Alishania quadrilamina Lu & Zhang, sp. nov.

Alishania quadrilamina Lu & Zhang sp. nov.

Body length (including tegmen): ♂, 4.0 mm; ♀ 4.1 mm. (Figs 1, A–B)

Body slender, pale brown and rarely black. Vertex with four pairs of black symmetrical triangular spots. Pronotum and scutellum pale brown, with some irregular mostly black markings. Forewings brownish translucent, with dark brown stripes on the base, clavus, corium and marginal region of subapical cells; apical cells and appendix smoky.

Head slightly broader than pronotum, anterior margin rounded to face, shagreen; vertex obtusely angular or almost evenly arched, projecting forward but not strongly produced, longer medially than next to eyes; pronotum equal to the length of scutellum, slightly longer than the length of vertex, anterior margin slightly convex, posterior margin straight (Figs.1, A–C); clavus of forewings with transverse veins (Fig. 1, F); hindwings with four apical cells (Fig.1, G). Fore femur with anteroventral (AV1) seta long, intercalary (IC) row with about 6~8 setae; AM1 seta large, situated near apex; AV about 7 setae (Fig. 2, N).

Male abdomen: 2nd acrotergite apodeme (2T) with trunk near horizontal, neck strikingly slender, 2nd tergite apodeme vestigial (Fig. 2, K); 1st sternal apodemes with posterior lobes produced rounded, not convergent.; 2nd sternal apodemes with posterior lobes reduced, triangular in shape (Figs 2, L–M).

Male genitalia: Pygofer lobe long, tapered to apex in lateral view and with numerous long macrosetae. Subgenital plates each completely divided into separate medial and lateral lobes (Fig. 2, C), medial lobe simple, depressed, nearly parallel-sided and medially fused to counterpart at base (Fig. 2, I); lateral lobe strongly attached to style near base and with apex emarginate, with medial corner spinelike (Figs 2, D, H) and with numerous irregularly distributed macrosetae (Fig. 2, H); valve broadly hexagonal (Figs. 2, I). Style with apex cheliform with slender preapical spine and broader, laterally dentate apex (Figs 2, D, H). Connective Y-shaped, stem slightly shorter than arms (Fig. 2, G). Aedeagus simple and short, with shaft curved dorsad and bent at right angle strongly, with small basal hamulus on ventral surface in lateral view (Fig. 2, E), shaft T-shaped with gonopore at apex of each branch on posterodorsal surface (Figs 2, F, G).

Female genitalia: Seventh sternite with apical margin sinuately emarginate (Fig. 2, J). First valvula with dorsal sculpture maculose, nearly marginal apically and submarginal preapically; apicoventral sculptured area present (Figs 1, L, K). Second valvula with dorsal margin straight and some distinct teeth from near base to apex, thereafter tapered to acute apex (Fig. 1, J). Third valvula near same length as pygofer, without macrosetae (Fig. 1, J).

Holotype: male, Xizang Autonomous Region, Rikaze, Lower Yadong countryside, 5.vi.2015, 3100~ 3200m, Coll. Xue Qinquan. Paratype: 1 female, same data as holotype.

Remarks. This new species is very similar to the other three known species (A. formosana, A. fodingensis, A. attenuata) based on external morphological characteristics (color, vertex, face, wings, etc.), but it can be differentiated from the others based on the characteristics of the subgenital plates, which have the medial lobes basally separated from the lateral lobes. The aedeagus of the new species resembles that of A. fodingensis but the former differs from the latter in having the styli with a stocky apical unforked process. The new species also differs from A. formasana in lacking a preapical tooth on the aedeagal shaft. It differs from A. attenuata in having the shaft of the aedeagus shorter and the styli having the apical process stocky and distal margin denticulate.

Etymology. The species epithet “ quadrilamina ” refers to the four small parts of the subgenital plates and the base of paired plates between inside and outside being separate.