Homogryllacris armigera, 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 : 194-197

Homogryllacris armigera sp. nov.

Figs. 68 A–G, 69A–C, 69G–I

Material examined. holotype (male): Vietnam: Nguyen Binh, Cao Bang, Phia Den (Phia Ðén), (22°34'N, 105°53'0''E), 6–8.viii.2010, leg. J. Constant & P. Limbourg (I.G. 31.668)—(Brussels RBINS) .

Other specimens studied: Vietnam: BacKan pr., BaBe N.P., (22°24'19''N, 103°36'55''E), 2–7.vii.2015, leg. J. Constant & J. Bresseel (I.G. 33.092)— 1 male (paratype) (Brussels RBINS); Hoa Binh Prov., Ngo Luong Nat. Res., (20°26'16''N, 105°20'15''E), 25–30.vii.2016, leg. J. Constant & J. Bresseel (I.G.: 33.282 GTI project)— 1 female (Brussels RBINS) .

Diagnosis. With regard to the projections of the male tenth tergite the new species is similar to Homogryllacris gladiata Liu, 2007 . It differs by the apical stiffened part of those projections being broader at base, distinctly curved and regularly narrowed to acute tip. The subgenital plate is also similar between both species but in H. armigera with inner angles on both sides of apical excision more rounded and with somewhat longer styli ( Figs. 69 A–C).—The female is characterized by the very long and straight ovipositor that reaches about the same length as the body of the female. From H. gladiata , it differs by the shape of the subgenital plate having the apical margin convexly rounded instead of concave ( Figs. 69 G–H). The inner dorsal spur of the hind tibia is moderately prolonged and slightly curved while the external dorsal spur appears somewhat truncate or shortened although its tip is acute ( Fig. 69I ). Otherwise, The female is characterized by the shapes of the seventh abdominal sternite, subgenital plate and the intermediate membranous zone. As it was collected from a different locality than the males, it is not included in the type series.

Description. Small to medium sized species. Head (males): Face narrow ovoid; forehead nearly smooth; fastigium verticis about as wide as scapus; ocelli little distinct; fastigium frontis separated from fastigium verticis by a very fine suture; subocular furrows absent in upper area, wide and shallow in lower area. Abdominal tergites two and three with stridulatory pegs ( Fig. 68G ). Head (female): Face rather narrow; forehead nearly smooth with scattered impressed dots and some fine transverse riffles; fastigium verticis slightly narrower than scapus; ocelli indistinct, only median ocellus marked by different color; a fine suture separating fastigium frontis from fastigium verticis only indicated on both sides; subocular furrows shallow ( Fig. 68B ). Abdominal tergites two and three each with two rows of stridulatory pegs (5, 15; 16, 20; n=1; Fig. 68C ).

Wings (males) reaching or little surpassing hind knees ( Fig. 68E ). Tegmen: Radius with two branches, both forked near tip; media anterior free from base; cubitus anterior at base with a single branch that forks into two veins, shortly after the anterior branch divides again into two parallel branches, MP and CuA1, while the posterior branch (CuA2) does not divide further; in left tegmen of male from Phia Den and female from Hoa Binh MA and MP fuse for a very short distance after MP divided from CuA and before MP divides into two branches; in right tegmen of female from Hoa Binh MP is fused in basal area with MA while CuA is single branched and undivided; cubitus posterior undivided, free throughout; with 4 anal veins, the last branch short and arising from a common stem with preceding branch. Wings (female) covering about abdomen and reaching hind knees ( Fig. 68A ). Tegmen: Radius with two branches, R and RS, both forked near tip; media anterior free from base, on left tegmen single-branched, on right tegmen releases MP before mid-length that shortly after divides into MP1 and MP2;—left tegmen: CuA with long single-branched base, an anterior branch separates in a curvature at about end of basal third and connects for one cell length with MA then separates again and shortly after divides into two branches, MP and CuA1; right tegmen: CuA single-branched free throughout; cubitus posterior undivided, free throughout; with 4 anal veins.

