Bioacoustics of Gryllacris

Diagnosis. Body medium to large, form robust, with femoro-abdominal stridulatory organ. Male ninth abdominal tergite specialized, basal area medially projected with 1 pair of digitate processes or with a single process, apical area with 1 narrowing lobe which directing ventrad and forward, its apex with transverse carina bearing paired lateal tubercles or processes. Male subgenital plate transverse, with widely spaced large styli and with median emargination posteriorly; genitalia membranous. Posterior margin of female seventh abdominal sternite without median process or lobe. Female subgenital plate triangularly oblong, basal area wide, narrowing; basal area of ventral surface triangular prominence, behind this with 1 simple cylindrical lobule, sometimes apices apically. Species included. There are 82 species are reported worldwide, only 1 species is distributed in China .

Description. Medium large to large species. Head: Face ovoid; forehead nearly smooth with scattered impressed dots and very fine transverse riffles (formerly conserved in alcohol); fastigium verticis wider than scapus, separated by a fine transverse suture from fastigium frontis; ocelli distinct; subocular furrows distinct ( Fig. 12P ). Abdominal tergites two and three each with two rows of stridulatory pegs (3, 7; 9, 13; n = 1). Wings surpassing hind knees ( Fig. 11H ). Tegmen: Radius releases RS between basal third and mid length of tegmen, both branches forked in apical area. Media anterior fused in basal area with radius, divides behind end of basal third; media posterior absent; cubitus anterior divides little before mid-length of tegmen into CuA1 and CuA2; cubitus posterior undivided, free throughout; with 4 anal veins. Legs: Fore coxa with a spine at fore margin; fore and mid femora unarmed; fore and mid tibiae with 4 pairs of large ventral spines and one pair of smaller ventral spurs; hind femur with 9 external and 7–8 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine; with 3 apical spurs on both sides. Coloration. General color uniformly light brownish. Face including anterior area of vertex and basal segments of antennae black; compound eyes light, ocelli light yellow; lateral and ventral areas of clypeus brownish yellow. Pronotum light brownish with black rim (along hind margin little wider than rim). Legs with a small black spot at genicular area; ventral spines of hind femur and dorsal spines of hind tibia black. Tegmen yellowish semitransparent, towards base cells faintly infumate; veins and veinlets yellow; hind wing semi-transparent greyish; veins dark yellow, cross-veins yellow. Male. Eighth abdominal tergite prolonged, with lateral areas nearly rectangularly bent to dorsal surface, although the angle itself is gradually curved. Ninth abdominal tergite at very base laterally rounded, otherwise in dorsal view roughly triangular with rather flat surface (in lateral view slightly concave), at tip rounded; lateroapical areas nearly rectangularly bent to dorsal surface, although the angle itself gradually curved; angle between dorsal, lateral and apical surfaces simply conical; apical surface in middle little flattened, bent ventro-proximad, widening ventrally, with a faint furrow along midline; at ventral margin (in situ hidden) with a compressed and except at base black projection at each side; projections with approaching margins to about two thirds of their lengths, then bent medio-proximad and widening to truncate tip ( Figs. 15 G–I). Subgenital plate wide in about basal half, then strongly narrowed and at tip bilobate; styli inserted at apico-lateral angles of wide area and largely surpassing tip of plate. Female unknown. Measurements ( 1 male ).—body w/wings: 47; body w/o wings: 34; pronotum: 8.5; tegmen: 36; tegmen width: 10.5; hind femur: 23; antenna: male 150 mm .

