Aancistroger vietus Gorochov, 2004

Figs. 32 E–F, 33D–F, 34H

Material examined. Vietnam: Ninh Thuan Prov., Phuoc Binh N.P., (12°4'N, 108°45'0''E), 26.vii.–1.viii.2014, leg. J. Constant & J. Bresseel (I.G.: 32.779)— 1 male (Brussels RBINS) .

First description of male. Small to medium sized species. Head: Face narrow ovoid; forehead nearly smooth with very fine transverse riffles; fastigium verticis about 1.5 times wider than scapus; ocelli visible but little distinct; fastigium frontis not clearly separated from fastigium verticis; subocular furrows present but not strong (Fig. 32F). Abdominal tergites two and three each with two rows of stridulatory pegs (15–16, 15–18; 26–28, 26; n = 1 male).

Wings surpassing stretched hind tibiae (Fig. 32E). Tegmen: Radius with two branches, both forked near tip; media anterior free from base but leaning on R, single branched; cubitus anterior at base single branched, after division into two branches near end of basal quarter, the anterior branch makes a curvature and receives a very short but strong connection branch from MA, shortly after it divides into MP and CuA1, which are running parallel; CuA2 without further division; cubitus posterior undivided, free throughout; with 3–4 anal veins; the fourth incomplete and with a long common stem with third anal vein.

Legs: Fore coxa with a small spine at fore margin; fore and mid femora unarmed; fore and mid tibiae with four pairs of large ventral spines and one pair of smaller ventral spurs; hind femur with 9–10 external and 5–6 internal spines on ventral margins; hind tibia with five spaced spines on both dorsal margins; ventral margins with one preapical spine; with 3 apical spurs on both sides; both dorsal spurs moved up, distinctly away from the tip of the tibia with dorso-internal spur curved and more than twice as long as dorso-external spur (Fig. 34H).

Coloration. General color uniformly yellowish brown. Face uniformly yellowish or greyish brown, indistinctly marbled in dried specimen. Tegmen semitransparent yellow, along fore and hind margins whitish; veins yellow; hind wing semitransparent white; veins yellow, cross-veins pale.

Male. Eighth abdominal tergite of normal length. Ninth abdominal tergite globular, hind margin with a projecting bulge that is furrowed in midline; from both ventro-lateral angles of that bulge with an upcurved thin and sharp spine (Fig. (Fig. 33 E–F). Tenth abdominal tergite hidden under bulge of ninth tergite; in middle with a pair of stout upcurved spines (Fig. 33D. Subgenital plate with faintly convex, sub-parallel lateral margins and a deep and wide medial groove; apical area bilobate without styli (Fig. 33E).

Female see Gorochov (2004).

Measurements (1 male).—body w/wings: 25; body w/o wings: 12.5; pronotum: 3.5; tegmen: 21; tegmen width: 5.5; hind femur: 7 mm.

Discussion. The species has been described from a single female. The male described here was collected close to the type locality. With regard to the general structure of the male abdominal apex, A. vietus is similar to Aancistroger primitivus Gorochov, 2005 . It differs by the apical bulge of the ninth tergite being more pronounced and the lateral spines longer, with a sharp tip and by the spines of the tenth tergite running parallel not diverging and being much stouter at base than in A. primitivus . The male subgenital plate of the species differs by the deep medial groove and bilobate apex while that of A. primitivus terminates into a single median lobe. The armature of the hind tibia is also similar to that of A. similis Gorochov, 2008 of which the male is unknown. A. vietus differs from the latter by smaller body and much shorter wings with hind wings projecting behind tip of tegmen against not projecting.