Bioacoustics of Metriogryllacris (Metriogryllacris) bimacula

Description. Male. Body medium-sized. Frons ovoid with very fine transverse riffles and sparse punctures ( Fig. 1A ). Ocelli indistinct. Pronotum with anterior margin slightly projecting, posterior margin nearly straight ( Fig. 1B ); lateral lobes longer than deep, posterior margin of ventral margin slightly extending downward ( Fig. 1C ). Fore coxae with 1 spine. Fore and middle femora unarmed on ventral surfaces, tibiae with 5 pairs of ventral spurs, including 1 pair of apical ones. Hind femora with 9–12 internal and 7–8 external spines on ventral surface; tibiae with 5–6 internal and 5 external spines on dorsal surface, apices with 1 pair of dorsal spurs, 1 pair of subapical ventral spurs and 2 pairs of ventral spurs. Wings short, only reaching the middle area of fifth abdominal tergite. Tegmina ( Fig. 2 ): Radius forks into two branches near apical forth area; MA fused with R in basal forth area, then raised from R; in the left tegmen ( Fig. 2A ) MP and CuA free at base but fused with each other in subbasal area for about one cell length, then suddenly separated, then MP fused with MA in short distance and again separated, then MP and CuA free, undivided; while in right tegmen ( Fig. 2B ) MP and CuA fused in basal area, undivided. Both tegmina: Cubitus posterior undivided, free throughout; with 3 anal veins. Abdominal tergites two and three each with two rows of stridulatory pegs ( Fig. 1D ). Eighth abdominal tergite prolonged downwards ( Fig. 1E–F ). Ninth abdominal tergite semi-globular, ventral margin with 1 pair of small spines in the middle which directing downwards and slightly outwards ( Fig. 1G–H ). Cerci short and slender. Subgenital plate basally broad, apical area trapezoidal projected in the middle, posterior margin with a shallowly concavity in the middle ( Fig. 1I ); long styli inserted at the lateral constriction ( Fig. 1I ). Female. Unknown. Coloration. General color yellow brown, face uniformly yellowish brown ( Fig. 1A ). Pronotum with brown margins, disc with 1 black spot at anterior and posterior margin respectively ( Fig. 1B–C ). Tegmina brown ( Fig. 2 ). Ventral surface of hind femora brownish. From fifth to ninth abdominal tergites with large black spots on dorsal surfaces ( Fig. 1E–F ); spines of male ninth abdominal tergite brown.

Figures 2 , 9E–F , 11A–C Female (new description). Wings reaching the middle area of sixth abdominal tergite. Tegmina ( Fig. 9E–F ): In left tegmen, radius forks into two branches between middle and apical third of tegmen, R forked in subapical area; MA fused with R in basal third of tegmen, then raises from R. While right tegmen, R undivided; MA raises from R in basal fourth of tegmen, then together with RS and raises from the latter in apical area. Cubitus anterior free from base, which divides into CuA1 and CuA 2 in subapical area ( Fig. 9E ) or behind middle of tegmen ( Fig. 9F ). Both tegmina: Cubitus posterior undivided, free throughout; with 3 anal veins. Fore coxae with 1 small coxae. Fore and middle tibiae with 4 pairs of spines and 1 pair of apical spines; middle tibiae dorsally with 1 internal spine. Hind femora with 8–11 internal and 4–6 external spines on ventral surface; tibiae with 6 pairs of spines on dorsal surface, subapical area with 1 pair of ventral spines, apices with 1 pair of dorsal spines and 2 pairs of ventral spines. Second and third abdominal tergites each with two rows of stridulatory pegs ( Fig. 2D ). Seventh abdominal sternite longer than wide, posterior margin narrowly rounded; ventral surface with one sclerotized transverse fold ( Fig. 2F ). Subgenital plate transverse, posterior margin widely rounded, ventral surface semi-membranous along the midline, which as wide as the transverse fold of seventh abdominal sternite and the both sides slightly convex ( Fig. 2F ). Ovipositor short, apart from subbasal gradually and obliquely curved upward, apical area slightly curved dorsad, apices obtuse; basal area of ventral valvulae with 1 pair of lobate processes, its apices widely arched ( Fig. 2E ). Other characters (including coloration) as the male’s description ( Yu et al. , 2022 ).