Phaesticus hainanensis ( Liang, 1988 ) Zha & Skejo & Mao & Ding, 2021

Zha, Ling-Sheng, Skejo, Josip, Mao, Ben-Yong & Ding, Jian-Hua, 2021, Taxonomic revision of Phaesticus Uvarov and synonymy with Flatocerus Liang & Zheng syn. nov. (Orthoptera: Tetrigidae), Zootaxa 4965 (3), pp. 501-514 : 509-511

Phaesticus hainanensis ( Liang, 1988) comb. nov.

Fig. 5

( Flatocerus hainanensis Liang, 1988 )

Nomenclatural comment. Orthoptera species file ( Cigliano et al. 2021) cites ‘Liang & Zheng’ as the authors of the species. However, only Liang authored the description of P. hainanensis comb. nov. ( Liang, 1988).

Material examined. Two males and two females, PR China: Hainan, Wuzhishan ( Wuzhishan Mountain ), 18°52′32.3′′N, 109°40′3.6′′E, 640 m, 16 September 2018, collected by Ling-Sheng Zha.

Description. Male.

General appearance. Body slender and tapered, size small, brown to dark brown, surface smooth, but covered with numerous fine granules. Antennae dark brown, but the basal part of the 7 th and most part of the 10 th and 11 th segments yellow; hind wings black; surfaces of pronotum (especially between sulci) and all femora often maculated with yellowish brown and obscure spots; ventral external area of hind femur black, spots on tibiae inconspicuous.

Head. Vertex and occiput clearly separated by a ridge (posterior margin of fossulae). Vertex extremely short, only restricted between anterior and posterior margins of fossulae which are shallow but conspicuous; anterior margin low and narrowest, nearly straight, 1.5 times as wide as one eye, and reaching the middle of inner margins of eyes in dorsal view; medial carina extending to the occiput but very indistinct, lateral carinae also indistinct. In lateral view, face obtusely angled forwards, vertex and upper part of the face (above antennal sockets) nearly at the same slope (in P. mellerborgi and P. moniliantennatus , medial carina and frontal costa distinct and forming an obtuse angle); frontal costa indistinct, facial carinae between antennal grooves strongly arcuate forwards. In frontal view, facial carinae diverge above lateral ocelli (at the middle of the inner margins of eyes), then parallel downwards; longitudinal furrow deep, nearly as wide as the diameter of antennal scapus. Antennae inserted slightly below lower margin of the eyes (upper margin of antennal sockets and the lower margin of eyes nearly at the same level), 13-segmented (or 14-segmented, because the 3 rd segment is usually separated into two short segments), 9 th segment widest and about 3.7 times as long as it is wide; segments from 3 rd to 6 th gradually slightly broadened and flattened, from 7 th to 10 th (long and elliptical) considerably broadened and flattened, the 11 th slightly flattened, and the last two very short and not flattened. Eyes exserted, almost as high as the top of vertex and the anterior margin of pronotum, in lateral view globose, in dorsal view with angled inner margins; in frontal view ovate, with nearly straight inner margins that are a little contracted upwards. Superior ocelli situated at the lower quarter of the inner margins of eyes.

Pronotum. Pronotum clearly roof-like before shoulders, and less roof-like behind shoulders; anterior margin broadly arcuate forwards from dorsal view, behind shoulders slightly depressed on both sides of median carina; median carina distinct, erect, and entire, in lateral view low arcuate before shoulders and straight behind shoulders. Prozonal carinae visible, short, and strongly contracted backwards; humeral angles broadly arcuate; hind process tapered, reaches variably from base to 2/3 of hind tibiae, apex truncated; posterior angel of lateral lobe extending obliquely, downwards, and backwards, apex truncated; ventral and tegminal sinuses presented.

Wings. Visible part of tegmen long, ovate, and distinctly narrower than mid femur; hind wings very developed, more or less surpassing the apex of hind pronotal process (1–1.8 mm).

Legs. Dorsal and ventral margins of fore and mid femora straight and finely serrated; hind femur approximately 2.7 times as long as it is wide, dorsal and ventral margins finely serrated, and serrations on the posterior part of dorsal margin conspicuous; antegenicular tooth relatively low and apex acutely angled, genicular tooth acute; outer/ inner side of hind tibia with 6/6–8 spines; first segment of hind tarsus slightly shorter than the third; three pulvilli nearly equal in length and with obtuse apices.

Abdomen. Subgenital plate short cone-shaped, apex bifurcate and forms two short and tapered teeth.

Females and the differences from males. Body size slightly larger than that of male. Hind pronotal process shortened, only reaches the apices of hind femora; hind wings slightly surpass the apex of hind process (about 0.5 mm). Ovipositor long and narrow, about four times as long as it is wide, dorsal margin of upper valve and ventral margin of lower valve armed with saw-like teeth. Posterior margin of subgenital plate nearly truncated, with an acutely triangular protrusion in the middle, which is slightly folded inwards. Other characters same as those in male.

Measurements (in mm). Length of body: male 8.7–10.0, female 11.0–12.0; length of pronotum: male 9.9–12.0, female 9.0–10.0; length of hind femur: male 5.4–5.9, female 5.6–6.0; width of pronotum between humeral angles: male 3.0–3.1, female 3.1–3.2; length of antennae: male and female 6 mm.

Distribution ( Fig. 1 ). PR China (Hainan).

Ecology and habits. Individuals of P. hainanensis ( Liang, 1988) comb. nov. were collected and observed in a bamboo forest ( Fig. 6 c, d ) and on the edge of roads in humid tropical rainforests. They dwell on layers of fallen leaves or among sparse shrubs, and are able to quickly jump into dense shrubs when disturbed. They mainly feed on humus.

Notes. Phaesticus hainanensis ( Liang, 1988) comb. nov. was described only based on one female specimen from Hainan ( Liang, 1988; Liang & Zheng, 1998). We redescribed the species because 1) lengths of hind pronotal process and hind wings vary among individuals, and 2) some important characters were previously inaccurately described. According to the original description and our specimens, anterior margin of its pronotum is ‘broadly arcuate’, which was imprecisely recorded as ‘nearly straight’ in some Flatocerus species keys ( Liang et al., 2008; Zheng et al., 2011a, b; Deng, 2016). Besides, the antennae of Phaesticus are all 13-segmented (or 14-segmented due to the third segment being separated into two short segments), instead of 12-segmented, which was commonly recorded in generic characteristics and related species descriptions ( Liang & Zheng, 1984, 1998; Liang, 1988; Zheng, 2005; Deng, 2016).

Figures

FIGURE 1. Distribution of the genus Phaesticus and its three species.

FIGURE 5. Phaesticus hainanensis (Liang) comb. nov. a) dorsal view of male body; b) lateral view of male body; c) frontal view of male head; d) lateral view of male subgenital plate; e) dorsal view of female body; f) oblique-lateral view of female head; g) lateral view of female body. Scale bars a, b, e–g=1 mm; c, d=0.5 mm.

FIGURE 6. a, b) Habitats of Phaesticus moniliantennatus (Günther) and c, d) habitats of P. hainanensis (Liang) comb. nov. Pictures were photographed in: a) Fanjingshan Mountains (Jiangkou, Guizhou), b) Xuefengshan Mountains (Dongkou, Hunan), c) and d) Wuzhishan Mountain (Wuzhishan, Hainan).