Description. Medium large to large species. Head: Face ovoid; forehead nearly smooth with scattered impressed dots and very fine transverse riffles (formerly conserved in alcohol); fastigium verticis wider than scapus, separated by a fine transverse suture from fastigium frontis; ocelli distinct; subocular furrows distinct ( Fig. 12O ). Abdominal tergites two and three each with two rows of stridulatory pegs (3, 8; 9, 12; n = 1). Wings surpassing hind knees ( Fig. 11I ). Tegmen: Radius releases RS between basal third and mid length of tegmen, both branches forked in apical area. Media anterior fused in basal area with radius, divides behind end of basal third; media posterior absent; cubitus anterior divides little before mid-length of tegmen into CuA1 and CuA2; cubitus posterior undivided, free throughout; with 4 anal veins. Legs: Fore coxa with a spine at fore margin; fore and mid femora unarmed; fore and mid tibiae with 4 pairs of large ventral spines and one pair of smaller ventral spurs; hind femur with 5–7 external and 6–7 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine; with 3 apical spurs on both sides. Coloration. General color uniformly light brownish, frons and rim of pronotum but not at fore margin black; with a small black spot at genicular area of all legs; ventral spines of hind femur and dorsal spines of hind tibia black. Face including anterior area of vertex and basal segments of antennae black; compound eyes light, ocelli light yellow; lateral and ventral areas of clypeus brownish yellow. Tegmen yellowish semi-transparent, towards base cells faintly infumate; veins and veinlets yellow; hind wing semi-transparent greyish; veins dark yellow, cross-veins yellow. Male. Eighth abdominal tergite prolonged, with lateral areas nearly rectangularly bent to dorsal surface, although the angle itself is gradually curved. Ninth abdominal tergite strongly curved down from sub-flattened dorsal to lateral surfaces, at tip rounded and in middle strongly bent ventro-proximad, more laterally apico-ventrad; apical surface in about dorsal half in middle strongly swollen, forming a projecting cone and at lower margin of swelling with a pair of transverse black sclerotizations, surface bent ventro-proximad and strongly furrowed; on proximate margin of ventro-apical surface with a compressed and except at base black projection at each side; projections with approaching margins to about two thirds of their lengths, then bent proximad and widening to truncate tip; somewhat more laterally there is a compressed, black (except in basal area) projection at each side bent proximad in subapical area [the projections have been artificially pressed backward to make them visible; the folds of the margin of the tergite at their base are a result of that handling] ( Figs. 15 J–L). Tenth abdominal tergite reduced to a short transverse area mediad of bases of cerci. Epiproct triangular with concave surface and rounded tip; paraproctes prominently projecting between remnants of tenth tergite. Subgenital plate wide in about basal half, then strongly narrowed and at tip bilobate; styli inserted at apico-lateral angles of wide area and largely surpassing tip of plate. Female unknown. Measurements ( 1 male ).—body w/wings: 44; body w/o wings: 30; pronotum: 8.5; tegmen: 34; tegmen width: 12; hind femur: 23 mm .

Description. Large species ( Fig. 10 A–B). Head: Face narrow ovoid (F) to ovoid (M); forehead nearly smooth; fastigium verticis about as wide as or little wider than scapus; ocelli distinct; fastigium frontis separated from fastigium verticis by a faint suture interrupted in middle; subocular furrows only indicated as a weak depression above bases of mandibles; fastigium frontis laterally outlined by faint furrows ( Fig. 12A ). Abdominal tergites two and three each with two rows of very small, hardly visible stridulatory pegs (M: 6, 4; 7, 10; F: 0, 4; 5). Wings surpassing hind knees and almost reaching middle of stretched hind tibiae. Tegmen: Radius with two branches, both forked near tip; media anterior fused in basal area with radius, in apical third of tegmen forks once (F) or unforked (M); media posterior absent; cubitus anterior forks into CuA1 and CuA2 (male) or stays singlebranched (female); cubitus posterior undivided, free throughout; with 4–5 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 ventral spurs; hind femur with 6–8 external and 8–11 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine each; with 3 apical spurs on both sides. Coloration. General color light brown; vertex unicolored; disc of pronotum with indistinct pattern, hind margin rim dark brown. Tegmen with little distinct darkened transverse veinlets in posterior area ( Fig. 10 A–B). Legs of general color. Face medium brown with some indistinct lighter spots. Tegmen yellowish transparent, veins brown; in male with a spot of dark brown veinlets; hind wing along anterior margin yellowish transparent, otherwise ochre transparent, main veins brown; cross veins blackish brown bordered by a brown band on both sides. Male. Eighth abdominal tergite strongly prolonged behind, along apical margin flattened and apical margin concave in middle. Ninth abdominal tergite much narrower than eighth and with central and basal areas hidden under that tergite; central area dorso-ventrally thickened and on underside with two small obtuse bumps; posterior area compressed, projecting from below eight tergite and divides in the same plane into two flattened ovoid lobes; anterior area curved down towards base and divides into two triangular lobes ( Figs. 13 A–C). Subgenital plate almost twice as wide as long; lateral margins slightly convex; apical margin convex but notched in middle and on both sides of notch slightly projecting; styli stout and straight, inserted at the lateral angles. Phallus membranous. Female. Seventh abdominal sternite wider than preceding sternites but rather short. Subgenital plate wide at base with stout, bulging and strongly converging lateral margins, posterior area ovoid but triangularly cut at tip; surface strongly grooved and in basal area between the bulging margins membranous; in middle of oval area with narrow elongate swelling finely fissured at tip ( Fig. 16K ). Base of ovipositor dorsal valves with a pit with stiffened margin at very base. Ovipositor elongate but curved especially in subbasal area, with faintly approaching margins; dorsal margin with a slight expansion before tip ( Fig. 17A ). Measurements ( 4 males , 5 females ).—body w/wings: male 41–61, female 44–50; body w/o wings: male 35– 44, female 34–36; pronotum: male 8.0–9.5, female 7–9; tegmen: male 35–42, female 32–36; tegmen width: male 12, female 12; hind femur: male 21–24, female 19–22; antenna: male 135–160, female 100–165; ovipositor: female 22–24 mm .

