some of the species recently described from Nepal by Martens (1972) have stout teeth on the inner sides of the proximal part of the distal cheliceral article, but none have the lateral depression seen in astoriensis. The small size
Figs, 29-35. -Anatomy of Sabacon and Tomicomerus species: 29, Body of male S. astoriensis, dorsal view; 30, Left chelicera of male S. astoriensis, lateral view; 31, Penis of Tomicomerus bryanti (partly hypothetical, see text); 32, Penis of S. astoriensis, lateral view of tip; 33, Genital operculum of female S. briggsi, ventral view; 34, Right chelicera of T. bryanti, mesal view; 35, Right palpus of T. bryanti, mesal view.
and heavy sclerotization are also of interest. Collectors in northern coastal Oregon should search carefully for females.
The type was taken in a Berlese sample of dried seaweed, vegetable debris and spruce duff in sand dunes, near the beach.
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Sabacon briggsi, new species Fig. 33, Map 2
Types— Female holotype from Bolinas Ridge, Marin Co., California, collected 16 November 1968 by T, Briggs (deposited in California Academy of Sciences); female paratype from Valencia Lagoon, Santa Cruz Co., California, collected 25 November 1966 by K. Horn (MCZ).
Diagnosis— Distinct from females of all other species in the pointed and lightly sclerotized tip of the genital operculum (Fig. 33).
Description— Female holotype. Total length, 3.86 mm. Carapace 0.71 mm long, 1.37 mm wide. Carapace with lateral margins indistinct, as in occidentalis, but anterior margin deeply and broadly indented in midline. Eye tubercle 0.45 mm wide, eyes small. Ozopores small but prominent, anterior margins sclerotized. Second thoracic tergite poorly and narrowly sclerotized, postocular spines small and not conspicuous. All abdominal tergites marked by undivided separate sclerotized plates set with short black setae. Venter typical, but genital operculum apically pointed, with lightly sclerotized rim (Fig. 33). Chelicerae typical. Palpus with short femur, extremely robust tibia; femur 0.92 mm long, 0.31 mm wide, patella 1.22 mm long, 0.34 mm wide, tibia 1.43 mm long, 0.80 mm wide, tarsus 0.68 mm long, 0.47 mm wide. Legs short, stout, femora 1-4 2.02, 3.10, 1.95, 3.14 mm long respectively, tibiae 1-4 1.94, 3.10, 1.64, 2.63 mm long respec- tively. Ovipositor as in occidentalis. Coloration: Ground color of body light purple mottled medium tan, sclerotized parts brown. Venter white, abdominal sternites brown. Chelicerae brown dorsally, palpi medium brown, legs medium brown, not annulated.
Males not known.
Known only from type and paratype localities listed above.
Notes— The Santa Cruz Co. female agrees well in structure with the holotype but is lighter in color, possibly a result of longer preservation. It was taken from oak litter.
Genus Tomicomems Pavesi
Tomicomems Pavesi, 1899, Rend. Inst. Lombardo 32 532-533; Roewer, 1914, Arch.
Naturg. 80(3): 126, 1923, Weberknechte der Erde, p. 696; Comstock, 1940, The
Spider Book (rev. by W. Gertsch), p. 78.
Phlegmacera Banks (in part), 1898, Ent. News 9: 16, P. bryanti only.
Type-species— r. bispinosus Pavesi, 1899, (=r. bryanti [Banks]), by original designa- tion.
Diagnosis— The leg femora have false articulations, a character also found in some Sabacon species, but the chelicerae of T. bryanti are much enlarged. Distinct from species of Taracus, Ischyropsalis and Nipponopsalis by the shorter, more densely setose palpi and the smooth chelicerae.
Description— Carapace (Fig. 36) wider than long, well sclerotized, lateral limit well marked, indented in midline. Ozopores in usual position. Eye tubercle much broader than long, indented in midline, without setae or ornamentation. Second thoracic tergite free and well-sclerotized, bearing on midline pair of a very prominent postocular spines (in Taracus species there is usually a single spine in this position). Condition of abdominal tergites not discernable from single available specimen. Carapace connected to labrum by chitinous strip, labrum large, subtriangular. Labium small, oval. Sternum not obvious, poorly sclerotized. Endites of pedipalps and legs as in Sabacon, but coxae slightly com-
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
27
pressed and elongated proximally. Genital operculum bluntly pointed anteriorly. Spira- cles slit-like. Legs moderately long, with false articulations in femora and tibiae. Palpi prominent, intermediate in form between Sabacon and Taracus (Fig. 35), tarsus blunt, reflexed against asetose area on tibia, without a claw, patella with mesoapical teeth in males. Chelicerae very large, basal joint as long or longer than carapace without a promi- nent glandular swelling in males, distal joint with two proximodorsal teeth and mesal ridge (Fig. 34). Male genitalia typical, perhaps approaching form of Taracus species (Fig. 31). Form of ovipositor not known.
Distribution— Southeastern coastal strip of Alaska.
Tomicomems bryanti (Banks)
Figs. 31, 34-37
Phlegmacera bryanti Banks, 1898, Entomol. News 9: 16.
Tomicomems bispinosus Pavesi, 1899, Rend. Inst. Lombardo 32:533.
Tomicomems bryanti, Roewer, 1914, Arch. Naturg. 80(3); 126, 1923, Weberknechte der Erde, p. 696; Comstock, 1940, The Spider Book (rev. by W. Gertsch), p. 78.
Types— Female (immature?) holotype from Malaspina Glacier, Mt. St. Elias, Alaska, collected 4 July 1897 by H. G. Bryant, probably lost, not found with other Banks opilionid types in MCZ; male holotype of T. bispinosus from Mt. St. Elias, whereabouts unknown. An inquiry of the Zoological Laboratory of the University of Pavia, where Pavesi worked, brought no answer. In the absence of types, there is a certain amount of conjecture involved in assigning the American Museum specimen described below to this species, and indeed in accepting the synonymy of the two proposed names. The AMNH specimen matches Pavesi’s description well, but Banks’ account is less detailed and is probably based on an immature specimen, judging from the size given.
Description— Specimen from Tsirku River, Alaska. The specimen is in poor condition, as is much of the older material in the AMNH opilionid collection, due to a yellow
Figs. 36, 31 Tomicomems bryanti: 36, Lateral view of male from Tsirku River. Abdomen un- shaded, shown in outline only to denote shriveled condition due to poor preservation; 37, Leg 4 (?) femur, showing false articulations.
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substance dissolved out of either cork or rubber stoppers. In addition to staining the specimens, this substance seems to give them a cheese-like texture that renders study and dissection difficult. When fresh alcohol is added without extensive rinsing, a heavy white precipitate forms.
Structure as described for genus. Abdomen completely shriveled, but described by Pavesi (1899) as “polished.” Legs separated from body and badly broken. Carapace 1.11 mm wide, 0.77 mm long, eye tubercle 0.46 mm wide. Chelicera (Fig. 34) with basal segment 0.85 mm long, 0.36 mm wide, distal segment, excluding fixed finger, 1.00 mm long, 0.44 mm wide. Palpal femur 1.20 mm long, 0.27 mm wide, patella 1.07 mm long, 0.27 mm wide, with three mesodistal teeth, the largest most distal and contiguous with the smallest, the third some distance proximal of the other two (Fig. 35), tibia 1.36 mm long, 0.28 mm wide, tarsus 0.47 mm long, 0.18 mm wide. Legs with false articulations in femora and tibia numerous (Fig. 37). Legs broken or not identifiable. Male genitalia (Fig. 31) partially reconstructed, badly damaged by attempted dissection, but generally re- sembling those of Taracus species.
Notes— AU reported specimens come from the St. Elias Range area of the Alaskan coastal strip extending south to British Columbia. The specimen in the AMNH is labelled as being from the head of the Tsirku River, Alaska, and was collected in July or August of 1910, by 0. M. Leland. This stream rises from the Tsirku Glacier at an elevation of 1 100 ft and flows east to the Chilkat River, joining that river just before it empties into Chilkat Inlet. The head of the Tsirku River is at 137 degrees 30 minutes west longitude and 60 degrees 30 minutes north latitude, just north of the northern boundary of Glacier Bay National Monument.
ACKNOWLEDGMENTS
The bulk of the material reported on here is from the collection of the American Museum of Natural History, New York (AMNH). Any records not marked otherwise are from that collection, which was generously loaned by Dr. Norman 1. Platnick. Dr. H. W. Levi of the Museum of Comparative Zoology, Cambridge (MCZ), loaned important types and other specimens. A second small collection came from the Chicago Natural History Museum (CNHM) through the courtesy of Mr. H. Dybas and Dr. J. Kethley. The follow- ing individuals loaned materials from their personal collections: Dr. J. A. Beatty, Carbon- dale, 111. (JAB), Dr. R. L. Hoffman, Radford, Va. (RLH), Dr. A. A. Weaver, Wooster, 0. (AAW). An especially large and important collection of western Sabacon was loaned by Mr. Thomas Briggs, San Francisco, Cal. (TB). Dr. Fred Coyle and Judith E. Coyle have my gratitude for their hospitality and help during several trips to the mountains of North Carolina to study and coViQci Sabacon.
LITERATURE CITED
Banks, N. 1898. Arachnida from the Malaspina Glacier, Alaska. Entomol. News9:16.
Bishop, S. C. 1949. The Phalangida (Opiliones) of New York. Proc. Rochester Acad. Sci. 9(3):159-235.
Crosby, C. R., and S. C. Bishop. 1924. Notes on the Opiliones of the southeastern United States with descriptions of the new species. J. Elisha Mitchell Sci. Soc. 40:8-26, 2 Plates.
Dresco, E, 1970. Recherches sur la variabilite et la phylogenie chez les opiliones due genre Ischyropsalis C. L. Koch (Earn. Ischyropsalidae), avec creation de la famille nouvelle des Sabaconidae. Bull, Mus. Nat, Hist. Natur. 41(5): 1200-1213.
SHEAR-OPILIONID GENERA SABACON AND TOMICOMERUS
29
Edgar, A. L. 1971. Studies on the biology and ecology of Michigan Phalangida (Opiliones). Misc. Publ. Mus. Zool. Univ. Michigan 144:1-64,
Goodnight, C. J., and M. L. Goodnight. 1942. New American Phalangida. Amer, Mus. Novitates 1164:1-4.
Gruber, J, 1970. Die “Nemastoma-” Arten Nordamerikas (Ischyropsalidae, Opiliones, Arachnida), Ann. Naturhist. Mus. Wien 74:129-144.
Hoffman, R. L. 1955. Distributional records of some scarce phalangids in the southern Appala- chians. J. Elisha Mitchell Sci. Soc, 71(1): 17-19.
Koch, L. 1879. Arachniden aus Siberien und Novaja Semlja. Kongl. Sueva Vet. Akad. Handl. 16(5):111.
Martens, J. 1969. Die Abgrenzung von Biospecies auf biologisch-ethologischer und morphologischer Grundlage am Beispiel der Gattung Ischyropsalis C. L. Koch 1839 (Opiliones, Ischyropsalidae). Zool. Jb. Syst. 96:133-264.
Martens, J. 1972. Opiliones aus dem Nepal-Himalaya. I, Das Genus Sabacon Simon (Arachnida:
Ischyropsalidae), Senckenbergiana Biol, 5 3:308-323,
Packard, A. S. 1884, New cave arachnids, Amer. Nat, 18(2):202-204.
Pavesi, P, 1899. Un nuovo nemastomide Americano, Rend. Inst, Lombardo 32:530-533,
Simon, E. 1879. Opiliones, Les Arachnides de France 7:116-311, Plates 21-24.
Roewer, C. 1914, Die Familien der Ischyropsalidae und Nemastomatidae der Opiliones-Palpatores, Arch. Naturg. 89(3):99-169.
Roewer, C. 1923. Die Weberknechte der Erde, 1 1 16 p. Gustav Fischer-Verlag, Jena,
Roewer, C, 1950. Uber Trogulidae und Ischyropsalidae, Senckenbergiana Biol. 31:1-156.
Suzuki, S. 1964. A new member of the genus Sabacon from Japan. Ann. Zool. Japon. 37(l):58-62. Suzuki, S, 1965. Three species of Ischyropsalidae from Hokkaido. Ann. Zool. Japon. 38(1): 39-44, Suzuki, S, 1966, Four remarkable phalangids from Korea. Ann, Zool. Japon, 39(3):95-106, Wachmann, E, 1970. Der Feinbau der sogenannt Kugelhaare der Fadenkanker (Opiliones, Nemastomatidae). Z. Zellforsch, 103:518-525,
Weed, C, M. 1893, An American species of Sabacon. Amer. Nat. 27:574-576.
Levi, H.W., and D.E. Randolph. 1975. A key and checklist of American spiders of the family Theridiidae north of Mexico (Araneae). J, Arachnol. 3:31-51.
A KEY AND CHECKLIST OF AMERICAN SPIDERS OF THE FAMILY THERIDIIDAE NORTH OF MEXICO (ARANEAE)
Herbert W. Levi and
Diane E. Randolph
Museum of Comparative Zoology Harvard University Cambridge, Mass. 02138
ABSTRACT
It is difficult to define the family Theridiidae. The 27 genera of Theridiidae represented north of Mexico can be separated by a key. There is a checklist to the 229-234 species of Theridiidae from north of Mexico.
A simple key to the genera of Theridiidae is needed for identifying spiders, but is difficult to construct. A mimeographed version of the key has had a limited circulation for several years as a tryout.
The checkhst got bigger while in preparation. Because of the. expense of printing, the style had to be modified slightly to make the list shorter. Therefore the synonymies are not complete but go back only to the first revision of the genus. For a complete synonymy it is necessary to consult the revisions.
We want to thank V. D. Roth for encouraging this project, guiding it and giving valuable advice, and W. J. Gertsch for his help throughout the study of American theridiid spiders. The key was prepared by H. W. Levi, and the checklist by D. E. Randolph. The researchers have been supported in part by grants from the Public Health Service Research Grant AI-01944 from the National Institute of Allergy and Infectious Diseases and by a National Science Foundation Grant GB-36161.
INTRODUCTION
Theridiid spiders differ from Nesticidae, Araneidae, Linyphiidae, and most Symphytognathidae by usually lacking the fleshy colulus (Fig. 47) found in all these other families (Fig, 1) (not always in Symphytognathidae). Theridiidae usually have a tarsal comb (Fig. 80), but this is present also in Nesticidae. Those theridiid genera that have a fleshy colulus {Steatoda, Latrodectus, Argyrodes, Robertus, and Crustulina) have comb setae on the fourth metatarsus and tarsus (present also in Nesticidae, but absent in Argyrodes). Theridiids that have a fleshy colulus and comb-setae on the fourth legs differ from Nesticidae by being dark colored, while Nesticidae are generally whitish, and by not having the paracymbium attached at the base of the cymbium of the male palpus, while in Nesticidae it is at the base of the cymbium and variously enlarged.
Members of the theridiid genus Argyrodes have a colulus, lack a comb on the fourth
31
32
THE JOURNAL OF ARACHNOLOGY
tarsus, but differ from other families with a fleshy colulus by having the paracymbium a small hook on the edge of the alveolus of the cymbium, hidden behind the bulb. The paracymbium (P in illustrations) is attached at the base of the cymbium and variously expanded in Nesticidae and some Araneidae {Meta, Zygiella), a hook at the base in Araneus (Araneidae), or a separate sclerite in the palpus in Linyphiidae. Some theridiids (e.g., Theridula, Faratheridula) lack a paracymbium.
The Symphytognathidae are probably polyphyletic, scondarily derived from the Theridiidae and Araneidae. All are minute, less than 2 mm, all lack a paracymbium in the male palpus; many have the eyes reduced. The carapace may be high, and both carapace and abdomen may be heavily sclerotized. The division between Symphytognathidae and Theridiidae is probably as arbitrary as that between Theridiidae and Nesticidae.
The colulus is derived from vestigial anterior spinnerets and is generally believed primitive, its loss secondary. However, the simplest male palpi in theridiid spiders are all found in genera that lack a colulus {Theridula, Faratheridula, Achaearanea). While the palpus of Theridula and Faratheridula might be interpreted as secondarily reduced, this probably is not the case in Achaearanea. Achaearanea {?indi Dipoena) palpi show how the various sclerites may have originated, possibly an early stage in the evolution of the complex linyphiid palpus. The complex appearing palpus of symphytognathids is secondarily simplified, judging by the absence or vestigial character of certain sclerites that are well developed in the theridiid palpus.
The Umits of the family Theridiidae are arbitrary. Better knowledge of southern hemisphere spiders, especially Symphytognathidae, may make it possible to define the family better.
KEY TO GENERA OF THERIDIIDAE IN AMERICA NORTH OF MEXICO (AND OF EUROPE)
by Herbert W. Levi
la. Abdomen sclerotized, with a series of humps and a sclerotized ring around
spinnerets (Fig. 20); carapace projecting anteriorly (Fig. 20); less than 2.7 mm total length; one species in eastern U.S Moroncidia
lb. Abdomen otherwise 2
2a(lb). A fleshy colulus present between anterior spinnerets (Fig. 1) 3
2b. Colulus absent (Fig. 47) or replaced by two setae (Fig. 19) 10
3a(2a). Tarsi longer than metatarsi; adults less than 1.3 mm long 4
3b. Metatarsi equal to, or longer than tarsi; adults usually longer than 1.5 mm . . 5
4a(3a). Six eyes, one rare species in California (Fig. 2) Comaroma
4b. Eight eyes; one species from Alaska to southeastern states (Fig. 3) . .Theonoe
5a(3b). Carapace, sternum with dumb-bell-shaped tubercles (Fig. 4); palpal cymbium
with a projection (Fig. 5) Cnistulina
5b. Carapace, sternum not tuberculate, or only very slightly so 6
6a(5b). Lateral eyes separated by their diameter or more; chelicerae without teeth
(Fig. 6); female internal genitalia with dumb-bell-shaped seminal receptacles and male palpus with coiled embolus (Figs. 7, 8) Latrodectus
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDIIDAE
33
6b.
7a(6b).
7b.
8a(7b).
8b.
9a(8b).
9b.
10a(2b).
10b.
lla(lOa).
11b.
12a(llb).
12b.
13a(12b).
13b.
14a(13b).
14b.
15a(14b).
15b.
16a(15a).
