Formosatettix serrifemora Deng, 2019 was reported from Liupanshui (Yushe) and Suiyang (Kuankuoshui), Guizhou, China (Wei et al. 2019), and is geographically closest to our new species. We have collected the species (9♂20♀) from the Tongzi County (Baiqing Natural Reserve), also in Guizhou. Apart from the number of antennal segments (14 or 15) and presented tegmina and hind wings (closely similar to F. leigongshanensis sp. nov.), our collections are identical to the description and photographs of F. serrifemora (14-segmented, tegmenulum and hind wing absent; Wei et al. 2019).

Formosatettix leigongshanensis sp. nov. is similar to F. serrifemora, but the latter has a narrower scutellum, an acutely angled anterior margin of the pronotum in dorsal view, undulate ventral margins of the fore and mid femora, and undulate dorsal margin of the hind femur (Wei et al. 2019, fig. 7b). The main differences between the two species are outlined in Table 1.

Formosatettix leigongshanensis sp. nov. is also similar to F. changbaishanensis Yuan et al., 2006 from Jilin, F. yunnanensis Zheng, 1992 from Yunnan, China, and F. martensi Ingrisch, 2001 from Nepal (Panchthar). Some of the main diagnostic differences are that in F. changbaishanensis: 1) vertex is 1.67♂–1.76♀ times as wide as one eye; 2) middle segments of the antennae are 5.16♀–6.3♂ times as long as wide; 3) prozonal carinae are contracted backwards; and 4) apex of the posterior angle of the lateral lobe is rounded (Yuan et al. 2006); in F. yunnanensis: 1) facial carinae before the eyes are indistinctly concave; 2) antennae are inserted slightly above the lower margin of the eyes; 3) scutellum is as wide as the diameter of scapus; 4) ventral margins of the fore and mid femora are undulate; and 5) apex of the posterior angle of the lateral lobe is rounded (Zheng 1992); and in F. martensi: 1) face is distinctly inclined and the frontal costa together with the medial carina of the vertex forms an acute angle; 2) anterior margin of the pronotum is slightly projected forwards and only reaches the posterior margin of the eyes; 3) ventral margin of the mid femur is undulate; and 4) the area between the internal and external lateral carinae of the pronotum is much narrower (Ingrisch 2001, Cigliano et al. 2020).

The new species is the second Formosatettix species, after F. serrifemora, reported in Guizhou Province, China.

Figure 1. 

Female of Formosatettix leigongshanensis sp. nov. a body in lateral b body in dorsal view c head in frontal view d wings in lateral view (tegmenulum in the smaller circle, hind wing in the bigger circle) e subgenital plate in ventral view. Pictures a, b were stacked using Photoshop CS6. Scale bars: 2 mm (a, b), 1 mm (c–e).

Figure 2. 

Male of Formosatettix leigongshanensis sp. nov. a body in lateral view b body in dorsal view. Pictures were stacked using Photoshop CS6. Scale bars: 2 mm.

General appearance. Body stout and short, size moderate, surface smooth and covered with numerous fine granules.

Head. Vertex slightly below the anterior margin of the pronotum, slightly roof-like, anterior part higher than posterior part and center part higher than both sides, 2 times as wide as a compound eye; anterior margin somewhat arcuate, clearly surpasses the anterior margin of eyes; lateral carinae distinct, folded upwards and slightly over the top of eyes; medial carina distinct and compresso-elevated in anterior half, almost touching the median carina of the pronotum; paired fossulae distinct, rounded. In lateral view face nearly vertical, frontal costa together with medial carina rounded; facial carinae above superior ocelli concave, between antennal grooves arcuate forwards. In frontal view frontal costa bifurcates into facial carinae at the lower one-third of between anterior margin of vertex and upper margin of superior ocelli, and run nearly parallel downwards; scutellum deep and wide, between grooves 1.3–1.4 times as wide as the diameter of scapus. Eyes globose and elevated over the anterior margin of the pronotum, but clearly lower than top of vertex; superior ocelli placed at the level of lower one-third of the inner margins of eyes. Antenna. Antenna filiform, 16-segmented, inserted slightly below the lower margin of eyes, with 9–11^th segments longest and 4–5 times as long as wide.

