Formosatettix strictivertex Deng, 2023

Deng, Wei-An, Luo, Jie-Ling, Huang, Chao-Mei & Lin, Li-Liang, 2023, Review of the genus Formosatettix Tinkham (Orthoptera: Tetrigidae) with description of new taxa, new synonymy and an updated key to species, Zootaxa 5228 (3), pp. 201-243 : 226-229

13. Formosatettix strictivertex Deng , sp. nov. ( Figs. 16 , 17 , 24Q , 25D )

Description. Female. Small size, short, body surface interspersed with sporadic short carinae.

Head. Head and eyes not exserted above pronotal surface ( Fig. 16B ). Fastigium of vertex short; in dorsal view, width of vertex between eyes 0.8–1.0 times width of compound eye ( Fig. 16C ); anterior margin of fastigium straight, slightly surpassing anterior margin of eye; median carina visible anteriorly; lateral margins turned backward; vertex uneven with paired fossulae. In lateral view, frontal ridge and vertex forming a right angle; frontal costa straight and not concave between eyes ( Fig. 16D ), protruded anteriorly and broadly rounded between antennal grooves. In frontal view, frontal costa bifurcated above lateral ocelli, longitudinal furrow divergent between antennae, width of longitudinal furrow of frontal ridge narrower than antennal groove diameter ( Fig. 16E ). Antennae short, filiform, antennal grooves inserted below inferior margins of compound eyes, 13-segmented, the 9th and 10th segment are the longest, about 3 times longer than its width. Eyes globose, lateral (paired) ocelli located in lowest third of compound eye height.

Thorax. Pronotum distinctly tectiform, its surface coarse and interspersed with sporadic short carinae between shoulders ( Fig. 16A ). In dorsal view, anterior margin of pronotum truncate; lateral carinae of prozona parallel; humeral angle absent; hind pronotal process broad and short, reaching 1/2 of hind femur and its apex broadly arcuate (apex of hind pronotal process suddenly become narrowly and sharp in individual individual). In profile, median carina of pronotum slightly lamellate and slightly arch-like; lower margin of hind process curved, external lateral carinae of metazona slightly curved, width of infrascapular area is 0.7 mm. Posterior angles of lateral lobes turned downwards, apex of posterior angles obtuse rounded, posterior margins of lateral lobes of pronotum only with ventral sinus and tegminal (upper) sinus absent. Tegmina and hind wings invisible (vestigial hidden under pronotum).

Legs. Fore and middle femora slightly compressed, margins finely serrated, with carinated, ventral margins straight ( Fig. 17A, B ). Hind femora robust and short, 2.6 times as long as wide; with carinated, margins finely serrated ( Fig. 17C ); antegenicular denticles right angle and genicular denticles acute. Outer side and inner side of hind tibia with 5–6 spines ( Fig. 17D ). First segment of posterior tarsi longer than third, three pulvilli of first segment of posterior tarsi are increased in turn, apices of all pulvilli right angle ( Fig. 17E ).

Abdomen. Ovipositor narrow and long, length of upper valvulae 3.0 times its width, upper and lower valvulae with slender saw-like teeth. Length of subgenital plate nearly equal to its width, middle of posterior margin of subgenital plate triangular projecting ( Fig. 17F ).

Coloration. Body dark brown or brown. Fore and middle tibiae with two black bands.C Hind femur brown or dark brown, outer part lower side black (outer part of hind femur with two or three black spots in some of individuals). Hind tibia black, with two light rings in the middle.

Male. Similar to female, but smaller and narrower ( Fig. 17G, H ). Width of vertex between eyes 0.7–0.8 times width of compound eye ( Fig. 17G ); width of infrascapular area is 0.4–0.5 mm. Subgenital plate short, cone-shaped, apex bifurcated.

Measurements (mm). Length of body: ♁ 6.0–6.5, ♀ 9.5–10.5; length of pronotum: ♁ 3.6–4.1, ♀ 4.5–5.0; length of hind femur: ♁ 3.5–4.2, ♀ 4.5–5.0.

Type material. Holotype: ♀, China, Xizang autonomous region, Bomi (Pailong), 30°1ʹ23ʹʹ N, 95°0ʹ20ʹʹ E, 2028 m alt., 14 June 2019, collected by Wei-An Deng, CLSGNU . Paratypes. 6♁, 13♀, same data, CLSGNU ; 2♁, 2♀, China, Xizang autonomous region, Motuo ( Motuo county highway), 29°27ʹ40ʹʹ N, 95°26ʹ27ʹʹ E, 670 m alt., 15 June 2019, collected by Wei-An DENG, CLSGNU .

Diagnosis. New species can be easily distinguished from other species of the genus by width of vertex between eyes 0.8–1.0 times width of compound eye. This new species is similar to Formosatettix gorkhanu s Ingrisch, 2001 from which it differs in width of vertex between eyes 0.8–1.0 times width of compound eye (width of vertex between eyes 2.0 times width of compound eye in F. gorkhanu s); in lateral view, frontal costa straight and not concave between eyes (in lateral view, frontal costa distinctly concave between eyes in F. gorkhanu s); lower margin of hind pronotal process curved (lower margin of hind pronotal process straight in F. gorkhanu s); hind pronotal process broad and its apex broadly arcuate (hind pronotal process narrow and its apex narrowly rounded in F. gorkhanu s).

Etymology. The specific epithet is derived from “ strictivertex ”, meaning vertex is extremely narrow, fastigium of vertex between eyes 0.8–1.0 times width of an eye.

Distribution. P. R. CHINA: Xizang.

Figures

FIGURE 16. Formosatettix strictivertex Deng, sp. nov., holotype female. A—Body, dorsal view; B—The same, lateral view; C—Head and anterior part of pronotum, dorsal view; D—The same, lateral view; E—Head, frontal view.

FIGURE 17. Formosatettix strictivertex Deng, sp. nov., holotype female: A—Left fore femur, lateral view; B—Left mid femur, lateral view; C—Left hind femur, lateral view; D—Left hind tibia, lateral view; E—Left posterior tarsus, lateral view; F—Subgenital plate of female, ventral view; male, paratype: G—Body in dorsal view; H—Body in lateral view.

FIGURE 24. The type localities of new species and new synonyms in the genus Formosatettix. A—F. torulosinota; B—F. hainanensis; C—F. guangxiensis; D— F. cliva; E—F. guangyuanensis; F—F. huapingensis; G—F. nanlingensis andF.undulatifemura; H—F.guposhanensis; I—F.latifemurus; J—F.leigongshanensis;K—F. longwangshanensis; L—F.tianmushanensis; M—F.nyalamensis; N—F. serrifemora; O—F. wulongensis; P—F.shuimogouensis; Q—F.strictivertex; R—F. tangjiaheensis; S—F. yueqingensis; T—F. zheminzhengi.

FIGURE 25. Habitats of seven new species of the genus Formosatettix in China. A—F. cliva (Yunnan, Weixin, Daxueshan); B—F. guangyuanensis (Sichuan, Guangyuan, Qingchuan); C—F. shuimogouensis (Sichuan, Chaotian, Shuimogou); D—F. strictivertex (Xizang, Bomi, Pailong); E—F. tangjiaheensis (Sichuan, Qingchuan, Tangjiahe); F—F. yueqingensis (Zhejian, Yueqing, Yandangshan); G—F. zheminzhengi (Guangxi, Jinxiu, Lianhuashan).