Lateral eyes slightly separated at most (Fig. 12); chelicerae with teeth (Figs. 14, 1 5); genitalia otherwise 7
No comb setae on fourth tarsus; male eye or clypeal region swollen and projecting, or a groove below eyes (Fig. 9); female abdomen higher than long with humps extending beyond spinnerets, or thread-shaped, often with silver spots (Figs. 10, 11); middle tarsal claw often longer than laterals . .Argyrodes Comb-setae on fourth tarsus (Fig. 80); male eye or clypeal region never so modified; female abdomen oval to spherical (Figs. 12, 13, 17), never with
silver spots; middle tarsal claw smaller than laterals 8
Abdomen without pattern, uniformly colored Robertus
Abdomen with a pattern (Figs. 12, 13, 17) 9
Female lacks a tooth on posterior cheliceral margin; male chelicerae never large. Paracymbium hook not on edge of male palpal cymbium; many species purplish-brown to black in color, with a white line around anterior of
abdomen (Figs. 12, 13) Steatoda
Female with at least one tooth on posterior cheliceral margin (Fig. 14); male with chelicerae often enlarged (Fig. 16); paracymbial hook on margin of cymbium (Fig. 18) Enoplognatha
Colulus replaced by two setae (Fig. 19) 11
Colulus absent (Fig. 47) 21
Posterior median eyes more than three diameters apart (Fig. 21); abdomen longer than wide, widest near anterior end (Fig. 21); one species in eastern
states Spintharus
Posterior median eyes at most two diameters apart; abdomen usually other- wise 12
Abdomen longer than wide, dorso-ventraUy flattened, widest posteriorly with median posterior or lateral posterior humps (Fig. 22); one species in eastern
states Episinus
Abdomen otherwise 13
Venter of abdomen and its anterior overhang black (Figs. 23, 24); abdomen variously shaped; eyes often reddish; palpal cymbium supports embolus, con-
ductor absent (Fig. 25) Chrosiothes
Coloration of abdomen otherwise; eyes not reddish; palpal cymbium never supporting embolus 14
Eyes large, closely grouped (Fig. 26); eye region black except between posterior median eyes (Fig. 26); fourth legs longer than first; abdomen often
with a white spot above spinnerets Stemmops
If eyes closely grouped and eye region black then the first legs are longer than fourth; abdomen rarely with white spot above spinnerets 15
Total length less than 1.8 mm 16
Total length greater than 2 mm . 19
Abdomen much wider than long (Fig. 27); rare; one species in Florida
Tekellina
34
THE JOURNAL OF ARACHNOLOGY
16b.
17a(16b).
17b.
18a(17b).
18b.
19a(15b).
19b.
20a(18, 19b).
20b.
21a(10b).
21b.
22a(21b).
22b.
23a(22a).
23b.
24a(22b).
24b.
Abdomen spherical to longer than wide 17
Anterior median eyes vestigial, minute, less than one-third that of laterals
(Fig. 29); one rare species in Arizona S typo sis
Diameter of anterior median eyes equal to radius of others or larger 18
Anterior median eyes smaller than others (Figs. 30, 31); chelicerae with teeth
on anterior margin, denticles on posterior Pholcomma
Diameter of anterior median eyes equal to others or larger (Figs. 40, 41, 42, 45, 46); chelicerae without teeth; females with two pairs of seminal recepta- cles 20
Chelicerae with teeth on anterior and posterior margins, fangs short (Fig. 33); abdomen oval, longer than wide, often with dorsal longitudinal band (Fig. 32); one pair of seminal receptacles; comb setae on fourth tarsus .Anelosimus Chelicerae without teeth, fang long and flattened (Figs. 34-37); abdomen triangular to subspherical; four seminal receptacles (Figs. 38, 39); comb setae lacking 20
Abdomen usually triangular (Figs. 40-42), widest anteriorly (Figs. 40-42); male palpus without median apophysis (Fig. 43); male carapace not modified;
fourth leg commonly longer than first Euryopis
Abdomen usually spherical; median apophysis usually present in palpus, radix a separate sclerite (Fig. 44); male carapace often modified or high (Figs. 45,46) Dipoena
Abdomen triangular, widest anteriorly; dorso-ventrally flattened; fourth legs
longer than first, lacking comb setae; two pairs of seminal receptacles in
female Euryopis
Abdomen otherwise; first legs longer than fourth, or if fourth longer, abdomen spherical; fourth with comb setae (Fig. 80); one pair of seminal receptacles in female (Fig. 74) 22
Abdomen higher than long, often with streaks on sides (Figs. 49, 51-53); male palpus with cymbium usually extending beyond bulb (Figs. 48, 54, 55) . . 23 Abdomen longer than high, to wider than long, to subspherical; if high then not streaked; cymbium rarely extending beyond bulb 24
A narrow longitudinal white line from highest point of abdomen to spinnerets (Fig. 49); males minute with only one palpus; male palpus with median apophysis and radix (Fig. 48); epigynum with a protruding knob (Fig. 50) . . .
Tidarren
White line much wider or absent from abdomen (Figs. 51-53); males with two palpi, lacking median apophysis; radix broadly attached (Figs. 54, 55) . . . Achaearanea
Abdomen longer than wide, high with tubercle or point above and posterior to spinnerets (Figs. 56, 57); palpus with all sclerites present (if the whole
carapace is black and eyes small, it is Coleosoma acutiventer. Fig. 64)
Chrysso
Abdomen otherwise, oval to spherical or wider than long 25
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDIIDAE
35
25a(24b). Female abdomen wider than long, each lateral point dark and abdomen with prominent dorsal white spot (Fig. 58); carapace with wide black longitudinal band (Fig. 58); palpus very simple with a twisted embolus on distal tip of
bulb (Figs. 59, 60) Theridula
25b. Abdomen, if wider than long marked otherwise and if male has simple palpus,
embolus is straight, not twisted 26
26a(25b). Males with simple palpus, lacking sclerites but having a straight distal embolus (Fig. 62); females with 3-6 dorsal black patches on oval abdomen (Fig. 61); epigynum a clear plate with two circular openings (Fig. 63), to 2.2 mm total
length, one species in Gulf states .Paratheridula
26b. Palpus with radix and median apophysis; epigynum otherwise 27
27a(26b). Males with sclerotized ring around abdomen encircling pedicel and covering epigastric area (Figs. 65, 66); abdomen often constricted in middle (Figs. 65, 66); less than 4 mm; females difficult to separate from Theridiou or Chrysso except for small eyes and projecting clypeus (Fig. 64); three small species in
southeastern U.S., one of which is found in Arizona Coleosoma
27b. Males otherwise, or larger than 6 mm; females rarely with projecting clypeus. .
28
28a(27b). Males usually with eye region of clypeus very high, bulging, projecting, or with groove in clypeus (Figs. 68, 69); most less than 1.5 mm long; often
orange in coloration; commonly with scuta on abdomen Thymoites
28b. Male eye region never modified; usually larger than 1.5 mm long; rarely
orange in color; no scutum on abdomen Theridion
A CHECKUST OF THE THERIDIIDAE IN AMERICA NORTH OF MEXICO by Diane Randolph and Herbert W. Levi
*Name with this spelling is on Official List of Generic Names in Zoology and cannot be changed.
**Application has been made to place name on Official List of Generic Names in Zoology. Application not acted upon; thus existing usage is to be maintained (Art. 80 of ICZN) and has been used in preference over other names in use and not widely accepted.
Achaearanea Strand, 1929. Levi, 1955a (Revision); 1963b (Keys, Maps).
Type species: zl. insignis (O.P.-Cambridge)
96 acoreemk (Berland, 1932). Levi, 1955a: 20, f. 39, 40, 46 (9d geochares); 1963b:
220; 1967a: 179, f. 12-14 (96). CA.
9 ambera Levi, 1963b: 204, f. 7-8 (9). UT, WY.
9c5 canionis (Chamberlin and Gertsch, 1929). Levi, 1955a: 24, f. 60-68 (93). UT, AZ, CA.
93 chiricahua Levi, 1955a: 26, f. 57-59 (9); 1963b: 213, f. 39-40 (3). AZ.
93 conjuncta (Gertsch and Mulaik, 1936). Levi, 1955a: 14, f. 14-18 (93). LA, MS,FL, NC.
93 florendida Levi, 1959c. 1955a: 15, f. 26-31 (96 florens); 1959c: 65, f. 17, 20-21 (93). TX, TAM.
93 fresno Levi, 1955a: 27, f. 53-55 (93). CA.
36
THE JOURNAL OF ARACHNOLOGY
9(5 globosa (Hentz, 1850). Levi, 1955a: 9, f. 19-25 (9c5); 1963b: 203. ONT to QUE to TAJVIandFL.
93 insula (Gertsch and Mulaik, 1936). Levi, 1955a: 19, f. 41-45 (93). TX, TAM.
93 porrm (Banks, 1896). Levi, 1955a: 30, f. 71-75, 80-82 (93); 1963b: 215. NY to KS to FL; NUL.
93 nipicola (Fmerton, 1882). Levi, 1955a: 21, f. 47-52, 56 (93); 1963b: 215. AL to ONT to ME;?BCA.
93 schullei (Gertsch and Mulaik, 1936). Levi, 1955a: 17, f. 32-38 (93); 1959c: 61; 1963b; 203. FL, TX,TAM, AZ, CA.
93 serenoae (Gertsch and Archer, 1942). Levi, 1955a: 28, f. 76-79 (93). AL, FL.
93 tepidariomm (C. L. Koch, 1841). Levi, 1955a: 32, f. 69-70, 83-84(93); 1963b: 215; 1967a: 178, f. 9-11. NOV to FL; ONT to TX; CO; KS; BCA to CA.
Anelosimus Simon, 1891. Levi, 1956b (Revision).
Type species: A. eximiiis (Keyserling)
93 analyticus (Chamberlin, 1924). Levi, 1956b: 421, f. 19, 40-42 (93). CA, BCN, SON. 93 studiosus (Hentz, 1850). Levi, 1956b: 418, f. 21-23, 37-39 (93); 1967b: 30, f. 2 (web photo). CT to FL; TN to TAM; NUL; SON.
Argyrodes*"^ Simon, 1864. Exline and Levi, 1962 (Revision).
Type species:^, argyrodes (Walckenaer)
93 americanus (Taczanowski, 1872). Exline and Levi, 1962: 161, f. 236-247 (93). FL, MS, TX, TAM.
93 baboquivari Exline and Levi, 1962: 1 19, f. 89-94 (93). AZ, CHI, SON.
93 cancellatiis (Hentz, 1850). Exline and Levi, 1962: 180, f. 323-336 (93). ONT, NH to FLtoTXto MO.
93 caudatus (Taczanowski, 1872). Exline and Levi, 1962: 176, f. 300-322 (93). TX, FL, TAM.
93 davisi Exline and Levi, 1962: 191, f. 370-374 (93). TX.
93 dracus Chamberlin and Me, 1936. Exline and Levi, 1962: 187, f. 352-358 (93). AL. 93 elevatus Taczanowski, 1872. Exline and Levi, 1962: 134, f. 128-132 (93). MO; VA to FLto TAM; SIN; CA.
93 fictilium (Hentz, 1850). Exline and Levi, 1962: 103, f. 6, 7,26-28 (93). ONT; ME to FL to TX to MO; NUL; BCA to CA.
93 furcatus (O.P-Cambridge, 1898). Exline and Levi, 1962: 116, f. 84-88 (93). SC to FL toTX; NUL; TAM; CA.
93 globosus Keyserling, 1884. Exline and Levi, 1962: 164, f. 248-260 (93). SC to FLto
TX.
93 maculosus O.P.-Cambridge, 1898. Exline and Levi, 1962: 168, f. 271-275 (93). FL.
93 nephilae Taczanowski, 1872. Exline and Levi, 1962: 139, f. 133-137 (93). FL.
93 pluto Banks, 1906. Exline and Levi, 1962: 143, f. 138-142 (93). MD, VA, MO, TX, CHI, TAM.
93 projiciens (O.P.-Cambridge, 1896). Exline and Levi, 1962: 106, f. 8-10, 29-31 (93). FL,TX.
93 subdolus O.P.-Cambridge, 1898, Exline and Levi, 1962: 190, f. 365-369 (93). TX, AZ, NUL.
93 trigonum (Hentz, 1850). Exline and Levi, 1962: 122, f. 66-78 (93). ME to FLtoTX to ONT.
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDIIDAE
37
Chrosiothes Simon, 1894. Levi, 1954a (Key); 1964e (Revision).
Type species: C silvaticus Simon
9(5 chirica (Levi, 1954). Levi, 1954a: 184, f. 7, 8, 20, 30, 31 (9c5 Theridiotis). AZ, CO, UT.
9 iviei Levi, 1964e: 87, f. 37-39 (9). CA.
96 focosus (Gertsch and Davis, 1936). Levi, 1954a: 180, f. 1-5, 10, 19, 26, 27 (9c5 Theridiotis). TX, TAM.
96 minusculus (Gertsch, 1936). Levi, 1954a: 182, f. 11, 16-18, 21, 28, 29 (9c5). TX, TAM. 9c5 portalensis Levi, 1964e: 89, f. 19-22 (9c5). AZ.
96 silvaticus Simon, 1894. Levi, 1954a: 187, f. 25, 36, 37 (9 probabilis), f. 13-15 (c5 barrowsi); 1964e: 84. FL.
Chrysso O.P.-Camb ridge, 1882. Levi, 1955b (Revision); 1962b (Keys).
Type species: C. albomaculata O.P.-Cambridge 96albormculata O.P.-Cambridge, 1882. Levi, 1955b: 61, f. 1-4, 18, 19, 25-27 (9d). NC to FL to TX.
9(5 nordica (Chamberlin and Ivie, 1947). Levi, 1957c: 105, pi. 8, f. 1-2, 7-11 (9c5 Arctachaea). AK, NWT, MT, CO, UT, CA.
9(5 pelyx (Levi, 1957). Levi, 1957c: 104, pi. 8, f. 3-6, 12, 13 (96 Arctachaea). UT, OR. 96 pulcherrima (Mello-Leitao, 1917). Levi, 1962b: 231, f. 71-75 (9(5 clementinae); 1967a: 182, f. 28-31 (96). FL.
O.P.-Cambridge, 1882. Levi, 1959b (Revision).
Type species: C blandum O.P.-Cambridge 96 acutiventer (Keyserling, 1884). Levi, 1959b: 4, f. 6-11 (9(5). GA to TX;TAM.
96 floridanum Banks, 1900. Levi, 1959b: 6, f. 12-17 (9c5). ME, MA, NJ, FL.
9(5 normale Bryant, 1944. Levi, 1959b: 3, f. 1-5 (9c5). NC, FL, AZ.
Comaroma Bertkau 1889. Levi, 1957a (Rev. Archerius).
Type species: C simoni Bertkau
9(5 mendocino (Levi, 1957). Levi, 1957a: 115, f. 38-47 (96 Archerius). CA.
Crustulina Menge, 1868. Levi, 1957b (Revision).
Type species: C. guttata (Wider.).
96 altera Gertsch and Archer, 1942. Levi, 1957b: 372, f. 4-6, 8-10 (9(5). MA to FL to LA to WI.
9(5 sticta (O.P.-Cambridge, 1861). Levi, 1957b: 370, f. 1-3, 7 (9(5). AK to BCN; ID to TX; MAN to QUE; MN; MI; IL; NB; NEF to VA.
Dipoena ThoxtW, 1869. Levi, 1953 (Revision); 1963a (Key).
Type species: D. melanogaster (C. L. Koch)
96 abdita Gertsch and Mulaik, 1936. Levi, 1953: 37, f. 77-82, 108-109 (9(5). FL to CA; NV.
96 Keyserling, 1886. Levi, 1953: 12, f. 11-15, 120-121 (9(5 lineatipes). FL to TX.
9(5 atopa (Chamberlin, 1948). Levi, 1953: 35, f. 65-71, 116-117 (96daltoni). UT, CA.
9 bermrdino Uevi, \963>2i: 147, f. 125-127 (9). CA.
96 buccalis KeyserUng, 1886. Levi, 1953: 27, f. 6, 16-18, 33-34, 98-101 (9(5). ONT,OH, NY to MD; AL, MS, AZ, CHI, SON.
6 cathedralis Levi, 1953: 15, f. 19-22 (c5). TX.
9 chathami Levi, 1953: 21, f. 85-86 (9). GA.
38
THE JOURNAL OF ARACHNOLOGY
96 dorsata Muma, 1944. Levi, 1953: 17, f. 87-88, 19, f. 23-29 (96 appalachia). MD to FL; TN, MS, AZ.
9 lana Levi, 1953: 36, f. 112-113(9). CA,OR.
93 malkini Levi, 1953: 33, f. 8,60-64, liaill (93). UT, NM, AZ, OR, CA.
9 neotoma Levi, 1953: 36, f. 7, 1 18-1 19 (9). CA.
93 nigra (Emerton, 1882). Levi, 1953: 21, f. 30-32, 37-46, 91-97 (93). Throughout U.S. and southern Canada.
93 prona (Menge, 1868). Levi, 1953: 30, f. 50-59, 105-106 (93 hamata). MA, RI, NY, NC, MI, IL, SD; NM, CO to CA.
9 provalis Levi, 1953: 34, f. 114-115 (9). UT, OR.
9 rita Levi, 1953: 32, f. 107 (9). AZ.
93 sulfurica Levi, 1953: 29, f. 4-5, 47-49, 83-84, 102-104 (93). NM, AZ.
9 washougalia Levi, 1953: 35, f. 72-76 (3). WA, OR.
Enoplognatha* Pavesi, 1880. Levi, 1957d (Revision); 1962a (Key).
Type species: Theridion mandibulare Lucas
93 intrepida (Sorensen, 1898). Levi, 1957d: 17, f. 40, 41, 48, 51, 52 (93). AK, ALB, SAS, ONT; NH to PA; WI, MN, MT, WY, CO, NM.
93 joshua Chamberlin and Ivie, 1942. Levi, 1957d: 15, f. 42-46, 54-56 (93). VA, GA, WY, WA; ID to AZ, CA.
93 maricopa Levi, 1962a: 15, f. 1-5 (93). CA, AZ.
93 marmorata (Hentz, 1850). Levi, 1957d: 11, f. 24, 26, 27, 30-33 (93). ONT to NOV to AL to MO; ND; MT to TX to CA to WA.
93 ovata (Clerck, 1757). Levi, 1957d: 7, f. 1-10 (93). ME to NY;ONT;BCA to CA.
93 selma Chamberlin and Ivie, 1946. Levi, 1957d: 10, f. 15, 16, 19, 20,22, 23 (93). OR, CA.
93 tecta (Keyserling, 1884). Levi, 1957d: 13, f. 11, 25, 28, 29, 34-37 (93). ONT to NEF to VA to 10; TX, CO, WA.
93 thoracica (Hahn, 1831). Levi, 1957d: 9, f. 13, 14, 17, 18, 21 (93). OR.
93 wyuta Chamberlin and Ivie, 1942. Levi, 1957d: 15, f. 38, 39, 47, 49, 50, 53 (93). SD, WY, UT.
Episinus Latreille, 1809. Levi, 1954d (Revision); 1964b (Key).
Type species :E’. truncatus Latreille
93 arnoenus Banks, 1911. Levi, 1954d: 68, f. 4, 17, 18, 32, 39 (93). MD toFL;TN, AL.
93 cognatus O.P.-Cambridge, 1893. Levi, 1954d: 71, f. 8-10, 21, 22, 33, 41 (93). TX, TAM.
Euryopis Menge, 1868. Levi, 1954b (Revision); 1963a (Key).
Type species: flavomaculata (C. L. Koch)
93 argentea Emerton, 1882. Levi, 1954b: 11, f. 4, 7, 11-14 (93). MA to VA; ONT to OH, IL;CO,OR.
93 emertoni Bryant, 1933. Levi, 1954b: 15, f. 19-22, 29, 31, 34, 37 (93). SC to FLto TN; MA, NY.
93 funebris (Hentz, 1850). Levi, 1954b: 26, f. 53, 65, 69, 83, 84, 100, 120, 121, 129 (93 limbata). QUE to ONT to FL; ND.
93 gertschi Levi, 1951. Levi, 1954b: 9, f. 3, 6, 15, 16 (93). MA to VA; MI, IN, IL.
93 mulaiki Levi, 1954b: 19, f. 17, 18, 27, 28, 32 (93). TX, AZ.
93 quinquemaculata Banks, 1900. Levi, 1954b: 46, f. 133-136 (9). 1963a: 131, f. 11-16.