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 3–8 external and 5–12 internal spines (in female 8–9 external and 15 internal spines) on ventral margins; although on both margins the spines increasing in size from base to apex, the last two inner spines markedly 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, the dorsal internal spur much larger than the dorsal external spur ( Fig. 69I ).

Coloration. Males with general color uniformly light to medium brown with indistinct pattern; hind femur and tibia in part indistinctly suffused with purple. Face uniformly yellowish or greyish brown, with small black oval spots on fastigium verticis and ventral surface of scapus. Tegmen semitransparent yellow, along fore and hind margins whitish; veins yellow; hind wing semitransparent white; veins yellow, cross-veins pale.—Female general color uniformly yellowish to reddish brown. Face light brown, clypeus, mouthparts and palpi yellow; a transverse spot on fastigium verticis, rim of antennal scrobae, and two spots on scapus black; medial ocellus red. Tegmen yellowish, darker towards base; main veins yellow; cross veins in apical half little distinct, in basal half behind radius dark brown to black; hind wing semi-transparent white with yellowish veins.

Male. Eighth abdominal tergite of normal length. Ninth abdominal tergite not globular, only lateral margins curved ventrad; apico-lateral margins obliquely truncate and in dorsal area bent mediad. Tenth abdominal tergite forming a pair of narrow sclerites ascending from lateral margin to middle on the vertical back-side of abdomen below tip of ninth tergite, in between with a rather stiff triangular zone with stout medial carina. Both halves of tenth tergite on top with a long projection, in basal area cylindrical and of general color, running first posteriorly than mediad and then ventrad, that way the processes of both sides crossing each other in basal area; longest part of process dark brown, compressed with acute tip, concave posterior and convex anterior surface ( Figs. 69 A–B). Epiproct small triangular; paraproctes flat but curved below basal plates of cerci. Subgenital plate little wider than long, lateral margins convex, converging; apical margin obliquely truncate, in middle with V-shaped excision with rounded bottom; styli inserted at apico-lateral angles ( Fig. 69C ).

Female.Seventh abdominal sternite largely membranous with strong transverse folds; at base with a stiffened but nearly transparent, semi-oval flap with rounded tip overlapping the base of a brown rhombic zone in the membranous area. Subgenital plate in basal area membranous with strong transverse folds as in seventh sternite, only lateral margins with stiffened bulges; the sclerotised plate vaulted, roughly semi-circular in general outline but with slightly concave apical margin ( Fig. 69 G–H). Ovipositor very long and straight, margins slightly converging in apical half; tip narrowly obtuse ( Fig. 68D ).

Measurements (2 males, 1 female).—body w/wings: male 24–27, female 29.5; body w/o wings: male 17.5– 24.0, female 29; pronotum: male 4.5–5.0, female 5.2; tegmen: male 19, female 22; tegmen width: male 5.5–5.6, female 5.5; hind femur: male 13.5–15.0, female 17; antenna: female 95; ovipositor: female 27 mm.

Figures

FIGURE 68. Genus Homogryllacris: A–G, H. armigera sp. nov. female (A–D) and male holotype (E–G); H–J, H. stabilis sp. nov. male holotype.—Habitus dorsal view (A, E, H), face (B, F, I), stridulatory pegs on second and third abdominal tergites, front is right (C, G, J), ovipositor (D). Scales 10 mm.

FIGURE 69. Genus Homogryllacris: A–C, H. armigera sp. nov. holotype (A–B) and paratype (C); D–F, H. stabilis sp. nov. holotype; G–I, H. armigera sp. nov. female.—Male abdominal apex in lateral (A), apical (B, F), ventral (C, E), and dorsal view (D), female end of abdomen with seventh sternite, subgenital plate and base of ovipositor (G in ventral, H in anterior view), end of left hind tibia in dorsal view (I).