Hedotettix triangularis Zha & Hyde

Zha, Ling-Sheng, Wen, Ting-Chi, Kang, Ji-Chuan & Hyde, Kevin D., 2016, Records of Hedotettix and Teredorus in Thailand with the description of three new species (Orthoptera, Tetrigidae), ZooKeys 556, pp. 83-95 : 85-86

Taxon classification Animalia Orthoptera Tetrigidae

Hedotettix triangularis Zha & Hyde sp. n. Figs 1, 2

Diagnosis.

Hedotettix triangularis sp. n. is similar to Hedotettix gracilis (De Haan, 1843) ( Zheng 2005), the former differs from the latter by: 1) anterior margin of pronotum truncate (Fig. 2B); 2) apex of posterior angle of lateral lobe of pronotum acutely angled or very short truncate, not rounded; 3) hind process short, reaching one third of hind tibia (Fig. 1B, C); 4) upper valvula of female ovipositor distinctly short, only 2.5 times as long as wide (Fig. 2E).

Description.

Female. Body size medium.

Head. Head not protruding over level of pronotal surface, vertex 1.1 times as wide as one eye; anterior margin of vertex arcuate, protruding forward and slightly surpassing beyond anterior margins of eyes, lateral margin distinctly folded upwards; median carina protruding forward and surpassing beyond anterior margin of vertex, conspicuous in anterior half while obscure or disappearing in posterior half, both sides of median carina distinctly concave (Fig. 2B); vertex together with frontal ridge rounded, which is visible before eyes in profile, not concave between lateral ocelli (Fig. 2D); longitudinal furrow decidedly narrower than width of first segment of antenna (0.7-0.8 times), and nearly parallel below level of antennae (Fig. 2A); antenna filiform and short, 16-segmented, length of a segment in middle about 4 times its width, inserted slightly above level of lower margins of eyes (Fig. 2A); eyes globose, lateral ocellus situated slightly above middle of inner margin of eye (Fig. 2A).

Thorax. Anterior margin of pronotum truncate, midkeel of pronotum complete and distinct (Figs 1B, 2B); pronotal disc smooth, with numerous fine granules, pronotum slightly tectiform in anterior half and long cone-shaped in posterior half (Fig. 1A, B); in profile upper margin of pronotum arcuate in anterior half (the highest point located between transverse sulcus) while straight in posterior half (Fig. 1A); lateral keels of prozona conspicious and parallel; shoulders broad, then gradually constricted backward; abbreviated carinae elongate or shortened, and present, obscure or absent between shoulders; humeral angle obtusely angled; length of distal part of hind process which surpass beyond apex of hind femur 1.5-2.0 mm, reaching one third of hind tibia (Fig. 1B); posterior angle of lateral lobe of pronotum extending downwards, nearly triangulate, apex acutely angled or very short truncate backwards, posterior margin of each lateral lobe with two concavities; visible part of tegmina ovate, 2.5-2.6 times as long as wide (Fig. 1A); length of distal part of hind wing which surpass beyond apex of hind process of pronotum 1.3-1.8 mm, and reaching about two thirds of hind tibia (Fig. 1A, B); fore femur slender and cylindrical, upper and lower margins straight; upper margin of mid femur slightly undulate, lower margin undulate; middle femur flat, distinctly narrower than width of visible part of tegmen (Fig. 1A); upper and lower margins of mid and hind femora finely dentate, hind femur about 3.0 times as long as wide; antegenicular denticles nearly right angled, genicular denticles fingered extending backward and apex triangulate (Fig. 1A); outer side of hind tibia with 9-11 spines, inner side with 6-9 spines; first hind tarsal segment about 2 times third in length, third pulvillus longer than first and second, apices of first and second pulvilli sharp, apex of third pulvillus nearly right angled.

Abdomen. Ovipositor: upper valvula about 2.5 times as long as wide, outer margins of upper and lower valvulae with small saw-like teeth (Fig. 2E); posterior margin of subgenital plate truncate, in the middle acutely triangularly protruding, which is slightly folded inward (Fig. 2C).

Coloration. Body yellowish brown. Antenna yellowish brown and distal segments dark brown; hind wings dark brown; for and mid tibiae with 3 obscure dark brown bands (basal and middle bands small while distal band big) respectively; hind tibia light yellowish brown, distal part obscure dark brown.

Male.

Body size slightly smaller and slender than female (Fig. 1C). Antenna 15-segmented; middle femur: slightly narrowing from basal to distal side, basal part slightly thicker than distal part, upper margin slightly arcuate and lower margin nearly straight, slightly wider than visible part of tegmen; subgenital plate: cone-shaped, apex notched and not bidentate. Other characters same as female.

Measurements.

Length of body ♂7.0-8.0 mm, ♀9.0-10.5mm; length of pronotum ♂9.3-9.8 mm, ♀10.8-11.5 mm; length of hind femur ♂4.5-5.0 mm, ♀5.5-6.0 mm.

Type material.

Holotype female (Nos. 15-0625, MFLU), Thailand, Chiang Rai, N20°16'17", E99°48'13", 1076.4 m alt, 30 Sep. 2014, collected by Ling-Sheng ZHA. Paratypes: 2 males and 1 female (Nos. 15-0626, 15-0627, 15-0628, MFLU) and 1 male (HNU), same data as holotype; 2 males and 2 females (HNU), Thailand, Chiang Rai, N20°9'16", E99°37'21", 1504.2 m alt, 22 Oct. 2014, collected by Ling-Sheng ZHA.

Biology and ecology.

Hedotettix triangularis sp. n. inhabits open meadow in tropical regions. Color of margin of pronotum green when alive which is just like color of the meadow where they inhabit. From collecting time we infer they overwinter as adults.

Etymology.

This new species’ name derives from Latin triangular, which means posterior angles of lateral lobes of pronotum triangulate.

Distribution.

Thailand (Chiang Rai).