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDIIDAE
39
OH, NY, MD, DC, VA, GA, TX.
saukea Levi, 1951. Levi, 1954b: 7, f. 2, 5 (d). 1963a: 130, f. 7-9 (9). NJ, MI, WI, MN. 9d spinigera O.P.-Cambridge, 1895. Levi, 1954b: 20, f. 23, 24, 30, 33, 36 (96). NUL, TAM, TX, OK, NM, AZ, UT, CA.
9d taczanowskii Keyserling, 1886. Levi, 1954b: 24, f. 38-52 (96 nigripes). FL, TX, NM, CO,UT,AZ.
6 tavam Levi, 1954b: 29, f. 54, 66, 70, 131 (d). FL.
9 varis Levi, 1963a: 130. Levi, 1954b: 23, f. 25, 26, 35 (9 variabilis). FL. d weesei Levi, 1963a: 134, f. 21 (d). OK.
Confusion reigns among the following names of Euryopis. A new study is necessary to delimit the species. Specimens cannot be placed at the present time.
9d californica Banks, 1904. Levi, 1954b: 39, f. 61, 74, 77, 92, 93, 105, 132 (9d). NV, CA, BCN.
9d coki Levi, 1954b: 33, f. 58, 68, 85, 86, 102, 130 (9d). UT, ID, WY.
9d formosa Banks, 1908. Levi, 1954b: 40, f. 62, 75, 78, 94-96, 106, 107 (9d). BCA to CA;ID, WY,UT.
9d lineatipes O.P.-Cambridge, 1893. Levi, 1954b: 36, f. 60, 73, 76, 90, 91, 104, 125, 126 (9d). NUL, TAM,TX.
d pepini Levi, 1954b: 32, f. 55, 61, 71, 101 (d). WI.
9d scriptipes Banks, 1908. Levi, 1954b: 43, f. 59, 63, 79, 80, 82, 97-99, 108-114, 116-119, 127, 128 (9d). Limits uncertain: ALB to CHI;SD, NB. d spiritus Levi, 1954b: 46, f. 64, 81, 115 (d). CO.
9d texam Banks, 1908. Levi, 1954b: 34, f. 57, 58, 72, 87-89, 103, 122-124 (9d). TX, AZ, UT, CO, NUL, SON, COA.
Latrodectus^ Walckenaer, 1805. Levi, 1959a (Revision). Changes: McCrone and Levi. 1964; Kaston, 1970.
Type species: L. mactans tredecimguttatus (Rossi)
9d bishopi Kaston, 1938. McCrone and Levi, 1964: 15, f. 2, 4-7, 21-22 (9d). FL.
9d geometricus C. L. Koch, 1841. Levi, 1959a: 21, f. 8-10, 25-28, 37, 39-50, 80-83 (9d). 1967a: 185, f. 57-59 (9d). FL.
9d hesperus Chamberlin and Ivie, 1935. Kaston, 1970. Doubtful if valid species (unpubl.).
9d mactans (Fabricius, 1775). Levi, 1959a: 24, f. 1, 5-7, 19-21, 38, 53-55, 56-67, 72-79 (9d); 1967a: 185, f. 60-62 (9d). NY to CA and south; TAM and BCN. Doubtful if west coast specimens same species.
9d variolus Walckenaer, 1837. McCrone and Levi, 1964: 13, f. 3, 8-13, 27 (9d). ONT to BCA; MA, VT; FL to CA. Doubtful if BCA to CA same species.
Paratheridula Levi, 1957. Levi, 1957a, 1966 (Revision).
Type species: P. perniciosa (Keyserling)
9d perniciosa (Keyserling, 1886). Levi, 1957a: 106, f. 1-6, 48 (9d). 1967a: 176, f. 1-4 (9d). FL, AL, MS, LA.
PholcommaJhoiQW., 1869. Levi, 1957a (Revision).
Type species: P. gibbum Westring 9d barnesi Levi, 1957a: 1 14, f. 31-37 (9d). NC, PA.
9d carota Levi, 1957a: 113, f. 28-30 (d), in press 9. NC, GA, FL.
9d hirsuta Emerton, 1882. Levi, 1957a: 110, f. 19-27, 48 (9d). NH to FL to MSto WI; MO.
40
THE JOURNAL OF ARACHNOLOGY
Phoroncidia Westwood, 1835. Levi, 1955c (Rev. Oronota).
Type species; P. aculeata Westwood
9(3 americana (Emerton, 1882). Levi, 1955c: 334, f. 1-8 (96 Oronota americana). 1964c: 74, ONT to MS to FL to MA; NOV; AR.
Robertus"^* O.P.-Cambridge, 1879. Kaston, 1946 (Revision Ctenium).
Type species: R. neglectus O.P.-Cambridge Name protected by Art. 80 of ICZN.
96 banksi (Kaston, 1946). Kaston, 1946: 5, f. 1-8, 49 (9c5). ONT; NH to MD; ML 96 borealis (Kaston, 1946). Kaston, 1946: 6, f. 41-43, 50 (9(5). ME, NY, ML 9 crosbyi (Kaston, 1946). Kaston, 1946: 7, f. 52 (9). NY.
9d eremophilus Chamberlin, 1928. Kaston, 1946: 7, f. 26-28, 54 (9c5). NY, OH, MI, IL, UT.
9 floridensis (Kaston, 1946). Kaston, 1946: 7, f. 48 (9). FL.
9c5 frontatus (Banks, 1892). Kaston, 1946 : 7, f. 48 (96). CT, NY to MD; NC, TN, OH.
9c5 fuscus (Emerton, 1894). Kaston, 1946: 7, f. 38-40, 56 (9(5). LAB, ME to NY; ONT, MI, WY.
96 laticeps (Keyserling, 1884). Kaston, 1946: 9, f. 14-16 (9c5). CT; NY to NC;TN;OH to NB.
96 lividus (Blackwall, 1836). Kaston, 1946: 9, f. 17-19, 58 (9(5). AK.
96 longipalpus (Kaston, 1946). Kaston, 1946: 10, f. 20-22, 47 (96). NH to NJ;ONT; ML 96 pumilus (Emerton, 1909). Kaston, 1946: 10, f. 32-34, 53 (9c5). ME to PA.
9c5 riparius (Keyserling, 1886). Kaston, 1946: 11, f. 11-13, 44 (9(5). QUE to NC; TN, ONT, SD, MN, MI, WY.
9 similis (Kaston, 1946). Kaston, 1946: 12, f. 45 (9). NY.
96 spiniferus (Emerton, 1909). Kaston, 1946: 12, f. 23-25, 57 (9(5). NH, MA, CT, MI, NB.
96 vigerens (Chamberlin and Ivie, 1933). Kaston, 1946: 13, f. 9, 10, 29-31, 55 (9(5). AK; BCA to MT to CA.
Spintharus Hentz, 1850. Levi, 1954d (Revision).
Type species; S. flavidus Hentz
9d flavidus Hentz, 1850. Levi, 1954d: 79, f. 46, 48-50, 52, 53 (9c5). 1963d: 225, f. 1-6. MA, NY to FL; OH to AL; AR, TX, BCN.
Steatoda Sundevall, 1933. Levi, 1957b (Revision). Gertsch, 1959. Levi, 1959d (Discus- sion); 1962a (Key).
Type species: S. castanea (Clerck, 1757)
9c5 albomaadata (DeGeer, 1778). Levi, 1957b: 396, f. 56-65 (9c5). NWT to CA; ALB to CHI; MAN to NB; MN, 10 to NH, CT.
96 americana (Emerton, 1882). Levi, 1957b: 400, f. 66-69 (9(5). ME to FL; OH to AL;
ONT to MO; NB to TX; ID to SON, NM; BCA to OR.
96 atascadera Chamberlin and Ivie, 1942. Levi, 1957b: 419, f. 106-109, 134-141 (9c5). CA.
96 bipunctata (Linnaeus, 1758). Levi, 1957b: 413, f. 86-89, 155-156 (96). NOV to NH; NEF to ONT.
96 borealis (Hentz, 1850). Levi, 1957b: 422, f. 116-118, 148-154 (96). AK; NWT; ALB to CO to NC to NOV;MS;TX.
96 erigoniformis (O.P.-Cambridge, 1884). Levi, 1957b: 402, f. 70-73 (96 septemmaculata)\ 1967a: 184, f. 46-49 (96). FL.
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDHDAE
41
fulva (Keyserling, 1882). Levi, 1957b; 391, f. 32, 33, 45-47, 52 (93). OR to BCN to TAM to NB;FLto TX.
93 grandis Banks, 1901. Levi, 1957b: 415, f. 92-97, 1 19-123 (93). SD, WY, CO, UT, OR, NM, AZ.
93 grossa (C. L, Koch, 1838). Levi, 1957b: 404, f. 74, 83-85 (93). 1967a: 184, f. 50-52 (93). WA to BCN; CHI, SON; MA to CT; FL to MS.
93 hespem Chamberlin and Ivie, 1933. Levi, 1957b: 420, f. 90, 91, 110-115, 142-147 (93). BCA to CA; WA to CO to MT.
9 medians (Banks, 1898). Levi, 1957b: 388, f. 34-36, 42-44, 53-55 (93). OR to BCN to TAM to WY. Gertsch (1960) considers this five species (answ. Levi, 1959d): punctulata (Marx, 1898). TX, AZ to C. MEX. medialis (Banks, 1898). AZ, CA to MEX. washona Gertsch, 1960. OR, NV, UT, AZ, CA. variata Gertsch, 1960. WY to TX; UT to MEX. variata china Gertsch, 1960. TX, NUL.
93 mexicana Levi, 1957b: 417, f. 98-103, 124-128 (93). ID to TX; UT to CHI.
9 palomara Chamberlin and Ivie, 1935. Levi, 1957b: 419, f. 104, 105, 129-133 (9). CA. 93 pulcher (KeyserUng, 1882). Levi, 1957b: 393, f. 3741, 48-51 (93). CO, TX, NM, AZ, OR, CA, COA, CHI. Gertsch (1960) considers this three species (answ. Levi, 1959d): pulcher (Keyserling, 1882). OR, CA. alamosa Gertsch, 1960. TX to MEX. apacheana Gertsch, 1960. CO, NM, AZ.
93 quadrimaculata (O.P.-Cambridge, 1896). Levi, 1957b: 385, f. 28-31 (93). FL to TX; TAM.
93 transversa (Banks, 1898). Levi, 1957b: 383, f. 23-27 (93). TX, AZ, CA, SON.
93 triangulosa (Walckenaer, 1892). Levi, 1957b: 407, f. 75, 76, 80-82 (93). 1967a: 185, f. 53-56 (93). MA, NY to NB to TX to GA; OR, CA; ID, UT, CO.
Stemmops O.P.-Cambridge, 1894. Levi, 1955c (Revision); 1964e (Key).
Type species: S. bicolor O.P.-Cambridge
93 O.P.-Cambridge, 1894. Levi, 1955c: 338, f. 14, 17, 18, 35, 36 (93). FLtoTX,
NUL, TAM.
93 ornatus (Bryant, 1933). Levi, 1955c: 341, f. 16, 21, 22, 29, 30 (93). NJ, OH, MO, NC, GA, MS.
Tekellina Levi, 1957a.
Type species: T. archboldi 93 archboldi Levi, 1957a: 107, f. 7-12 (93). FL.
r/ieoMoe** Simon, 1881. Levi, 1955a (Rev. Coressa).
Type species: T. minutissima (O.P.-Cambridge)
93 stridula Crosby, 1906. Levi, 1955a: 4, f. 2-6 (93 Coressa). AK, WI, ONT, NY, VA, MO.
Theridion* W^lckemer, 1805. Levi, 1957d (Revision); 1963c (Key).
Type species: T. pictum (Walckenaer)
93 adamsoni Berland, 1934. Levi, 1957d: 62, f. 198-199, 209, 213-214 (93 hobbsi); 1963c: 568; 1967a: 181, f. 20-23 (93). FL to TX.
9 aeolium Levi, 1963c: 547, f. 96-97 (9). AZ.
93 agrifoliae Levi, 1957d: 83, f. 284, 285, 302, 303 (93). BCA to CA.
93 alabamense Gertsch and Archer, 1942. Levi, 1957d: 58, f. 202, 203, 206-208 (93). WI to MA to FL to MS; TX; CA.
93 albidum Banks, 1895. Levi, 1957d: 82, f. 286, 287, 300, 301 (93). ONT;MA to WI
Figs. 1-18.-Theridiids with large colulus between anterior spinnerets: 1, Co lulus with three setae; 2, Comaroma mendocina (Levi), male; 3, Theonoe stridula Crosby, female; Figs. 4, 5-Cnistulina altera Gertsch and Archer: 4, Female; 5, Male, left palpus; Figs. 6-S.-Latrodectus mactans (Fabricius): 6, Left chelicera of female posterior view; 7, Female genitalia, dorsal view; 8, Left male palpus; Figs. 9, 10.— Argyrodes elevatus Taczanowski: 9, Male carapace and chelicerae; 10, Female abdomen; 11, Argyrodes americanus (Taczanowski), female abdomen; 12, Steatoda hespera Chamberlin and Ivie, female; 13, Steatoda medialis (Banks), female abdomen; Figs. \A-\S.-Enoplognatha marmorata (Hentz), female, left chelicera: 14, Posterior view; 15, Anterior view; 16, Enoplogmtha intrepida (Sorensen), left male chelicera, posterior view; 17, Enoplognatha tecta (Keyserling), female abdomen; 18, Enoplognatha marmorata (Hentz), left male palpus, lateral view showing paracymbial hook (P) on upper part of cymbium.
Scale lines, 1 mm.
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDIIDAE
43
to LA to NC.
9d antonii Keyserling, 1884. Levi, 1957d: 60, f. 196, 197, 205, 215, 216, 219, 220 (96). CT, NY, MD, TN, FL, MS, TX.
96 arizonense Levi, 1957d: 49, f. 137, 138, (9). Levi, 1969: 68, f. 104 (6). NM, AZ.
93 atropunctatum Petrunkevitch, 1930. Levi, 1957d: 66, f. 225-228, 232-234 (93). FL. 93 aumntium Emerton, 1915. Levi, 1957d: 93, f. 337-339, 350-352 (93). AK; BCA; WY; NEF to NY;QUE to WI.
93 amtrale Banks, 1899. Levi, 1957d; 41, f. 131, 132, 148-151 (93). NJ; MD; NC to TAM; UT.
93 berkeleyi Emerton, 1924. Levi, 1957d: 52, f. 166, 167, 171, 172, 174 (93). IL; MN to NJ; ONT to MA; OR; CA; UT.
93 bimaculata (Linn., 1767). Levi, 1956b: 409, f. 1-10 (96, Neottiura). BCA, WA.
93 californicum Banks, 1904. Levi, 1957d: 84, f. 273, 276, 277,304, 305 (93). BCA to CA.
9 cameronense Levi, 1957d: 40, f. 114, 115 (9). Levi, 1959c: 81, f. 74, 75 (9). TX, TAM, NUL.
93 cheimatos Gertsch and Archer, 1942. Levi, 1957d: 96, f. 335, 336, 354-357 (93). OH, TN, GA,FL.
3 dnctipes Banks, 1898. Levi, 1957d: 29, f. 87, 88, 99 (3). TX.
93 cocMse Levi, 1963c: 553, f. 123, 124 (3). Levi, 1969: 69, f. 5-8 (9). AZ.
9 cowlesae Levi, 1957d: 31, f. 91, 92 (9). CA.
93 crispulum Simon, 1895. Levi, 1957d: 64, f. 222-224, 229-231 (93 intervalla turn).
Levi, 1963c: 564, f. 166-172 (93). NOVtoFL;TNto TX, NUL, TAM; OR, CA.
93 cynicum Gertsch and Mulaik, 1936. Levi, 1957d: 39, f. 126-128 (93). TX, TAM, NUL.
93 differens Emerton, 1882. Levi, 1957d: 32, f. 100, 101, 104-106 (93). Throughout So.
Canada and all U.S., most common in NE states.
93 dilutum Levi, 1957d: 37, f. 112, 113, 123-125 (93). UT, TX, AZ, CA, NV, SON, CHI, NUL.
93 dividuum Gertsch and Archer, 1942. Levi, 1957d: 25, f. 67, 68, 71-74 (93). NC, SC, AL.
93 dulcineum Gertsch and Archer, 1942. Levi, 1957d: 26, f. 69, 70, 75, 76 (93). MD, TN, GA, AL.
93 flavonotatum Becker, 1879. Levi, 1957d: 34, f. 102, 103, 107-109 (93). MD;OHto TN; NC to TX.
93 frondeum Hentz, 1850. Levi, 1957d: 81, f. 288, 289, 298, 299 (93). BCA, WA, CA, AZ, SAS, ND; ONT to NOV to NC, AL to MN.
93 geminipunctum Chamberlin, 1924. Levi, 1957d: 43, f. 135, 136, 142-144 (93). CA, BCN.
9 gertschi Levi, 1959c: 89, f. 91, 92 (9). AZ, CHI.
93 glaucescens Becker, 1879. Levi, 1957d: 44, f. 152, 153, 155, 156 (93). NEF to WI to FL;NB, LA,TX.
93 goodnightonim Levi, 1957d: 41, f. 129, 130, 145-147 (93). WY to CA and TX; CHI. 93 hidalgo Levi, 1957d: 43, f. 133, 134, 139-141 (93). TX, TAM.
93 impressum L. Koch, 1881. Levi, 1957d: 89, f. 321, 326-328 (93). AK, NWT, ALB.
93 intritum (Bishop and Crosby, 1926). Levi, 1957d: 35, f. 110, 1 1 1, 120-122 (93). GA, AL, FL.
93 istokpoga Levi, 1957d: 67, f. 235, 236, 247, 248 (93). FL.
Figs. 19-33.— Theridiids with colulus between spinnerets replaced by two setae; 19, Spinnerets with two colulus setae; 20, Phoroncidia americana (Emerton), female; 21, Spintharus flavidus (Hentz), female; 22, Episinus amoenus (Banks), female, 23, Chrosiothes jocosa (Gertsch and Davis), female; 24, Chrosiothes minuscula (Gertsch), female; 25, Chrosiothes jocosa (Gertsch and Davis), left male palpus; 26, Stemmops O.P.-Cambridge, female; Figs. 27, 2^. -Tekellina archboldi Levi: 27, Female; 28,
Left male palpus; 29, Styposis ajo Levi, female carapace; 30, Pholcomma carota Levi, female; 31, Pholcomma hirsuta Emerton, eye region and chelicerae of female; Figs. 32, 'i'i.-Anelosimus studiosiis (Hentz): 32, Female; 33, Left chehcera, posterior view.
Scale lines, 1 mm.
LEVI AND RANDOLPH- KEY AND CHECKLIST OF THERIDHDAE
45
9 kawea Levi, 1957d: 48, L 118, 119 (9). UT, CA, CHI.
96 lawrencei Gertsch and Archer, 1942. Levi, 1957d: 71, f. 257-260 (9c5). ID, WA,OR, CA.
9d leechi Gertsch and Archer, 1942. Levi, 1957d: 74, f. 267, 268, 290, 29 1 (96). BCA to CO to CA.
96 llano Levi, 1957d: 28, f. 77-80 (96). TX.
9 lowriei Barrows, 1945. Levi, 1957d: 98, f. 353 (9). TN.
