Published 10 Jan. 1985

Transcription

1 Published 10 Jan Vol. 18: ORIENTAL INSECTS 1984 James R. Reddell Texas Memorial Museum, University of Texas at Austin, 2400 Trinity, Austin, Texas 78705, USA and James C. Cokendolpher Department of Biological Sciences, Texas Tech University, Lubbock,Texas , USA ABSTRACT. Trithyreus grassii (Thorell) from Burma is redescribed from the single known specimen, the holotype female. The spermathecae are illustrated for the first time. The genus Trithyreus Kraepelin is rediagnosed and is consi.dered a distinct and separate member of the subfamily Schizominae. The spermathecae of the African Megaschizomus E- sambicus (Lawrence) are illustrated for the first time and are compared to those of L. grassii. INTRODUCTION The nomenclatorial history of the arachnid order Schizomida is unusually complex for such a small and seldom encountered group. Ten generic names have been proposed for the species now placed in the subfamily Schizominae of the family Schizomidae. Rowland (1973) has reviewed the nomenclature of the order and demonstrated that Trithyreus Kraepelin is the oldest available generic name in the Order. This genus was erected by Kraepelin in March 1899 as a replacement name for Tripeltis Thorell, 1889, which was preoccupied. In April 1899 Cook proposed Triplomus as a replacement name for the same genus. Cook in this same paper also proposed the name Schizomus for Schizonotus Thorell, 1888, which was also ~reoccu~ied. Trithvreus is. therefore. the name which must be used for all extant schizomines if Trithyreus and Schizomus are synonyms as Hansen and Sorensen (1905), Mello-Leitao (1931), Lawrence (19691, and others have suggested. Unfortunately, the type-species of neither Trithyreus (Tripeltis grassii Thorell, 1889) nor of Schizomus (N yctalops crassicaudatus 0. P. Cambridge, 1872) have been adequately described. This has led to uncertaintv in the correct ~lacemcnt of all species of schizomine described since. The principal character used to separate the two genera was the ~ature of the metapeltidium (split or entire). Hansen and Sorensen (1905) questioned the usefulness of this character at the generic level, tentatively suggesting that it might have some use to distinguish subgenera. Nevertheless, they continued to describe species in both genera. Mello-Leitao (1931) considered this character to. have no validity and transferred all species to Schizomus, being appa;$y unaware that Trithyreus had priority. Lawrence (1969) in his revision of the Schizomida of the Ethiopian Region, influenced by the general conformity of species in the order, also considered Schizomus and Trithyreus to be synonymous; and, lilcc Mello-Lcitao, he apparently failed to recognize the priority of Trith leus and placed it In the sync,- nymy of Schizomus. In this samc p&awrence crcctcd the

2 4 4 ORIENTAL INSECTS Vol. 18 genus Megaschizomus for two distinctive African species. Megaschizomus was characterized by the presence of true spines on the pedipalp - -. tibia and tarsus, only thiee large teeth on the fiked finger of the chelicera, and distinctive setational features. Rowland (1973) continued to recognize the validitv of both Trithvreus and Schizomus. but considered the African species (excluding Megaschizomus) to belong in Trithyreus. Rowland (1975) and Rowland and Reddell (1979) stated that the genus - Trithyreus should be considered provisionally to include only L. grassii, but that should a restudy of that species demostrate it to be congeneric - with species assigned to Schizomus, all species presently placed in the subfamily Schizominae would belong to Trith reus. Other authors, however, have continued to use Trithyreus*omus) without adequate knowledge of either genus. In an attempt to resolve the problem of the correct generic placement of species belonging to the subfamily Schizominae we re-examined the holotype of Tripeltis grassii and below include a redescription of the s~ecies and a rediaenosis - of Trithvreus based on characters considered now to be of phylogenetic significance. This can, however, be considered only the first step in clarifying the generic affinities of the numerous Old World species. Unlike descriptions of New World species, most descriptions of Old World species lack any discussion of chaetotaxy, spination, or genitalia. In fact, the spermathecae of only two Old World species have been illustrated. Borner ( DI fie. 62) illustrates the u spermathecae of a species he refers to Trithyreus cambridgei Thorell (species inquirenda of Sissom, 1980). Unfortunately,Bornerls illustration is rather diagrammatic and shows few details, but Schizomus biocellatus Sissom from Sumatra is clearly illustrated by Sissom (1980, fig. 3). METHODS All anatomical measurements are in millimeters and were obtained using a binocular microscope equipped with an ocular micrometer. Appendage lengths were measured from a lateral view along the dorsal surfaces. The genitalia were removed from the body, examined and illustrated, and then placed in a microvial, which in turn was placed in the specimen vial. After the membranes bordering the second and third abdominal sterna were cut with a microscalpel, the sterna and the spermathecal structures were easily lifted out by the use of fine-tipped forceps. The entire piece consisting of sterna, spermathecae, and assorted muscular tissues, was then dehydrated in ethyl alcohol and examined in 100% clovc oil. The sterna were soaked in absolute ethyl alcohol (to remove all traces of clove oil) prior to rehydration and placement in a microvial. All illustrations were prepared with the aid of a camera lucida. The morphological terminology and description format cssentially follow that of Rowland (1975) and Rowland and Reddell (1979). Due to the possible confusion regarding the nomenclature of spines and setae, we are adopting the following system. There appears to be a complete gradation between true spines and setae such that it is difficult to decide which term best describes the condition of the structure. We have used the term "spines" to refer to structures which are extremely thickened, attached to protuberances on the exoskcleton, and remain rigid to their end. Spinose setae are also attached to protuberances on the exoskeleton but are less thickened and taper to comparatively fine points. Setae are

