Thoradonta varispina Zha & Sheng

Zha, Ling-Sheng, Sheng, Maoyin, Wen, Ting-Chi & Hyde, Kevin D., 2016, A new species and a revised key of the genus Thoradonta (Orthoptera, Tetrigidae), ZooKeys 607, pp. 69-79 : 70-73

Taxon classification Animalia Orthoptera Tetrigidae

Thoradonta varispina Zha & Sheng sp. n. Figs 1, 2, 3

Diagnosis.

Thoradonta varispina sp. n. is distinguished from Thoradonta obtusilobata Zheng, 1996 by the following characters: 1) vertex 1.8-2.0 times as wide as one eye (width of the widest part of an eye in dorsal view); 2) midkeel of pronotum not reaching anterior margin of pronotum; 3) upper margin of hind femur before antegenicular denticle with a small protrusion only, but not forms into 2-3 lamellae; 4) lower margin of hind femur entire, without protrusion; 5) third pulvillus of first segment of hind tarsus distinctly longer than first and second.

Description.

Female. Body size small, covered with numerous small granules and many nodules.

Head. Head not protruding over level of pronotal surface; vertex 1.8-2.0 times as wide as one eye, anterior margin straight, protruding but not surpassing anterior margins of eyes, lateral margins folded upwards but not surpassing top of eyes; median carina conspicuous and protruding in anterior half which is visible before eyes in profile, while obscure or absent in posterior half; vertex together with frontal ridge arcuate and protruding, distinctly concave between lateral ocelli, then strongly arched and protruding between antennae, longitudinal furrow between antennae slightly wider than diameter of first segment of antenna, margins of longitudinal furrow finely serrate. Antenna filiform, 17-segmented, inserted slightly below lower margins of eyes, length of longest segment (segment IV, male in VIII) 4.5 times its width. Eyes globose, protruding but not above level of pronotum; lateral ocellus situated slightly below middle of anterior margin of eye.

Thorax. Pronotum very coarse, covered with numerous small granules and many nodules; middle of anterior margin little concave; lateral keels of prozona erected, distal part higher than basal part, slightly contracted backward, sometimes distal part excessively contracted inward. Midkeel not reaching anterior margin of pronotum, otherwise nearly entire, in profile upper margin of pronotum distinctly undulate with wave peaks becoming lower backward. These sinusoidal waves lamellate and erected, first highest, with intumesced base, both sides of intumescence with a pair of big nodules at margins of pronotum; second lamella longest and undulate, on both sides pronotal disc distinctly concave followed by a pair of long oblique nodules, and lateral margins of pronotum distinctly folded upwards; the latter midkeel with 4-5 lamel lae of intumesced base. Humeral angle obtusely angled; a pair of abbreviated carinae present between shoulders, slightly contracted forwards; pronotum slightly uplifted between shoulders; hind process of pronotum long cone-shaped, reaching (few specimens) or slightly surpassing (most specimens) apex hind femora, distal part slightly down-curved and apex sharp. Posterior angles of lateral lobes of pronotum laminate and expanded and extending outwards, apex varies distinctly in different individuals: upper lobe not produced, slightly produced or triangularly laterally produced; subtruncate behind which is margined with fine teeth (Fig. 3). Posterior margin of each lateral lobe has two concavities. Visible part of tegmina ovate, 2.7 times as long as wide, apex rounded. Hind wing not reaching top of hind process of pronotum, not reaching or reaching apex of hind femur. Margins of all femora with fine teeth; upper margin of fore femur slightly undulate, lower margin distinctly undulate; upper and lower margins of mid femur distinctly undulate; mid femur slightly wider than fore femur and visible part of tegmen, not narrowed or thicker from basal to distal area. Hind femur about 2.5 times as long as wide, rear of upper margin before antegenicular denticle slightly protruding; antegenicular denticle isolated and long triangular, its apex relatively sharp, genicular denticle fingered extending backward and apex obtuse. Hind tibia distally slightly wider than basally, outer side with 5-7 spines, inner side with 4-6 spines; first segment of hind tarsus 1.3-1.4 times longer than third, third pulvillus longer than first and second, apex of third pulvillus relatively obtuse, apices of first and second sharp.

Abdomen. Ovipositor: upper valvulae 3.3 times as long as wide, outer margins of upper and lower valvulae with saw-like teeth. Posterior margin of subgenital plate: narrowing backward; middle triangularly protruding, sometimes this protrusion folded inward, forming a basal concavity and a protrusion on both sides (Fig. 2d, e).

Coloration. Body dark brown. Antenna brown, distal segments darker than basal segments; hind wings black; for and mid femora and tibiae with 3 yellowish brown bands each, bands of all femora obscure; lower outside of hind femur black, center of inner side of hind femur dark brown; hind tibia with 2 long yellowish brown bands.

Male. Body size slightly smaller than female. Antenna 16-segmented. Fore femur nearly the same as that of female; mid femur distinctly wider than fore femur and visible part of tegmen, narrowing from basal to distal side, and basal part thicker than distal part. Subgenital plate short cone-shaped, apex bifurcate but not bidentate.

Measurements.

Length of body ♂6.2-7.8 mm, ♀7.5-9.0 mm; length of pronotum ♂6.1-7.0 mm, ♀7.5-8.7 mm; length of hind femur ♂3.5-4.2 mm, ♀4.7-5.4 mm.

Type material.

Holotype female, China, Guizhou, Jinsha County, Lengshuihe Natural Reserve, N27°54', E106°00', 650 m alt, 7 Aug. 2015, collected by Ling-Sheng ZHA. Paratypes: 27 males and 19 females, 500-800 m alt, 5-9 Aug. 2015, other data same as holotype.

Ecology and habits.

All specimens of the new species were collected in humid, sandy, and stony environments alongside streams (Fig. 4). Body surfaces of most individuals are covered tightly by numerous sand grains. They move frequently in sunshine, and they feed on mosses, algae, lichens and all sorts of humus.

Etymology.

This new species epithet means spine of upper lobe of posterior angle of lateral lobe of pronotum varies in different individuals.

Distribution.

China (Guizhou).