96 lyricum Walckenaer, 1841. Levi, 1957d: 89, f. 322, 323, 329-331 (96). WI to ME to FLtoTX.
96 melanumm Hahn, 1831. Levi, 1957d: 55, f. 181-186 (96). BCA to CA, UT.
96 michelbacheri Levi, 1957d: 47, f. 159-163 (96). MT, WA to CA.
96 montanum Emerton, 1882. Levi, 1957d: 71, f. 251-256 (96). BCA to OR; ALB to NM; MAN to NEE; MN to NY; TN.
96 momlum O.R-Cambridge, 1898. Levi, 1957d: 79, f. 271, 280, 281, 296, 297, (96 jeanae). AZ to MEX.
96 murarium Emerton, 1882. Levi, 1957d: 22, f. 12, 57, 58, 61-63. So. Canada to No. MEX, throughout U.S., espec. E. U.S.
96 myersi Levi, 1957d: 31, f. 95-98 (96). EL, TAM, NUL.
96 neomexicanum Banks, 1901. Levi, 1957d: 76, f. 269, 274, 275, 292, 293 (96). BCA, W. U.S.
96 neshaminiljdvU 1957d: 88, f. 31 1, 312, 317-319 (96). IL; PA to GA.
96 ohlerti Thorell, 1870. Levi, 1957d: 98, f. 324, 325, 332-334. (96). AK, NWT to CA; NM, QUE, Rocky Mts., Cascades.
96 orhndo (Archer, 1950). Levi, 1957d: 87, f. 309, 310, 315, 316 (96). GA, EL, LA.
96 pennsylvanicum Emerton, 1913. Levi, 1957d: 87, f. 306-308, 313, 314, 320 (96). ONT; MA to EL; TN, AL, IL, MO.
96 petraeum L. Koch, 1872. Levi, 1957d: 24, f. 59, 60, 64-66 (96). ME, NY, MI, ND, NB; WA to CO to CA.
96 pictipes Keyserling, 1884. Levi, 1957d: 77, f. 270, 278, 279, 294, 295 (96). SC, AL, GA, EL.
96 pictum (Walckenaer, 1802). Levi, 1957d: 50, f. 164, 165, 168-170, 173 (96 omatum). ALB to NOV to WI: SD to WA to UT.
96 positivum Chamberlin, 1924. Levi, 1957d: 68, f. 237-239, 243-246 (96). 1963c: 565, f. 177-178 (96). CA, TX, TAM, BCN.
96 punctipes Emerton, 1924. Levi, 1957d: 75, f. 261-266 (96). WA to BCN.
96 punctosparsum Emerton, 1882. Levi, 1957d: 60, f. 194, 195, 204, 217, 218, 220, 221 (96). MA to NCtoAR.
96 rabuni Chamberlin and Ivie, 1944. Levi, 1957d: 28, f. 81-86 (96). NJ to GA; SD, NB, CO, UT, TX, CA.
96 mfipes Lucas, 1849. Levi, 1957d: 56, f. 188-193 (96). Levi, 1967a: 179, f. 24-27 (96). FL, TX.
96 saanichum Chamberlin and Ivie, 1947. Levi, 1957d: 70, f. 240-242, 249, 250 (96). AK to CA.
6 sarde Chamberlin and Ivie, 1944. Levi, 1957d: 30, f. 89, 90 (6). GA.
96 sexpunctatum Emerton, 1882. Levi, 1957d: 91, f. 340-349 (96). AK to CA; BCA, ALB to AZ; west of Rocky Mts.; MAN; ONT to NEE to NC; Appalachian Mts.
96 simile C. L. Koch, 1936. Levi, 1957d: 53, f. 179, 180, 187 (96). BCA, WA.
96 submissum Gertsch and Davis, 1936. Levi, 1957d: 38, f. 116, 117 (6); 1959c: 84, f.
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THE JOURNAL OF ARACHNOLOGY
Figs. 'iAA^.-Euryopis and Dipoem: Figs. 34, 35. -Euryopis funebris (Hentz), female, left cheFcera: 34, Anterior view; 35, Posterior view; Figs. 36, 31 .-Dipoena nigra (Emerton), left female chelicera: 36, Anterior view; 37, Posterior view; 38, Euryopis flavomaculatis (C. L. Koch), seminal receptacles, dorsal view; 39, Dipoena melanogaster (C. L. Koch), seminal receptacles, dorsal view; Figs. 4 04 2. -Females: 40, Euryopis taczanowskii Keyserling; 41, Euryopis emertoni Bryant; 42, Euryopis funebris (Hentz); 43, Euryopis emertoni Bryant, left male palpus expanded and cleared; 44, Dipoem atopa (Chamberlin), left male palpus; 45, 46, Dipoena aha (Keyserling), male carapace.
Figs. 47-55.-Theridiids without colulus between anterior spinnerets: 47, Spinnerets without colulus; Figs. A^-SQ.-Tidarren sisyphoides (Walckenaer): 48, Left male palpus, expanded; 49, Female abdomen from side; 50, Epigynum, lateral view; Figs. 51-53.— Achaearanea female abdomen from side: 51, A. globosa (Hentz); 52, A. tepidariorum (C. L. Koch); 53, A. ambera Levi; Figs. 54, 55. -Achaearanea left male palpus: 54,4. globosa, expanded; 55,4. tepidariorum (C. L. Koch).
Scale lines, 1 mm.
Abbreviations. C, conductor; E, embolus; M, median apophysis; P, paracymbium; R, radix; T, tegulum.
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDHDAE
47
89-90 (9). TX, NM, AZ, SON, CHL 9 timpanogos Levi, 1957d: 31, f. 93, 94 (9). UT.
93 tinctiim (Walckenaer, 1802). Levi, 1957d: 61, f. 200, 201, 210-212 (93). OR, WA.
93 transgressum Petrunkevitch, 1911. Levi, 195 7d: 47, f. 154, 157, 158 (93). CO, UT, NM, AZ, cm.
93 varians Hahn, 1831. Levi, 1957d: 52, f. 175-178 (93). BCA, WA.
3 yuma Levi, 1963c: 535, f. 42-43 (3). AZ.
Theridula Emerton, 1882. Levi, 1954c (Revision); 1966 (Key)
Type species: T. ^phaenila (Hentz)
93 emertoni Levi, 1954c: 333, f. 1-5 (93). ONT to WI to CT to NEF; WV, TN.
93 gonygaster {Simon, 1873). Levi, 1954c: 340, f. 18-22 (93). FL, AZ.
93 opulenta (Walckenaer, 1837). Levi, 1954c: 334, f. 9-13. NY to FL to TX; MO, UT, OR.
Thymoites Keyserling, 1884. Levi, 1957d (Rev. Paidisca); 1959c (Rev. Sphyrotinus); 1964a (Key).
Type species: T. crassipes Keyserling
93 camano (Levi, 1957). Levi, 1957d: 105, f. 367-373 (96 Paidisca). UT, WA to CA.
93 expulsus (Gertsch and Mulaik, 1936). Levi, 1957d: 109, f. 400, 416, 417 (93 Paidisca)', 1959c: 146, f. 365-366 (93 Sphyrotinus). NC to FL to TX; CA, TAM, NUL. 93 illudens (Gertsch and Mulaik, 1936). Levi, 1957d: 110, f. 396, 399, 414, 415 (93 Paidisca). TX, TAM, NUL.
93 maderae (Gertsch and Archer, 1942). Levi, 1957d: 106, f. 397, 398, 420, 421 (93 Paidisca)', 1959c: 147, f. 350-356 {96 Sphyrotinus). AZ, Cm, NUL.
93 marxi (Crosby, 1906). Levi, 1957d: 111, f. 393-395, 401, 418, 419 {96 Paidisca)', 1959c: 148, f. 363-364 (9 Sphyrotinus). CT to TX to FL; MO.
93 minnesota Levi, 1957d: 81, f. 272, 282, 283 (9 Theridion pretense)', 1964a: 467, f. 74-76 (3). MN,ML
93 missionensis (Levi, 1957). Levi, 1957d: 102, f. 380-383 {96 Paidisca). TX.
93 pallidus (Emerton, 1913). Levi, 1957d: 99, f. 358-366 (93 Paidisca)', 1959c: 158.
MA, RI, NY, TN, NC to FL to TAM, CO, UT, CA.
93 pictipes (Banks, 1904). Levi, 1957d: 102, f. 374-379 {96 Paidisca). WA to AZ.
9 sarasota (Levi, 1957). Levi, 1957d: 105, f. 402-405 {9 Paidisca). FL.
9 sclerotis (Levi, 1957). Levi, 1957d: 104, f. 384-387 {9 Paidisca). NM.
93 unimaculatus (Emerton, 1882). Levi, 1957d: 106, f. 388-392,406-413 {96 Paidisca). ME, QUE, ONT to MN; NY, MA to FL to TX.
Tidarren Chamberlin and I vie, 1934. Levi, 1955b (Revision).
Type species: T. sisyphoides (Walckenaer)
93 haemorrhoidale (Bertkau, 1884). Levi, 1955b: 73, f. 49-57, 61-64 {96 fordum). FL to CA;TAM.
93 sisyphoides (Walckenaer, 1841). Levi, 1955b: 70, f. 41-45, 58-60. KY; FL to TX, TAM, NUL, AZ, CA, BCN.
SYNONYMS OF NORTH AMERICAN THERIDIID GENERA AND SPECIES WHOSE NAME CHANGED SINCE FIRST REVISION
appalachia, Dipoena = Dipoena dorsata Archerius = Comaroma
48
THE JOURNAL OF ARACHNOLOGY
Arctachaea = Chrysso
barrowsi, Theridiotis = Chrosiothes silvaticus bryantae, Euryopis = Euryopis quinquemaculata dementinae, Chrysso = Chrysso pulcherrima Coressa = Theonoe Ctenium = Robertas
curacaviensis, — Levi, 1959a, Latrodectiis = Latrodectus variolas
daltoni, Dipoena = Dipoena atopa
florens, — Levi, \ 9S5, Achaearanea = A. florendida
fordam, — Levi, 1956, Tidarren = Tidarren haemorrhoidale
goe chares , Achaearanea =A. acoreensis
hamata, Dipoena = Dipoena prona
hobbsi, Theridion = Theridion adamsoni
intervallatam, Theridion = Theridion crispalam
jeanae, Theridion = Theridion mom lain
limbata, Earyopis = Earyopis fanebris
lineatipes, Dipoena = Dipoena alta
Neottiara = Theridion
nigripes, Earyopis = Earyopis taczanowskii
omatam, Theridion = Theridion pictam
Oronota = Phoroncidia
Paidisca = Thymoites
pretense, — Levi, 1957, Theridion = Thymoites minnesota
probabilis, Theridiotis = Chrosiothes silvaticus
quadrimacalata, Paratheridula = Paratheridala perniciosa
septemmaculata, Steatoda = Steatoda erigoniformis
Sphyrotinas = Thymoites
Theridiotis = Chrosiothes
variabilis, - Levi, Euryopis = Euryopis varis
y Figs. 56-80.-Theridiids without colulus: 56, Chrysso pulcherrima (Mello-Leitao), female, 57, Chrysso albomaculata O.P.-Cambridge, female; Figs. -Theridula emertoni 'LQvi: 58, Female; 59,
Left male palpus; 60, Left male palpus, expanded; Figs. 61-62), -Paratheridula perniciosa (Keyserling): 61, Female; 62, Left male palpus; 63, Epigynum; Figs. 6A-66.-Coleosoma acutiventer (Keyserling): 64, Female; 65, 66, Male; 67, Coleosoma normale Bryant, left male palpus; 68, Thymoites illudens (Gertsch and Mulaik), male carapace; 69, Thymoites maderae (Gertsch and Archer), male carapace; 70, Thymoites expulsa (Gertsch and Mulaik), left male palpus; Figs. 1\-1 2. -Theridion female abdomens: 71, r. differens Emerton; 72, T. pictum (Walckenaer); 73, T. pictipes Keyserling; Figs, 14-11.-T. pictum (Walckenaer): 74, Seminal receptacles, dorsal view; 75, Epigynum; 76, Left male palpus; 77, Palpus expanded; Figs. 78, 19.— Theridion neomexicanum Banks, left male palpus: 78, Mesal view; 79, Ventral; 80, Fourth leg of Steatoda borealis with comb setae and a comb seta.
Scale lines, 1 mm.
Abbreviations. C, conductor; E, embolus; M, median apophysis; P, paracymbium; R, radix; T, tegulum.
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDIIDAE
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LITERATURE CITED
Exline, H. and H. W. Levi. 1962. American spiders of the gQnm Argyrodes (Araneae, Theridiidae). Bull. Mus. Comp. Zool. 127 (2): 75-202.
Gertsch, W. J. 1960. The fulva-group of the spider genus Steatoda (Araneae, Theridiidae). Amer. Mus. Novitates 1982:148.
Kaston, B. J. 1946. North American spiders of the genus Ctenium. Amer. Mus. Novitates 1306:1-19. Kaston, B. J. 1970. Comparative biology of black widow spiders. Trans. San Diego Nat. Hist. Soc. 16:33-82.
Levi, H. W. 1953. Spiders of the genus Dipoena from America North of Mexico (Araneae, Theridiidae). Amer. Mus. Novitates, 1647:1-39.
Levi, H. W. 1954a. Spiders of the new genus Theridiotis (Araneae: Theridiidae). Trans. Amer. Microscop. Soc. 73(2): 177-189.
Levi, H. W. 1954b. Spiders of the genus Euryopis from North and Central America (Araneae, Theridiidae). Amer. Mus. Novitates 1666:148.
Levi, H. W. 1954c. The spider genus Theridula in North and Central America and the West Indies (Araneae: Theridiidae). Trans. Amer. Microscop. Soc. 73(4):331-343.
Levi, H. W. 1954d. The spider genera Episinus and Spintharm from North America, Central America and the West Indies (Araneae: Theridiidae). J. New York Entomol. Soc. 62:65-90.
Levi, H. W. 1955a. The spider genera Coressa Achaearanea in America north of Mexico (Araneae, Theridiidae). Amer. Mus. Novitates 1718:1-33.
Levi, H. W. 1955b. The spider genera Chrysso and Tidarren in America (Araneae: Theridiidae). J. New York Entomol. Soc. 63:59-81.
Levi, H. W. 1955c. The spider genera Oronota and Stemmops in North America, Central America and the West Indies (Araneae: Theridiidae). Ann. Entomol. Soc. Amer. 48(5):333-342.
Levi, H. W. 1956a. The spider genus Mysmena in the Americas. Amer. Mus. Novitates 1801:1-13. Levi, H. W. 1956b. The spider genera Neottiura and Anelosimus in America (Araneae: Theridiidae). Trans. Amer. Microscop. Soc. 74(4):407-422.
Levi, H. W. 1957a. The North American spider genera Paratheridula, Tekellina, Pholcomma and Archerius (Araneae: Theridiidae). Trans. Amer. Microscop. Soc. 76(2):105-115.
Levi, H. W. 1957b. The spider genera Crustulina and Steatoda in North America, Central America, and the West Indies (Araneae, Theridiidae). Bull. Mus. Comp. Zool. 1 17(3):367-424.
Levi, H. W. 1957c. Spiders of the new genus Arctachaea (Araneae, Theridiidae). Psyche 64(3):102-106.
Levi, H. W. 1957d. The spider genera Enoplognatha, Theridion, and Paidisca in America north of Mexico (Araneae, Theridiidae). Bull. Amer. Mus. Nat. Hist. 1 12(1):5-123.
Levi, H. W. 1959a. The spider genus Latrodectus (Araneae, Theridiidae). Trans. Amer. Microscop. Soc. 78(1):743.
Levi, H. W. 1959b. The spider genus Coleosoma (Araneae, Theridiidae). Breviora, Mus. Comp. Zool. 110:1-8.
Levi, H. W. 1959c. The spider genera Achaeranea, Theridion, and Sphyrotinus from Mexico, Central America and the West Indies (Araneae, Theridiidae). Bull. Mus. Comp. Zool. 121(3):57-163. Levi, H. W. 195 9d. Problems in the spider genus Steatoda (Theridiidae). Syst. Zool. 8:107-1 16.
Levi, H. W. 1962a. The spider genera Steatoda and Enoplognatha in America (Araneae, Theridiidae). Psyche 69(l):ll-36.
Levi, H. W. 1962b. More American spiders of the genus Chrysso (Araneae, Theridiidae). Psyche 69(4):209-237.
Levi, H. W. 1963a. American spiders of the genera Audifia, Euryopis and Dipoena (Araneae:
Theridiidae). Bull. Mus. Comp. Zool. 129(2): 121-185.
Levi, H. W. 1963 b. American spiders of the genus Achaearanea and the new genus Echinotheridion (Araneae, Theridiidae). Bull. Mus. Comp. Zool. 129(3): 187-240.
Levi, H. W. 1963c. American spiders of the genus Theridion (Araneae, Theridiidae). Bull. Mus. Comp. Zool. 129(10):481-589.
Levi, H. W. 1963d. The American spider genera Spintharus and Thwaitesia (Araneae: Theridiidae). Psyche 70(4): 223-234.
Levi, H. W. 1964a. The spider genus Thymoites in America (Araneae: (Theridiidae). Bull. Mus. Comp. Zool. 130(7):445-471.
LEVI AND RANDOLPH-KEY AND CHECKLIST OF THERIDIIDAE
51
Levi, H. W. 1964b. American spiders of the genus E’pwmws (Araneae: Theridiidae). Bull. Mus. Comp. ZooL 131(1): 1-25.
Levi, H. W. 1964c. American spiders of the genus Phoroncidia (Araneae: Theridiidae). Bull. Mus. Comp. Zool. 131(3): 6 5-86.
Levi, H. W. 1964d. The American spiders of the genera Styposis and Pholcomma (Araneae, Theridiidae). Psyche 7 1(1): 3 2-39.
Levi, H. W. 1964e. The spider genera Stemmops, Chrosiothes, and the new genus Cabello from America. Psyche 7 1(2): 7 3-9 2.
Levi, H. W. 1966. American spider genera Theridula ?Lnd Paratheridula (Araneae: Theridiidae). Psyche 73(2): 123-130.
Levi, H. W. 1967a. Cosmopolitan and pantropical species of theridiid spiders (Araneae: Theridiidae). Pacific Insects 9(2): 175-186.
Levi, H. W. 1967b. Habitat observations, records and new South American theridiid spiders (Araneae, Theridiidae). Bull. Mus. Comp. Zool. 136(2): 21-38.
Levi, H. W. 1969. Notes on American theridiid spiders. Psyche 76(l):68-73.
Levi, H. W. (in press). The female of the spider Pholcomma carota described (Arachnida: Araneae;
Theridiidae). Trans. Amer. Microscop. Soc. 94:279-280.
McCrone, J. D., and H. W. Levi. 1964. North American widow spiders of the Latrodectus cura- caviensis group (Araneae: Theridiidae). Psyche 71(1): 12-27.
Roth, V.D., and W.L. Brown. 1975. Comments on the spider Saltonia incerta Banks (Agelenidae?). J. Arachnol. 3:53-56.
COMMENTS ON THE SPIDER SALTONIA INCERTA BANKS (AGELENIDAE?)
