Agroeca nigra, Mu & Jin & Zhang, 2019

Mu, Yannan, Jin, Chi & Zhang, Feng, 2019, A survey of Agroeca Westring, 1861 from China (Araneae: Liocranidae), Zootaxa 4615 (1), pp. 91-112 : 101

Agroeca nigra sp. n.

Figs 9 , 11 A–C

Type material. Holotype ♂, CHINA: Ningxia Hui Autonomous Region, Guyuan City , Jingyuan County, Dawan Town , Xigou Village (35°46.440′N, 106°16.492′E), 1940 m a.s.l., 23 Aug 2017, leg. Xiao Zang. Paratypes: 4♂, same data as the holotype .

Etymology. The specific name is a Latin adjective meaning “black”. It refers to the colour of the body.

Diagnosis. The new species is similar to A. mongolica , but can be distinguished by: 1) the narrow subtegulum (vs wide); 2) the presence of one lateral apophysis on the sheet-like embolus (vs two); 3) the beak-like medium apophysis, with a straight tip (vs the tip of MA curved down); and 4) the short, thick RTA (vs long). Female unknown.

Description. Male. Holotype ( Figs 9 A–D) total length 4.41. Carapace 2.24 long, 1.81 wide; abdomen 2.17 long, 1.56 wide. Carapace deep brown, margin dark. Two longitudinal black bands mediolaterally, with distinct radial groove, fuzzy cervical groove laterally of fovea; fovea dark reddish-brown. Sternum brown, with two lighter brown patches. Eye sizes and interdistances: ALE 0.11, PLE 0.09, PME 0.11, AME 0.10, AME–AME 0.04, AME–ALE 0.05, PME–PME 0.11, PME–PLE 0.10. MOA 0.25 long, 0.31 posterior wide, 0.24 anterior wide. Legs fuscous; tibia I and II with two pairs of ventral spines. Metatarsi I and II with three pairs of ventral spines. Measurements of legs: leg I 6.36 (1.77+0.88+1.51+1.20+1.00), leg II 5.75 (1.57+0.88+1.27+1.12+0.91), leg III 5.52 (1.50+0.74+1.10+1.3 5+0.83), leg IV 8.11 (2.10+0.91+1.77+2.22+1.11).

Palp ( Figs 9 E–G, 11A–C) as illustrated. Palp grey, tegulum brown. RTA short and thick, with two outgrowths distally; embolus sheet-shaped, with broad base and one lateral upward apophysis; tip curved and thin; conductor membranous; median apophysis beak-like, needle-shaped apically. Tegulum wide, with faint sperm duct.

Distribution. Known only from the type locality ( Fig. 17 ).

Figures

FIGURE 9. Agroeca nigra sp. n. male: A habitus, dorsal view; B same, ventral view; C cephalothorax, ventral view; D cephalothorax, frontal view; E male left palp, prolateral view; F same, ventral view; G same, retrolateral view. Scale bars: 1 mm (A–B); 0.2 mm (C–G).

FIGURE 11. Agroeca nigra sp. n. (A–C) and A. tumida sp. n. (D–E): A male left palp, prolateral view; B same, ventral view; C same, retrolateral view; D male left palp, ventral view; E same, retrolateral view. Scale bars: 0.25 mm (A–E). Abbreviations: C, conductor; E, embolus; PA, patella apophysis; MA, median apophysis; RTA, retrolateral tibial apophysis; SD, sperm duct; ST, subtegulum; T, tegulum.

FIGURE 17. Distribution in China of the Agroeca species treated in this paper.