Gryllotalpa fraser Tan & Nizam

Tan, Ming Kai & Kamaruddin, Khairul Nizam, 2013, A new species of mole cricket (Orthoptera: Gryllotalpidae: Gryllotalpinae) from Bukit Fraser, Malay Peninsula, with taxa notes on another similar mole cricket, Zootaxa 3691 (3), pp. 324-332 : 325-330

Gryllotalpa fraser Tan & Nizam , new species

( Figs. 1–4 )

Material examined. Holotype (male): Malay Peninsula, Pahang, Bukit Fraser , along Mager Road, near Singapore House, N03.70806, E101.73912, 1263 ± 6 m, calling from underground burrow on slope with short grasses, coll. M. K. Tan & S. T. Toh, 27 December 2012, 1951 hours (ZRC).

Paratypes: 2 males, same locality as holotype, along Mager Road, near Singapore House, calling from underground burrow on slope with short grasses, coll. M. K. Tan & S. T. Toh, 19 May 2013: N03.70804, E101.73917, 1273 ± 4.3 m, 1943 hours; N03.70820, E101.73927, 1268 ± 6.5 m, 1947 hours (all ZRC).

Acoustic recordings. Malay Peninsula: 2 males, same locality as for holotype, along Mager Road, coll. M. K. Tan & S. T. Toh, 27 December 2012: N03.70833, E101.73994, 1278 ± 6 m, calling from underground burrow among fern, 1938 hours; N03.70824, E101.73986, 1271 ± 5 m, calling from underground burrow among short grasses, 1942 hours.

Diagnosis. See Table 1 . This species was compared with photographs and type specimens of Gryllotalpa hirsuta Burmeister, 1838 and Gryllotalpa nymphicus Tan, 2012 .

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.

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 .

Etymology. This species is named after the type locality, Bukit Fraser ; noun in apposition.

Calling song. Along Mager Road, callings of numerous specimens were first heard at around 1930 hours and last heard at around 2000 hours (both in December and May). Calling song is a loud resonant hum emitting from within a shallow burrow. Pitch is low (frequency = about 1.5 kHz) and pulse rate consistent of 140 s -1 ( Fig. 4 ).

Remarks. In Bukit Fraser , this species appears to be found in greater abundance among short grasses along Mager Road near the Singapore House. Variations in the distribution and abundance between the wet (December) and dry (May) seasons are however not distinct.

Figures

FIGURE 1. Gryllotalpa fraser sp. n. male holotype: habitus in lateral view (A); head and pronotum in dorsal view (B); abdomen (with right tegmen removed) in dorsal view (C); foreleg in interior view (D); hind leg in exterior view (E). Scale bars: 10 mm (A); 5 mm (B – E).

FIGURE 2. Gryllotalpa fraser sp. n. male holotype: right tegmen in dorsal (A) and ventral (B) views. Scale bar: 5 mm.

FIGURE 3. Gryllotalpa fraser sp. n. male paratype: male genitalia in anteriorly-dorsal (A) and anterior (B) views; epiphallus in dorsal view (C). Scale bar: 1 mm.

FIGURE 4. Gryllotalpa fraser sp. n. male acoustic recording: oscillograms (A, B), spectrogram (C) and amplitude spectrum (D) of the calling song.

Tables

TABLE 1. Comparison of three similar Gryllotalpa species: Gryllotalpa fraser sp. n., Gryllotalpa hirsuta Burmeister, 1838 and Gryllotalpa nymphicus Tan, 2012.

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

TABLE 2. Measurement of males of Gryllotalpa fraser sp. n. (in mm, mean values in brackets).

	BL	PL	PW	RTL	RTW	HFL	HTL	SFL	NST
Holotype	44.0	15.2	11.1	16.5	12.6	12.4	11.2	5.3	23 + 14
Paratype 1	41.5	15.3	11.0	17.9	13.4	13.6	11.1	4.8	17 + 13
Paratype 2	46.4	16.3	11.1	16.8	13.6	13.4	11.4	5.3	18 + 11
Male (n = 3)	41.5–46.4 (44.0)	15.2–16.3 (15.6)	11.0–11.1 (11.1)	16.5–17.9 (17.1)	12.6–13.6 (13.2)	12.4–13.6 (13.1)	11.1–11.4 (11.2)	4.8–5.3 (5.1)	17–23 + 11–14 (19 + 13)