Varitrella (Cantotrella) tabin, Tan & Japir & Chung & Robillard, 2022

Tan, Ming Kai, Japir, Razy, Chung, Arthur Y. C. & Robillard, Tony, 2022, New taxa and notes on bark and bush crickets (Orthoptera, Grylloidea, Gryllidae Landrevinae and Podoscirtinae) from Sabah, Zootaxa 5178 (3), pp. 201-228 : 223-227

Varitrella (Cantotrella) tabin sp. nov.

( Figs 17–19 )

Material examined. Holotype: EAST MALAYSIA • ♂; Sabah State, Tabin Wildlife Reserve ; N5.19447, E118.50259, 80.1± 7.8 m.a.s.l.; 15 May 2022, 22h57; on a foliage of a tree along the forest edge; coll. M.K. Tan, T. Robillard & R. Japir; SBH.22.101 ( FRC)

Diagnosis. The new species is most similar to Varitrella (Cantotrella) sukau Gorochov, 2014 from Sukau in Kinabatangan by the shape of male genitalia, but differs by the shape of ectoparamere. It also differs from V. sukau by the shape and pattern of anal plate. From species found nearby, this new species also differs from Varitrella (Cantotrella) tawau Gorochov, 2014 from Tawau (south of Tabin Wildlife Reserve) by the oval patch on anal plate nearly touching other and fusing (instead of widely spaced apart), the dorso-anterior pseudepiphallic spine (ds) larger and the pseudepiphallic paramere [ectoparamere] not short and membranous; and from Varitrella (Cantotrella) suikei from Sepilok (north of Tabin Wildlife Reserve) by the dorso-anterior pseudepiphallic spine (ds) and the latero-apical lobular parts larger and more robust as well as the calling song (see above). The pronotum and FW colouration are somewhat similar to Varitrella (Cantotrella) orion Tan & Gorochov, 2014 .

Etymology. The species is named after its type locality, Tabin Wildlife Reserve; noun in apposition.

Description. Habitus very typical of the genus, medium sized, generally grey-brown. Head with dorsum slightly flattened, very finely pubescent ( Fig. 17A ). Rostrum dark-coloured, about 0.8 times as wide as scapes, with apex broadly rounded (in dorsal view) ( Fig. 17B ). Eyes projected anteriorly in dorsal view ( Fig. 17B ). Median ocellus round and small; lateral ocelli oval, located near eyes. Maxillary palpi with apical segment longest, distinctly flattened and oblong with subobtuse apex; with subapical segment cylindrical and slightly expanding apically; third segment very short and stout ( Fig. 17A ). Gena greyish with tint of black patches ( Fig. 17A ). Face in anterior view 1.1 times as tall as wide; with a black patch between antennal grooves ( Fig. 17C ). Pronotal disc brown with numerous dark spots (especially distinct along anterior margin); about 1.3 times as wide as long, faintly widening posteriorly (posterior margin 1.2 times as wide as anterior margin); finely and densely pubescent; anterior margin of disc broadly concave; posterior margin of disc nearly straight ( Fig. 17B ). Pronotal lateral lobe 1.4 times as long as high; with a longitudinal dark band in dorsal half, numerous black spots of different sizes in ventral half; with ventral margin faintly convex ( Fig. 17A ). Metanotal gland absent ( Fig. 17D ). TI slightly swollen; with inner tympanum slit-like; with outer tympanum open and having oval tympanal membrane. TIII with 6 inner and 5 outer long spines; with 2–4 denticles between spines; 4 denticles before most proximal spines; and with inner spurs (apical spines) longer than corresponding outer ones. Legs generally pale brown with irregular and sparse dark spots. Thoracic and abdominal segments yellow brown to brown.

