Metriogryllacris (Metriogryllacris) nigrilimbis Liu & Bian, 2021

Liu, Jing, Bin, Wei & Bian, Xun, 2021, Contribution to the knowledge of Chinese Gryllacrididae (Orthoptera) III: New additions of Metriogryllacris Karny, 1937, Zootaxa 5068 (1), pp. 142-148 : 143

Metriogryllacris (Metriogryllacris) nigrilimbis Liu & Bian sp. nov.

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Description. Female. Body medium. Face ovoid, with impressed dots ( Fig. 1A ). Ocelli distinct.

Fore coxae with 1 small spine. Fore and middle tibiae ventrally with 4 pairs of spurs and 1 pair of apical spurs; middle tibiae with one internal spine on dorsal surface. Hind femora with 11 internal and 8–11 external spines on ventral surface, dorsal surface of tibiae with 6 pairs of spines, ventral surface with 1 pair of subapical spines, apices with 1 pair of dorsal spurs and 2 pairs of ventral spurs.

Wings just reaching the apex of abdomen ( Fig. 2A–B ). Tegmina: Radius with two branches R and RS, both forked near tip or not. Media of left tegmen divides before mid-length of tegmen into two veins, MA and MP; cubitus anterior undivided, free throughout ( Fig. 2C ). While media anterior of right tegmen single-branched, media posterior absent, cubitus anterior forks about mid-length of tegmen into two veins, CuA1 and CuA2 ( Fig. 2D ). Both tegmina: cubitus posterior undivided, free throughout; with 3 anal veins.

Second and third abdominal tergites each with two rows of stridulatory pegs ( Fig. 1D ). Seventh abdominal sternite longer than wide, lateral margins widening, posterior margin arched; ventral surface with one sclerotized transverse fold ( Fig. 1F ). Subgenital plate transverse with a pair of tubercles ( Fig. 1F ). Ovipositor short, apart from sub-basal gradually and obliquely curved upward, apical area slightly curved dorsad, apices obtuse; basal area of ventro valvulae with 1 pair of lobate processes, its apices widely arched.

Male. Unknown.

Coloration. General color yellow brown ( Fig. 2A–B ). Eyes black; ocelli pale ( Fig. 1A ). Pronotum with black margins, which widened at anterior and posterior margins ( Fig. 1B ). Dorsal surface of abdomen with black central area. Tegmina yellowish brown ( Fig. 2C–D ).

Measurements (mm). Body 20.6; pronotum 5.2; tegmina 15.9; hind femur 11.1; ovipositor 7.4.

Material examined. Holotype: female, Mengdong, Malipo , Yunnan, July 27, 2021, coll. by Wei Bin, Xiaoyu Peng & Xun Bian.

Etymology. The new species name is derived from Latin words “ nigr ” and “ limb ” referring to the pronotum with black margins.

Discussion. According to the female seventh abdominal sternite with transverse fold and subgenital plate with 1 pair of tubercles, we place the new species under the Metriogryllacris (Metriogryllacris) amitarum group. The new species differs from Metriogryllacris (Metriogryllacris) amitarum (Griffini, 1914) and Metriogryllacris (Metriogryllacris) distincta Gorochov, 2004 by: pronotum with black margins which widened at anterior and posterior margins; the transverse fold of female seventh abdominal sternite crescent-shaped; female subgenital plate with 1 pair of small tubercles, posterior margin widely rounded; ovipositor about 0.67 times as long as hind femur, basal processes of ventrovalvulae lobate with widely arched apices. While Metriogryllacris (Metriogryllacris) amitarum (Griffini, 1914) has pronotum with black margins, black median band on disc and yellowish longitudinal spots on lateral lobes ( Gorochov, 2004: Fig. 18; Ingrisch, 2018: Fig. 76C–E); the transverse fold of seventh abdominal sternite semi-circular; ventral surface of subgenital plate with 1 pair of conical processes ( Gorochov, 2004: Fig. 29), apical area projected, posterior margin narrowly rounded; ovipositor 0.6 times as long as hind femur, basal processes of ventrovalvulae with obtuse apices ( Gorochov, 2004: Fig. 29; Ingrisch, 2018: 77 L). In Metriogryllacris (Metriogryllacris) distincta Gorochov, 2004 , pronotum with black margins, narrow brown or black spots on disc and larger yellowish spots on lateral lobes ( Gorochov, 2004: Fig. 14); the transverse fold of female seventh abdominal sternite crescent-shaped; ventral surface of female subgenital plate with 1 pair of long conical processes, posterior margin widely rounded ( Gorochov, 2004: Fig. 28); ovipositor about half as long as hind femur, basal processes of ventrovalvulae spine-shaped with subacute apices ( Gorochov, 2004: Fig. 28). Based on the description of the above two known species by Gorochov (2004) and Ingrisch (2018) and the specimens from Fujian, Guangxi and Hunan, we think the Chinese specimens originally treated as Metriogryllacris (Metriogryllacris) amitarum (Griffini, 1914) may be the Metriogryllacris (Metriogryllacris) distincta Gorochov, 2004 .

Figures

FIGURE 1. Metriogryllacris (Metriogryllacris) nigrilimbis Liu & Bian sp. nov. Female: A. head in frontal view; B–C. head and pronotum: B. dorsal view, C. lateral view; D. second and third abdominal tergites in lateral view; E. apex of abdomen in ventral view; F. seventh abdominal sternite and subgenital plate in ventral view.

FIGURE 2. Metriogryllacris (Metriogryllacris) nigrilimbis Liu & Bian sp. nov. Female: A–B. habitus in lateral view; C–D. tegmina in dorsal view: C. left tegmen, D. right tegmen.