Records of Hedotettix and Teredorus in Thailand with the description of three new species (Orthoptera, Tetrigidae)

Abstract We are studying the fungi associated with insects in northern Thailand and as a result several rarely collected insect species have been uncovered. The genera Hedotettix with one new species and Teredorus with two new species are reported from Thailand. Hedotettix triangularis Zha & Hyde, sp. n., Teredorus chiangraiensis Zha & Hyde, sp. n. and Teredorus combfemorus Zha & Hyde, sp. n. are introduced, described and photographed and compared with other species. Keys to species of Hedotettix and Teredorus from Thailand are provided.


Introduction
The genera Hedotettix and Teredorus belong to Tetriginae, Tetrigidae of Orthoptera. Hedotettix includes 46 species (Ou et al. 2014, Zheng 2014a, 2014b, Eades et al. 2015, and has a worldwide distribution; only one species, Hedotettix gracilis (De Haan, 1843) is known from Thailand (Ingrisch 2001, Zheng 2005, 2014a. Teredorus includes 29 species; although they mainly occur in South America, China, India and Nepal (Deng et al. 2014), there are no records of this genus in Thailand.
The aim of this paper is to report two species of Hedotettix and two of Teredorus from Thailand. Hedotettix triangularis Zha & Hyde, sp. n., Teredorus chiangraiensis Zha & Hyde, sp. n. and Teredorus combfemorus Zha & Hyde, sp. n. are described and illustrated as new to science and compared with other similar species. Keys to species of both Hedotettix and Teredorus in Thailand are provided.

Material and methods
Specimens were examined and photographed using a stereo microscope (Olympus Corporation, SZX16, Tokyo, Japan). Morphological terminology and measurements follow those of Vickery and Kevan (1983) and Zheng (2005). Measurements are given in millimeters (mm Anterior margin of pronotum slightly obtusely protruding; apex of posterior angle of lateral lobe of pronotum rounded; hind process reaching middle of hind tibia; upper valvula of female ovipositor narrow and elongate, 3.5 times as long as wide .  (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.
Head. Head distinctly protruding over level of pronotal surface (Fig. 4D); in dorsal view, vertex strongly contracted forward, two eyes nearly connected with each other on anterior margin of vertex, vertex not protruding beyond anterior margins of eyes; lateral margins folded upward and up to same height as anterior part of median carina; median carina conspicuous and protruding in anterior half, while obscure in posterior half (Fig. 4A); vertex a little visible before eyes in lateral view, vertex together with frontal ridge right angled, frontal ridge straight and not concave between lateral ocelli, slightly arc-protruding between antennae (Fig. 4D), longitudinal furrow narrower than first segment of antenna in width; antenna filiform, 16-segmented, inserted below lower margin of eyes (Fig. 4B), mid segment 5-6 times as long as wide; eyes globose, erected above level of pronotal surface, lateral ocellus situated on one fifth of lower inner margin of eye (Fig. 4B, D). Thorax. Disc of pronotum smooth, with numerous small granules, midkeel of pronotum complete; in profile upper margin of pronotum straight, only a little protruding before shoulders (Fig. 3A, B); anterior margin of pronotum truncate, lateral keels of prozona conspicuous and parallel (Fig. 4A), humeral angle obtusely angled, abbreviated carinae absent between shoulders; hind process of pronotum narrow, long cone-shaped, surpassing beyond apex of hind femur and not reaching or slightly surpassing beyond middle of hind tibia (length of distal part which surpass beyond apex of hind femur variable between 1.5 and 2.5 mm, pronotum 4.0-5.7 times as long as the distal part)   3B); posterior angle of lateral lobe of pronotum extending downwards, apex nearly truncate, posterior margin of each lateral lobe with two concavities; visible part of tegmina ovate, apex narrowly rounded, 2.8 times as long as wide; hind wings developed, reaching or slightly surpassing beyond apex of hind process of pronotum (Fig. 3A,  B); upper and lower margins of all femora finely dentate; upper margin of fore femur slightly arcuate, distal part of lower margin slightly concave; upper margin of mid femur nearly straight, lower margin slightly undulate; mid femur slightly wider than visible part of tegmen; hind femur about 3.1 times as long as wide, antegenicular triangulate, genicular denticles fingered extending backward and apex triangulate; outer side of hind tibia with 6-7 spines, inner side with 4-5 spines; first segment of posterior tarsus equal to third in length, three pulvilli nearly equal in length, apices of all pulvilli obtuse. Abdomen. Ovipositor: upper valvula about 3.0 times as long as wide, outer margins of upper and lower valvulae with small saw-like teeth (Fig. 4E); posterior margin of subgenital plate truncate and in the middle triangularly protruding which is folded inward (Fig. 4C).
Coloration. Body dark brown. Antenna brown, colour of distal segments deep; hind wings black; all femora with the same color as body; lower outer side of hind femur black, inner side of hind femur yellowish brown; all tibiae yellowish brown, with 3 black bands respectively (basal band small while middle and distal bands big).
Male. Slightly smaller than female (Fig. 3C). Antenna 15-segmented Hind femur slightly stubby, about 2.8 times as long as wide; subgenital plate briefly cone-shaped, apex notched and not bidentate. Other characters same as female.
Biology and ecology. Teredorus chiangraiensis Zha & Hyde, sp. n. inhabits stony place on border of a stream in tropical region. From collecting time we infer they overwinter as adults.
Etymology. This new species is named after Chiang Rai, its type locality. Distribution. Thailand (Chiang Rai). Diagnosis. Teredorus combfemorus sp. n. is similar to T. choui Zheng, Ou & Lin, 2012, the former differs from the latter mainly by: 1) lateral ocellus situated on a quarter of lower inner margin of eye (Fig. 6A); 2) apex of posterior angle of lateral lobe of pronotum nearly truncate (Fig. 5A, C), not rounded; 3) lower margins of fore and mid femora comb-shaped (Fig. 6F, G); 4) upper valvulae of female 3.0 times as long as wide (Fig. 6E) (also see in Table 1). Description. Female. Body size small and slender, length of body (from vertex to apex of hind process) 3.5 times its width (between posterior angles of lateral lobes of pronotum) (Fig. 5B).

