Dexia tenuiforceps Zhang et Shima, 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 : 66-68

Dexia tenuiforceps Zhang et Shima , sp. nov.

Figs. 81−84

Diagnosis. Prementum 5−6 times as long as wide; 3 katepisternal setae; tegula mostly black except reddish brown base; legs reddish yellow; abdominal syntergite 1+2 with 1 pair of median marginal setae; and surstylus narrow and bent.

Description. Body length. 10.0−15.0 mm.

Male. Head with yellowish gray pruinosity, frontal vitta brownish black, lunule brown; antennae and palpi reddish yellow. Frons 1/6−1/7 as wide as head width; fronto-orbital plate slightly wider than or subequal in width to frontal vitta at middle; parafacial 2.5−3 times as wide as 1st flagellomere; facial carina developed, ridge arched in lateral view, widened below; lower margin of face protruding forward; gena about 3/7 as wide as eye height. Inner vertical seta 0.27−0.4 times as long as eye height, about twice as long as fine, hair-like, outer vertical seta; ocellar seta as strong as upper frontal setae; 12−13 inclinate frontal setae; vibrissa inserted above lower margin of face. Antenna falling short of lower margin of face by 0.6−0.7 times length of 1st flagellomere, latter about 4 times as long as pedicel; total width of arista including plumosity about 4 times as wide as 1st flagellomere. Prementum 5−6 times as long as wide; palpus slightly longer than antenna.

Thorax black in ground color, with grayish yellow pruinosity, 4 longitudinal black vittae on presutural area of scutum and 5 on postsutural scutum, an inner vitta 0.4−0.5 times as wide as pruinose portion between inner and outer vittae on presutural area. All thoracic hairs black; prosternum bare, twice as long as wide; proepisternum bare; 1−2 presutural and 2 postsutural acrostichal setae; 3 presutural and 3 postsutural dorsocentral setae; 2 postsutural intra-alar setae; 3 supra-alar setae, anterior seta about 1/2 as long as posterior two; 3 katepisternal setae. Wing brownish hyaline; basicosta black; tegula mostly black except reddish brown base; lower calypter yellowish, with short fringe on outer margin. Costal spine distinct, about as long as r-m crossvein; relative lengths of 2nd, 3rd and 4th costal sectors approximately 1:2:1; vein M from dm-cu crossvein to its bend 2.5−3.3 times distance between the bend and wing margin, appendix very short. Legs reddish yellow except for dark brown tarsi and brown ventrodistal portions of femora. Mid tibia with 2 posterodorsal setae; hind tibia with 1−3 anterodorsal, 2−3 posterodorsal and 2 ventral setae. Fore claw and pulvillus slightly longer than, or subequal in length to, tarsomere 5.

Abdomen long ovate, translucent yellow, black on mid-dorsal longitudinal areas and on posterior 1/4−1/5 of tergites 4 and 5, black marking on bases of lateral marginal setae of each tergites; grayish white pruinosity on narrow anterior margin of tergites 3, anterior 1/4−4/5 of tergite 4 and entire tergite 5. Syntergite 1+2 with 2 median marginal and 1 lateral marginal setae; tergite 3 with 1−2 pairs of median discal, 1 pair of median marginal and 1 lateral marginal setae; tergite 4 with 1−2 pairs of discal and a row of marginal setae; tergite 5 with a row of discal and marginal setae. Male terminalia. Sternite 5 subsquare, V-shapedmedian cleft about 3/5 length of the sternite, posterior lobe wide and blunt apically; cerci slender on apical half and pointed apically; surstylus narrow and slender, pointed apically; postgonite shorter than basiphallus.

Female. Frons 0.28−0.33 times as wide as head width; frontal vitta slightly narrower than fronto-orbital plate at middle; 1st flagellomere about 5 times as long as pedicel. Tegula and basicosta brown to dark brown. Legs wholly yellow; claws and pulvilli short. Abdomen ovate; reddish yellow; tergites 4 and anterior half of tergite 5 black, with gray pruinosity; abdominal syntergite 1+2 without median marginal setae, tergites 3 and 4 without discal setae. Other characters almost same as in male.

Type material. Holotype male, CHINA. Yongsheng, Liude , 2300 m, Yunnan, 10.vii.1984, R. Wang ( IZCAS) . Paratypes. CHINA. Fujian (= Fukien): 1 male, Shaowu, Taohulan , 1000 m, 14−18.vii.1946, T. Maa . 2 males, Chungan, Kuatun , 22−25.viii.1945, T.C. Maa ( BPBM) . Sichuan (= Szechuen): 1 male, Emei Shan, Xixiangchi , 1800−2100 m, 28.viii.1957, K.-R. Huang . 1 male, 1 female, Moxi, 1500−2400 m, Luding , 15- 18.ix.1982, X.-Z. Zhang ( IZCAS) . 1 male, 1 female, Mt. Omei [= Emei Shan], 4000−7 000 ft, 16−22.viii.1934, D.C. Graham ( USNM) . 4 males, Hongkou, Dujiangyan, Chengdu , 12–13.viii.2009, C.-T. Zhang, C. Fu, Z. Zhao ( SNU) . Yunnan: 1 male, Xishan, 2100 m, Kunming , 17.viii.1996, H. Shima . 1 female, Dagaoping, 1900−2400 m, Baoshan , 7−9.ix.1996, H. Shima . 2 females, Laowo, 2000−2400 m, Nujiang , 4−5.iv.1996, H. Shima ( BLKU) . 28 males, 1 female, Wuliang Shan, 2800 m, Jingdong, Simao , 8−9.vi.2010, C. FU & Y.-Y. Zhou . 7 males, 1 female, Cang Shan, 2700 m, Dali , 11.vi.2010, C. FU & Y.-Y. Zhou . 1 male, Gaoligong Shan, 2400 m, Pianma, Lushui , 22.vi.2010, Y.-Y. Zhou . 2 females, Xi Shan, 1950-2350 m, Kunming , 27.vii.2010, C.-T. Zhang, Q. Wang . 1 female, Gaoligong Shan, 2400 m, Xujiaping, Lushui , 14.viii.2010, Q. Wang ( SNU) . Xizang: 1 male, Médog , 17.viii.1977, G.-T. Jin. Zhejiang : 7 males, Baishanzu, 1080−1200 m, Qingyuan , 23−26.vii.1963, G.-T. Jin ( SEMC) . Taiwan : 1 male, Taihezan, 1960, Baranov ( USNM) . NEPAL. 6 males, 2 females, Basantapur, 2300 m, E. Nepal, 25−26.vii.1972, H. Shima . 1 male, Ramaechap Dist. Jiri, 1950 m, 24.vii.1992, H. Kurahashi . 1 female, Solukhumbu, Bandar-Sete , 2150−2575 m, 26.vii.1992, H. Shima ( BLKU) . 1 male, Ktmd. [= Kathmandu], Pulchauki , 6600 ft, viii.1967, Malaise trap ( CNC) .

Etymology. The specific epithet is taked from a diagnostic character of this species, the narrow surstylus.

Distribution. China (Fujian, Sichuan, Taiwan, Yunnan, Zhejiang), Nepal.

Remarks. This species is similar to D. fraseri , but differs from it by 1st flagellomere and prementum longer, basicosta dark, and wing brownish hyaline, not strongly tinged brown along veins and anterior portion.