Javagone, Tanasevitch, 2020

Tanasevitch, Andrei V., 2020, On linyphiid spiders from Java, Indonesia, with the description of three new genera and four new species (Araneae: Linyphiidae), Revue suisse de Zoologie 127 (1), pp. 63-74 : 64

Javagone gen. nov.

Type species: Javagone maribaya sp. nov.

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

Diagnosis: The genus contains medium-sized erigonines, with a total length of about 1.7, which are characterized by the following combination of somatic and genitalic characters:

1) Carapace unmodified, eyes somewhat enlarged, cephalic pits (= sulci) absent ( Figs 1-4 ).

2) Legs relatively long and slender.

3) Leg chaetotaxy formula 1.1.1.1; metatarsi I-IV each with a trichobothrium; TmI about 0.31.

4) Palpal tibia simple, slightly modified ( Figs 10, 13 ).

5) Paracymbium relatively large, L-shaped ( Fig. 12 ).

6) Median membrane reduced.

7) Distal suprategular apophysis moderately developed (see Fig. 10 ).

8) Embolus relatively thin, semi-looped; radix small; convector present, massive ( Figs 10-11, 14 ).

Species included: Only the type species, Javagone maribaya sp. nov.

Taxonomic remarks: Among more than 400 known genera of the subfamily Erigoninae only 23 show the leg chaetotaxy formula 1.1.1.1 coupled with the presence of a trichobothrium on MtIV. No other genera with the same chaeto- and trichobothriotaxy have been recorded from the Oriental Region, except for the monotypic genus Cirrosus Zhao & Li, 2014 , known from Xishuangbanna, Yunnan Province, China ( Zhao & Li, 2014), an area situated on the border between the Palaearctic and Oriental realms. Judging from the male palp conformation, Javagone maribaya sp. nov. does not fit into Cirrosus or any other known linyphiid genus. The peculiar structure of the male palp and the absence of the corresponding female make it difficult at the moment to evaluate the possible relationships of the new genus. It is most likely with still unknown Oriental erigonines.

Distribution: Known only from the type locality on Java, Indonesia.

Figures

Figs 1-9. Photographs of males: the holotype of Javagone maribaya sp. nov. (1-4), the paratype of Javanaria gracilipes sp. nov. (5-6) and the holotype (7) and both paratypes (8-9) of Javanyphia gede sp. nov. (1, 5, 8-9) Habitus, dorsal view. (2, 6-7) Prosoma, lateral view. (3) Prosoma, frontal view. (4). Prosoma, dorsal view.

Figs 10-14. Details of male palp structure of Javagone maribaya sp. nov., holotype. (10-11) Right palp, retrolateral and prolateral views, respectively. (12) Palpal tibia and paracymbium, lateral view. (13) Palpal tibia, dorsal view. (14) Embolic division, retrolateral view.