Teredorus combfemorus
Head. Head distinctly protruding over level of pronotum; in dorsal view, vertex strongly contracted forward and two eyes nearly connected with each other on anterior margin of vertex, vertex not protruding beyond anterior margins of eyes; lateral margins folded upward and up to the same height as anterior median carina; median carina conspicuous and protruding in anterior half, while obscure in posterior half (Fig.  6D); vertex a little visible before eyes in lateral view, vertex together frontal ridge forming right angled, frontal ridge straight and not concave between lateral ocelli, slightly arc-protruding between antennae (Fig. 6C), longitudinal furrow nearly as wide as first segment of antenna; antenna filiform, 15-segmented, inserted below lower margins of eyes (Fig. 6A), mid segment 5-6 times as long as wide; eyes globose, erected above level of pronotal surface, lateral ocellus situated on a quarter of lower inner margin of eye (Fig. 6A, C).
Thorax. Disc of pronotum smooth, with numerous small granules, midkeel of pronotum complete; upper margin of pronotum with a very small protrusion before shoulders, in profile upper margin of pronotum slightly undulate (nearly straight) before shoulders and straight behind shoulders ( Fig. 5A-C); anterior margin of pronotum truncate, lateral keels of prozona conspicuous and parallel, about 0.5 times as long as the width between them (Fig. 6D); humeral angle obtusely angled, abbreviated carinae absent between shoulders; hind process of pronotum narrow, long cone-shaped, reaching three quarters of hind tibia (length of distal part which surpass beyond apex of hind femur 3.3 mm, pronotum about 3.5 times as long as the distal part) (Fig. 5B); posterior angle of lateral lobe of pronotum extending downwards, apex nearly truncate, posterior margin of each lateral lobe with two concavities; visible part of tegmina ovate, apex narrowly rounded, 2.8 times as long as wide (Fig.  5A, C); hind wings developed, reaching or slightly surpassing beyond apex of hind process of pronotum; fore and mid femora flat, upper margins of all femora and lower margins of hind femora finely dentate, sawteeth of lower margins of fore and mid femora elongate, forming comb-shaped; upper margin of fore femur slightly arcuate, distal part of lower margin incomplete; upper margin of mid femur nearly straight, lower margin slightly undulate (Fig. 6F, G); width of mid femur distinctly wider than visible part of tegmen; hind femur about 2.9 times as long as wide, antegenicular triangulate, genicular denticles fingered extending backward and apex quadrangular (Fig. 5A); outer side of hind tibia with 7-8 spines, inner side with 4-5 spines; first segment of posterior tarsus equal to third in length, three pulvilli nearly equal in length, apices of all pulvilli obtuse.
Abdomen. Ovipositor: upper valvulae about 3.0 times as long as wide, outer margins of upper and lower valvulae with small saw-like teeth (Fig. 6E); posterior margin of subgenital plate truncate and in the middle triangularly protruding which is folded inward (Fig. 6B).
Coloration. Body gray. Antenna brown, color of distal segments darker; hind wings black; all femora with the same color as body; lower outer side and inner side of hind femur partially dark brown; all tibiae yellowish brown, with three black bands (the distal band longest) respectively.
Male. Unknown. Measurements. Length of body (from vertex to apex of abdomen) ♀8.5-9.0 mm; length of pronotum ♀11.5-12.0 mm; length of hind femur ♀5.5-6.0 mm. Etymology. This new species' name is derived from the Latin comb and femora, which means lower margins of fore and mid femora comb-shaped.

Species of
Hedotettix generally inhabit open meadow in semi-humid subtropical or tropical regions. Partial body surfaces are often covered by bright green when alive which is just like color of the meadow where they inhabit, but the green will be faded gradually after their deaths or with the change of seasons. Together with their smooth body surface, we infer that most of life cycles they live on the ground instead of in soil, and maybe most of them cannot overwinter as adults.
Teredorus chiangraiensis sp. n. and T. combfemorus sp. n. are easily differed from other species of the genus by posterior angle of lateral lobe of pronotum nearly truncate (while rounded occur in all other species (Deng et al. 2014)). Based on molecular phylogeny using cytochrome c oxidase subunit I (CO I) gene (Fang et al. 2010) and morphological characteristics, Deng et al. (2014) thought Teredorus and Systolederus (Metrodorinae) can combine to the same genus, after all, they are mainly different by shape of posterior angle of lateral lobe of pronotum. Truncate posterior angle of two new species from Thailand provides a new important support for this inference, also we infer Tetriginae are not monophyly in their phylogeny and evolution.