3 1984 REDDELL & COKENDOLPHER : ARACHNIDA 4 5 set in small pits in the exoskeleton and retain virtually the same dimensions throughtout their length, lacking the rigid base of spinose setae. Genus TRITHYREUS Kraepelin Tripeltis Thorell, Ann. Mus. Civ. Stor. Nat. Genova, (2) 7: 554 (not Tripeltis Cope, 1886). Type-species: Tripeltis grassii Thorell; original designation. Trithvreus Krae~elin Das Tierreich. 8: 234 (n. name for ~ki~eltis ~horell, 1889). Triplomus Cook, Proc. Ent. Soc. Washington, 4: 250 (n. name for Tripeltis Thorell, 1889). Diagnosis: Body large (length, excluding flagellum 7 mm); carapace with three apical and six dorsal setae; eve spots absent; mesopeltidia separated b; 1.4 x width of one plate; metapeltidium divided; ^female flagellum with single annulus; pedipalp tibiae with spinose setae having large bulbous bases; spurs on pedipalpal tarsus-basitarsus large (about 0.5 length of tarsus-basitarsus) and asymmetrical, claws about length of tarsus-basitarsus; chelicerae with eight teeth on fixed finger,no file on movable finger, brush and serrula present; spermathecae of two pair of equal sized lobes, with numerous spherical nodes surrounding lobes; sclerotized loop surrounding uterus externus twisted at base and strongly constricted forming a posterior lobe at the genital opening. Distribution : Burma. Included species: Trithyreus grassii (Thorell). Discussion: The relationships of Trithyreus will remain obscure until the discovery of the male T. grassii and more detailed descriptions are available for other Old world schizomine species. Trithyreus as currently defined differs from all other schizomines (with one possible exception) in its possession of the highly modified spinose setae on the pedipalp tibia; in having only one annulus on the female flagellum; in its large body size; in having large claws and spurs on the pedipalps; and in the structure of the spermathecae and associated sclerotized loop. Unlike Trithyreus, species currently assigned to Schizomus (and incorrectly to Trithyreus) lack the modified spinose setae on the pedipalp tibia; have two or three annuli on the female flagellum; are less than 6.0 mm in body length; have claws less than 0.75 and spurs less than 0.5 length of tarsus-basitarsus: - swermathecal lobes that are either smooth or eranulated: and A " sclerotized loops which are rounded near the genital opening (never with a constriction forming a basal lobe as in Trithyreus). Trithyreus shares with Megaschizomus large size and prominent pedipalpal claws and spurs. The robust spinose setae on the pedipalpal tibia of Trithyreus are probably homologous to the spines on Megaschizomus. - The spermathecae of Megaschizomus, however, possess. only a single pair of slightly rugose lobes and the sclerotized basal loop is evenly rounded near the genital opening (Figs. 1-2). Trithyreus lacks a file on the movable finger - of the chelicera. resent. in Meaaschizomus) ". :. Dossesses eight teeth on the fixed finger of the chelicera (three in Megaschizomus); has an unsegmented female flagellum (distinctly segmented in Megaschizo- mus); three apical setae on the carapace ( a row of eight to nine in Mega- - schizomus); and one row of setae on the abdominal tergites (two rows in Megaschizomus). Based on published descriptions only one other species would appear likely to belong in Trithyreus, T. claviger Hansen (Hansen and Sorensen, 1905). This species, known only from a male and juvenile

