Asiafroneta atrata, Tanasevitch, 2020

Tanasevitch, Andrei V., 2020, Asiafroneta, a new genus of the spider subfamily Mynogleninae, with two new species from Borneo, East Malaysia (Araneae: Linyphiidae), Raffles Bulletin of Zoology 68, pp. 56-61 : 59-60

Asiafroneta atrata , new species

( Figs. 6–10 , 13–15 , 18–20 )

Holotype. Male ( MHNG), EAST MALAYSIA, Sabah (West Coast Residency), Kinabalu Park , Mt Kinabalu , 2600 m a.s.l., near Layang Layang, mist forest, sifting very wet moss and dead leaves, 2 May 1987, coll. D. Burckhardt and I. Löbl [11a].

Paratypes. 5 females ( MHNG), together with the holotype.

Etymology. The specific epithet is a Latin adjective referring to the dark prosoma in the new species.

Description. Male holotype. Total length 1.93. Carapace unmodified, 1.03 long, 0.73 wide, dark reddish brown, with an indistinct grey median spot and radial stripes ( Fig. 6 ). Clypeus below each anterior lateral eye with a narrow and elongated groove (sub-ocular sulci), as in Fig. 9 . Chelicerae 0.38 long, anterior margin with one small and two strong teeth, mastidion absent. Legs yellow. Leg I 2.86 long (0.80 + 0.28 + 0.70 + 0.58 + 0.50), IV 2.66 long (0.70 + 0.25 + 0.63 + 0.63 + 0.45). Chaetotaxy: TiI: 2-1-1-0, II: 2-0-1-0, III: 2-0-0-0, IV: 1-0-0-0. Femora and metatarsi unarmed. Length of spines 1–2 diameters of corresponding leg segment. TmI 0.45. Metatarsi IV without trichobothrium. Palp ( Figs. 13–15 ): Patella with a stout spine. Tibia long, subequal in length to cymbium. Cymbium narrow, conical distally, bearing three macrosetae. Paracymbium simple, small, flat, L-shaped. Tegulum with a conical extention distally. Distal suprategular apophysis short and slender. Median membrane very small, poorly visible. Embolus short and narrow, radix small, oblong-oval. Abdomen ( Fig. 6 ) 0.98 long, 0.60 wide, dark grey.

Female. Total length 2.10. Carapace unmodified ( Fig. 7 ), 1.03 long, 0.72 wide. Clypeus below each anterior lateral eye with a narrow and elongated groove (sub-ocular sulci), as in Fig. 10 . Chelicerae 0.40 long, anterior margin with one small and two strong teeth, mastidion absent. Legs yellow. Leg I 2.53 long (0.70 + 0.28 + 0.60 + 0.50 + 0.45), IV 2.45 long (0.70 + 0.25 + 0.60 + 0.45 + 0.45). Length of spines 1–2 diameters of corresponding leg segment. TmI 0.46. Metatarsi IV without trichobothrium. Abdomen ( Fig. 7 ) 1.15 long, 0.75 wide, grey to dark grey. Epigyne and vulva ( Figs. 8 , 18–20 ): Epigyne small, anterior wall (= ventral plate, auct.) with a notch, posterior median plate (= dorsal plate, auct.) with a rudimentary parmula (= scapus, auct.), a pit present. Receptacles sub-spherical, median ducts globularly expanded distally, almost in contact. Body colouration and chaetotaxy as in male.

Taxonomic remarks. The species is very similar to A. pallida , new species, the only congener so far known (see above), but both sexes of A. atrata , new species, can easily be distinguished from A. pallida , new species, by a dark carapace: dark reddish brown vs. pale greyish brown ( Figs. 6, 7 cf. Figs. 1, 2 ). The male differs by both twice shorter embolus and distal suprategular apophysis. The female genitalia in both species are very similar, but the median ducts in A. atrata , new species, seem to be larger.

Distribution. Known only from the type locality in Sabah (East Malaysia) on Borneo Island.

Figures

Figs. 1–10. Photographs of Asiafroneta pallida, new species, male holotype (1, 4), female paratype from Layang Layang (2, 3, 5); A. atrata, new species, male holotype (6, 9) and female paratype (7, 8, 10). 1, 2, 6, 7, body, dorsal view; 3, 8, posterior part of body, ventral view; 4, 5, 9, 10, prosoma, frontal view.

Figs. 11–15. Details of male palp structure of Asiafroneta pallida, new species, male holotype (11, 12) and A. atrata, new species, male holotype (13–15). 11, 13, right palp, retrolateral view; 12, 14, right palp, prolateral view; 15, embolic division, mesal view, not to scale.

Figs. 16–20. Epigyne and vulva structure of Asiafroneta pallida, new species, female paratype from Layang Layang (16, 17) and A. atrata, new species, female paratype (18–20). 16, 18, epigyne, ventral view; 17, 19, 20, vulva, dorsal view, different aspects.