Male. FW ( Fig. 17E ) covering abdomen and barely surpassing apex of FIII. Colouration: yellow brown, with darker infumation. Dorsal field of FW yellow brown with basal area, proximal part of region of chords, and apical area almost dark brown, and with large white spot between disto-lateral edge of mirror and stock of MP+CuA1. Lateral field of FW paler, light brown with blackish marks near Sc between branches of Sc. Venation: diagonal straight, with 5 oblique veins in harp area; mirror 1.7 times as long as wide, dividing vein typical of subgenus; lateral field around 16 branches on Sc ( Fig. 17E ). Hind wings clearly surpassing FWs.

Anal plate with anterior half broad and black; at base with two whitish oval parts fusing in the anterior half and appearing as cranium-shaped; posterior half truncated, faintly emarginated in the middle ( Fig. 17F ). Subgenital plate typical of subgenus.

Male genitalia as shown in ( Fig. 18 ): Pseudepiphallus [epiphallus] stout, in profile view tall. Pseudepiphallus [epiphallus] with dorso-anterior pseudepiphallic spine (ds) strongly sclerotized with acute apex; elongated and slender in dorsal view; elongated pointing dorsad in profile view, with anterior margin straight and posterior margin slightly curved. Posterior end of pseudepiphallus [epiphallus] produced into two latero-apical lobular parts (al), in dorsal view broad, with apex obtuse; deeply V-emarginated between latero-apical lobules in dorsal view; in profile with posterior part rounded with a dorso-apical spinule and a row of widely-spaced small spinules on dorsal margin, dorsal margin convex in profile view. Pseudepiphallic paramere [ectoparamere] elongated, tapered abruptly into a slender and curved hooked-like apical third with apex acute, and pointing ventrad posteriorly. Ectophallic fold [rachis] rather long, slightly surpassing pseudepiphallus [epiphallus], produced into two broadly-obtuse lateral lobes (lo) at posterior end, with apical emargination wider between lateral lobes in dorsal view. Endophallic sclerite [formula] elongated, typical of genus. Spermatophore oval.

Female. Unknown.

Measurements (♂, in mm). PronL = 3.0; PronW = 3.3; FWL = 18.1; FIIIL = 13.2; TIIIL = 12.9.

Ecology. Unknown.

Distribution. Known only from type locality, Tabin Wildlife Reserve (Borneo, Sabah State).

Calling song (1 male, in captivity, 32.0°C) ( Fig. 19 ). The calling song consists of a well-defined echemesequence made up of 6 or 7 echemes. The echeme-sequence has an average duration of 1.23±0.10 s (1.10–1.39 s). The interval between consecutive echeme-sequence is 7.4±1.2 s (6.1–10.5 s). Each echeme consists of two closelyspaced syllables and has an average duration of 114.7±11.1 ms (100.1–127.9 ms). The interval between consecutive echemes is 92.3±11.6 ms (72.6–107.5 ms). Each syllable has an average duration of 45.4±5.0 ms (36.3–53.1 ms) and the interval between consecutive syllables is 17.5±4.5 ms (9.5–22.2 ms). The dominant frequency is 6.28±0.03 kHz (6.20–6.32 kHz).

Figures

FIGURE 17. Varitrella (Cantotrella) tabin sp. nov. ♂ holotype: head and pronotum in dorsal (A) and lateral (B) views; face in anterior view (C); metanotal gland in dorsal view (D); FW in dorsal view (E); abdominal apex in dorsal view (F). Scale bars: 5 mm (E); 2 mm (rest).

FIGURE 18. Varitrella (Cantotrella) tabin sp. nov. ♂: genitalia in dorsal (A), lateral (B) and posterior (C) views; spermatophore in lateral view (D). al = two latero-apical lobular part at the posterior end of pseudepiphallus; ds = dorso-anterior pseudepiphallic spine; lo = lateral lobe at the posterior end of ectophallic fold. Scale bar: 1 mm.

FIGURE 19. Varitrella (Cantotrella) tabin sp. nov. ♂ calling song: oscillograms showing three echeme-sequence (A) and one echeme-sequence showing six echemes of doublet syllables (B); spectrogram of the same echeme-sequence (C); power spectra of a syllable (D) where the grey line represents the power [dB] (axis name and scale in grey) and the black solid peak represents the relative amplitude (axis name in black).