4 46 ORIENTAL INSECTS Vol. 18 from Singapore, is described as having spines on the pedipalps, a long pedipalpal claw (0.75 as long as tarsus-basitarsus), and a divided metapeltidium. Until this species is restudied, however, its generic placement must remain uncertain. TRITHYREUS GRASS11 (Thorell) (Figs. 3-14) Tripeltis Grassii Thorell, Ann. Mus. Civ. Stor. Nat. Genova, (2) 7: 526, , 560, 562; Simon, Feuill. Jeun. Nat., (3).. 26: 92. Tripeltis grassii: Kraepelin, Abh. Naturw. Ver. Hamburg, 15: 53, 60. pl. I1 (fig. - 58b). Trithyreus grassii: Kraepelin, Das Tierreich, 8: 234, 235; Pocock, Fauna of British India, p. 122; Giltay, Bull. Mus. Roy. Hist. Nat. Belgique, 11 (32): 7; Rowland, J. New York Ent. Soc., 80: 202; Brignoli, Rev. Suisse Zool., 81: 731, 732, 734; Rowland, Classification, phylogeny and zoogeography of the American arachnids of the order Schizomida, pp. 26, 36; Rowland & Reddell, J. Arachnol., 6: 161; Sissom, J. Arachnol., 8: 187. Trithyreus Grassii: Hansen & Sorensen, Ark. Zool., 2 (8): 14, 53, 65, 66, 68, 77, pl. 6 (fig. 4a), pl. 7 (fig. 1 a-d). Triplomus grassii: Cook, Proc. Ent. Soc. Washington, 4: 250. Trithyreus grassi: Kishida, Lansania, 2 (12): 18 (lapsus calarni). Schizomus erassii: Mello-Leitao Arch. Mus. Nac.. Rio de Janeiro. Type data.: Fernale holotype in vial with white, hand printed faded label written in pencil: "Trithyreus /-- grassii Thor., 90 [?]I Birmania, Teinzo / FeaW. Left chelicera had been removedand clued - to a small piece of cardboard. The tarsus of right leg IV was missing; the left leg I1 was broken at the basc of the tibia and loose in the vial; the left leg I was partially broken at the femur and became detached during study. The specimen has been placed in a microvial and the chelicera, two leg parts, and the dissected genital sternite placed in a second microvial. The specimen is in the collection of the Museo Civico di Storia Naturale "Ciacomo Doria", Genova. Description: Holotype female (length from distal edge of carapace to base of flagellum, 7.1 mm): Body, Icgs, and pedipalps orangishbrown; chelicerae slightly darker. Cephalothorax (Fig. 3): Carapace 2.2 mm long, 1.4 mm wide; with three apical setae (one pair near distal edge of carapace and a third seta immediately posterior to pair) and three pair of dorsal setae (two pair near center of carapace and a third closely spaced pair near posterior margin of carapace). Anterior margin of carapace drawn to a sharply downturned point between chelicerae. Eye spots absent. Mesopeltidia separated by 1.4 times the width of one plate. Anterior margins of metapeltidial plates straight and parallel to mesopeltidia. Metapeltidium divided by prominent membranous gap; greatest length to width ratio of metapeltidial plates about 1:l. Anterior sternum with 13 bifid setae; two very long anteriorly directed setae arise from small chitinized strip hidden by anterior sternum; posterior sternum triangular, with 10 setae. Abdomen: Sternum IV about 2.7~ as wide as long. Tergum I with olie air of dorsal setae on posterior margin; tergum 11 with three paiks of small setae on anterior portion of plate and onc pair of large dorsal setae near posterior margin; tcrga 111-IV with one pair of dorsal setae

