Stedocys Ono, 1995

Labarque, Facundo M., Grismado, Cristian J., Ramírez, Martín J., Yan, Hengmei & Griswold, Charles E., 2009, The Southeast Asian genus Stedocys Ono, 1995 (Araneae: Scytodidae): first descriptions of female genitalia and a new species from China, Zootaxa 2297, pp. 1-14 : 2-3

Genus Stedocys Ono, 1995

Stedocys Ono 1995: 132 . Type species by original designation: Stedocys uenorum Ono, 1995 . Platnick 2009.

Diagnosis. Males of Stedocys are distinguished from those of the other genera of Scytodidae by having the papal tarsus subequal or smaller than the tegulum, not prolonged apically, without prolateral blunt macrosetae; the tegulum long, inserted apically on the tarsus; embolus slightly shorter than bulb, aciculate distally ( Figs. 10—11 , 29 ). Females are distinguished by the presence of epigynal pouch anterior to the epigastric furrow and by lacking foveae and positioning ridges below it ( Figs. 9 , 39 ).

Description. Total length (males and females) 9.09–14.3. Prosoma longer than wide, posteriorly bulging. Six eyes arranged in three diads, lateral eyes on a tubercle ( Figs. 1–4 ). PLE subequal or larger than ALE; PME smaller. Chelicerae with an acute lamina separated from paturon by deep depression ( Figs. 17–18 ) with retromarginal gland area beside it ( Fig. 18 ); three to four large, well spaced ectal stridulatory ridges ( Fig. 19 ); a membranous promarginal lobe between lamina and base of fang ( Fig. 16 ); venom outlet slit-shaped, at base of relatively short fang ( Fig. 42 ). Endites elongated, converging anteriorly, with membranous apical edge. Labium fused to sternum, longer than wide in males, wider than long in females. Sternum longer than wide in both sexes with marked borders ( Figs. 5–8 ). Leg formula I-II-IV-III. Tarsi with well developed onychium ( Figs. 21–24 ). Superior claws of legs I and II with two rows of teeth on proclaws and a single row on retroclaws ( Figs. 21–22 ), in both cases reaching the tip of the claw. Superior claws of legs III and IV with a single row of teeth, not reaching the tip of the claw ( Figs. 23–24 ). Inferior claws with a single tooth ( Figs. 21– 24 ). Tarsal organ exposed ( Fig. 25 ). Proximal plate of trichobothrial socket smooth ( Fig. 26 ). Female palps with a central apical lobe (perhaps a relict of claw), a pair of apical prolateral blunt macrosetae ( Fig. 27 ) and femoral stridulatory thorn ( Fig. 28 ). Abdomen elongated, posteriorly acute. Male epiandrous spigots scattered along the margin of the epigastric furrow ( Fig. 20 ). Tracheal system with a unique median apodemal lobe ( Fig. 12 ). Spinnerets similar in males and females ( Fig. 31 ). Anterior lateral spinnerets (ALS) with two major ampullate gland spigots (MAP) ( Figs. 32–33, 35 ). Piriform gland spigots (PI) field somewhat isolated from MAP field by a slight depression ( Figs. 32–33, 35 ). Posterior median spinnerets (PMS) tetrahedral, with a single aciniform gland spigot (AC), and a projecting median lamina bearing a field of spicules ( Figs. 34, 36 ). Posterior lateral spinnerets (PLS) conical with a blunt AC ( Figs. 34, 36 ). Colulus well defined ( Fig. 31 ), with developed posterior projection ( Fig. 44, 46 ).

Male palp: Atypical for Scytodidae , tarsus subequal or smaller than tegulum, not prolonged apically, without prolateral blunt macrosetae which do occur in females ( Fig. 27 ); tegulum long inserted apically on the tarsus with coiled spermatic duct; embolus long, slightly shorter than bulb, aciculate distally; embolus outlet on retromargin ( Figs. 10—11 , 29 ).

Female genitalia: Also atypical for the family, by lacking foveae and positioning ridges below the epigastric furrow, but with an epigynal pouch anterior to it, like in most Scytodidae ( Figs. 9 , 39 ). Vulva with two pairs of rounded, thick spermathecae arising from the epigastric furrow ( Figs. 13—14 , 37–41 ). Inner spermathecae twice as large as outer. Spermathecae with gland ductules well spaced or in patches of two to many glands ( Fig. 41 ).

Natural history. A male specimen was found under a log, hanging on its web (M. Ramírez, personal observation).