Pronotum. Pronotum distinctly compresso-elevated, surface smooth, between sulci somewhat swollen at the base of median carina and a little concave on both sides of the discus. The anterior margin projected forwards and reaching the middle of eyes, in dorsal view obtusely angled; prozonal carinae extend to the anterior sulcus, parallel, indistinct; hind pronotal process short, only reaching 3/4 of hind femur, apex pointed-rounded. Median carina of pronotum lamellate, in lateral view low arcuate; lower margin of hind process curved, internal lateral carina slightly incurved, the area between internal and external lateral carinae of the pronotum about 1.4 mm wide. Posterior angles of the lateral lobes of the paranota extend obliquely, downwards and backwards, with rounded-truncated apices; ventral sinus present while tegminal sinus absent.

Wings. Tegmina and hind wings reduced, very small, triangular, hidden beneath pronotum and invisible (the ‘abbreviated’ type after Zha et al. 2016).

Legs. Dorsal and ventral margins of all femora finely serrate; fore and mid femora compressed, dorsal and ventral margins nearly straight; hind femur robust, about 2.6 times as long as wide, dorsal and ventral margins entire; antegenicular tooth slightly folded outwards with acute apex, apex of the genicular tooth obtuse; hind tibia with finely serrate inner margins, terminal part slightly wider than basal part, outer/inner side with 7–9/6–8 spines; first segment of hind tarsus 1.8 times as long as third, the first pulvillus short, while the second and third long, tips of all the pulvilli obtuse.

Abdomen. Ovipositor narrow and long, upper valvae about 3.2 times as long as wide, outer margins of upper and lower valvae armed with saw-like teeth. Subgenital plate in ventral view: median carina entire and distinct; posterior margin truncated, in the middle has a broadly triangular protrusion which is folded inwards, base of the protrusion elevated and slightly higher than posterior margin.

Coloration. Body dark brown. Antennae brown to dark brown. Pronotum behind shoulder usually has a pair of blackish spots (posthumeral spots), median carina of pronotum dotted with yellowish-brown. Ventral external area of hind femur mainly black, ventral margin of hind femur has a series of small yellow spots. Fore and mid tibiae with 3 yellowish-brown rings each, hind tibia with 2 elongate yellowish-brown rings.

Slightly smaller than female. Antenna 15-segmented, with 8–10^th segments longest. The area between internal and external lateral carinae of the pronotum about 1.2–1.3 mm wide. Subgenital plate short and cone-shape, distal end nearly obliquely truncated in lateral view, apex bifurcate and forms into two short and obtuse teeth. Other characters same as females.

(mm). Length of body♂10–11.5, ♀11–13.5; length of pronotum ♂7.5–8.0, ♀8.5–9.1; length of hind femur ♂6.4–6.9, ♀7.1–7.7, width of hind femur ♂2.5–2.7, ♀2.7–2.9; length of antenna ♂3.8–4.0, ♀4.1–4.5.

Holotype female, PR CHINA, Guizhou Province, Leishan County (Leigong-shan Mt.), 26°22'45.69"N, 108°11'42.83"E, 1460 m alt., 2 Aug. 2016, collected by Ling-Sheng Zha. Paratypes: 15 males and 6 females, Leigong-shan Mt., 1400–1600 m alt., 1–3 Aug. 2016, collected by Ling-Sheng Zha.

Individuals of Formosatettix leigongshanensis sp. nov. inhabit fall-leaf layers in humid subtropical rainforests of Karst Region (Fig. 3a, c, d). They move slowly and can easily be caught. They mainly feed on humus. Specimens are capable of burrowing their bodies in shallow soil layer.

The new species is named after the type locality, Leigong-shan Mt., Leishan, Guizhou, China. The specific epithet is a third Latin declension adjective.

