Asiafroneta, 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 : 57

Asiafroneta , new genus

Type species. Asiafroneta pallida , new species.

Etymology. The generic name is a combination of two words: “Asia”, the “terra typica”, and part of the generic name Afroneta . The gender is feminine.

Diagnosis. The new genus clearly belongs to the subfamily Mynogleninae which is mainly characterised by the presence of sub-ocular sulci, and a primitive structure of the genitalia in both sexes. Asiafroneta , new genus, is diagnosed by the following combination of somatic and genitalic characters:

1) small-sized spiders (compared to most Mynogleninae ), with a total length of 1.85–2.12;

2) sub-ocular sulci present in both sexes as a narrow elongated groove under each anterior lateral eye ( Figs. 4, 5, 9, 10 );

3) carapace unmodified, distinct dorsal abdominal pattern absent in both sexes;

4) leg chaetotaxy formula: FeI: 0-1(0)-0-0, II–IV: 0-0- 0-0; TiI: 2-1-1(0)-0, II: 2-0-1(0)-0, III: 2-0-0-0, IV: 1-1(0)-0-0; metatarsi unarmed; apical spines on leg tibiae absent;

5) metatarsi IV without trichobothrium;

6) a strong spine on palpal patella present ( Figs. 11, 13 );

7) two retrolateral trichobothria on palpal tibia ( Figs. 11, 13 );

8) palpal tibia unmodified, almost as long as cymbium;

9) cymbium with three macrosetae (M1, M2, M 3 in Figs. 11, 13, 14 );

10) distal suprategular apophysis a narrow spit;

11) median membrane (= “conductor”, auct.) strongly reduced;

12) embolic division extremely simple: radix continuous with embolus ( Fig. 15 );

13) epigyne with a small notch anteriorly, parmula (= scapus, auct.) rudimentary, median ducts (sensu Merrett, 2004) broadly expanded distally, receptacles more or less spherical ( Figs. 17, 19, 20 ).

Species included. Asiafroneta pallida , new species, and A. atrata , new species.

Taxonomic remarks. Asiafroneta , new genus, resembles many genera of Mynogleninae because of a limited diversity of somatic characters and a primitive/simple structure of the genitalia in the group. Nevertheless, the new genus seems to be particularly similar to Parafroneta Blest, 1979 , a speciose genus from New Zealand. Both representatives of Asiafroneta , new genus, differ from other known mynoglenines by by a significantly smaller size, the chaetotaxy (absence of ventral spines on legs; leg segments without apical spines), the presence of only two prolateral trichobothria on the palpal tibia vs. three in the majority of the subfamily’s members, and by structural details of the genitalia in both sexes (see below in the Taxonomic Remarks under A. pallida , new species).

Distribution. Known from Sabah and Sarawak (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.