Distribution. Southeast Asia ( Thailand, Malaysia, South of China)

Figures

FIGURES 10 – 14. Genitalia and tracheal system. Stedocys leopoldi (Giltay) (10 MACN-Ar 23713, MR 0484; 12 – 13 MACN-Ar 23718, TP 0979). Stedocys pagodas n. sp. (11 holotype, CASENT 9021385; 14 paratype, CASENT 9021385). 10 — 11 Male palp, retrolateral view (10 right - image inverted-, 11 left). 12 Female tracheae dorsal view. 13 — 14 Female vulva dorsal view. (E, embolus; SC, spermatic canal; B, bulb; T, tibia; Ta, tarsus; BA, blunt apically; EF, epigastric furrow; IS, inner spermathecae; OS, outer spermathecae). Scale bars: 10 – 14, 500 µm.

FIGURES 25 – 30. 25 – 29. Stedocys leopoldi (Giltay) (25 – 28 Female MACN-Ar 23714, MR 0486, 29 MACN-Ar, MR 0484). 30. Scytodes globula Nicolet (MACN-Ar, ARAMR 000558). 25. Left tarsal organ IV. 26. Right metatarsal I trichobothria. 27 – 28. Left palp (27 tarsus apical, 28 femur prolateral). 29 – 30. Male left palp (29 retrolateral, 30 apical) (Th, thorn; BM, blunt macrosetae; E, embolus; B, bulb). Scale bars: 29 – 30, 500 µm; 28, 100 µm; 25, 50 µm; 25 – 26, 20 µm.

FIGURES 1 – 9. Preserved specimens. Stedocys leopoldi (Giltay). Male (1, 5 MACN-Ar 23713, MR 0484). Female (2, 6 MACN-Ar, TP 0979; 9 MACN-Ar 23714, MR 0486). Stedocys pagodas n. sp. Male (3, 7 type, CASENT 9021385). Female (4, 8 paratype, CASENT 9021385). 1 – 8 Prosoma (1 – 4 dorsal view, 5 – 8 ventral view). 9. External genitalia (EP, epyginal pouch; EF, epigastric furrow). Scale bars: 1 – 7, 2 mm; 8, 1 mm; 9, 0.5 mm.

FIGURES 37 – 41. Stedocys leopoldi (Giltay) (MACN-Ar 23714, MR 0486). 37, 39. Vulva. (37 dorsal, 39 ventral view). 38, 40 – 41. Right spermathecae close. (38 dorsal, 40 ventral, 41 pore detail, lateral view) (EP, epyginal pouch, GD, gland ductules; IS, inner spermathecae; OS, outer spermathecae). Scale bars: 37, 39 200 µm; 38, 40 – 41 100 µm.

FIGURES 15 – 20. Stedocys leopoldi (Giltay) (15 – 19 MACN-Ar 23714, MR 0486; 20 MACN-Ar 23713, MR 0484). 15 – 19 Female left chelicerae (15 anterior, 16 promargin, 17 posterior, 18 retromargin, 19 ectal view). 20. Male epiandrum, ventral view (ML, membranous lobe; CG, cheliceral gland; CL, cheliceral lamina; SF, stridulatory field). Scale bars: 15, 17, 19 200 µm; 16, 20 100 µm; 18 50 µm.

FIGURES 42 – 47. Stedocys leopoldi (Giltay) (42, 44 Female MACN-Ar 23714, MR 0486; 46 Male MACN-Ar 23713, MR 0484). Scytodes globula Nicolet (43, 45 Female MACN-Ar 10789, 47 male MACN-Ar, ARAMR 000558). 42 – 43 Left chelicerae, apical view. 44 – 47 Colulus (44 right lateral, 45 ventral-posterior, 46, 47 ventral) (VO, venom outlet; CP, cololus projection). Scale bars: 44 – 46 200 µm; 42 – 43 100 µm; 47 50 µm.

FIGURES 21 – 24. Stedocys leopoldi (Giltay) (MACN-Ar 23714, MR 0486), female right legs. 21 – 22. Claws I (21 retrolateral-apical, 22 retrolateral view). 23 – 24 Claws IV (23 retrolateral-apical, 24 apical view) (BPC, bipectinated proclaw; Ony, onychium; PC, proclaw; RC, retroclaw). Scale bars: 21 – 24 100 µm.

FIGURES 31 – 36. Stedocys leopoldi (Giltay) (31 – 34 Male MACN-Ar 23713, MR 0484, 35 – 36 Female MACN-Ar 23714, MR 0486). 31 Spinnerets field, posterior-ventral view. 32, 33, 35. ALS (32 left, MAP detail, 33, 35 right field) 34, 36. PMS-PLS (34 right, mesal view, 36 Left field) (MAP, major ampullate gland spigot; PI, piriform gland spigot; AC, aciniform gland spigot; numbers, ALS articles; arrows, PMS spicules). Scale bars: 31 200 µm; 33 – 36, 50 µm; 32 20 µm.