Nippononeta Eskov, 1992

Yan, Ming, Liang, Xiaokai & Tu, Lihong, 2015, On the desmitracheate " micronetine " genus Nippononeta Eskov, 1992 (Araneae, Linyphiidae), ZooKeys 484, pp. 95-109 : 98-99

Taxon classification Animalia Araneae Linyphiidae

Nippononeta Eskov, 1992

Composition.

The genus includes 24 species; the type species is Nippononeta kurilensis Eskov, 1992.

Diagnosis (updated).

Nippononeta species are similar to Agyneta in many genital characters and the desmitracheate system, but differ in the presence of a dorsal pattern on the abdomen, which is absent in most Agyneta . Male palps of Nippononeta can be distinguished from Agyneta by the conical elevation on the cymbium absent in the former (Fig. 1A), present in the latter; the presence of proximal cymbial fold (Fig. 1D) and the spine-like embolus thumb (Fig. 1G) in Nippononeta , absent in Agyneta . The scaped epigynum in Nippononeta can be distinguished by its narrowed epigynal basal part covered by a transversal fold, the well developed stretcher and remnant lateral lobes (Fig. 2 A–B), while in Agyneta the epigynal basal part is normal, the stretcher usually small or absent, but the lateral lobes are well developed bearing lateral pockets and copulatory openings ( Tu and Hormiga 2010: fig. 6a).

Description (updated).

Chelicerae of normal size, with narrowed fang base and stronger stridulatory ridges in the male than in the female (Fig. 3 C–F). Female palpal claw absent (Fig. 2F). Tracheal system: Median trunks wider in diameter than lateral pair, highly branched and extending into prosoma (Fig. 2E); tracheoles with taenidia. Lateral pair and median trunks arising independently from spiracular atrium. Epiandrous gland spigots absent in the male (Fig. 1H). Spinnerets: PLS in females having the mesal cylindrical gland spigot base enlarged (Fig. 2G), the triplet formed by one flagelliform and two aggregate gland spigots present in males PLS (Fig. 2H). For other somatic characters and measurements see Eskov (1992).

Male palp (Fig. 1 A–G). Tibia short, with serrated distal apophysis and pointed retrolateral process, sometimes with additional proximal process. Cymbium with small retrolateral lobe and proximal fold above paracymbial base. Paracymbium U-shaped, with median branch arising from inner margin. Distal suprategular apophysis modified into pit hook and hook sclerite. Embolic membrane large, with many papillae. Embolic division: radix boat shaped, connected to embolus by S-shaped membranous column. Embolus with pointed proper and serrated area, thumb modified into many spine-like projections, large apex and basal apophysis. Lamella characteristica usually splitting into two or three branches, at least one of them ribbon like with thread projections distally. Terminal apophysis composed by one large basal sclerite and one or two branches with papillae apex.

Epigynum (Figs 2 A–D, 5). Epigynal basal part narrowed, covered by transversal fold formed by the tegument connecting to dorsal side of epigynum. Median plate absent and epigynal cavity dorsally opened. Scape sigmoid folded with well developed stretcher furnished with a pit; lateral lobes remnant; copulatory openings covered by folded scape.

Distribution.

China, Japan, Korea, Russia.