Striogyia bifidijuxta J. Wu & Han, 2022

Wu, Jun & Han, Hui-Lin, 2022, Striogyia bifidijuxta sp. nov., a new slug caterpillar moth (Lepidoptera: Zygaenoidea: Limacodidae) from China, Zootaxa 5219 (1), pp. 92-96 : 93-95

Striogyia bifidijuxta J. Wu & Han , sp. nov.

Figures 1, 2, 7, 8

Type-material. Holotype: male, CHINA, Xizang Autonomous Region (= Tibet), Linzhi (= Nyingchi ) City , Lulang Town , Layue Village , 14–15.viii.2013, leg. HL. Han , in NEFU.

Paratypes: 2 males, same data as for holotype, genit. prep. WuJ-701-1, in NEFU ; 1 male, CHINA, Yunnan Province, Tengchong City, Mt. Qiumou, 5.viii.2014, leg. HL. Han , genit. prep. WuJ-710-1, in NEFU ; 1 male, CHINA, Xizang Autonomous Region, Linzhi City , Bomi County, Yigong Township , 6.viii.2017, leg. HL. Han , genit. prep. WuJ-431-1, in NEFU .

Diagnosis. Externally, Striogyia bifidijuxta sp. nov. (Figs 1, 2) is similar to S. obatera (Fig. 3), S. simianshana (Fig. 4), S. snelleni (Fig. 5) and S. spinosa (Fig. 6), but it can be distinguished by the following characters: (1) the inner side of postmedial line is bordered with dark scales, while in S. snelleni the outer side of the fascia shows a dark shadow, in S. obatera and S. spinosa the same fascia is only presented as a single bright line, and in S. simianshana is absent; (2) in the male genitalia, the uncus of S. bifidijuxta sp. nov. (Figs 7, 8) is rectangular, with a deep V-shaped cleft apically, however, it is nearly triangular and not notched apically in S. obatera (Fig. 9) and S. simianshana (Fig. 10), rectangular and slightly bifid in S. snelleni (Fig. 11), and shorter, broader, elbowed, and covered with dense scale tuft in S. spinosa (Fig. 12); (3) the transtilla is unarmed, while there is a pair of developed horn-shaped process in S. simianshana and S. obatera , corrugated “saddle-shaped” in S. snelleni , and slender in S. spinosa ; (4) the sclerotized plate of anellus is bifurcated into a pair of stout, pointed spines, while it is spiniform in S. simianshana and chimney-shaped in S. obatera , and absent in S. snelleni and S. spinosa ; (5) the valva is shorter and broader when compared to S. obatera , S. simianshana , S. snelleni and S. spinosa ; (6) the base of sacculus bears a distinct setose papilla, while it is smaller in S. obatera and S. simianshana , and in S. snelleni and S. spinosa it is a prominent spine; (7) the terminal part of phallus bears several strong spines on one edge, whereas finer and denser in S. simianshana and S. obatera , and only with a single, small, digitiform process on one side distally in S. snelleni . This character has not been examined in S. spinosa .

Description. Male. Adult (Figs 1, 2). Forewing length 11–13 mm, wingspan 23–25 mm.

Head. Dark brown; labial palpus dark brown; antenna filiform, somewhat flattened, ca. 3/4 the length of costal margin of forewing.

Thorax. Densely covered with dark brown scales. Forewing broad, with reddish-brown ground color; basal and terminal areas relatively darker; postmedial line distinct, straight, bright and with dark scales bordering its inner side; terminal line thin, pale brown; fringe brown mixed with dark. Hindwing brownish grey, while pale grey in costal margin area; fringe along outer margin brown at base with medial and outer dark brown layers. Legs greyish brown to dark brown; tibial spurs 0-2-4.

Abdomen. Black with brownish-grey scale tuft terminally. Eighth segment (Figs 7c, 8c) modified, slightly sclerotized and densely covered with granules and setae.

Male genitalia (Figs 7, 8). Uncus slightly shorter than valva, nearly rectangular, slightly shrunk at middle part, with a longitudinal sclerotized median band; apically with scale tuft and with a deep V-shaped cleft apically. Gnathos absent. Valva broad, smooth at base and bristly apically; costa slightly sclerotized, obviously arched; cucullus narrowly rounded; base of sacculus with a conspicuous setose papilla; sacculus process broad, strongly sclerotized terminally, denticulate; upper half of saccular margin S-shaped, while concave at basal half. Transtilla strongly sclerotized, broad at base, then gradually tapering to the end, digitiform. Juxta approximately an inverted trapezoid, dorsally concave; sclerotized plate of anellus three pronged, deeply bifurcated into a pair of long, pointed spines apically. Vinculum robust, strongly sclerotized, broadly U-shaped. Saccus triangular. Phallus tubular, terminating in a small, sclerotized, slightly hooked and digitiform process, and bearing a row of stout, strongly sclerotized, variable-length spines on one edge.

Female. Unknown.

Phenology and habitat. The type series was collected in August at altitudes range of 2,080–2,540 m. Only known from southwestern China .

Distribution. China (Xizang, Yunnan).

Etymology. The specific name is derived from the Latin “bifidus”, which means bifid or split in two, and combined with “juxta”, corresponding to the forked upper part of juxta in the male genitalia.