Poltys stygius Thorell, 1898

Smith, H. M., 2006, A Revision of the Genus Poltys in Australasia (Araneae: Araneidae), Records of the Australian Museum 58, pp. 43-96 : 59-62

Poltys stygius Thorell

Figs 4, 42–45, 52–55, 64–66, 70, 72.

Poltys stygius Thorell, 1898: 344 . Female holotype from Malewoon, Tenasserim, Burma, L. Fea; in MSNG, examined.

Poltys microtuberculatus Rainbow, 1916: 118 , pl. 22, f.44. Juvenile holotype from Gordonvale , Queensland; in AM KS8693 , examined. New synonym.

Remarks. Rainbow’s type is a juvenile and cannot be said to be this species (rather than P. illepidus ) with complete confidence. It has, however, the combination of physical features that are particularly common in this species and P. stygius is frequent today in this geographical area.

Material examined. AUSTRALIA: QUEENSLAND: ƋƋ KS86247–8 , Cape Kimberley , track to lookout W of caravan park, 16°16'28"S 145°28'05"E, 21 Sep. 2003 ; ♀♀ KS33937 , KS33934 , KS33916 , KS33842 , KS86261 , Edmonton , 17°01'S 145°44'E, 14 & 16 May 1972, Dec. 1969, 29 Aug. 1970, 18 Sep. 2003 ; Ƌ KS58024 , ♀ KS70357 , Goldsborough Valley SF, side track to quarry, 17°12'43"S 145°44'56"E, 22 May 2000 ; ♀ S42529 , Rokeby Stn, Cape York , 13°40'S 142°40'E, 31 May 1973 ; Ƌ KS73155 , Trinity Park, track to Earl Hill via Reed Rd , 16°47'59"S 145°42'33"E, 21 May 2000 ; Ƌ KS75631 , ♀ KS86260 , Ƌ KS86092 , Trinity Park , 16°48'17"S 145°42'04"E, 7 Jan. 2002 , 16 & 18 Sep. 2003; ♀ KS90969 , Trinity Park , Melaleuca swamp, 16°48'12"S 145°42'04"E, 14 May 2000 ; ♀ ( MMUS) Cairns, N Queensland . INDONESIA: SUMATRA: ♀ ex 21303 ( MNHNP) Sumatra . MALAYSIA: PINANG: ♀ ( BMNH), Penang, Glugor Estate, Banyan Lepas, 25 Jun. 1960 . SABAH: Ƌ ( RMNH ex coll. CLD, 2000-704), Mt Kinabalu NP, Poring Hot Springs, 6°02'N 116°50'E, 22 Mar. 1996 ; Ƌ ( RMNH ex coll. CLD, 2000-704), Crocker Range, 5°26'N 116°08'E, 19 Feb. 2001 . PAPUA NEW GUINEA: EAST SEPIK: ♀ KS8065 , Kairiru Island near waterfall, 3°20'S 143°33'E, 12 Jun. 1976 . MADANG: ƋƋ ( RBIN) Baiteta forest , 5°01'S 145°45'E, 21 Apr. 1994 & 13 Jul. 1996 . SINGAPORE: Ƌ 20982 ( JAM), Kranji, Singapore, 7 July 1992 . COUNTRY NOT GIVEN: ( RMNH) China Sea Islands , May 1894 .

Reared specimens deposited in other institutions: ex ♀ KS86260 : Ƌ to QM S66573 , Ƌ to MSNG.

Diagnosis. Female. As P. illepidus ( Figs 33–45) but with deep and wide foveae that are often distinctly paddle shaped ( Figs 53, 55); posterior epigyne long, extending into the epigynal fold; posterior lobes of spermathecae usually visible entirely dorsal to the margin of the epigynal furrow in posterior view. Male. As P. illepidus ( Figs 56–60), but with a longer, gently curving embolus and correspondingly longer conductor ( Figs 64, 66, 70).

Description. Female. Carapace length range 6.25–7.50. Drawn specimens Figures: 42–43 KS86260; 44, 55, KS70357, 45, 52–54, MSNG (holotype). General characters see P. illepidus .

