Two new species of the genus Formosatettix Tinkham, 1937 (Orthoptera, Tetrigidae) from Guizhou and Chongqing, PR China

Abstract Two new pygmy grasshopper species are described from PR China and are assigned to Formosatettix Tinkham, 1937, a large Asian tetrigin genus composed of species with reduced tegmina and hind wings: F. leigongshanensis Zha & Ding, sp. nov. from Guizhou and F. wulongensis Zha & Ding, sp. nov. from Chongqing. We provide descriptions of morphology and habit, supplemented with photographs. Flying organs of the genus Formosatettix are discussed and the genus is compared with other Asian genera with reduced flying organs, such as Formosatettixoides Zheng, 1994 and Alulatettix Liang, 1993 in Tetriginae, Deltonotus Hancock, 1904, Epitettix Hancock, 1907 and Pseudepitettix Zheng, 1995 in Cladonotinae, and Macromotettixoides Zheng, Wei & Jiang, 2005 and Pseudomacromotettix Zheng, Li & Lin, 2012 in Metrodorinae.


Introduction
The genus Formosatettix Tinkham, 1937 (subfamily Tetriginae) was originally established for only two species from Taiwan, China -F. arisanensis Tinkham, 1937 (type species) and F. karenkoensis Tinkham, 1937, but today it is a large genus composed of 68 known species in China, Japan, Korea, Nepal, Pakistan and Russia (Wei et al. 2019, Cigliano et al. 2020. Formosatettix is similar to the Tetriginae genera Alulatettix Liang, 1993 andFormosatettixoides Zheng, 1994. Members of Alulatettix have a pair of conspicuous tegminal sinus (Zhang et al. 2014), while those of Formosatettixoides have visible tegmina and hind wings . Member of Formosatettix, on the other hand, lack a pair of tegminal sinus and both tegmina and hind wings are invisible (Wei et al. 2019). Formosatettix is also similar to the Cladonotinae genera Deltonotus Hancock, 1904, Epitettix Hancock, 1907, and Pseudepitettix Zheng, 1995 [which is a likely synonym of Epitettix as suggested by Deng (2016) and Zha et al. (2017b)], and to the Metrodorinae genera Macromotettixoides Zheng, Wei &Jiang, 2005 andPseudomacromotettix Zheng, Li &Lin, 2012 [syn. of Macromotettixoides as suggested by Zha et al. (2017a)]. Relations among the aforementioned genera have never been systematically investigated.
During investigations of pygmy grasshoppers in PR China, we have collected new data on members of the genus Formosatettix. In this study, we introduce two new members of the genus Formosatettix, namely F. leigongshanensis Zha & Ding, sp. nov. and F. wulongensis Zha & Ding, sp. nov., from Southwest China. At the same time, we provide brief discussion on the morphology of the flying organs of Formosatettix, and compare the genus to allied genera.

Material and methods
Photography. Specimens were photographed using Canon EOS 800D with 100 mm macro lens, and partial images were stacked using Photoshop CS6. Photographs of the habitat were made using Nikon Coolpix P520.
Depository. Type and voucher specimens are deposited in the Specimen Room of the School of Life Sciences, Huaibei Normal University (HNU), Huaibei, Anhui Province, China.
Taxonomy. Taxonomy follows Cigliano et al. (2020) (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., 2006from Jilin, F. yunnanensis Zheng, 1992from Yunnan, China, and F. martensi Ingrisch, 2001. 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. Detailed description of females. 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 rooflike, 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 pointedrounded. Median carina of pronotum lamellate, in lateral view low arcuate; lower mar-gin 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.
Brief description of the males. 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 coneshape, distal end nearly obliquely truncated in lateral view, apex bifurcate and forms into two short and obtuse teeth. Other characters same as females.
Ecology and habits. 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.
Etymology. The new species is named after the type locality, Leigong-shan Mt., Leishan, Guizhou, China. The specific epithet is a third Latin declension adjective.
Distribution. China (Guizhou). For now, only found in Leigong-shan Mt. in Leishan County (Fig. 4).   Diagnosis. 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 pointedrounded 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.
Detailed description of female. 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.
Brief description of males. 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.
Ecology and habits. 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.
Etymology. The new species is named after the type locality, Wulong, Chongqing, China. The specific epithet is a third Latin declension adjective.

Discussion
There has been a lot of discussion on how to properly describe the tegmina and hind wings of Formosatettix. Tinkham (1937) and Zheng (2005Zheng ( , 2009) described them as 'absent or degenerated', while Wei et al. (2019) referred to 'tegmina' as absent, while hind wings as 'absent or very short'. Authors in other continents have similar issues, such as North America (Hancock 1902) or Europe (Skejo et al. 2014), and have already proven that the flying organs of some Tetriginae species are degenerated, not absent. We have now also checked the flying organs of the Formosatettix specimens (ten species altogether). Specimens of Formosatettix indeed have tegmina and hind wings present, but degenerated, very small, triangular and scaly or long-ovate, hind wind being distinctly longer than tegmenulum (Figs 1d, 5d). Formosatettix thus, has reduced tegmina and hind wings, not absent, just as members of the genus Nomotettix (Hancock 1902) in North America or Tetrix nodulosa and Tetrix transsylvanica in Europe (Skejo et al. 2014). We now have reasons to doubt that tegmina and hind wings of many brachypterous species in Tetrigidae taxonomy do exist, in reduced fashion, as they originated from winged ancestors. According to the classification standard of the hind wings of pygmy grasshoppers suggested by Zha et al. (2016Zha et al. ( , 2017a, flying organs of the members of the genus Formosatettix should be assigned to the 'abbreviated' type (hind wings never reach middle of hind pronotal process, but are distinctly longer than tegmina). Formosatettix is morphologically similar to members of the genera Alulatettix and Formosatettixoides (Tetriginae), Deltonotus and Epitettix (with Pseudepitettix syn.) in (Cladonotinae), and Macromotettixoides (with Pseudomacromotettix syn.) (Metrodorinae). Based on previous work (Zheng 2005, Tumbrinck 2014, Zha et al. 2016, 2017a and specimens in our hands, we provide brief comparison between Formosatettix and aforementioned genera, including summarized differences among Tetriginae, Cladonotinae and Metrodorinae (see Tables 2, 3; Fig. 7).  Not elevated, not reaching the level of the anterior margin of the compound eyes * Hind wings of Tetrigidae can be divided into four types: 'normal' (developed, surpassing middle of hind pronotal process), 'abbreviated' (never reaching middle of hind pronotal process, but distinctly longer than tegmina), 'vestigial' (equal to or shorter than tegmina) and 'apterous' (completely absent) (Zha et al. 2016(Zha et al. , 2017a. Deltonotus is considered as the 'apterous' type based on Storozhenko (2011) and  We furthermore suggest that the length of the medial carina of the vertex could be one of the important traits that could help in separating Cladonotinae from other related subfamilies (Table 2). Alulatettix differs from Formosatettix by clear tegminal sinus, usually absent or weak in Formosatettix (Table 3). Future research may discover numerous synonyms in Chinese Tetrigoidea, as already proposed in some studies. Formosatettixoides and Formosatettix could represent synonyms of each other, as well as Epitettix and Pseudepitettix, but also Macromotettixoides and Pseudomacromotettix (Table 3). Many Formosatettix species were either described as having wings absent, or lack photographs to be checked. Revisions are necessary in the future, as is good taxonomic practice (Lehmann et al. 2017).