Dexia chinensis Zhang et Chen, 2010

Zhang, Chun-Tian, Shima, Hiroshi & Chen, Xiao-Lin, 2010, A review of the genus Dexia Meigen in the Palearctic and Oriental Regions (Diptera: Tachinidae) 2705, Zootaxa 2705, pp. 1-81 : 24-26

Dexia chinensis Zhang et Chen , sp. nov.

Figs. 21−24

Diagnosis. Antenna reddish yellow; prementum 3 − 4 times as long as wide; 3 katepisternal setae; legs black; abdominal syntergite 1+2 without median marginal setae.

Description. Body length. Male: 13.0− 14.5 mm, female: 12.5−13.5 mm.

Male. Head with grayish white pruinosity, frontal vitta brownish black; gena reddish brown, with thin grayish pruinosity; antenna reddish yellow, pedicel and arista brownish; prementum black; palpus reddish yellow. Frons 1/8−1/9 head width; parafacial about 3 times as wide as 1st flagellomere; face well concave, lower margin slightly protruding forward; facial carina developed, sharp on ridge; gena about 0.4 times as wide as eye height. Inner vertical seta fine, 0.2−0.3 times as long as eye height and distinctly shorter than ocellar seta; outer vertical seta hair-like; 10−12 inclinate frontal setae; fronto-orbital plate with sparse hairs on inner side; parafacial bare; ocellar seta as strong as upper frontal seta; vibrissa inserted above lower margin of face. Antenna falling short of lower margin of face by about length of antenna; 1st flagellomere about 2.5 times as long as pedicel; total width of arista including plumosity about 3 times as wide as 1st flagellomere. Prementum 3−4 times as long as wide; palpus longer than antenna, subequal in length to prementum.

Thorax black in ground color, with grayish brown pruinosity on scutum and gray pruinosity on pleura, 2 pairs of longitudinal black vittae on dorsum, which extend back to anterior 2/5−2/3 postsutural scutum, narrow inner vitta 1/3 as wide as pruinose portion between inner and outer vittae on presutural scutum; scutellum brownish black on basal 1/2−2/3, with yellowish gray pruinosity at apex. Prosternum 2.0−2.5 times as long as wide; proepisternum bare; hairs all black; postpronotal lobe with 3−4 setae, 3 basal setae set in a triangle; 1−2 presutural and 2 postsutural acrostichal setae; 3 presutural and 3 postsutural dorsocentral setae; 2 postsutural intra-alar setae; 2 supra-alar setae; 2−3 pairs of discal scutellar setae; 3 katepisternal setae. Wing hyaline, brownish; tegula and basicosta brownish black; lower calypter yellow. Costal spine slightly shorter than crossvein r-m; relative lengths of 2nd, 3rd and 4th costal sectors approximately 1:2.2:1.1, vein M from dm-cu crossvein to its bend about 3 times distance between the bend and wing margin, appendix absent. Lower calypter with short fringe on outer margin. Legs. Femora brownish black; tibiae reddish yellow except darkened on apical 1/3 and basal 1/3 ventrally; claws black, pulvilli yellowish. Mid tibia with 2 (seldom 1) posterodorsal setae; hind tibia with 2 anterodorsal, 2 posterodorsal and 2 ventral setae. Claws and pulvilli slightly longer than tarsomere 5.

Abdomen long ovate, yellow, dark brown to black on mid-dorsal longitudinal portion, posterior portion of tergite 4 and almost entire tergite 5, with grayish white pruinosity on anterior margin of tergites 3 and 4, and almost entire tergite 5; syntergite 1+2 to tergite 4 each with a brown or dark markings on basal areas of lateral marginal setae. Syntergite 1+2 without median marginal setae; tergite 3 with 1 pair of median discal and 1 pair of median marginal setae; tergite 4 with 2 pairs of median discal, 0−1 lateral discal and a row of marginal setae; tergite 5 with several discal and a row of marginal setae. Male terminalia. Sternite 5 rectangular, V-shaped median cleft deep, about 2/3 length of the sternite, posterior lobe bluntly rounded at apex; distal half of cerci slender and pointed apically; surstylus short and narrow, slightly pointed at apex; pregonite short, bent posteriorly; postgonite shorter than basiphallus; distiphallus long, plate-like.

Female. Frons widened anteriorly, 0.3−0.4 times as wide as head width at narrowest point; gena 0.6−0.7 times as wide as eye height; 1 prevertical and 2 proclinate orbital setae; outer vertical seta about 1/2 as long as inner vertical seta. 1−2 pairs of discal scutellar setae. Fore claws shorter than tarsomere 5. Abdomen ovate, reddish brown except for black mid-dorsal longitudinal portion and brown venter of tergite 4 and 5, grayish white pruinosity on anterior margin of tergite 3, anterior 2/3 of tergite 4 and entire tergite 5; tergites 3 to 5 without discal seta. Other characters same as in male.

Type material. Holotype male, CHINA. Heshangmao Forestry Center , 106°26'E, 35°35'N, 2100−2300 m, Jingyuan, Ningxia, 23−24.vi.2008, Z.-Y. Yao ( SNU) . Paratypes. CHINA, Beijing: 1 male, Xiaolongmen , 13.vii.2005, (light trap), K.-Y. Zhang . 1 female, Tangzigou, 730–920 m, Songshan , 24.vii.2009, D. Zhang ( SNU) . Guizhou: 1 male, Fanjing Shan , 1300−1900 m, 29.vii.2001, W.-Z. Cai ( CAU) . Hebei: 2 males, 1 female, Mt. Xiaowutai , 21−29.vi.2009, Y.-Y. Zhou & C. Fu . Ningxia: 1 female, same data as holotype . 1 male, 1 female, Lüyuan Forestry Center, 1700−1800 m, Jingyuan , 30.vi.2008, Z.-Y. Yao &, J.-Y. Liu . 1 female, Qiuqianjia Forestry Center, 1800 m, Jingyuan , 4.vii.2008, J.-Y. Liu ( SNU) .

Etymology. Specific epithet is taken from the country of origin, China.

Distribution. China (Beijing, Guizhou, Hebei, Ningxia).

Remarks. This new species is similar to D. chaoi , but differs from it in having wholly reddish yellow 1st flagellomere and 2 supra-alar setae, and tergite 4 dark brown on posterior portion.