Female MSNG (holotype). Prosoma. Carapace: length 7.08, width 5.92, height 1.92; broad and low; eye tubercle distinct but short, broad basally both in dorsal and lateral views. Chelicerae: paturon with 4 promarginal teeth ( Fig. 44). Labium: length 0.90, width 1.35. Sternum: length 2.86, width 2.98; deeply indented anteriorly for labium; sternal extensions at bases of legs II–IV. Eyes. AME>PME≥ PLE> ALE ; ALE c. 1× its own diameter from AME; ventral margin of ALE is ventral of mid point of AME. Legs. P+TL I: 11.67, II: 10.42, III: 6.67, IV: 8.42; front femora slightly broadened; patellal and tibial macrosetae not flattened (but may be in juveniles and adults from some areas). Abdomen. ( Fig. 45). Length 14.83, width 12.08; broadest anterior to main apodemes; “microsigillae” well developed. Epigyne. A broad fan-shaped plate, widest point about half-way in anterior view ( Fig. 52); foveae broad, deep, paddle-shaped hollows, narrowing and partly overhung basally, separated by a long, strongly developed median ridge ( Fig. 53, see also Fig. 55); posterior lobe of spermathecae visible dorsal to line of epigynal groove ( Fig. 53); no copulatory ducts visible; spermathecae separated by half a spermatheca width or less; well sclerotized overall. Colour in alcohol. Carapace dark reddish-chestnut, slightly paler on dorsal caput and anterior eye tubercle. Chelicerae dark yellow basally, darkening distally to deep chestnut. Labium, maxillae and sternum orange-brown. Pedipalps yellow at femora darkening to black distally. Femora I, II and IV deep chestnut with a blue shine; femur III paler orange-brown; distal legs dark, mottled orange with copious brown–black. Abdomen ventrally fawn around pedicel, ringed by paler area then dorsal colouration, also pale around spinnerets; dorsally blackish background with paler patches and brown markings edged with yellow; remains of whitish patches on flanks.

Male. Carapace length range 0.98–1.41. Drawn specimen Figs 64–66, KS86092. General characters see P. illepidus .

Male KS86092. Prosoma. Carapace: length 1.33, width 0.96, height 0.47; eye tubercle poorly defined, broad and almost without any dip between caput and eye tubercle in lateral view. Labium: length 0.11, width 0.18. Sternum: length 0.53, width 0.51. Eyes. AME>PME>PLE= ALE ; ALE c. 1 ⁄ 3 × its own diameter from AME; height of ventral margin of ALE is at mid point of AME. Legs. P+TL I: 1.57, II: 1.49, III: 0.82, IV: 1.10; macrosetae of distal patella and tibia of legs I and II slightly flattened basally. Abdomen. Length 1.75, width 1.20; a rather skewed ellipsoid, widest point near apex. Palpal organ. ( Figs 64– 66, 70). Radix–stipes joint retrolateral, almost all of stipes hidden by cymbium, embolus and TA arise dorsally (normally obscured by cymbium, Fig. 66); embolus a stout, evenly curving rod, tapering slowly then abruptly ( Figs 64, 70); TA narrow at base, flanking the embolus, broadens to a lamina and free of embolus apically ( Fig. 70); PM a pointed sclerotized bump ( Figs 64–65, 70). Colour in alcohol. Carapace dark olive, most of caput dark brown– black; dorsal eye tubercle and part of caput orange. Chelicerae as carapace with light prolateral V near tip. Labium, maxillae and sternum dark olive. All femora orange basally darkening to dark olive-brown distally; distal legs orange with black markings, tarsi cream with black rings. Abdomen ventrally olive ringed by black; white flanks; dorsal with dark pattern on a white ground. Palpal cymbium black, edges brownish; tibia, and patella with black on cream, femur mainly creamy-white.

Remarks. On average P. stygius have longer legs than P. illepidus . Many P. stygius females have a more extensive pale patch on the caput than most P. illepidus and a shorter eye tubercle. Not all specimens, however, have either character and both are within the variation range of P. illepidus .

Variation. Few specimens are available for examination but there appears to be a similar range of variation to that seen in P. illepidus . Examined adult females from Australia and New Guinea have lacked flattened macrosetae on the patellae. Some Australian males and both the male from Singapore and the adult female from Sumatra have these flattened macrosetae but otherwise appear identical.

Biology. The webs of P. stygius appear to be similar to those of P. illepidus . A female collected at Trinity Park was hiding hung beneath a dead curled leaf on a living sapling during the day ( Fig. 4). The species seems to prefer moist habitats, with a narrower habitat range than P. illepidus . Egg sacs have not been seen in the wild by the author but one laid in captivity was a white fluffy inner sac overlaid with rose pink silk. The unidentified egg sac shown in Clyne (1969: fig. 152) appears to belong to this species. This egg sac is pictured on the underside of a green leaf.

Distribution. Coastal far northeast Queensland through Sumatra and Borneo to Burma ( Fig. 72).