Hyadina sauteri Cresson

Zhang, Junhua & Yang, Ding, 2009, Species of the genus Hyadina from China (Diptera: Ephydridae), Zootaxa 2152, pp. 55-62 : 60-61

Hyadina sauteri Cresson

( Figs. 13–16)

Hyadina sauteri Cresson, 1934: 206 [ Taiwan. Tainan; HT 3]

Diagnosis. Wing ( Fig. 13) with 2 faint white spots on anterior and posterior sides of posterior crossvein. Cercus short and thick; surstylus short and broad with 3 setae at apex in posterior view ( Fig. 14); aedeagus slender with dorsal process in lateral view ( Fig. 16).

Material studied. 13, China, Sichuan, Jiajiang, 29°46'N, 103°35'E, 21.IX.1978, Fasheng Li leg.; 13, China, Yunnan, Jinping, Dazhai, 22°50'N, 103°20'E, 17.V.2006, Junhua Zhang leg.; 13, China, Yunnan, Mengyang, Yexianggu, 22°04'N, 100°53'E, 05.IV.1999, Ding Yang leg.

Description. Male. Body length 1.45–1.50 mm, wing length 1.85–1.90 mm.

Head black; frons subshiny brown with thin brownish yellow microtomentum. 1 strong inner vertical seta, outer vertical seta absent; 1 pair of strong ocellar setae; fronto-orbital seta absent. Face subshiny brown with thin grayish white microtomentum, without conspicuous setae. Gena with dense silvery microtomentum, without conspicuous setae. Antennae brown, first flagellomere brown dorsally and yellow ventrally; arista short-haired. Gena-to-eye ratio 0.24–0.26.

Thorax subshiny brown; mesonotum and notopleuron brownish yellow microtomentose; anepisternum, anepimeron, katepisternum and katepmeron grayish white microtomentose; scutellum brownish yellow microtomentose with velvety black lateral margin. Acrostichal and dorsocentral setae small; 1 strong prescutellar seta; anterior notopleural seta absent and posterior notopleural seta large; humeral and posthumeral setae very small; anepisternum with 1 small seta at posterior margin; scutellum with 1 pair of strong apical setae and 1 pair of small lateral setae. Wing ( Fig. 13) yellow, with 2 white spots on anterior and posterior sides of posterior crossvein; crossveins not blackened. Costal vein ratio 1.16–1.17; M vein ratio 0.36–0.38. Base of coxae brownish yellow; apex of coxae, femora, tibiae and tarsomeres 1–3 yellow; tarsomeres 4–5 brownish yellow.

Abdomen subshiny brown. Male genitalia ( Figs. 14–16). Cercus short and thick; surstylus short and broad with 3 setae at apex in posterior view ( Fig. 14); aedeagus slender with dorsal process in lateral view ( Fig. 16).

Distribution. China (Sichuan, Yunnan, Taiwan); Philippines.

Remarks. This species is somewhat similar to H. fenestrata Becker from the Palearctic Region in the wing markings, but it can be distinguished from the latter by the costal vein ratio 1.16–1.17 and M vein ratio 0.36–0.38, and the yellow legs. In H. fenestrata , the costal vein ratio is 0.80–0.87 and M vein ratio is 0.31–0.33, and the legs are brown. The species is distinctly different from H. guttata (Fallén) from the Palaearctic Region in the grayish white anepisternum. In H. guttata , the anepisternum presents a velvety blackish spot on its dorsal half ( Mathis and Zatwarnicki 2004a).