Description. Large species ( Fig. 11B ). Head: Face ovoid; forehead nearly smooth; fastigium verticis about little wider than scapus; ocelli indistinct; fastigium frontis separated from fastigium verticis by a faint suture interrupted in middle; subocular furrows only indicated as a weak depression above bases of mandibles; subantennal furrows weak ( Fig. 12G ). Abdominal tergites two and three with obviously present but extremely minute stridulatory pegs. Wings surpassing hind knees and reaching about middle of stretched hind tibiae. Tegmen: Radius with two branches, both forked near tip; media anterior fused in basal area with radius, MA forks behind middle of tegmen into MA and MP; cubitus anterior single branched, undivided; cubitus posterior undivided, free throughout; with 4 anal veins. Legs: Fore coxa with a large spine at fore margin; fore and mid femora unarmed; fore and mid tibiae with four pairs of large ventral spines and one pair of ventral spurs; hind femur with 9–10 external and 9 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine each; with 3 apical spurs on both sides. Coloration. General color light brown (probably discolored); vertex unicolored; disc of pronotum with indistinct pattern, hind margin with rim dark brown. Legs of general color. Face medium brown with some indistinct lighter spots; a small cone at base of scapus, ventral area of subocular furrow, around dorsal angles of clypeus, ventral areas of labrum and tip of mandibles black. Tegmen yellowish transparent, little darker towards base; veins brown to pale brown; hind wing along anterior margin yellowish transparent, otherwise ochre transparent, main veins brown; cross veins blackish brown bordered by a brown band on both sides. Male. Eighth abdominal tergite strongly prolonged behind, apical margin broadly truncate in middle. Ninth abdominal tergite ( type H in Brunner 1888 ) with flattened bell-mouthed dorsal surface and nearly rectangularly bent into lateral areas; dorsal surface at tip slightly furrowed; down-curved apical surface furrowed in basal half, with swollen carinae along lateral margin and along medial furrow; after that apical surface bent somewhat proximad and widening apically, with forked carinae, and in ventro-apical view with trilobate apical margin; in lateral view the down-curved apical part appears as a semicircle with the ventro-lateral angle projecting as a short stout tooth with subacute tip ( Figs. 15 C–F). Tenth abdominal tergite band-shaped with sinuate dorsal margin; interrupted in middle. Epiproct small, hidden. Subgenital plate somewhat less than twice as wide as long; lateral margins convexly approaching; apex wide with a large, bilobate and slightly grooved process in middle; styli long and little upcurved, inserted at lateral angles. Phallus membranous. Female unknown. Measurements ( 1 male ).—body w/wings: 50; body w/o wings: 37; pronotum: 7.5; tegmen: 36; tegmen width: 13; hind femur: 20 mm .