Asarcogryllacris (Asarcogryllacris) robusta, 2018

Ingrisch, Sigfrid, 2018, New taxa and records of Gryllacrididae (Orthoptera, Stenopelmatoidea) from South East Asia and New Guinea with a key to the genera, Zootaxa 4510 (1), pp. 1-278 : 123-124

Asarcogryllacris (Asarcogryllacris) robusta sp. nov.

Figs. 40 D–F, 41L–N

Material examined. Holotype (female): Vietnam: Hanoi prov., BaVi N.P., (21°4'4''N, 105°21'30''E), 25– 29.vi.2015, leg. J. Constant & J. Bresseel (I.G.: 33.092)—(Brussels RBINS).

Diagnosis. Medium sized, long winged, uniformly light colored species. The wings are longer than in most other species of the genus. It differs from other species of the genus by the characteristic female seventh abdominal sternite consisting of a transverse oval central plate that is prolonged posteriorly into a pair of stout, upcurved projections ( Fig. 41 M–N). That sternite has a faint similarity with the corresponding sternite of A. jambiensis Gorochov, 2005 , but is shorter with the stouter projections divided from base and markedly upcurved. The subgenital plate is rather wide and in middle of apical margin slightly concave, which differs from the situation in most other species of the genus. Another so far unique character of the species are the shapes of the dorsal apical spurs of the hind tibia, of which the internal spur is prolonged and very stout while the external spur is shortened and constricted before the acute tip ( Fig. 40E ).

Discussion. At first glance A. robusta has the appearance of a species of the genus Aancistroger with regard to wing shape and the long internal spine at the end of the hind tibia, that spine is the dorsal internal apical spur that is markedly prolonged and moved up tibia. However, the rounded tip of the ovipositor also speaks for Asarcogryllacris while it is subacute in Aancistroger . Moreover, the shape of the female seventh abdominal sternite that is apically prolonged into two projections surpassing the base of the subgenital plate also speaks of its belonging to the genus Asarcogryllacris . On the tegmen, the media anterior is free from base while often fused at base with radius in other species of Asarcogryllacris , but it is very thin in basal area and close to radius.

Description. Small to medium sized species. Head: Face narrow ovoid; forehead nearly smooth, in middle with very fine riffles and scattered shallow impressed dots; fastigium verticis little wider than scapus; ocelli visible but little distinct; fastigium frontis separated from fastigium verticis by a fine suture; subocular furrows only indicated ( Fig. 40F ). Abdominal tergite two with one and tergite three with two rows of stridulatory pegs.

Wings about reaching tip of stretched hind tibiae ( Fig. 40D ). Tegmen widest at beginning of apical third. Radius with two branches, both forked near tip; media anterior sub-fused in basal quarter with radius, veins attached to each other, but recognizable as two veins; cubitus anterior single-branched at base, after it divides into CuA1 and CuA2, the first branch receives a connection vein from MA, then divides into two parallel veins, MP and CuA1; cubitus posterior undivided, free throughout; with 3–4 anal veins, the last branch short and indistinct, arising from a common stem with preceding branch.

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 4 external and 5 internal spines on ventral margins; although on both margins the spines increasing in size from base to apex, the two posterior inner spines are markedly but not much larger than the others; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine; with 3 apical spurs on both sides; dorso-internal apical spur 2.1 times longer than dorso-external spur.

Coloration. General color uniformly yellowish brown. Face uniformly yellowish or greyish brown with indistinct pattern. Tegmen semitransparent yellow, along fore and hind margins whitish; veins yellow; hind wing semitransparent white; veins yellow, cross-veins pale.

Male unknown.

Female. Seventh abdominal sternite little narrower than preceding sternite, with two stout, conical and upcurved projections with tips touching membranous base of subgenital plate ( Figs. 41 M–N). Subgenital plate with extended membranous basal area with only lateral margins sclerotised; apical sclerotised area bilobate at tip ( Fig. 41M ). Apical tergite with ventro-posterior angle extended to base of ovipositor. Ovipositor elongate, slightly curved throughout and with gradually approaching margins; tip obtuse ( Fig. 41L ).

Measurements (1 female).—body w/wings: 36; body w/o wings: 22; pronotum: 4; tegmen: 28; tegmen width: 8; hind femur: 11; ovipositor: 14 mm.

Etymology. Named for the strong apical internal spur of the hind tibia.

Figures

FIGURE 40. Genus Asarcogryllacris: A–B, A. m. ardjunae Karny, 1937 male; C, A. parapat sp. nov. female holotype; D–F, A. robusta sp. nov. female holotype; G–I, A. brevis sp. nov. female holotype.—Habitus dorsal view (A, C, D, G), face (B, H, F), apical area of left hind tibia (E), stridulatory pegs on 2nd and third abdominal tergites (front is left, I). Scale 10 mm (A, C, D, G with equal magnification).

FIGURE 41. Genus Asarcogryllacris: A–D, A. m. ardjunae Karny, 1937; E–H, A. parapat sp. nov.; I–K, A. brevis sp. nov.; L– N, A. robusta sp. nov.—Habitus female in lateral view (A, E), female end of abdomen in ventral view (B, F, J–K, M) and in lateral view (G–H, N ventral side is left!), ovipositor (I, L), male abdominal apex in apical (C) and lateral view (D). Scales 10 mm.