Setostylus chinensis Cao, Evenhuis et Zhou

Xu, Huachao, Cao, Jian, Zhou, Zuji, Wu, Hong & Huang, Zhiwei, 2007, First record of the tribe Keroplatini from China, with descriptions of two new species (Diptera: Keroplatidae), Zootaxa 1497, pp. 35-40 : 38-39

Setostylus chinensis Cao, Evenhuis et Zhou n. sp.

( Figs. 5–7 )

Description. MALE. Lengths: Body: 5.0 mm; wing: 3.3 mm.

Head. Vertex and occiput yellowish brown with fairly dense small black recumbent hairs. Three ocelli. Frons obscurely brown, bare. Antennae: brown; Flagellum: flagellomeres strongly compressed with a few long setae. Face and palpi pale yellow.

Thorax. Prosternum with short setae. Mesonotum with uniformly setae, obscurely yellow with three broad yellowish brown stripes on disc, medial stripe extending anteriorly to pronotum. Scutellum brown, with long dark setae on posterior margin. Anepisternum pale brown with patch of short hairs above; katepisternum, laterotergite and mediotergite obscurely yellow, bare. Halter pale brown.

Legs. Yellow (apex of mid and hind coxae, base of mid and hind femur brown). Fore tibia without comb, mid tibia with only black posterior comb, hind tibiae with black anterior and posterior comb. Tibial spurs black; anterior spur of mid tibia 0.3x length of its posterior spur, two spurs of hind tibia subequal in length.

Fore basitarsus 1.3x length of fore tibia, mid and hind basitarsi 0.8–0.9x lengths of their respective tibiae. Claws strong.

Wing ( Fig. 5 ). Subhyaline, yellow. Veins brown. Costa slightly beyond one-third distance from vein R5 to vein M1; Sc ends in C reaching the level of middle of Rs; Sc2 absent. Distance between tips of R1 and R4 0.4– 0.5 times as long as R4. Ratio of radiomedial fusion / petiole of M: 1.0–1.1. Petiole of M one-sixth as long as length of M1; vein A1 reaching wing margin.

Abdomen. Tergite I brown, tergites II–V brown with yellow on basal half, tergites V–VIII brown. Sternum patterned as on tergites.

Hypopygium ( Figs.6–7 ). Tergite IX obscurely yellow, tapered from base to apex and slightly exceeding length of gonocoxites. Cercus visible in dorsal view, tapered apically. Gonocoxites yellow with stiff setae medially and long setae laterally, with a deep cleft medially. Gonostylus long, tapered from base to apex; hairy on basal 3/4, inferior setae short and thick, the remaining setae longer; apex with a long and thick black hair.

FEMALE. Unknown.

Types. Holotype ɗ (ZJFC 060204) and paratypes from: CHINA: Sichuan province: Wolong National Natural Reserve, 21 July 2006, Jian Cao.

Etymology. The species name refers to the first record of the genus from China.

Diagnosis. This species is similar to the Japanese species S. abdominalis (Sasakawa & Tamu) , but it is easily distinguished by areas from petiole of M to basal branches of M without spot (with a brown spot in S. abdominalis ) and two spurs of hind tibia subequal in length (posterior spur of hind tibia very shorter than its anterior spur in S. abdominalis ). Having compared S. chinensis , n. sp. with the Malaysian species S. rufobrunneus Matile , we have found that the new species differs in having scutellum with long dark setae on posterior margin (without long setae in S. rufobrunneus ) and the gonocoxites with a medial cleft deeper than in S. rufobrunneus and the gonostylus thinner than in S. rufobrunneus .

Figures

FIGURES 5 – 7. Setostylus chinensis, n. sp. 5. wing; 6. male terminalia, ventral view; 4. male tergite IX and cercus, dorsal view. Scale bar = 0.1 mm.