Vincent D. Roth
Southwestern Research Station Portal, Arizona 85632
Wynne L. Brown
Department of Biological Sciences University of Arizona Tucson, Arizona 85721
ABSTRACT
The female of Saltonia incerta (Banks) is redescribed, the presence of large tracheal trunks extend- ing into the thorax is recorded, the epigynum is illustrated and S. imperialis Chamberlin and Ivie is placed as a junior synonym. The type locality, now under water, and other collecting sites of this species are discussed. The systematic position of the spider is uncertain because of the agelenid-like external characters and the dictynid-like palpi and tracheal trunks.
INTRODUCTION
Saltonia incerta (Banks) is a rare spider known from an island in the northern part of the Gulf of Cahfornia and from the shores of the Salton Sea in Southern California. Re- cently the type specimen, a mature female, was made available by Dr. Herbert Levi of the Museum of Comparative Zoology. We are taking this opportunity to illustrate the epigynum of this species and to review its history.
Saltonia incerta (Banks)
Fig. 1
Cybaeodes {!) incerta Banks, 1898:185.
Saltonia imperialis Chamberlin and Ivie, 1942:23, Figs. 24-25. NEW SYNONYMY. Saltonia incerta (Banks), Roth and Brame, 1972:34, Fig. 46.
The above synonymy was noted by W. Me (personal communication) a few years before his untimely death but was not pubUshed. The new combination was used inad- vertently by Roth and Brame (1972:34) without explanation nor synonymic data.
The female is similar to the male in size and general appearance but differs slightly in the leg spination: tibia I, lr-2-0; metatarsus I, 2(or lp)-2-l median. The slightly scle- rotized epigynum has lateral openings under heavily sclerotized ridges (Fig. 1).
The internal genitalia were not examined but appear to consist of an atrium, a pair of globular spermathecae with simple connecting canals extending to the epigastric furrow.
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THE JOURNAL OF ARACHNOLOGY
Fig. l.-Epigynum of Saltonia incerta Banks (type specimen).
A male in The American Museum of Natural History shows two large tracheae entering the thorax.
Type data— Adult female and immature (thorax and legs only) from Salton, California (27 March 1897, H. G. Hubbard), in the Museum of Comparative Zoology, Cambridge, Massachusetts, collected from debris on salt crust.
Other Rqcox&s— California: Fish Springs, Salton Sea (12 March 1941, Wilton Ivie), in The American Museum of Natural History, male, under a stick on the open ground. Sonora: Isla Pelicano, Mar de Cortes (20 April 1944, B. Osorio Tafall), in The American Museum of Natural History, male.
Two of the three collecting sites can still be located. Unfortunately, Fish Springs is now partially developed into a mineral bath at the Rancho Marina Campground at Desert Shores on the Salton Sea. Salton, California, on the northeastern edge of the Salton Sea, was a railroad station for a salt mining company which worked a nearby salt de- posit. This deposit is now underwater but was in the area between the Salton and the Mecca beaches of the present Salton Sea State Park. In 1891 there was a salt marsh west of the railroad at Salton which may be the type locality.
The third locality is questionable as there are three “Pelican Islands” in the Gulf of California (Sea of Cortez), one now nonexistent and the other two somewhat inacces- sible. One is known locally as Isla El Alcatraz (Spanish for “The Pelican”) and is so recorded on at least one Mexican map (Map 1) but is commonly known by American fishermen as Pehcan Island, or Isla Pelicano(s) (Maps 2-4). Elsewhere it is listed as Isla Tassne (Map 5). It is a high rocky mountain with some low sandy land covered with desert brush, located at the edge of Kino Bay at latitude 28°49', longitude 1 1 1°58'. It has none of the salt marshes one finds around the type locality at the Salton Sea.
The oldest maps (Maps 6-7) place Pelican Island near the junction of the Colorado and Hardy Rivers about 10-12 miles upstream from the Montegue and Gore Islands at the mouth of the Colorado River. The diversion and later damming of this river and the subsequent decrease in water flow caused the island to become permanently attached to the river bank and it was essentially lost. These early maps showed two separate islands whereas more recent maps show the islands joined but partially divided at the southern end with a third unnamed island eastward (Map 8). On the latest maps (Maps 9-10) it is called Pelican Island. This island, which is more likely to be the collecting site of S. incerta, lies at the mouth of the Colorado River at latitude 31°45', longitude 1 14°38'.
The three collections, all containing adult specimens, were made in the months of March and April near salt springs, salt water or salt marshes. Repeated trips to similar
ROTH AND BROWN-COMMENTS ON SALTONIA INCERTA
55
areas including Fish Spring and other springs in the Salton Sea region, Pelican Island at Kino Bay, and along the shores of the Gulf of California have failed to produce additional specimens. Perhaps Saltonia has a specialized habitat that has not been exploited by collectors. The similarity of its colulus to two genera of intertidal zone spiders, Corteza Roth and Brown and Desis Walckenaer suggests that S. incerta may be found in a similar marine habitat, Corteza interaesta is found at night on rocks and reefs at the upper barnacle zone in the Gulf of California. Desis is a widespread genus the species of which are found in rock crevices and worm tubes in the intertidal zone of the Southern Pacific and Indian Oceans from the Galapagos Islands to Eastern Africa.
The systematic position of Saltonia incerta remains a puzzle. Banks (1898:185) origi- nally placed it questionably in the genus Cybaeodes, commenting, “am uncertain of its position, but I think it very near Cybaeodes C Why he placed it in this genus is puzzling since Cybaeodes is characterized by its contiguous spinnerets. At that time this genus was placed in the Drassidae by Simon (1893:390) and later Petrunkevitch (191 1 :532) placed Cybaeodes incerta in the Agelenidae. Both Roewer (1954:581) and Bonnet (1956:1297), following Petrunkevitch (1928:175), listed the genus Cybaeodes, including incerta, in Liocraninae, a subfamily of the Clubionidae. Lehtinen (1967:355) originally placed Saltonia in the family Dictynidae, and the subfamily Cybaeinae, but added a footnote on the same page transferring it to Tricholathysinae in the same family without providing evidence for either change.
Except for the widely spaced spinnerets and broad colulus, Saltonia has all the exter- nal characteristics of the family Agelenidae and will key out readily to this family in Petrunkevitch’s (1939:141-148) key to the spider families. The two large tracheal trunks which extend into the thorax are not, however, typical of any of the Agelenidae but are of the Dictynidae.
Recent extensive reclassification of the cribellate spiders and related ecribellate families by Lehtinen (1967), Forster (1970) and Forster and Wilton (1973) leaves one with the alternatives of utilizing a phylogenetic classification without being able to place specimens in their proper family or using an artificial classification and making it possible to place specimens where they might be found by other workers. With spider classifica- tion in such a state of flux, it appears to us to be desirable to take a conservative stand and use the family Agelenidae for Saltonia for the present, until some of the problems are settled.
LITERATURE CITED
Banks, N. 1898. Some new spiders. Canadian Entomol. 30(7): 185-188.
Bonnet, P. 1956. Bibliographia Araneorum: Analyse Methodique de toute la literature araneologique jusqu'en 1939. 2(pt. 2):919-1925.
Chamberlin, R. V., and W. Ivie. 1942. A hundred new species of American spiders. Bull. Univ. Utah 32(13):1-117.
Forster, R. R. 1970. The spiders of New Zealand, Part III. Otago. Mus. Bull. 3:1-184.
Forster, R. R., and C. L. Wilton. 1973. The spiders of New Zealand, Part IV. Otago Mus. Bull. 4:1-309.
Lehtinen, P. 1967. Classification of the cribellate spiders and some allied families. Ann. Zool. Fenn. 4:199-468.
Petrunkevitch, A. 1911. A synonymic index-catalog of spiders of North, Central and South America with all adjacent islands, Greenland, Bermuda, West Indies, Terra del Fuego, Galapagos, etc. Bull. Amer. Mus. Nat. Hist. 29:1-810.
Petrunkevitch, A. 1928. Systema Aranearum. Trans. Connecticut Acad. Arts and Sci. 29:1-270. Petrunkevitch, A. 1939. Catalog of American spiders. Trans. Connecticut Arts and Sci. 33:133-338. Roewer, C. F. 1954. Katalog der Araneae. Brussels, 2(pt. a): 1-923.
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Roth, V. D., and P. L. Brame. 1972. Neartic genera of the spider family Agelenidae (Arachnida, Araneida). Amer. Mus. Novitates 2505:1-52.
Roth, V. D., and W. L. Brown. 1975. Description of a new genus of Mexican intertidal zone spider (Desidae) with biological and behavioral notes. Amer. Mus. Novitates 2568:1-7.
Simon, E. 1893. Histoire naturelle des arainees. Paris, 1(2): 257-488.
MAPS CITED
1. Oficina de Cartografia y Talleres, Departamento Geografico, Tacubaya, D.F. Sonora. No date.
2. World Aeronautical Chart 471, Sonora River, 24th edition, 9 March 1956. U.S. Coast and
Geodedic Survey, Washington, D.C.
3. Ibid, 26th edition, 17 March 1960.
4. Comision Intersecretarial Coordinadora del Levantamiento de La Carta Geografica de la Re-
publica Mexicana. Primera Edicion, 1958, Isla Tiburon 12R III.
5. American Geographical Society. Map of Hispanic America, Provisional edition. New York,
1937. Sheet NH-12, Sonora, North America.
6. Derby, George. H. 1852. In Report of the Secretary of War, 32nd Congress, First Session. Ex-
ecutive Document 81:1 1-28. (Map is dated 1 850).
7. Rio Colorado of the West, explored by First Lieutenant Joseph C. Ives, 1858. In the University
of Arizona map collection.
8. Operational Navigation Chart, H-22, edition 8, 1969. Aeronautical Chart and Information Center,
United States Air Force, St. Louis, Missouri.
9. Tactical Pilotage Chart H 22-A, edition 1, 1969. Ibid.
10. Tactical Pilotage Chart H 22-B, edition 1, 1971. Ibid.
(continued from inside front cover)
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CONTENTS
THE JOURNAL OF ARACHNOLOGY
Volume 3 January 1975 Number 1
Feature Articles
A New Genus and Species of Chthoniid Pseudoscorpion from
Mexico (Pseudoscorpionida, Clithoniidae), William B. Muchmore 1
The Opilionid Genera Sabacon and Tomicomerus in America
(Opiliones, Trogulidae, Ischyropsalidae), 5
A Key and Checklist of American Spiders of the Family
Theridiidae North of Mexico (Araneae), Herbert W. Levi and
Diane E. Randolph 31
Comments on the Spider Saltonia incerta Banks (Agelenidae?),
Vincent D. Roth Wynne L. Brown 53
Cover Illustration, the larva of Cryptocellus pelaezi, Kay McCorkle
Printed by the Speleo Press, Austin, Texas Posted at Santa Barbara, California, U.S.A., June, 1975
i
MrSi
1 he Journal or
Krachnology
^ OFFICIAL ORGAN OF THE AMERICAN ARACHNOLOGICAL SOCIETY
MAY 1975
NUMBER 2
X
'i'. ’
i
%
UME 3
THE AMERICAN ARACHNOLOGICAL SOCIETY
President Beatrice R. Vogel Billings, Montana
Vice Presiden t Secretary- Treasurer
Vincent D. Roth Mel E. Thompson
Southwest Research Station, Whittier Narrows Nature Center, Portal, Arizona South El Monte, California
Journal Editor Robert W. Mitchell Texas Tech University, Lubbock, Texas
Charles D. Dondale
Entomology Research Institute, Ottawa, Ontario
Directors Jon Reiskind University of Florida, Gainesville, Florida
Robert X. Schick
California Academy of Sciences, San Francisco, California
The Society was founded in August, 1972, to promote the study of arachnids, to achieve closer coopera- tion and understanding between amateur and professional arachnologists, and to publish The Journal of Arachnology. Membership is open to all persons interested in the Arachnida. Annual dues, which include subscription to the Journal, are $10.00 for regular members and $5.00 for student members. Institutional subscriptions to the Journal are $10.00. Correspondence concerning membership and subscription should be sent to the Secretary -Treasurer, Mel E. Thompson, Whittier Narrows Nature Center, 1000 North Durfee, South El Monte, California 91733.
THE JOURNAL OF ARACHNOLOGY
Editorial Board
Willis J. Gertsch B. J. Kaston Martin H. Muma Anita Hoffmann-Sandoval
Portal, Arizona San Diego State College, Silver City, New Mexico Instituto Politecnico Nacional,
San Diego, California Mexico, D.F.
William B. Muchmore William A. Shear Stanley C. Williams
University of Rochester, Hampden-Sydney College, San Francisco State College,
Rochester, New York Hampden-Sydney, Virginia San Francisco, California
Norman Platnick Herbert W. Levi
American Museum of Natural History Harvard University
New York, New York Cambridge, Massachusetts
Assistant Editor J. Mark Rowland Texas Tech University, Lubbock, Texas
Editorial Assistants
James R. Reddell Paula Steed
Texas Tech University, Lubbock, Texas
The Journal is published in January, May, and August with the assistance of the Graduate School, Texas Tech University. Members should send their manuscripts and related correspondence to the Editor, Robert W. Mitchell, Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409.
INSTRUCTIONS TO AUTHORS
GENERAL COMMENTS
1) Papers are acceptable from members of the Society in the following languages: English, French, Portu- guese, and Spanish. 2) All manuscripts must be typed and must be double or triple spaced. 3) Use good bond paper but not erasable bond. 4) Leave ample right and left margins, at least 1 UA in. on the left. 5) Do not hyphenate any words at the right margin; it is immaterial how irregular this margin is in manuscript. 6) Manuscripts need not be letter-perfect, but any corrections should be minor ones and should be neatly done. 7) One copy of the manuscript is sufficient; authors should retain a copy. 8) Manuscripts requiring substantial revision after review must be retyped.
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(continued on inside back cover)
Obencham, ¥. D., and J. H. Oliver, Jr. 1976. The heart and arterial circulatory system of ticks (Acari; (Ixodioidea). J. ArachnoL 3:57-74.
THE HEART AND ARTERIAL CIRCULATORY SYSTEM OF TICKS (ACARI: IXODOIDEA)i
Frederick D. Obenchain James H. Oliver, Jr.
Institute of Arthropodology and Parasitology Department of Biology, Georgia Southern College Statesboro, Georgia 30458
ABSTRACT
The heart and arterial (efferent) circulatory system in Argas radiatus and Ornithodoros turicata (Argasidae) and in Ixodes scapularis, Dermacentor variabilis and Amblyomma tuberculatum (Ixodidae) are consistent in form with the plan observed in other apulmonate Arachnida. Specialized sinuses or vessels for channelization of venous (afferent) hemolymph are absent, but heart, arterial vessels and sinuses are well-developed. The heart lies in a sinus formed by the pericardial septum which is continuous with connective tissue processes of dorso-lateral and ventro-lateral suspensory muscles of the heart. Hemolymph flows from the pericardial sinus into two segmental cardiac cavities via two pairs of ostia. Walls of this pulsatile portion of the heart are formed from radiating muscle bands. On contraction, hemolymph is pumped through an anterior thin-walled heart region (aortic-myocardial cone), past an aortic septal valve which prevents back flow, into the anterior aorta and on to the periganglionic sinus. Hemolymph reaches peripheral parts of the body via arterial vessels which surround the pedal nerve trunks. Hemolymph also flows anteriorly, through the periesophageal sinus which surrounds the esophagus and the pharyngeal musculature, and into vessels surrounding nerves to the capitular appendages.
An endosternum is present in argasid ticks. Its reported continuity with tissues forming the peri- ganglionic sinus walls is confirmed in this group. No trace of an endosternum is observed in ixodid ticks. Loss of the endosternum appears to facilitate the extensive engorgement behavior observed in ixodid females. Extrinsic muscles present in the periganglionic sinus of all investigated tick species may be derived from dorso-ventral suspensory muscles of a prototypic endosternum. These muscles, together with the intrinsic muscles in the ventral wall of the aorta and the action of the aortic septal valve, may function in the maintenance of elevated arterial pressures. The specialized structure of the ventro-lateral suspensory muscles of the heart suggests that they may play an important role as proprioceptors. The presence of a highly condensed and regionally specialized heart, the existence of a pericardial sinus, and specializations of arterial vessels and sinuses, attest to the complexity and evolutionary advancement of the circulatory system in Ixodoidea.
INTRODUCTION
Classical data on the form of the heart and arterial circulatory system in ticks come from general anatomical studies by Christophers (1906) on species of Ornithodoros and Hyalomma, Nordenskidld (1909) on Ixodes, Robinson and Davidson (1913-1914) on Argas, and Douglas (1943) on Dermacentor. Although there are many contradictory
* Supported by Public Health Service Research Grant AI-09556 from the National Institute of Allergy and Infectious Diseases (Principal Investigator, J. H. Oliver, Jr.).
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details in these reports, they indicate the presence of characteristic features from the basic plan of apulmonate arachnid-type circulatory systems in representative Argasidae and Ixodidae.
In Arthropoda the open-type circulatory system is considered an evolutionary con- sequence of the disintegration of coelomic walls which were present in their ancestral annelid-like prototypes (Beklemishev, 1968). Most arthropods retain only the dorsal pulsatile vessel (heart) and a few associated lateral arches of the annelid closed-type system. Certain higher Crustacea, some Myriapoda, larval Xiphosura and most pulmonate Arachnida (those taxa with book lungs) also retain ventral vessels (the paired thoracic arterial sinuses of Firstman, 1973) in association with the ganglionic chain of the central nervous system. Together, these vessels function as an arterial system; hemolymph is pumped through their branches into lacunar spaces in the body and appendages.
In those Xiphosura and pulmonate Arachnida (including the Scorpiones, Uropygi, Amblypygi and Araneae) which have been investigated (Kaestner, 1968; Firstman, 1973) hemolymph passes ventrally from lacunae of the appendages and body into one or more venous sinuses. Within connective tissue-lined extensions of these cavities it is channeled through the gills or leaves of the book lungs where dissolved respiratory pigments (hemo- cyanins) are oxygenated. Several pairs of lateral dorso-ventral sinuses, incorrectly called veins, transport oxygenated hemolymph to the pericardial cavity, a specialized sinus surrounding the multi-segmented heart and other portions of the dorsal vessel. The heart is suspended within the pericardial sinus by a series of dorso-lateral and ventro-lateral muscles or elastic Ugaments (Stewart and Martin, 1974). During diastole the recoil of these tissues expands the previously contracted heart and hemolymph is pumped forward through the anterior aorta. Simultaneously, hemolymph may be pumped laterally through segmentally arranged lateral arteries or to the rear through a posterior aorta.
Anatomical data on the circulatory system in apulmonate Arachnida (including the Palpigradi, Opiliones, Acari, Pseudoscorpiones, Ricinulei and Solifugae) are limited (First- man, 1973). Nevertheless, consistent differences between the pulmonate and apulmo- nate-type plans are known. In apulmonate arachnids, particularly those which show reductions in number of body tagmata, the heart is more condensed and the anterior (dorsal) aorta more highly differentiated, but unbranched (Beklemishev, 1969). In place of ventral vessels the thoracic arterial sinuses are expanded as a perineural sinus enclosing the entire central nervous system (Kaestner, 1968; Firstman, 1973). This perineural sinus receives the aorta and gives rise to an anterior (periesophageal) sinus and lateral arterial vessels which surround nerve trunks to the appendages. Hemolymph passes from these vessels into lacunae within each appendage, then flows into the general body lacunae and, finally, back to the heart.