5 1984 REDDELL & COKENDOLPHER : ARACHNIDA 4 7 each; tergum VII with one pair of dorsal and one pair of dorsolateral setae; tergum VIII with one pair of dorsal and two pair of dorsolateral setae; tergum IX with one pair of dorsolateral and one pair of lateral setae. ~eiment X with six setae; segment XI with ten setae; segment XI1 with 14 setae. Flagellum (Figs. 4-5) 1.1 mm long, unsegmented; with one very faint annulus, about 0.33 distance from anterior end. Genital sternite (second abdominal sternite) concave posteriorly, with scattered setae over most of surface (Fig. 6); two rows of setae on third abdominal sternite, with setae of anterior row very short, setae of posterior row broken. Spermathecae (Figs. 7-8) with two pair of slightly curved, equal sized lobes; lobes covered with numerous small spherical nodes. Even at higher magnifications, the connections of the nodes to the spermathecal lobes are not distinct. Pedipalps (Fig. 9) : Lengths of segments in Table I. Trochanter sharply produced distally and compressed laterally; row of spinose setae of varying lengths on ventrolateral margin; some small setae slightly laterad of ventral margin. Femur with one small and two prominent spines on ventrolateral margin, three smaller spines slightly laterad of ventral margin, and one seta distal to lateral row of spines; dorsal margin with row of about 10 distally direc-ted spinose setae- (most broken); disto~atera~ margin with several setae. Patclla ventrally concave; four spines on ventrolateral margin and a fifth spine distal to these in a submarginal position; ventral margin with one long seta; lateral face with about 10 setae; a row of about six setae near dorsolateral margin; mesa1 margin with five spinose setae of varying degrees of robustness. Tibia with a row of six spinose setae on ventrolateral margin, the bases of which increase distally; one long seta on distolateral margin about 15 setae on lateral and dorsal surface; an irregular row of setae (three spinose with plumose ends) on ventrolateral margin; long plumose setae on ventral surface. Tarsus-basitarsus with about 10 long plumose setae on ventral and mesoventral margins; smaller scattered setae on other margins.two prominent spurs flank claw; mesa1 spur slightly closer to claw and somewhat smaller than lateral spur; spurs about 0.5 the length of dorsal surface of tarsusbasitarsus; claw essentially equal to length of tarsus-basitarsus. Table I. Measurements (mm) of female holotype of Trithyrcus grassii 1 1 i Trochanter I Leg I Leg I1 Leg I11 Leg IV Femur 1 l-l Tibia I Basi tarsus Tarsus Totals

6 48 ORIENTAL INSECTS Vol. 18 Chelicerae (Figs ) : Fixed finger with eight teeth ; large dorsal tooth distinctly cleft, with third small projection between two marginal projections. Mesa1 surface: Brush at base of fixed finger with curved row of about 14 plumose setae; serrula of movable finger with about 25 small teeth, with larger tooth at distal end of row; surface of movable finger with row of about 25 plumose setae; three long enlarged setae arise from distal margin of first segment of chelicera. Other setae as shown in Fig. 11. Lateral surface: Row of 14 or 15 plumose setae on ventral surface, extending onto base of fixed finger (Fig. 10); five long setae at base of movable finger and two setae near distal margin between fingers. Legs: Length of segments in Table I. Leg I, excluding coxa, about 11.7 mm in total length. Coxa very long (1.4 mm); with eight spines on dorsal surface (five in one row, three in a second row). Tarsus-basitarsus as in Fig. 13. Leg IV slightly longer than body, with four prominent spines on dorsal surface of trochanter; two prominent spinose setae on ventrolateral distal end of patella; strong spine on ventrodistal end of tibia; row of spines on ventral and dorsal surfaces of femur as shown in Fig. 14; femur 2.8 x longer than wide. Discussion : Among the Schizomida Trithyreus grassii is exceeded in size only by Megaschizomus mossambicus (8.5 mrn) and some species of the family Protoschizomidae (up to 11 mm). The extreme spination of the pedipalps is greater than in any member of the subfamily ~chizominae. With the exception of a few minor differencesin measurements, the description of Ilansen and Sorensen (1905) is generally accurate. The only significant difference found was in the description and illustration of thc flagellum as being three segmented. A careful examination of the flagellum revealed only one faint annulus. ACKNOWLEDGMENTS. We wish to express our deep appreciation to Dr. Cianna Arbocco of the Museo Civico di Storia Naturale "Giacomo Doria", Genova, for thc loan of the holotype of 2. grassii. We also wish to thank Dr. Oscar F. Francke, Texas 'Tech University, for critically reading the manuscript. The junior author would also like to thank Dr. William B.Peck, Warrensburg, Missouri, for the gift of the camera lucida used during this study. REFERENCES BORNER, C., Beitrage zur Morphologic der Arthropoden I. Ein Beitrag zur Kenntnis der Pedipalpen. Zoologia,Stuttgart, 42: 1-174, pls BRIGNOLI, P. M., Un nuovo Schizomida delle Batu Caves in Malesia (Arachnida, Schizomida). Rev. Suisse Zool., 81: CAMBRIDGE, 0. P., On a new family and genus and two new species of Thelyphonidea. Ann. Mag. Nat. Hist., (4) 10: , pl. XXII. COOK, 0. F., Hubbardia, a new genus of Pedipalpi. Proc. Ent. Soc. Washington, 4: COPE, E. D., An analytical table of the genera of snakes. Proc. Amer. Phil. Soc., 23: GILTAY, L., Notcs Arachnolog~ques Africaines. VII. Description d'un Pedipalpe nouvcau du Congo belge (Trithyreus ghesquierei, n. sp.). Bull. Mus. Roy. Hist. Nat. Belgique, 11 (32): 1-8.

