Bioacoustics of Gryllotalpa fraser

Description. Habitus typical of this genus; very large, with BL greater than 40 mm ( Fig. 1 A). Head, in particular the face and frons, covered with numerous fine setae. Ocellus convex and medium. Pronotum pilose, oval, about 1.4–1.5 times longer than wide (m = 1.4, n = 3); with distinct longitudinal medial furrow, bordered with irregular depressions, most distinct near medial region; anterior margin concave; posterior margin roundly smooth ( Fig. 1 B). Hind wing reduced, completely covered by tegmen ( Fig. 1 C). Forelegs and middle legs setose. Anterior trochanter with process long, 1.8 times longer than wide (n = 1); with convex ventral and substraight dorsal margins; apex acute ( Fig. 1 D). Dactyls of anterior tibiae moderately long, decreasing in size from dorsal to ventral dactyls; ventral dactyl substraight, others slightly curved; apices fairly acute ( Fig. 1 D). Anterior tibia with internal tympanum slit-shaped ( Fig. 1 D). Hind tibia each armed with 2 internal subapical spines ( Fig. 1 E). Male. Tegmen about 1.2–1.3 times longer than wide (m =1.3, n = 3), reaching the 5th abdominal tergite. Right tegmen over left tegmen (except for paratype 1). Venation on left and right tegmina not different. Venations of right tegmen in dorsal and ventral views as shown in Figs. 2 A & 2B respectively; harp (enclosed by CuA+CuPa, CuPb, c and CuPaβ; = discoidal cell) very transverse at base, tapering in the medial area (c and CuA+CuPa subparallel), with distal margin obtuse and broadly rounded, with diving vein closer to CuA+CuPa than c, veinlet between diving vein and CuA+CuPa extends to near distal end; cell 2 (enclosed by CuPaβ and CuPaα2) elongated with CuPaβ angulated and CuPaα2 sinuous; area between c’ and CuPb and CuPaβ with dividing veins between CuPb and CuPaβ, not between CuPb and c’; radius vein not diverged into RA and RP (denoted as RA+ RP ). Stridulatory file gently sinuate, anterior end slightly arched, posterior end substraight; with about17–23 distinct teeth plus about 11–14 indistinct teeth anterior end (m = 19 + 13, n = 3); teeth densely distributed at the anterior end, very sparsely distributed at the posterior end. Gryllotalpa fraser sp. n. Gryllotalpa hirsuta Burmeister Gryllotalpa nymphicus Tan Anterior trochanter with process narrower (1.8 times longer than wide) ? Anterior trochanter with process wider (1.6 times longer than wide) Hind tibia with two internal subapical spines Hind tibia with three internal subapical spines Hind tibia with two internal subapical spines Tegmen reaching the 5th abdominal tergite; TL = 17.1 mm (mean) Tegmen reaching distal end of the 5th abdominal tergite, sometimes basal end of 6th abdominal tergite; TL = 12.5 mm Tegmen reaching distal end of the 4th abdominal tergite; TL = 12.2 mm Harp with distal margin obtuse and broadly rounded; veinlet between diving vein and CuA+CuPa extends to near distal end Harp with distal margin less obtuse and narrowly rounded; veinlet between diving vein and CuA+CuPa extends to near distal end Harp with distal margin obtuse and broadly rounded; veinlet between diving vein and CuA+CuPa only distinct near basal end Cell 2 (area enclosed by CuPaβ and CuPaα2) less wide than harp at distal end Cell 2 (area enclosed by CuPaβ and CuPaα2) as wide as or slightly wider than harp at distal end Cell 2 (area enclosed by CuPaβ and CuPaα2) less wide than harp at distal end CuPaα2 sinuous CuPaα2 substraight, very gently curved CuPaα2 strongly bowed-shaped Area between c’ and CuPb and CuPaβ with dividing veins between CuPb and CuPaβ, not between CuPb and c’ Area between c’ and CuPb and CuPaβ with two faint dividing veins between CuPb and CuPaβ Area between c’ and CuPb and CuPaβ with two strong dividing veins, one between CuPb and c’; the other between CuPb and CuPaβ each Stridulatory file longer (m = 5.1, n = 3), gently sinuate, anterior end slightly arched, posterior end substraight; with about 19 teeth plus about 13 indistinct teeth anterior end ? Stridulatory file shorter (m = 3.5, n = 1), gently sinuate, anterior end slightly arched basally, posterior end slightly arched distally; with about 33 teeth plus about 4 indistinct teeth anterior end Transverse sclerite of epiphallus wide and broadly U-shaped centrally; with a pair of fairly narrow and long lateral branches, strongly and roundly curved ventrally, apically hooked internally with very acute apices; length between apices of lateral branches about 3.2 mm Transverse sclerite of epiphallus wide and broadly U-shaped centrally; with a pair of fairly narrow and long lateral branches, straight, apically broad before tapering into subacute apices; length between apices of lateral branches about 2.4 mm Transverse sclerite of epiphallus wide and substraight centrally; with a pair of wide but short lateral branches, angulated curved ventrally, gently curved anteriorly at apex, apically hyalinous, dilated and round at the apices in dorsal and ventral views; length between apices of lateral branches about 2.9 mm Median prolongation of epiphallus of median width; apically distinctly isos- triangular on dorsal surface, emarginated posteriorly Median prolongation of epiphallus narrow basally and widen apically; apically broadly triangular on dorsal surface Median prolongation of epiphallus broad, gently concaved on both sides in dorsal view; apically irregularly rounded on dorsal surface Paramere of ectophallus broad and irregularly shaped in ventral view; with subacute lobe on latero-posterior margin pointing ventrad, and with smaller conical lobe on latero-anterior margin pointing dorsad; internal process of ectophallus paramere barely visible, apex broadly rounded Paramere of ectophallus bean-shaped; with broadly rounded bulbous lobes on latero-anterior and posterior margins; internal process of ectophallus paramere barely visible, apex subacute Paramere of ectophallus somewhat rounded-parallelogram-like in ventral view; with internal process of ectophallus paramere pointing anteriodorsally, apex subacute Calling song: pitch is lower (frequency = about 1.5 kHz) and pulse rate lower at 140 s -1 ? Calling song: pitch is higher (frequency = about 2.0 kHz) and pulse rate higher at 220 s -1 Genitalia as shown in Figs. 3 A – 3C. Transverse sclerite of epiphallus wide and broadly U-shaped centrally; with a pair of median branches pointing dorsally, with rounded apices; with a pair of fairly narrow and long lateral branches, strongly and roundly curved ventrally, apically hooked internally with very acute apices; length between apices of lateral branches about 3.2 mm (n =1). Median prolongation of epiphallus of median width; apically flattened and distinctly isos-triangular on dorsal surface, emarginated posteriorly. Paramere of ectophallus broad and irregularly shaped in ventral view; with subacute lobe on latero-posterior margin pointing ventrad, and with smaller conical lobe on latero-anterior margin pointing dorsad; internal process of ectophallus paramere barely visible, apex broadly rounded. Female. Unknown. Colouration. Overall brown. Ocellus pale yellow. Abdominal sternites and thorax yellow brown. Dactyls in the anterior tibia black apically. Femur generally lighter brown than tibia. Measurements. See Table 2 .