Hexacentrus bifurcata, Farooqi & Usmani, 2018

Farooqi, Mohd Kaleemullah & Usmani, Mohd Kamil, 2018, A new species and a new record of genus Hexacentrus Serville, 1831 (Orthoptera: Tettigoniidae: Hexacentrinae) from India, Zootaxa 4526 (4), pp. 547-560 : 553-557

Hexacentrus bifurcata sp. nov.

( Fig. 6, 7 , 8 )

Description. Holotype male: Body medium sized and slender. Antennae without dark bands apically. Vertex sulcate. Fastigium of vertex compressed laterally, not sulcate, apex narrow, tapering forward as obtusely rounded in lateral view; 1.66 times as wide as scapus. Fastigium of vertex separated from the fastigium of frons by a furrow. Eyes are globular. Pronotum saddle-shaped, slightly expanded posteriorly; anterior dorsal margin concave, posterior margin rounded, slightly depressed behind first transverse sulcus; with three transverse sulci, second and third ones restricted to disc, a Y shaped sulcus is present between second and third transverse sulcus. A special pale brown with dark brown margin colored band covers the pro, meso and metanota. Lateral lobes inclined; longer than deep; humeral sinus absent. Prosternum armed with a pair of long, cylindrical spines; mesosternum and metasternum armed with thick, slightly curved backward sternites. Thoracic auditory spiracle large, oval, slightly hidden under the lateral lobe of pronotum with tubercle at mid- anterior edge. Tegmina longer than hind wings. Wings reaching beyond the middle of hind tibiae. Male tegmen broad at the middle. Stridulatory file with 32 teeth, teeth are wide in the middle, teeth are wide and thick in the middle; file gradually narrowing at distal end, abruptly narrowing with few teeth towards proximal end. Legs: genicular lobes of fore femora armed with a single spine on inner side and unarmed on outer side, mid genicular lobes armed with a single spine on inner side and bispinose on outer side, posterior genicular lobes bispinose on both sides. Fore coxa with a forward outward projecting spine. All femora dorsally unarmed. Fore femora ventrally armed with 5 to 6 minute spines arranged on inner margin; minute spines on outer margin. Mid femora ventrally armed with minute spines on inner margin; 2–3 minute spines with minute spines on outer margin. Hind femora ventrally armed with 7–8 spines with minute spines each on inner and outer margin. Tympanum on fore tibiae bilaterally closed, tympanal slits facing dorsally with a small pits on each side at the base of tympanal slits. Fore tibiae dorsally unarmed. Fore tibiae ventrally armed with 6 long, movable, outwardly bowed opposing spines decreasing in length from basally to apically each on inner and outer margin. The first four spines of fore tibiae on inner margin are longer than spines on outer margin. Mid tibiae dorsally unarmed. Mid tibiae ventrally armed with 6 long, movable, outwardly bowed opposing spines decreasing in length from basally to apically each on inner and outer margin. Hind tibiae dorsally armed with 28–30 spines on inner margin; 32–34 spines on outer margin. Hind tibiae ventrally armed with 10–12 spines on inner margin, 12–14 spines on outer margin. Single pair of spurs and two ventral pairs (inner small and outer large) of spurs present on the apical region of hind tibiae. Ninth abdominal tergite feebly excised medially. Tenth abdominal tergite with shallow triangular excision. Supra-anal plate triangular with dorsal groove; slightly broader than long; apex slightly rounded. Subgenital plate elongate with broad longitudinal median furrow, lateral ridges well developed, apical margin with median triangular excision; styles thick basally, apically thin; diverging basally and converging apically. Cerci robust basally with a tubercle on internal side, then abruptly narrowing to a short digitiform apical appendage with incurved apex.

Female: Tenth abdominal tergite with rounded median excision. Supra-anal plate short, apex semicircular. Subgenital plate triangular; broader than long; bifurcated apically (elongated triangular excision); apical margin triangular, apices rounded. Cerci conical, slightly upcurved; apex narrow slightly incurved. Ovipositor slightly upcurved; broad at base, apex narrow.

Morphometry (length in mm)

Material Examined: India—Uttar Pradesh: Bijnor, Kiratpur (29°29'56.98"N, 78°12'26.80"E), (Holotype: ♂), 3♂♂, 2♀, 28.IX.2016, on bushes, (coll. M. K. Farooqi). Distribution : Uttar Pradesh.

Comments: The new species similar to Hexacentrus major Redtenbacher, 1891 , Hexacentrus unicolor Serville,1831 and Hexacentrus japonicus Karny, 1907 but differs in the following characters: Fastigium of vertex triangularly rounded in lateral view, median sulcus absent; wings reaching beyond the middle of hind tibiae; stridulatory file with 32 teeth; male subgenital plate with apical median triangular excision; mid tibiae dorsally unarmed; styles thick basally, apically thin, diverging basally and converging apically; female subgenital plate triangular, bifurcated apically.

Etymology: The specific epithet indicates the character of subgenital plate which is bifurcated apically.

Figures

FIGURE 7. Hexacentrus bifurcata sp. nov. (A–R): A—Lateral view of head and pronotum ♂, B—Lateral view of fastigium of vertex ♂, C—Dorsal view of pronotum ♂, D—Lateral view of sternum ♂, E—Dorsal view of left basal tegmen ♂, F— Dorsal view of right basal tegmen ♂, G—Stridulatory file ♂, H—Dorsal view of supra-anal plate ♂, I—Ventral view of subgenital plate ♂, J—Dorsal view of cercus ♂, K—Dorsal view of supra-anal plate ♀, L—Ventral view of subgenital plate ♀, M—Dorsal view of cercus ♀, N—Lateral view of ovipositor ♀, O—Dorsal view of fore tibia ♂, P—Dorsal view of left mid tibia ♂, Q—Dorsal view of right mid tibia ♂, R—Dorsal view of hind tibia ♂.

FIGURE 8. Stridulatory file of Hexacentrus bifurcata sp. nov. A—Entire file, B—Enlarged fragment.