Although preliminary anatomical studies have been made on the heart and arterial circulatory systems of ticks and other apulmonate Arachnida, there is no firm anatomical basis for the investigation of physiological and pharmacological processes. Such studies have not been initiated despite the relative ecological and economic importance of these taxa. The small size of most parasitic Acari makes them unsuitable for many basic anatomical and physiological investigations, but the larger size of ticks (Ixodoidea) and their importance as vectors of disease (Balashov, 1972) make them prime subjects for such studies. Furthermore, the possibly critical role of the circulatory system during feeding in Ixodidae makes an understanding of this system particularly important. Our previous examination of the central nervous system (Obenchain, 1974a) and neuro- secretory system of Dermacentor variabilis (Obenchain, 1974b; Obenchain and Oliver,
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1975) revealed the probable involvement of tissues forming the wall of the aorta and periganglionic arterial sinus in neuroendocrine mechanisms. The present study was under- taken as the basis for further studies on the roles of tick cardioglial tissues in such mechanisms and to provide the anatomical data prerequisite to a fuller understanding of the functional role(s) of the circulatory system in engorged and unengorged ticks.
MATERIALS AND METHODS
Anatomical and histological observations on tick hearts and arterial circulatory systems were made on laboratory-reared and wild-caught specimens representing four sub-families from the two major tick families. Species examined include Argas radiatus Railliet (Argasidae: Argasinae), Ornithodoros turicata (Duges) (Argasidae: Ornitho- dorinae), Ixodes scapularis Say (Ixodidae: Ixodinae), and Dermacentor variabilis (Say) and Amblyomma tuberculatum Marx (Ixodidae: Amblyomminae). Laboratory rearing conditions, tick-hosts and collection data were reported previously (Obenchain and Oliver, 1973). Anatomical observations on the heart of intact nymphal and adult ticks were facilitated by application of paraffin oil to the tick’s dorsum. Under these condi- tions the cuticle became semi-transparent. Although the transparent heart musculature and associated tissues could not be observed directly, heart position and its rate of contraction were determined from the movements of tracheae and tracheoles. Detailed structural observations were made on dorsal and ventral dissections of the circulatory system, performed under Shen’s physiological saline (9.0gNaCl, 0.42 g KCl, 0.25 g CaCU /liter of distilled water).
Some dissections were made on specimens previously injected with supravital dyes, including 0.5% ammoniacal carmine, 0.02-0.5% trypan blue in Shen’s saline, or 1.0% methylene blue in 1.3% NaCl. Other dissections were stained in toto with leucomethylene blue (about 0.1% after reduction with 0.0 IM ascorbic acid, Larimer and Ashby, 1964) for demonstration of neural elements. Whole mount preparations of the circulatory system were fixed in a calcium formal or 5% ammonium molybdate for direct microscopic examination. Other dissections were fixed in Heidenhain’s SUSA or Carnoy’s fixatives (Humason, 1967) and routinely dehydrated in Cellosolve, embedded in Tissuemat- Paraplast by the dioxane method, and sectioned at 7 pm. Staining techniques included Hubschman’s (1962) simplified azan and Rosa’s aldehyde fuchsin with Halmi’s counter- stain (Meola, 1970). Fresh or vitally stained tissues were stretched on slides in Shen’s saline or 50% glycerol in distilled water for examination by bright field, dark field/ fluorescence, phase contrast, or polarized light microscopy. Histological sections were dehydrated through xylene, mounted in Harleco synthetic resin and examined with the above mentioned optics. Photomicrographs were taken on a Wild M20KGS photomicro- scope. Dimensions of tissues were determined with an ocular micrometer and from calibrated photomicrographs.
OBSERVATIONS
In all examined tick species the heart (Ht) is suspended by a series of dorso-lateral and ventro-lateral suspensory muscles (dlSM, vlSM) within a pericardial sinus (pcS) located medially below the dorsal cuticle. The heart and tissues forming the boundries of the pericardial sinus are bordered anteriorly by insertions of the cheliceral retractor muscles (Figs. 1, 2). Laterally, they lie between mid-dorsal loops of the malpighian tubules and
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Fig. 1. -Diagrammatic representation of the heart, pericardial septum, suspensory muscles and associated tissues of Amblyomma tuberculatum, in ventral view. Scale equals 0.1 mm. Ao, anterior aorta; AoMC, aortic-myocardial cone; ChRM, cheliceral retractor muscles; dlSM, dorso-lateral sus- pensory muscles; GdT-dF, glandular tissues of the dorsal foveae; Ht-P, pulsatile portion of the heart; Ost, ostia; pdvBM, posteromedian dorso-ventral body muscles; pcSp, pericardial septum; vlSM, ventro- lateral suspensory muscles.
insertions of the dorso-genital muscles (and by insertions of the coxal adductor muscles III and IV in Argasidae). Posteriorly, they are bordered by insertions of the postero- median dorso-ventral body muscles (and by tissues associated with the dorsal foveae in Ixodidae-Amblyomminae). The tick heart is in the form of a dorso-ventrally flattened sack. During diastole the heart outline is sub-triangular (Argasidae) to pentagonal (Ixodidae, Fig. 1), but generally spherical in the contracted state (Figs. 4, 5). The thin- walled aorta (Ao) emerges from the anterior apex of the heart and runs forward below the chehceral retractor muscles and above the central portion of the midgut (Fig. 2). At the median notch between the anterior ramifications (caeca) of the midgut, the aorta
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Figs. 2, 3.— Diagrammatic representation of the form and anatomical associations of heart, arterial sinuses and vessels in a representative male ixodid tick (about the size of Dermacentor variabilis): 2, Near-sagittal reconstruction, with addition of a cheliceral shaft, associated muscles, and dorsal foveae (non-mid-line structures); 3, Cross-sections of tick arterial sinuses at levels indicated in Fig. 2. Scale on figures equals 0.1 mm. Ao, anterior aorta; AoSV, aortic septal valve; Cap, capitulum; ChRM, cheliceral retractor muscles; ChS, cheliceral shaft; chN, cheliceral nerves; daS, dorsal anterior sinus; dF, dorsal foveae; E, esophagus; exM, extrinsic muscles of the periganghonic sinus; GdT-dF, glandular tissues of the dorsal foveae; Gen Acc Gd, male genital accessory gland; Ht, heart; hN II, second hemal nerve; IsN, lateral “sympathetic” nerve; MG, midgut; optN, optic nerves; Ph, pharynx; PhM, pharyngeal musculature; pcSp, pericardial septum; peS, periesophageal sinus; pgS, periganghonic sinus; p II Vs, second pedal arterial vessels; Scut, scutum; Syn, synganglion; stN, stomodeal nerve; VasM, vascular membrane; vaS, ventral anterior sinus.
descends into the periganglionic arterial sinus (pgS). No traces of a posterior aorta are observed in any of the examined tick species.
Anatomically, the periganglionic sinus and associated arterial vessels of Dermacentor variabilis are representative of similar circulatory structures in other tick species. Sinus walls completely envelop the condensed mass of the central nervous system (synganglion)
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and the esophagus which passes through it. These walls are closely applied to ventral, lateral and posterior surfaces of the synganglion, but are more removed dorsally (Figs. 2, 3). Here, the aorta enters the sinus just above the point where the esophagus passes out of the synganghon. The periganglionic sinus communicates anteriorly with the peri- esophageal arterial sinus (peS) and laterally with four pairs of pedal vessels (p MV Vs) which surround the major pedal nerve trunks (Fig. 3BB'). Postero-dorsally it terminates around the neuroendocrine retrocerebral organ complex at the level of the proventriculus. The four pairs of pedal vessels extend to the coxal-trochanter junction in the walking appendages. A short distance in front of the synganglion (Figs. 2, 3AA^) the peri- esophageal sinus divides into a dorsal anterior sinus (daS) surrounding paired optic and cheliceral nerves and a ventral anterior sinus (vaS) surrounding paired pedipalpal nerves, the unpaired stomodeal nerve and the esophagus. Extensions of the dorsal anterior sinus surround the peripheral nerves which enter cheliceral shafts, while similar vessels arise from the ventral anterior sinus and surround nerves which enter the pedipalps. The median extension of the ventral anterior sinus expands broadly and irrigates the pharyn- geal musculature (Fig. 2).
Differences in the proportions of the arterial circulatory system among species of Ixodidae parallel changes in overall body dimensions, as in the series of increasing body size from Ixodes scapularis, through D. variabilis and to Amblyomma tuberculatum respectively. Similar proportional differences are observed between Omithodoros turicata and Argas radiatus in Argasidae. The form of the periganglionic sinus is modified in argasid ticks by its continuity with tissues of the well-developed endosternum. The peri- esophageal sinus of argasid ticks is also slightly different in form from that observed in ixodids. Paired arterial vessels to the cheliceral shafts arise separately at the anterior boundary between periganglionic and periesophageal sinuses; consequently, the dorsal anterior sinus, as observed in representative Ixodidae, is poorly developed in Argasidae. This anatomical difference appears to be related to the different orientation of the capitulum and its associated musculature in Argasidae as compared to Ixodidae. In both groups, however, the appendages of the capitulum are supplied by arterial vessels and the pharyngeal musculature is contained within an extension of the ventral anterior (peri- esophageal) sinus. Sexual differences in the form of the heart and arterial circulatory system are minor in the species studied. Differences in the degree of tracheation are pronounced, particularly in Ixodidae, where the more extensive tracheal supply to tissue and organ systems in females allows for considerable expansion and differentiation of the idiosoma during engorgement.
The heart rate appears extremely variable in all tick species. In observations on restrained specimens of newly ecdysed D. variabilis, the rate varies between 18 and 120 beats per minute, with periods of inactivity from less than one to several minutes in duration. These observations were made at room temperature with low intensity fluores- cent illumination. Effects of changing levels of incandescent Hght intensity (and radiant heat) on ticks treated with paraffin oil are pronounced. Increasing or decreasing the intensity randomly accelerates or depresses the heart rate in Amb. tuberculatum, D. variabilis and A. radiatus.
Tick hemolymph contains a variety of hemocyte cell types (Dolp, 1970; Brinton and Burgdorfer, 1971). In specially dissected preparations, numerous cells are observed in circulating hemolymph within the dorsal aorta. Prohemocytes, plasmatocytes and various spherule cells are observed within the arterial vessels and sinuses in histological sec- tions. In all observed ticks, with the exception of Amb. tuberculatum, the hemolymph is
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generally colorless. In this single species, however, the distinct blue-green color of oxygenated hemolymph seems to indicate the presence of hemocyanin pigments.
Structure of the Myocardium
The anatomical form and histological structure of the heart is similar in all investigated tick species. The heart wall (myocardium) is formed from striated muscle. Cellular margins are indistinct and there is no detectable internal intima. Myofibrils take up acidophilic stains, but the myo plasm is generally chro mo phobic. The basophilic nuclei of these cells seem to be distributed randomly throughout the myocardium. Histological sections of contracted heart muscle demonstrate a complicated network of connective tissue fibers over the external surface of the heart muscle. In preparations of relaxed heart muscle, however, these tissues are recognized as the terminal processes of dorso- lateral and ventro-lateral suspensory muscles.
The tick heart is divided into two anatomical regions on the basis of constituent muscle fiber orientation. Each region seems to have a distinctive function. In the larger (posterior) region (Figs. 1, 5, 8) the myocardium is formed from seven semi-circular bands of muscle which radiate from slightly thickened central areas on the dorsal and ventral surfaces of the heart. The dorsal thickened area is loosely anchored to the over- lying cuticle by scattered connective tissues resembhng the tonofibrillae of major body muscles. The semi-circular muscle bands receive connective tissue processes from dorso- lateral suspensory muscles along the lateral margins of the heart (Figs. 1, 4). Ventro- laterally, two pairs of ostia open between radiating muscle bands. The muscular lips of these ostia (Figs. 2, 4) extend internally into the segmental cardiac cavities of the heart. When small amounts of 0.5% trypan blue solution are applied laterally to physio- logical preparations of the heart of Amb. tuberculatum or A. radiatus, anterior and posterior cardiac chambers are readily observed. These two bilaterally symmetrical chambers receive afferent hemolymph via the first and second pairs of ostia, respec- tively. This is the major pulsatile portion of the heart (HtP).
The anterior region of the myocardium (aortic-myocardial cone) links the pulsatile portion of the heart with the aorta (Figs. 1, 4, 8; AoMC). Muscle fibers in this portion of the heart are not organized into radiating bands. Instead, they have a primarily longitu- dinal orientation. Some muscle fibers appear to be extensions of the longitudinal striated fibers which lie in the ventral wall of the anterior aorta.
The myocardium is tracheated by way of an anastomosing plexus of the postero-dorsal tracheal trunks (Figs. 4, 5). Branches of these tracheae generally follow the paths of suspensory muscles on their way to the myocardium. Both regions of the myocardium are tracheated, but the posterior pulsatile portion receives the more extensive supply. After treatment with leuco methylene blue the presence of an intrinsic cardiac ganglion associated with the heart of Amb. tuberculatum is supported by the staining response of eight or more small cells. These are presumably neurons, and they are grouped mid-dorsally above the thickened central area of the myocardium. Nuclei of these cells stain more intensely than the axoplasm. Some neurons appear to be bipolar, others appear to be unipolar. Their processes penetrate the myocardium and can be traced into the cardiac cavity along the internal projections of radiating muscle bands. Similarly staining tissues are observed in other investigated tick species, but in the latter the presence of a discrete cardiac ganglion was not confirmed with vital staining methods.
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Other axon-like fibers were observed after application of leucomethylene blue in ventral and posterior heart walls in Amh. tuberculatum and A. radiatus. The paths of these fibers seem to indicate an extrinsic myocardial innervation. In Amb. tuberculatum some of these putative axons were traced posteriorly into adjacent gland-Hke tissues of the dorsal foveae or ventrally into the ventro-lateral suspensory muscles. In A. radiatus
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Fig. 4. -Frontal section through heart and anterior aorta of an adult male Amh. tuberculatum, aldehyde fuchsin stain, phase contrast optics. Anterior orientation to the top of figure, scale equals 0.1 mm.
Fig. 5.— Dissected heart preparation of an adult female Ornithodoros turicata after formol calcium fixation, in dorsal view with phase contrast optics. Scale equals 0.1 mm.
Fig. 6. -Dissected preparation of ventro-lateral suspensory muscle from the heart of an adult female Amb. tuberculatum in the proximity of the pericardial septum, leucomethylene blue tech- nique, after ammonium molybdate fixation with phase contrast optics. Scale equals 25 jum.
Fig. 7,— Ventro-lateral suspensory muscle of Amb. tuberculatum, as in Fig. 6, at junction of atrial and ventral contributing muscle fibers. Scale equals 25 jum. Ao, anterior aorta; AoMC, aortic- myocardial cone; dlSM, dorso-lateral suspensory muscles; GdT-dF, glandular tissues of the dorsal foveae; HC, hemocoel; Ht, heart; Ht-P, pulsatile portion of the heart; Ost, ostia; pcC, pericardial cells; pcSp, pericardial septum; spN, branch of the spiracular nerve; Tr, trachea; vlSM, ventro-lateral sus- pensory muscle; vlSMa, atrial contributing branch of vlSM; vlSMv, ventral contributing branch of vlSM.
similar fibers were traced posteriorly along branches of the postero-dorsal tracheal trunks. These fibers were followed to the bilateral ganglionic masses of dorsal photo- receptors (Binnington, 1972) which lie below the first pair of cuticular disks associated with the second rows of postero-accessory dorso-ventral body muscles.
Structure of the Pericardium and Suspensory Muscles
The pericardial sinus surrounds the heart on its ventral, lateral and posterior surfaces. It is bound by the perforated pericardial septum (Figs. 1,5; pcSp). This septum is formed by overlapping membranous sheets and strands of loose connective tissue, bound together and supported by fibrous terminal processes of the suspensory muscles of the heart. Along its lateral and posterior margins the septum is loosely attached to the dorsal body wall. Anteriorly, it connects to the walls of the aortic-myocardial cone (Fig. 4). Connective tissues of the pericardial septum serve as a support for pericardial cells (Figs. 4, 5; pcC). The distribution of these pinocytotic cells is best demonstrated in dissections treated with 0.02% trypan blue or other particulate vital dyes. In Amb. tuberculatum and D. variabilis pericardial cells are distributed over the surface of the septum with only a slight peripheral concentration. In A. radiatus and O. turicata, how- ever, lateral concentrations of these cells are pronounced.
The dorso-lateral suspensory muscles of the heart have their origins on specialized cuticular structures associated with origins of principal body muscles. In Ixodidae they arise from integumental grooves and/or unsHvered areas of the dorsal cuticle. These areas are also associated with the origins of the anterior and posterior genital muscles and the marginal dorso-ventral and posteroaccessory dorso-ventral body muscles. In Argasidae the dorso-lateral suspensory muscles of the heart have their origins on dorsal cuticular disks associated with adductor and abductor muscles of the coxae and with postero- accessory dorso-ventral body muscles.
The dorso-lateral suspensory muscles (dlSM) of the tick heart are long and filamentous with a markedly striated appearance under phase-contrast, dark field, or polarizing optics (Figs. 4, 5). Histological properties of suspensory muscle tissues are similar to those of myocardial muscles but their nuclei have a more consistent peripheral distribution. Near the pericardial septum, these muscles become highly branched. In Amb. tuberculatum we identify eight bilaterally symmetrical groups of dorso-lateral muscles (Fig. 1) which terminate as strands of connective tissue (Figs. 4, 5) contributing to the fibrous matrix of
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the pericardial septum. The first and second groups also send some terminal processes into the wall of the aortic-myocardial cone. Terminals of the third group of muscles insert on lateral margins of the anterior pair of muscle bands (pulsatile portion of the myocardium). Fourth and fifth dorso-lateral suspensory muscle groups insert on the second pair of muscle bands between the two pairs of ostia (Figs. 1 , 4). Sixth and seventh groups insert on muscle bands behind the second pair of ostia, while terminals of the eighth group insert on either side of the complex (unpaired) posterior band. Similar patterns are observed in A. radiatus, but dorso-lateral suspensors are grouped in three major sets. The first set seems to include suspensory groups one to four from Amb. tuberculatum, the second set includes suspensory groups five and six, and the posterior set includes groups seven and eight. Different grouping patterns of dorso-lateral suspen- sors between ixodid and argasid ticks seem to determine the shape of the uncontracted heart (pentagonal in Ixodidae and sub-triangular in Argasidae). In ticks from both families the dorso-lateral suspensory muscles are so highly branched that the degree of overlapping myocardiac insertions is not readily determined. A few scattered fibers and presumptive axon-terminals stain with leucomethylene blue in all four tick species. Although the complex patterns of peripheral innervation remain obscure, some dorso-lateral suspensory muscles appear to be innervated by the same nerves which supply body muscles with adjacent origins.
Dorso-lateral suspensory muscles hold the pericardium in place with respect to the heart, but the volumetric integrity of the pericardial sinus (especially in fully engorged adult ixodid ticks) is maintained by the action of right and left ventro-lateral suspensory muscles (vlSM). Branches of these muscles are joined medially as a flattened belt of fibrous connective tissue and slips of striated muscle, all embedded in the pericardial septum (Fig. 1). Other processes of the ventro-lateral suspensory muscles are larger in diameter and longer than dorso-laterals. In A. radiatus they have a flattened strap-like appearance, but in Amb. tuberculatum (Fig. 6) these muscles branch near the heart and have a gradually tapered outline. In ticks from both families the ventro-lateral muscles of the heart have dual origins (Fig. 7). Separate contributing muscles arise (l)from the atrial wall of the spiracular plate and (2) from the ventral body wall. In some species (particularly O. turicata) several muscle slips may arise from the general sites of origin, but these slips soon fuse within the common sheath of the atrial or ventral contribu- tion. Subsequently, the sheaths of the two muscles fuse and their fibers coalesce as the common ventro-lateral muscle to the heart.