China (Guizhou). For now, only found in Leigong-shan Mt. in Leishan County (Fig. 4).

Figure 3. 

Habitats of two new Formosatettix species in PR China a habitat of F. leigongshanensis sp. nov. b habitat of F. wulongensis sp. nov. c, d female F. leigongshanensis sp. nov. standing on fall-leaf layers. Pictures a, c, d were photographed in Leigong-shan Mt., Leishan, Guizhou, China; while picture b was taken in Wulong, Chongqing, China.

Figure 4. 

Formosatettix species inhabiting Guizhou and Chongqing, PR China. Red star: F. serrifemora from Liupanshui, Suiyang and Tongzi, Guizhou; Red triangle: F. leigongshanensis sp. nov. from Leishan, Guizhou; Blue circle: F. wulongensis sp. nov. from Wulong, Chongqing.

Formosatettix wulongensis sp. nov. is similar to F. serrifemora, but the latter has elevated, arcuate and much more projected anterior margin of the vertex, narrower scutellum, lower arcuate median carina of pronotum in lateral view, and pointed-rounded apex of hind pronotal process (Wei et al. 2019, fig. 7b). Main differences between F. serrifemora and F. wulongensis sp. nov., together with F. leigongshanensis sp. nov., are outlined in Table 1.

Formosatettix wulongensis sp. nov. is also similar to F. omeiensis Zheng, 2009 from Sichuan and F. baishuijiangensis Zheng, 1999 from Gansu, China. Formosatettix omeiensis differs from our new species in 1) frontal costa together with the medial carina of the vertex acutely angled; 2) superior ocelli situated between the lower margin of the eyes; 3) anterior margin of the pronotum reaching only the level of the half length of the compound eyes; and 4) parallel prozonal carinae (Zheng 2009); while F. baishuijiangensis can be separated from the new species in 1) vertex 3.6 times as wide as one eye; 2) vertex strongly surpassing the anterior margin of the compound eyes; 3) scutellum 2 times as wide as the diameter of the scapus; and 4) anterior margin of the pronotum reaching only the posterior one-third of the compound eyes length (Zheng et al. 1999).

The new species is the first Formosatettix species known from Chongqing Autonomous Region, China.

Figure 5. 

Female of Formosatettix wulongensis sp. nov. a body in lateral view b body in dorsal view c head in frontal view d reduced wings in lateral view (tegmenulum in the smaller circle, hind wing in the bigger circle) e subgenital plate in ventral view. Pictures a, b were stacked using Photoshop CS6. Scale bars: 2 mm (a, b), 1 mm (c–e).

Figure 6. 

Male of Formosatettix wulongensis sp. nov. a body in lateral view b body in dorsal view. Pictures were stacked using Photoshop CS6. Scale bars: 2 mm.

General appearance. Body stout and short, size moderate; surface coarse, covered with numerous fine granules.

Head. Vertex clearly below anterior margin of pronotum, 2.5 times as wide as a compound eye; middle portion higher than surrounding area; anterior margin straight and low, a little surpasses the anterior margin of the compound eyes; lateral carinae distinct, folded upwards and up to the top of eyes; medial carina distinct and compreso-elevated in the anterior half; paired fossulae distinct, rounded. In lateral view face nearly vertical; frontal costa together with medial carina rounded; facial carinae above superior ocelli distinctly concave, between the antennal grooves nearly obtusely triangular (strongly arcuate) forwards. In frontal view frontal costa bifurcates into facial carinae at the lower one-third of between anterior margin of vertex and upper margin of superior ocelli, and run nearly parallel downwards; scutellum deep and wide, between grooves 1.2–1.3 times as wide as the diameter of the scapus. Eyes globose and elevated over the anterior margin of pronotum, but clearly lower than vertex; superior ocelli placed slightly above the lower margin of eyes. Antenna. Antenna filiform, 16-segmented, inserted distinctly below the lower margin of eyes, segments 10–12^th longest and 4–5 times as long as wide.

