Metriogryllacris (Metriogryllacris) amitarum ( Griffini, 1914b )

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 : 216-219

Metriogryllacris (Metriogryllacris) amitarum ( Griffini, 1914b)

Figs. 76 A–E, 77A–C

Material examined. Vietnam: Prov. Vinhfu, Tam Dao N.P., (21°31'N, 105°33'E), 25–30.vii.2011, leg. J. Constant & J. Bresseel (I.G. 31.933)— 1 male (Brussels RBINS) ; Tonkin, Lang Son Province, Than-Moi (currently Dong Mo ), (21°33'N, 107°1'E), 1.vi.–31.vii.1892, leg. H. Fruhstorfer— 1 female (syntype) (Wien NHMW) ; Tonkin [North Vietnam], Montes Mauson , elev. 610–915 m (21°49'N, 106°57'E), 1.iv.–31.v.1892, leg. H. Fruhstorfer— 1 male (syntype) (Wien NHMW) .

Description. Small to medium sized species. Head: Face ovoid; forehead in middle with fine transverse riffles and conspicuous impressed dots; fastigium verticis little wider than scapus, indistinctly separated from fastigium frontis; fastigium frontis with a pair of faint bumps at top; ocelli indistinct; subocular furrow indicated only above clypeal suture ( Fig. 76A ). Abdominal tergites two and three each with two rows of stridulatory pegs (7, 10; 12, 18; n = 1, male type).

Wings little surpassing abdomen but not reaching hind knees ( Figs. 76 C–E). Tegmen: Radius gives rise to RS in about mid length of tegmen; media anterior free from base, sends also a short branch to RS and little further divides into two branches, MA and MP (male from Tam Dao). Variation: in male type from Than-Moi right t.: MA free from base, fuses for about one cell length with R, after that fuses with a branch from CuA and then divides into MA and MP; in female type from M. Mauson left t.: there is no fusion of MA with R; RS divides from R only in apical area as in male type; cubitus anterior at base uni-branched, after it divides into two branches, the anterior branch makes a curve and fuses with MA, then they divide into MA and MP+CuA1; the posterior branch CuA2 does not further divide (in all 3 specimens although they differ in details); cubitus posterior undivided, free throughout; with 3 anal veins.

Legs: Fore coxa with a 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 6–10 external and 7–12 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one preapical spine; with 3 apical spurs on both sides.

Coloration. General color yellow brown; pronotum black with large yellow spots on paranota; central to apical abdominal tergites black, a narrow ventro-apical rim of ninth tergite pale. Face uniformly yellowish brown. Tegmen medium to dark brown, along margins and at tip semi-transparent white, veins brown; hind wing semitransparent white, main veins dark brown, cross-veins brown.

Male. Ninth abdominal tergite globular, black, along ventral hind margin with a narrow zone of lighter color, from that area, a pair of small hooked processes with swollen pale base and black tip projects with tip bent ventrad ( Fig. 77A ). Epiproct small triangular; paraproctes as extended plates from base of cerci. Subgenital plate basally wide, in basal area with convex lateral margin, between half and two thirds of length constricted on both sides, thereafter lobular with faint bilobate tip; long styli inserted at the lateral constriction ( Fig. 77B ).

Female. Ventral area of abdominal apex in female syntype: Seventh abdominal sternite with a semi-circularly outlined central area. Subgenital plate transverse with a pair of ventral cones in central area ( Fig. 77C ). Ovipositor short, apart from subbasal curvature straight; tip slightly upcurved, obtuse ( Fig. 76B ).

Measurements (2 males, 1 female, partly after Griffini 1914b).—body w/wings: male 28; body w/o wings: male 18–23, female 25; pronotum: male 5, female 6; tegmen: male 15–18, female 16.2; tegmen width: male 6.2; hind femur: male 12–13, female 14; antenna: male 130; ovipositor: female 8 mm.

Discussion. The abdominal appendages of male and female as described and figured in Gorochov (2003) agree well with the situation in the syntypes in NHMW.

Figures

FIGURE 76. A–J, Genus Metriogryllacris: A–E, M. (M.) amitarum (Griffini, 1914) female syntype (A–C), male syntype (D), and male from Tam Dao (E); F–G, M. (M.) permodesta (Griffini, 1914) female holotype; H–J, M. (Xiphilarnaca) xiphiura (Karny, 1928) syntype.—K–N, Melanogryllacris atrata (Walker, 1869) female from Kinabalu.—Face (A, F, H, N), habitus dorsal view (C, E, I, K), habitus lateral view (B, D, G, J), stridulatory pegs on second and third abdominal tergites, front is left (L), female abdominal apex with ovipositor and subgenital plate (M).

FIGURE 77. Genus Metriogryllacris: A–C, M. (M.) amitarum (Griffini, 1914) male (A–B) and syntype female (C); D–F, M. (M.) permodesta? (Griffini, 1914) det. Karny from Guangdong (D–E) and M. permodesta det. Ebener from Chekiang (F); G– H, M. (M.) permodesta (Griffini, 1914) holotype from Montes Mauson (G) and from Guangzhou det. Karny (H); I–L, M. (X.) xiphiura (Karny, 1928) male (I–K) and female (L).—Male abdominal apex in about apical (A, D, J), oblique ventral (B, F, I), oblique lateral view (E, K); female abdominal apex with seventh abdominal sternite, subgenital plate and base of ovipositor in ventral view (C, G, H, L).