Certain cells associated with ventro-lateral suspensory muscles in Amb. tuberculatum and A. radiatus stain with leucomethylene blue. These are presumed to be the perikaryia of sensory neurons. Axons of these cells, together with other stained fibers which may represent a peripheral motor innervation, form a plexus over the surface of the ventro- lateral suspensors. This plexus is particularly dense in the region where atrial and ventral contributing muscles are joined. In both species some peripheral fibers can be traced into paired spiracular nerves, branches of which innervate the right or left ventro-lateral sus- pensor at that point. Spiracular nerves arise from the posterior margin of the synganglion in A. radiatus (Obenchain and Oliver, unpublished), but in Amb. tuberculatum and D. variabilis they have a dual origin from the posterior margin of the synganglion and from the lateral “sympathetic” nerves (Obenchain and Oliver, 1975).
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Structure of Arterial Vessels and Sinuses
A complex layer (possibly stratified) of squamous mesenchyme forms the cellular matrix within walls of the tick arterial circulatory system. These vascular structures are bound on their outer and inner surfaces by distinct basement membranes (collagenous matrices approximately 1 jum thick) which stain intensely with basophilic stains. In argasid and unfed ixodid adults constituent cells of the vascular membranes (vascular sheaths of Obenchain, 1974a; Obenchain and Oliver, 1975) are extremely flattened (Fig. 8) and have indistinct margins. The expansion and apparent secretory activity of mesenchymal cells is pronounced, however, in engorged ixodid females. At this time, several tissue types can be identified within the vascular membranes. Margins of adjacent mesenchymal cells overlap extensively, presenting the appearance of two distinct layers. Nuclei are large (2.5 to 4.0 jim) and stain heavily with acidophilic components of the aldehyde fuchsin and azan staining techniques. Ground cytoplasm is chromophobic, extensively vacuolated and becomes progressively filled with basophilic granules following the blood meal. When intrinsic muscles (restricted to the ventral wall of the anterior aorta), tracheal or neural tissues are observed within the vascular membranes, they lie between the overlapping margins of mesenchymal cells. Some putative axons, stained with the leucomethylene blue technique, can be traced from the walls of the peri- ganglionic sinus back to various pedal nerve trunks in Amb. tuberculatum and A. radiatus. These axonal pathways resemble the putative neurosecretory innervation to the perigang- lionic sinus walls described previously from D. variabilis (Obenchain and Oliver, 1975).
Walls of the periganglionic and periesophageal arterial sinuses and vessels to the appendages are formed from unspecialized vascular membrane. No intrinsic musculature is observed in the walls of these portions of the circulatory system, but the squamous layer of membrane-bound mesenchyme is frequently penetrated by tracheae which supply the central and peripheral nervous system. At the level of the retrocerebral neuro- endocrine complex and the proventricular (esophageal) valve, the wall of the perigang- lionic sinus fuses with similar mesodermal layers which form the annular walls of the esophagus, the sheath of the retrocerebral organ complex and the outer covering of the midgut. Structural details of these associations and evidence for the endocrinological involvement of mesenchymal tissues within the aorta and sinus wall (as a type of cardio- ghal tissue) were reported previously for D. variabilis (Obenchain and Oliver, 1975). Progressive expansion of these tissues, with the formation of intracellular basophilic granules, is observed in all three species of ixodid ticks during and after the adult blood meal. A similar involvement in adult argasids is not indicated at the light microscope level, but expansion of these mesenchymal tissues (complete with development of baso- philic granular inclusions) occurs during the molt from last stage nymph to adult in A. radiatus.
Extrinsic muscle fibers, observed within the periganglionic arterial sinus of all exam- ined ticks, have their origins on internal antero-dorsal projections of coxae I, II and IV. No similar muscles were associated with coxae III in the species examined. From their origins, these transversely striated muscles penetrate adjacent walls of pedal arteries, pass up those vessels into the periganglionic sinus, continue over the surface of the synganglion and penetrate the ventral wall of the anterior aorta (Figs. 3, 10). In ixodid and argasid ticks the sheaths of extrinsic muscles are occasionally fused with the internal basement membrane of the sinus wall, but in both groups they remain free within the sinus for most of their length. In Amb. tuberculatum and D. variabilis there are two muscle slips
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within each pedal vessel (I, II and IV). In A. radiatus and O. turicata there seem to be two muscle slips within the first pair of vessels, but pedal vessels II and IV contain single muscles. In both tick families there is a general agreement between the number of extrinsic muscle slips and the number of intrinsic muscle fibers in the ventral wall of the anterior aorta.
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Fig. 8. —Sagittal section through heart, aorta and aortic septal valve in an engorged adult male D. variabilis (scutum removed), after aldehyde fuchsin stain with bright field optics. Arrow indicates demarcation between aorta and heart. Anterior orientation to left of figure, scale equals 0.1 mm.
Fig. 9.— Dissected preparation of anterior aorta from an unfed adult female Amb. tuberculatum, leucomethylene blue technique after ammonium molybdate fixation with phase contrast optics. Scale equals 25 jum.
Fig. 10, -Frontal section through extrinsic muscles in the periganglionic sinus of a partially engorged adult D. variabilis, azan stain, with phase contrast optics. Posterior orientation to the top of figure, scale equals 0.1 mm.
Fig. 11.— Frontal section through the synganglion and the endosternum of an adult female Argas radiatus, showing association of the periganglionic sinus wall with endosternal tissues, aldehyde fuchsin stain, bright field optics. Orientation as in Fig. 10, scale equals 0.1 mm. Ao, anterior aorta; AoMC, aortic-myocardial cone; AoSV, aortic septal valve; dlSM, dorso-lateral suspensory muscles; E, esophagus; End, endosternum; exM, extrinsic muscles of the periganglionic sinus; GdT-dF, glandular tissues of the dorsal foveae; Gen Acc Gd, male genital accessory gland; He, hemocoel; Ht-P, pulsatile portion of the heart; intM, intrinsic muscles of the aorta; MG, midgut; NmesC, nuclei of mesenchymal cells; peSp, pericardial septum; pgS, periganglionic sinus; Syn, synganglion; VasM, vascular membrane.
No trace of an endosternum (End) is observed in the three species of ixodid ticks, but in A. radiatus and O. turicata paired collagenous masses lie alongside the dorso-lateral margins of the periganglionic sinus. These connective tissue formations bear the origins or insertions of a number of intercoxal, genital and dorso-ventral body muscles. Only enlarged posterior portions of the endosternites are continuous with posterior projections of the sinus walls in A. radiatus (Fig. 11), but in O. turicata the anterior arms of the endosternites are continuous with sinus walls. In these two argasids the right and left halves of the endosternum are joined by a series of transverse muscles. Preliminary observations on Antricola mexicanus Hoffman (Argasidae: Ornithodorinae) reveal that right and left halves of the endosternum are fused medially and that all internal margins of the horseshoe-shaped endosternum are continuous with the walls of the periganglionic sinus.
DISCUSSION
Most previous workers consider the circulatory system of ticks to be primitive or poorly developed (Robinson and Davidson, 1913-1914; Balashov, 1972). This judgement may rest in part, on the absence of a closed system of venous sinuses and segmental and posterior aortae, as well as the presence of a single periganglionic sinus in place of paired thoracic arterial sinuses. On the other hand, venous vessels found in Xiphosura and pulmonate Arachnida are believed to be secondary in origin, representing a “canalization of lacunar spaces” associated with the specialized respiratory structures of the gills or book lungs (Beklemishev, 1969). Absence of a channeled venous circulation, together with the general absence of dissolved respiratory pigments, may be correlated with the extensive tracheation of apulmonate Arachnida. Similarly, well-developed peripheral arterial systems, complete with metameric vessels arising from the dorsal vessel, are considered to be primitive in character (Beklemishev, 1969). Moreover, the normal devel- opmental sequence in Xiphosura involves condensation of paired thoracic arterial sinuses, as found in larval stages, into the single perineural sinus of the adult (Firstman, 1973). In comparison to the periganglionic arterial sinus of apulmonate Arachnida, Firstman con- siders the persistence of paired arterial sinuses in pulmonate Arachnida as an example of “neotenous developmental retardation.”
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THE JOURNAL OF ARACHNOLOGY
In ticks representing the sub-families Argasinae and Ornithodorinae (Argasidae) and Ixodinae and Amblyomminae (Ixodidae) the heart is highly condensed and regionally specialized. Various authors have reported only a single cardiac chamber and a single pair of ostia in both argasid (Robinson and Davidson, 1913-1914) and ixodid ticks (Douglas, 1943). Our data show that the posterior (pulsatile) portion of the heart contains two cardiac compartments in both tick families, although irregular internal projections of the myocardium often obscure this segmental nature in histological preparations of con- tracted hearts. The arrangement of radiating muscle bands (three pairs) which surround the two pairs of ostia (Fig. 1) seems to reflect the primitive metamerism of this portion of the dorsal vessel. In that light, the complex postero-median (unpaired) muscle band may represent a condensed remnant from posterior portions of the ancestral vessel. The ante- rior portion of the tick heart (aortic-myocardial cone) appears to be a transition zone between the muscular posterior myocardium and the aortic wall with its discrete internal basement membrane (Fig. 8).
In those Xiphosura and pulmonate Arachnida which have been most studied, intrinsic elements of the cardiac ganglion serve as pacemakers for the heart. Recent data on the organization of the cardiac ganglion, the pattern of peripheral innervation and sensory modulation of heart rhythmicity come largely from Xiphosura (Limulus polyphemus) (Corning and VonBurg, 1968; Bursey and Pax, 1970a, 1970b; Sperelakis, 1971; Stephens and Greenburg, 1973) and from Araneae (Wilson, 1967; Sherman and Pax, 1968; Bursey and Sherman, 1970; Ude and Richter, 1974). Similar data from Scorpiones is provided by Zwicky (1968). In these taxa the heart rhythm is neurogenic, but subject to modulation by various sensory stimuli and by potential neuroendocrine regulators (Kadziela and Kokocinski, 1966; Sundara and Krishnan, 1968; Ude and Richter, 1974). Identification of a putative cardiac ganglion in Amb. tuberculatum and evidences of peripheral innerva- tion from the central nervous system and from adjacent sensory complexes in other ticks (dorsal photoreceptors of Argasidae and dorsal foveae of Ixodidae-Amblyomminae), together with observations on the effects of various stimuli on heart rate, suggest that the tick heart also has a neurogenic rhythm which is subject to complex sensory modulation.
Although there is no closed system of venous vessels in ticks, there is a well-defined pericardial sinus. The highly perforated wall (pericardial septum) of the sinus is formed from connective tissues which are continuous with similar tissues associated with dorso- lateral and ventro-lateral suspensory muscles of the tick heart. No previous report of a pericardial sinus or septum in ticks is known to us. Although Douglas (1943) provides a brief description of the number and disposition of some suspensory muscles (dorso- laterals) from the heart of Dermacentor andersoni Stiles, the ventro-lateral suspensory muscles appear to be previously undescribed. One function of these suspensory muscles seems to be the maintenance of the space within the pericardial sinus.
The dorso-lateral suspensory muscles of tick hearts seem to resemble the alary muscles of insect hearts (McCann, 1970), both in terms of their general form and their structural couphng to the myocardium. Still, further studies at the ultrastructural level are needed in order to establish that these couplings constitute myo-myocardial junctions as reported from insect hearts (Sanger and McCann, 1968). Moreover, the functional importance of the dorso-lateral and ventro-lateral suspensory muscles, in relationship to the coordina- tion of diastole and systole in the tick heart, remains to be determined.
The ventro-lateral suspensory muscles of the tick heart appear to be homologous to the dorso-ventral muscles of scorpion and spider hearts (Kaestner, 1968). In these pulmonate Arachnida the dorso-ventral muscles have their origins on cuticular invagina-
OBENCHAIN AND OLIVER-CIRCULATORY SYSTEM OF TICKS
71
tions from the book lungs. The number of paired dorso-ventral muscles usually corre- sponds to the number of book lungs instead of the number of paired ostia in the heart. There is a similar correspondence in Ixodoidea; there are two pairs of ostia in tick hearts and the single pair of ventro-lateral suspensory muscles have some fibers which arise from the atrial wall of the spiracular plate. Furthermore, the specialized structure of the ventro-lateral suspensors may indicate their importance in processes not directly related to heart contraction or the maintenance of pericardial sinus integrity. The dual origins of these muscles and their complex association with putative neural elements may be indications that several of the muscle fibers are specialized as stretch receptors. In this respect they resemble stretch receptors of certain insects (Horridge, 1965; Wigglesworth, 1972). As proprioceptors they could function in the coordination of engorgement behavior or in the initiation of neuroendocrine mechanisms such as those demonstrated in the blood-sucking insect Rhodnius prolixus (Maddrell, 1963).
Certain specializations of the tick arterial circulatory system, as observed in this study, have not been previously reported. One such structure is the septal valve of the anterior aorta which effectively prevents the back-flow of hemolymph into the aortic-myocardial cone during diastolic expansion of the heart. In those arachnids which have distinct prosomatic and opisthosomatic body regions, the function of similar valves insures the maintenance of a higher internal pressure in the prosoma. This creates a pressure differ- ential which assists venous circulation of unoxygenated hemolymph in pulmonate Arach- nida and which is implicated as the principal mechanism for limb extension in Araneae (Wilson and Bullock, 1973; Stewart and Martin, 1974). Antagonistic extensor and flexor muscles are described from the appendages of ticks (Ruser, 1933), but pressure differ- entials may still be necessary for extension of the appendages. Specializations for main- tenance of increased pressure within arterial vessels and sinuses may also be important in extension of the capitulum during attachment and engorgement. From fragmentary observations on Rhipicephalus sanguineus (Latreille) Chow, et al. (1972) postulated that muscles at the entrance of the aorta into the periganglionic sinus function as valves which might prevent the reversal of arterial flow. That function seems to be fulfilled by the septal valve at the posterior end of the aorta and the muscles observed by Chow, et al., seem to be extrinsic muscles of the periganglionic sinus. If hemolymph flow from lacunae in the appendages into the general body cavity is controlled in ticks by valve-like structures similar to those described from the leg bases of pulmonate Arachnida (Kaestner, 1968), then the contraction of extrinsic periganglionic muscles and intrinsic aortic muscles may elevate the intra-arterial pressure above that of the idiosoma.
Firstman (1973) postulates that dorso-ventral muscles attached to the endosternum in ancestral arachnids originally played a role in generation of arterial pressures. It seems likely that the reduction of the endosternum in argasid ticks and its loss in ixodids is an adaptation which facilitates the expansion of the body during engorgement. Extrinsic muscles of the periganglionic sinus may then be interpreted as derivatives of ventral suspensors which originally inserted on the prototypic endosternum. Since the pharyngeal musculature and the entire length of the esophagus are contained within arterial sinuses, any increase in arterial pressure over that of the general body cavity should favor passage of ingested fluids into the midgut. Such a selective advantage might account for the evolutionary retention of the aortic septal valve and the modification of endosternal musculature (as extrinsic periganglionic muscles) in representative Ixodoidea.
Previous workers have reported the reduction of the arterial circulatory system (Beklemishev, 1969) or even the absence of a functional heart (Mitchell, 1957, 1964;
72
THE JOURNAL OF ARACHNOLOGY
Whitmoyer, et aL, 1972) in many mite species. Their data raise a serious question: Within the Acari, how representative is the circulatory system of ticks? Reduction of the circula- tory system in dwarf forms of most tracheate arthropods seems to parallel a similar reduction in the tracheal system. Reduction or loss of both of these systems is then seen as a secondary adaptation related to the lower oxygen transport requirements of smaller organisms. Anatomical comparisons of the heart and arterial circulatory system among Acari and other Arachnida should be more instructive when those larger Acari with well developed tracheal systems are considered. In this respect, the apparent presence of circulating hemocyanin pigments in the hemolymph of Amb. tuberculatum is of partic- ular interest. This species is the largest ixodid tick found in the United States and parasitizes relic populations of the burrowing gopher tortoise, Gopherus polyphemus. In the absence of concrete data on the role of the pigment in oxygen transport, it is not known whether the presence of circulating hemocyanin should be considered as a retained primitive characteristic or as a secondary adaptation correlated with the large size of this tick or some other parameter of the tick-host relationship. In any case, our identification of a condensed and regionally specialized myocardium (probably with an intrinsic cardiac ganglion), a well-developed pericardial septum associated with the dorso- lateral and ventro-lateral suspensory muscles of the heart, and arterial specializations, including the septal valve and the intrinsic and extrinsic musculature, attests to the complexity and evolutionary advancement of the circulatory system in Ixodoidea.
LITERATURE CITED
Balashov, Yu. S. 1972. A translation of Bloodsucking Ticks (Ixodoidea)— Vectors of Diseases of Man and Animals. Misc. Publ. Entomol. Soc. Amer., 8:159-376.
Beklemishev, W. N. 1969. Principles of Comparative Anatomy of Invertebrates. Vol. 2, Organ- ology. Chapter VIII. Origin and types of circulatory apparatus. 2, The blood vascular appa- ratus: Arthropods and Onychophora. Ohver and Boyd, London, pp. 369-378.
Binnington, K. C. 1972. The distribution and morphology of probable photoreceptors in eight species of ticks (Ixodoidea). Zeit. Parasitol., 40:321-332.
Brinton, L. P., and W. Burgdorfer. 1971. Fine structure of normal hemocytes in Dermacentor andersoni Stiles (Acari: Ixodidae). J. Parasitol., 57:1110-1127.
Bullock, T. A., and G. A. Horridge. 1965. Structure and Function in the Nervous Systems of Inver- tebrates, W. H. Freeman & Co., San Francisco.
Bursey, C. R., and R. A. Pax. 1970a. Cardioregulatory nerves in Limulus polyphemus. Comp. Biochem. Physoil. 35:41-45.
Bursey, C. R., and R. A. Pax. 1970b. Microscopic anatomy of the cardiac ganglion of Limulus polyphemus. J. Morphol. 130:385-395.
Bursey, C. R., and R. G. Sherman. 1970. Spider cardiac physiology, I. Structure and function of the cardiac ganglion. Comp. gen. Pharmacol., 1:160-170.
Chow, Y. S., S. H. Lin, and C. H. Wang. 1972. An ultrastructural and electrophysiological study of the brain of the brown dog tick, Rhipicephalus sanguineus (Latreille). Chinese BioSci., 1:83-92.
Corning, W. C., and R. Von Burg. 1968. Behavioral and neurophysiological investigations of Limulus polyphemus. In: Neurobiology of Invertebrates, J. Salanki, Ed., Plenum, New York. pp. 463-477.
Christophers, S. R. 1906. The anatomy and histology of ticks. Sci. Mem, med. sanit. Dept. India, (23), 55 pp.
Dolp, R. M. 1970. Biochemical and physiological studies of certain ticks (Ixodoidea). Qualitative and quantitative studies of hemocytes. J. Med. Entomol. 7:277-288.