Pronotum. Pronotum strongly compresso-elevated, surface coarse, bearing small tubercles and wrinkles; between sulci a little swollen at the base of median carina and a little concave on both sides of the discus. Anterior margin projected forwards and nearly reaches the level of the anterior margin of eyes, in dorsal view acutely angled; prozonal carinae distinct, but short, slightly contracted backwards; hind pronotal process short, reaching 3/4 of the hind femur; apex broadly arcuate in dorsal view. Median carina of pronotum strongly compresso-elevated, in lateral view highly arcuate; lower margin of hind pronotal process curved, interlal lateral carinae incurved, the area between internal and external lateral carinae of the pronotum about 1.4 mm wide. Posterior angles of the lateral lobes of paranota directed downwards and backwards, with truncated or nearly truncated apices; ventral sinus present, tegminal sinus absent.

Wings. Tegmina and hind wings extremely degenerated and very small, scaly, hidden beneath pronotum and invisible (the ‘abbreviated’ type after Zha et al. 2016).

Legs. Dorsal and ventral margins of all the femora finely serrated; fore and mid femora compressed, dorsal margins almost straight, ventral margins with 3 teeth each (at the base, in the middle and at the end). Hind femur robust, about 2.8 times as long as wide, dorsal margin before antegenicular tooth bearing three lappets; ventral margins with a series of small teeth, three to four visible; ventro-external carina bearing a series of small teeth, 2–3 larger and evident; antegenicular tooth slightly folded outwards with apex acute, apex of genicular tooth obtuse; hind tibia with finely serrate inner margins, terminal part slightly wider than basal part, outer and inner sides with 5–7 spines each; first segment of hind tarsus 1.8 times as long as third, three pulvilli nearly equal in length and with obtuse apices.

Abdomen. Ovipositor narrow and long; upper valvae about 3.2 times as long as wide; outer margins of upper and lower valvae armed with slender, saw-like teeth. Subgenital plate in ventral view: median carina evident in the anterior half while obscure in the posterior part; posterior margin truncated, in the middle with a broad triangular protrusion which is folded inwards.

Coloration. Body dark brown. Antennae brown to dark brown from base to distal end, except for the pale colored 14^th segment; pronotum behind shoulder in some specimen has a pair of blackish spots (posthumeral spots); anterior margin, median carina and lateral carinae of pronotum covered in yellowish-brown dots; teeth on femora generally yellowish-brown; fore and mid tibiae with three yellowish-brown rings each; hind tibia with two elongate yellowish-brown rings.

Slightly smaller than female. Vertex 2.3 times as wide as one eye; antennae 15-segmented, segments 9–11^th longest; 13^th segment light colored. The area between internal and external lateral carinae of the pronotum 1.3 mm wide. Subgenital plate short cone-shape, distal part abruptly narrowed, distal end obliquely truncated in lateral view, but apex bifurcates into two distinct and obtuse teeth. Other characters same as females.

(mm). Length of body ♂10.8, ♀12–14; length of pronotum ♂7.5, ♀8.2–9.2; length of hind femur ♂5.9, ♀6.3–6.8, width of hind femur ♂2.2, ♀2.3–2.5; length of antenna ♂3.5, ♀3.8–4.

Holotype female, PR CHINA, Chongqing Autonomous Region, Wulong County, 29°20'32.27"N, 107°45'23.35"E, 470 m alt., 11 July 2016, collected by Ling-Sheng Zha. Paratypes: 1 male and 2 females, same data as holotype.

Individuals of F. wulongensis sp. nov. inhabit slopes of bamboo forest in humid subtropical rainforests (Fig. 3b). They move slowly on fall-leaf layers among bushes. They may feed on mosses and/or humus. Most of their life cycles, they maybe burry their bodies in shallow soil layer.

The new species is named after the type locality, Wulong, Chongqing, China. The specific epithet is a third Latin declension adjective.

China (Chongqing). For now, only found in Wulong County (Fig. 4).