7 1984 REDDELL & COKENDOLPHER : ARACHNIDA 4 9 HANSEN, H. J. & SORENSEN, Vv., The Tartarides, a tribe of the order Pedipalpi. Ark. Zool., 2 (8): 1-78, pis ItISHIDA, K On the occurrence of the genus Trithyreus in Bonin Islands. Lansania, 2 (12): KRAEPELIN, K Revision der Uropygi Thor. (Thelyphonidae auct. ). Abh. Naturw. Ver. Hamburg, 15: 1-60, pis K RAEPELIN, K., Scorpiones und Pedipalpi. Das Tierrich, 8. xviii p. LRWRENCE, R. F., The Uropygi (Arachnida: Schizomidae) of the Ethiopian Region. J. Nat. Hist., 3: MELLO-LEITAO, C., Pedipalpos do Brasil e algumas notas sobre a ordem. Arch. Mus, Nac., Rio de Janeiro, 33: 1-72, figs POCOCK, R. I., The fauna of British India, including Ceylon and Burma. Arachnida. Taylor & Francis, London, xii p. ROWLAND, J. M., Revision of the Schizornida (Arachnida). J. New York Ent. Soc., 80: ROWLAND, J. M., Classification, phylogeny and zoogeography of the American arachnids of the Order Schizomida. Ph.D. Diss. Texas Tech Univ., Lubbock, ix p. ROWLAND, J. M. & REDDELL, J. R., The order Schizomida (Arachnida) in the New World. I. Protoschizornidae and durnitrescoae group (Schizomidae, Schizomus). J. Arachnol., 6: SIMON, E., Recherches zoologiques dans les serres du Museum de Paris. 11. Arachnides. Feuill. Jeun. Nat., (3) 26: SISSOM, W. D., The eyed schizomids, with a description of a new species from Sumatra (Schizornida: Schizornidae). J. Arachnol., 8: THORELL, T., Pedipalpi e Scorpioni dcll 'Archipelago Malese conservati nel Museo Civico di Storia Naturalc di Genova. Ann. Mus. Civ. Stor. Nat. Genova, (2) 6: THORELL, T., Aracnid; Artogastri Birrnani raccolti da L. Fea he Ann. Mus. Civ. Stor. Nat. Genova, (2) 7: , p1.v.

8

9 REDDELL & COKENDOLPHER : ARACHNIDA Figs Trithyreus grassii (Thorell), female holotype from Burma: 6, partial cleared genital sternites, ventral view; 7, spermathecae; 8, detail of spermathecal lobe; 9, left pedipalp, lateral view.

10 ORIENTAL INSECTS Vol. 18 Figs Trithyreus grassii (Thorell), female holotype from Burma: 10, left chelicera, lateral view: 11, left chelicera, mesa1 view; 12, left cheliceral fixed finger, lateral view; 13, leg I basitarsus-tarsus, dorsolateral view; 14, left leg IV, lateral view of trochanter and femur.