Bioacoustics of Metriogryllacris (Metriogryllacris) spinulosa

Figures 6–7 Description. Male. Body medium with wings. Head. Face smooth. Fastigium verticis wide, approximately two times the width of the scapes, lateral margins inconspicuously raised ( Fig. 6A ). Eyes oval, ocelli small. Apical segments of maxillary palpi slightly longer than subapical ones, apices obliquely truncated, slightly inflated. Thorax. Anterior margin of pronotum slightly projecting in middle, posterior margin widely arched ( Fig. 6B ); lateral lobes longer than high, anterior angle rounded, posterior margin oblique, humeral sinus indistinct ( Fig. 6C ). Fore coxae with 1 small spine. Fore and middle femora unarmed on ventral surfaces; hind femora with 7–11 internal spines and 5–6 external spines ventrally. Fore and middle tibiae ventrally with 4 pairs of spurs and 1 pair of apical spurs; middle tibiae with 1 apical spur on internal margin of dorsal surface; hind tibiae dorsally with 6 pairs of spines, subapices with 1 pair of spurs on ventral surface, apices with 1 pair of dorsal spurs and 2 pairs of ventral spurs. Tegmina reaching the middle of the eighth abdominal tergite or extending to the apices of the abdomen; hind wings slightly longer than tegmina. Abdomen. Lateral margins of the second and third abdominal tergites with two rows of stridulatory pegs. Eighth abdominal tergite prolonged, about two times the length of the seventh abdominal tergite. Ninth abdominal tergite curving ventrad ( Fig. 6E ), the middle of posterior margin with 1 pair of small and nearly rectangular processes ( Fig. 6F ), the apices of the processes with the upper margin connected and lower margin pointing ventrad with a small angle ( Fig. 6G ). Cerci short and gradually incurved. Subgenital plate slightly longer than wide, basal area wide, lateral margins convex and then narrowing towards tip, apical area trapezoidal projecting, posterior margin nearly straight ( Fig. 6L ); styli slender and nearly cylindrical, inserted on the both sides of apical third area of subgenital plate ( Fig. 6L ). Female. Body slightly larger than male. Abdomen. Basal margin of seventh abdominal sternite concave, lateral margins gradually converging, posterior margin narrowly rounded; ventral surface of apical half concave, posterior margin of the concave widely separated by a furrow along the midline and the lateral margins obviously sclerotized, at tips with 1 copulatory depression on each side ( Fig. 7F ). Subgenital plate wider than long, posterior margin narrowly rounded ( Fig. 7F ). Ovipositor short, apart from subbasal curvature straight, apices obtuse; base of ventral valvulae with 2 pairs of small spines ( Fig. 7E, F ). Coloration. Body yellowish brown, eyes dark brown. Pronotum yellowish brown, lateral margins brown. The apices of spines of hind leg light brown. Male eighth and ninth abdominal tergites black. Measurements (mm). BL: ♂ 18.0–19.4, ♀ 19.1–20.2; PL: ♂ 4.1–4.6, ♀ 4.4–4.7; TL: ♂ 12.2–13.6, ♀ 13.5– 13.7; HFL: ♂ 9.3–10.3, ♀ 10.1–10.4; OvL: 6.7–7.3.