Douglas, J. R. 1943. The internal anatomy of Dermacentor andersoni Stiles. Univ. California Pub. Entomol. 7:207-272.
Firstman, B. 1973. The relationship of the chelicerate arterial system to the evolution of the endo- sternite. J. Arachnol. 1: 1-54.
OBENCHAIN AND OLIVER-CIRCULATORY SYSTEM OF TICKS
73
Hubschman, J. H. 1962. A simplified azan process well suited for crustacean tissue. Stain Technol. 37:379-380.
Humason, G. L. 1962. Animal Tissue Techniques. W. H. Freeman and Co. San Francisco. 468 pp. Kadziela, W., and W. Kokocinski. 1962. The effect of some neurohormones on the heart rate of spiders. Experentia, 22:45-56.
Kaestner, A. 1968. Invertebrate Zoology, Vol. II, Arthropod relatives, Chelicerata, Myriapoda. Inter- science Pub., New York. 472 pp.
Larimer, J. F., and E. A. Ashby. 1964. Reduced methylene blue as a stain for crustacean nerves. Stain Technol., 39:369-371.
Maddrell, S. H. P. 1963. Control of ingestion in Rhodnius prolixus Stal. Nature 198:210.
McCann, F. V. 1970. Physiology of insect hearts. Ann. Rev. Entomol. 15: 173-200.
Meola, S. M. 1970. Sensitive paraldehydefuchsin technique for neurosecretory system of mosqui- toes. Trans. Amer. Microsc. Soc., 89:66-71.
Mitchell, R. 1957. Locomotor adaptations of the family Hydryphantidae (Hydrachnellae, Acari). Naturwiss. Abhandl., Bremen, 35:75-100.
Mitchell, R. 1964. The anatomy of an adult chigger mite Blankaartia acuscutellam (Walch). J. Morphol., 114:373-392.
Nordenskiold, E. 1909. Zur Anatomie und Histologie von Ixodes reduvius. II. Zool. Jahrb., Abt. Anat. 27:449-464.
Obenchain, F. D. 1974a. Structure and anatomical relationships of the synganglion in the American dog tick, Dermacentor variabilis (Acari: Ixodidae). J. Morphol., 142:205-223,
Obenchain, F. D. 1974b. Neurosecretory System of the American dog tick, Dermacentor variabilis (Acari: Ixodidae). I. Diversity of cell types, J. Morphol., 142:433-446.
Obenchain, F. D., and J. H. Oliver, Jr. 1973. A qualitative analysis of the form, function and inter- relationships of fat body and associated tissues in adult ticks (Acari-Ixodoidea). J. Exper. Zook, 186:217-236.
Obenchain, F. D., and J. H. Oliver, Jr. 1975. Neurosecretory system of the American dog tick, Dermacentor variabilis (Acari: Ixodidae). II, Distribution of secretory cell types, axonal path- ways and putative neurohemal-neuroendocrine associations; comparative histological and anatomical implications. J. Morphol,, 145:269-294.
Robinson, L. E., and J. Davidson. 1913-1914. The anatomy of Argas persicus (Oken, 1818). I- III. Parasitol., 6:20-48, 217-256, 382-424.
Ruser, M. 1933, Beitrage zur Kenntnis des Chi tins und der Muskulatur der Zecken (Ixodidae). Zeit. Morphol. Okol. Tiere, 27:199-261.
Sanger, J, W., and F. V. McCann. 1968. Ultrastructure of moth alary muscles and their attachment to the heart wall. J. Insect Physiol., 14:1539-1544.
Sherman, R. G., and R. A, Pax. 1968. The heart beat of the spider Geolycosa missouriensis . Comp . Biochem. Physiol. 26:529-536.
Sperelakis, N. 1971. Ultrastructure of the neurogenic heart of Limulus polyphemus. Z. Zellforsch. 116:443-463.
Stephens, L. B., and M. J. Greenberg. 1973. The localization of acetylcholinesterase and butyryl- chohnesterease in the heart, cardiac ganglion and the lateral and dorsal nerves of Limulus polyphemus. J. Histochem. Cytochem. 21:923-931.
Stewart, D. M., and A. W. Martin. 1974. Blood pressure in the tarantula, Dugesiella hentzi. J. Comp. Physiol. 88:141-172.
Sundara, R. S., and N. Krishman. 1968. Nature of the cardioexcitor neurohormone in an Arachnid Poecilotheria fasciata Schneider (Araneida). Monitore Zool. Italia., 2:207-216.
Ude, J., and K. Richter, 1974. The submicroscopic morphology of the heart ganglion of the spider Tegenaria atrica (C. L. Koch) and its neuroendocrine relations to the myocard. Comp. Biochem. Physiol., 48A: 301-308,
Whitmoyer, R. E., L. R. Nault, and O. E. Bradfute, 1972, Fine structure of Aceria tulipae (Acarina:
Eriophyidae). Ann. Entomol. Soc. Amer., 65:201-215.
Wigglesworth, V, B. 1972. The Principles of Insect Physiology. Chapter VII, Mechanical and chemical senses. Seventh ed. Chapman and Hall, London, pp. 256-309.
Wilson, R. S. 1967. The heart-beat of the spider, Heteropoda venatoria. J. Insect Physiol., 13:1309-1326.
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THE JOURNAL OF ARACHNOLOGY
Wilson, R. S., and J. Bullock. 1973. The hydraulic interaction between prosoma and opisthosoma in Amaurobius ferox (Chelicerata, Araneae). Z. Morphol. Tiere, 74:221-230.
Zwicky, K. T. 1968. Innervation and pharmacology of the heart of Urodacus, a scorpion. Comp. Biochem. Physiol., 24:799-808.
Enders, F. 1976. Effects of prey capture, web destruction and habitat physiognomy on web-site tenacity of Argiope spiders (Araneidae). J. Arachnol. 3:75-82.
EFFECTS OF PREY CAPTURE, WEB DESTRUCTION AND HABITAT PHYSIOGNOMY ON WEB-SITE TENACITY OF ARGIOPE SPIDERS (ARANEIDAE)
Frank Enders^
North Carolina Division of Mental Health Services
Research Section Raleigh, 27611
ABSTRACT
Both in the laboratory and in the field prey capture did not have a strong influence upon web-site tenacity of Argiope aurantia. But experimental web destruction increased the probability that A. aurantia changed its web-site, perhaps only due to the physical displacement of the spider. Removal of vegetation near the web of immature A. aurantia resulted in most of these spiders leaving their web-sites, especially in areas less sheltered from the v^indi. Argiope trifasciata, in contrast, did not leave web-sites after removal of nearby vegetation.
INTRODUCTION
Spiders often remain at the same web-site from one day to the next (McCook, 1889; Enders, 1975). Yet, little is known which factors might influence the probability that a spider will stay at a particular site. “Web-site tenacity” is defined as the per day proba- bility that a spider remains at the same web-site, or the number of changes of web-site divided by the number of observations of webs from one day to the next (Enders, 1975). The total number of changes of web-site includes animals found again nearby and also those which both take up their web and disappear from view. Thus animals which appar- ently have died are excluded from the calculation, since mortality of Argiope spiders is normally marked by the disappearance of the spider coupled with the persistence of the old web.
The initial and subsequent choices among habitats by the web spidiQx Argiope aurantia (Araneidae) have been described (Enders, 1973). And some speculation is available regarding the use of prey and habitat as resources by various araneid orb web spiders (Enders, 1974, 1975b). Turnbull (1964) reported a strong effect of prey abundance on web-site tenacity of Achaearanea tepidariorum (Theridiidae). But other studies (Arane- idae: Cherrett, 1964; Colebourne, 1974; spiders in general: Duffey, 1966) have empha- sized the greater importance of habitat structure (physiognomy or architecture) for selec- tion of web-sites by spiders. Field observations of Argiope aurantia 1975a)
revealed no marked influence of prey capture on web-site tenacity. Here, I report my experimental studies which estimate the relative importance of prey capture, web destruc- tion and habitat physiognomy on web-site tenacity of Argiope aurantia. I include a few
Present address: Biology, California State University, Fresno, 93740
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THE JOURNAL OF ARACHNOLOGY
observations on A. trifasciata for comparison with a species which selects less densely vegetated habitats than A. aurantia.
FIELD EXPERIMENTS ON THE EFFECT OF FEEDING
Methods— The study areas used were the edges of road cuts, where large numbers of Argiope aurantia occurred, near Raleigh, North Carolina. Areas were dominated by the herbaceous perennial plant Lespedeza cuneata and are described in greater detail else- where (Enders, 1972; 1974).
Different feeding rates were maintained for three groups of spiders in the field: (a) “no prey,” by removing any prey noticed in the web; (b) natural feeding rate, or whatever entered the web by itself; and (c) prey always present in the web, by adding to what the spider captured, roughly tripling the intake of prey biomass from group b. Spiders were originally assigned to treatments alternately. As the original spiders disappeared from particular treatment groups, the nearest available unmarked spiders were used as replace- ments.
Treatments were applied twice a day, late morning and late afternoon (eve- ning). Insects added to the web were usually grasshoppers slightly longer than the spiders, or else several houseflies. Since most natural prey (the most abundant, bees, grasshoppers and chauliognathid beetles) were kept in the web at least half a day, and since virtually no prey was taken during the night by Argiope spiders, the treatment schedule should have been effective to influence spider feeding rates. Two replicates of this experiment were performed, one during the period 22 to 25 June 1970 (using middle stage immatures) and the other 6 to 11 September 1970 (adult spiders). One additional experiment was done feeding spiders water sweetened with table sugar (Bays, 1962), but the negative results of that feeding replicate might be due to insufficient caloric uptake by spiders, even though the sugar water was accepted by them.
Results— Different levels of feeding could not be maintained every day because spiders occasionally refused to attack any insects offered. This occurred primarily in the June replicate. Analysis of results using only the actual feeding status of the spider did not change the conclusions. Only one statistically significant effect was found in eight statis- tical comparisons made (by chi square test, Snedecor and Cochran, 1967). The extreme comparison between prey removed and prey added groups for the September experiment indicated a 7% increase of web-site tenacity (Table 1), with p between 0.05 and 0.025.
LABORATORY EXPERIMENT ON THE EFFECT OF FEEDING
Methods— A cage was made 2.3 m high, 2.3 m wide and 4.6 m long from translucent plastic sheets stapled onto an exterior 5 cm X 5 cm wood frame. This cage was sealed by plastic tape along the seams, and the only entrance was a zipper sewn into one edge of the cage. The zipper was opened only once a day, in order to give the spiders water from a syringe and to feed them. The room containing the cage had a photophase of 16 hours, and an air conditioner running for three hours during the morning to provide a regular cycle of temperature.
Four marked (with fast-drying paint) A. aurantia taken from the field were released on successive days in different corners of the cage, starting on 1 July 1970. The spiders climbed to the top of the cage along the tape and built webs in the upper corners of the cage. Two spiders could and sometimes did build webs in the same corner.
ENDERS-WEB-SITE TENACITY OF ARGIOPE
11
Table 1. -Summary of feeding experiments Argiope aurantia in the field. Web site tenacity is the percentage probability a spider remains at the same web-site from one day to the next.
|
Web-site tenacity |
||
|
Treatment |
From initial day to the |
% of all observations |
|
Group |
second day of observation |
of which animals remained at |
|
(% of individuals) |
same site |
|
|
Prey removed |
90 (n=l) |
90 (n=90) |
|
Whatever spider caught |
||
|
by self (control) |
96 (n=28) |
87 (n=87) |
|
Prey added |
95 (n=20) |
93 (n=93) |
The cage was centered below the lighting fixture which had 320 watts of flourescent lighting. The entrance of the cage was away from the single boarded-up window, but near the door of the room. Only those spiders which built webs in the front right or back left corners were fed, a housefly a day. This arrangement neutralizes the effect of any gradi- ents of hght, noise, etc., which might have influenced preference for the corners in consequence of the location of door, light, window, and window air conditioner.
Results— Not even a small increase of web-site tenacity with prey catching was ob- served. Additional spiders in individual cages and a second four-spider replicate in the large cage which lasted only 20 days also revealed no differemce in web-site tenacity of A. aurantia in fed and in unfed corners. Instead, spiders moved out of corners in which they had been getting flies, as well as moving into them. In the course of the completed four-spider experiment, one spider was eaten by another, two emaciated spiders starved to death, and one well-fed spider died after several months on its web. In addition those spiders, including two A. trifasciata, that were starved but watered regularly did not show any decrease in web-site tenacity with time. Starvation did result in a reduction of frequency of renewal of webs as animals were near death.
EFFECT OF WEB DESTRUCTION AND OF DISTURBANCE IN ARGIOPE AURANTIA
Methods— This experiment was performed at the edges of lespedeza-covered road cuts. The treatment was total destruction of the web each day, while the spider was left wherever it went. The spider’s dragline which had been attached to the web was destroyed, so that no silk spanned the original web-site, but the spider was left on the vegetation whenever possible (most instances). The disturbance treatment is that certain nearby spiders were placed into individual jars, carried to the laboratory, taken from the jars, weighed, transported back to the web-site, and released in their original webs. Treat- ments were applied just after dark, and the spiders of the disturbance group were returned to their webs after 2-3 hours. Every third spider found was placed in the same treatment group (web destroyed, disturbance and control). Each spider was marked with an individual pattern of rapidly drying paint, and was retained in its treatment group if it could be found the following day, at the old web-site or at a new one (web sites were marked with masking tape). Due to the disappearance of the original members of the groups, more spiders were added to each group on subsequent days. All spiders used in this experiment were females, mostly fully adult, from 21 September to 7 October 1969. Chi square not corrected for continuity (Snedecor and Cochran, 1967) was used to test
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THE JOURNAL OF ARACHNOLOGY
for statistical significance of treatment effects.
Results— No significant effect of the handling disturbance was found (Table 2). Those animals whose webs were destroyed left web-sites significantly more often than the controls, both the night following destruction of the web, and also on subsequent nights when webs happened not to be destroyed.
Table 2. -Web-site tenacity of Argiope aurantia in the field after web destruction and after han- dling disturbance (** = difference with control group statistically significant at 0.01 level; * = difference with control group statistically significant at 0.05 level).
Web-site tenacity
Treatment group From initial day to the % of all observations of
second day of observation which animals remained at same site
(% of individuals)
|
Web destroyed |
33 |
(24)** |
50 |
(54)^ |
|
Undisturbed (control) Animal handled, web not |
91 |
(11) |
71 |
(52) |
|
destroyed Dates on which web-destroyed |
82 |
(17) |
78 |
(45) |
|
animals were not disturbed |
40 |
(10)* |
54 |
(13) |
|
Dates on which handled animals |
||||
|
were not disturbed |
88 |
( 8) |
88 |
( 8) |
EFFECT OF VEGETATION DENSITY ARGIOPE SPIDERS
Methods— Enders (1973) hypothesized that it was the density of the nearby vegetation and plant density in the plant community as a whole (habitat physiognomy) which controlled the occurrence of A. aurantia immatures, but not the occurrence of A. trifasciata. To test this, in July 1971 all vegetation was cut away in a band from 20 cm to 100 cm around the webs of spiders in the field. Bushes and branches of large trees to a distance of 4 m were also removed. Vegetation to which silk was attached was not removed, and, as in other experiments, I made a particular attempt not to disturb or damage the web or its inhabitant. As in other experiments, animals were used as they were found, with no exclusions. After initial experiments indicated color-marking to be superfluous, spiders were left unmarked. The location of the web was marked with masking tape, and the experimental site was also quite noticeable, in consequence of vegetation removal.
Results were planned to be compared with the known web-site tenacity of 80+ per cent (Enders, 1975a). In addition, three Argiope aurantia were left undisturbed at one study site to check that high web-site tenacity of undisturbed animals. The spiders used in this experiment were middle stage immatures, mostly being the sixth and seventh instars.
Two main study sites were used, one an old-field planted with pine trees and the other the center of a lespedeza-covered road cut. Within the old-field site two subsites were used, one a location with sparse vegetation with the nearest trees 5 m away; the second subsite had pine trees within 5 m of one another, that is, roughly four times the density of vegetation.
The old-field subsite with less vegetation probably had the greatest exposure to wind. The old-field subsite with more trees was expected to have less wind, and the road
ENDERS--WEB-SITE TENACITY OF ARGIOPE
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cut could be assumed to be the most sheltered at the height where immature A. aurantia build webs (Enders, 1974). The latter study area was entirely protected from wind on one side by the upward slope of a hill; and this site was also sheltered even on the downhill side by vegetation which was considerably denser than the old-field vegetation present at the other experimental site. Some trees were present at about 10 m further uphill.
Results— Removal of vegetation greatly reduced web-site tenacity of the immature A. aurantia. This reduction of web-site tenacity was statistically significant, whether one used as control the three animals observed the same year (none of which changed web- site), or the 83% web-site tenacity for Argiope aurantia in the lespedeza area in July of the previous year (Enders, unpubhshed data). Casual observation of untreated animals nearby and of post-treatment spiders also indicated a high web-site tenacity of animals living in the old-field site.
The effect of physiognomy of the study site was also statistically significant and of large magnitude: none of 13 experimental animals in the weedy old-field remained on the following day, 44% of nine remained in the old-field with denser trees, and 63% of 19 in the lespedeza-covered road cut. Since the old web of spiders which disappeared could not be found and since several spiders which left experimental web sites were found nearby after the experimental treatment, those spiders which did not remain had apparently left the web-sites for other locations.
Finally, there was also a statistically significant difference between the species A. aurantia and A. trifasciata: records show that seven immature A. trifasciata had vegeta- tion removed from around their web-sites at lespedeza (three animals) and old-field (four animals) areas, and no spider changed web-site or disappeared.
DISCUSSION
Different ecologically definable groups of spiders have various manners of hunting, but most spiders are sit-and-wait predators (Enders, 1975b). Exceptions are known primarily in errant, non-web spiders (chiefly clubionids and salticids; also smaller lycosids). Though web spiders are restricted to the web, even such species may effectively search for prey if they change web-site until they encounter a web-site with sufficiently high prey capture rate (TurnbuU, 1964). My results detailed above suggest that prey capture has no such effect in the orb-weaving spider Argiope aurantia: field experiments do indicate the possibility of small 7% (but compounded daily) increase in web-site tenacity of mature A. aurantia, as a consequence of a range in prey capture rate equal to three times normal feeding rates, compared to virtually zero in the comparison group. This effect, while statistically significant (0.05 level) may be a purely random statistical effect (p actually only 0.4, considering eight separate statistical contrasts made by me using 0,05 level of probability as criterion), or the result of partial destruction of webs (see below) during removal of prey items from webs of the comparison group. I emphasize that field obser- vations (three summers) and laboratory experiments (detailed above) give no support to the idea that web-site tenacity might be related to prey capture rate in Argiope aurantia (Araneidae). In other species of orb web spiders, Cherrett (1964) and Eberhard (1971) found, respectively, no relation of prey capture to web site use (several araneid species), and a negative effect of prey capture of web-site tenacity (one uloborid species; uses orb web made of different type of sticky silk). Therefore, it appears that these orb web spiders are not normally limited by prey abundance, so that they have not evolved a
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positive behavioral response to capture of prey. In contrast, Achaearanea tepidariorum (Theridiidae, three-dimensional web) appears to live in areas where prey are sometimes locally limiting, since most houses (natural habitat for this species) apparently have a high variance and low mean of insect abundance (potential spider prey). Houses probably also offer a lower density of potential predators on the spiders,