Dexia hainanensis Zhang, 2005

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 : 44-45

Dexia hainanensis Zhang, 2005

Figs. 49−52

Dexia hainanensis Zhang, 2005: 436 . — O’Hara et al. 2009: 29 (catalog).

Diagnosis. Thoracic dorsum with 4 longitudinal vittae, of which inner longitudinal black vitta is about 1/4 as wide as pruinose portion between inner and outer vittae on presutural scutum; abdominal tergites 3 and 4 each with a complete row of marginal setae in both male and female.

Description. Zhang (2005) described this species in detail. Here we give some diagnostic characters.

Body length. 9.0−15.0 mm.

Male. Frons 0.14−0.17 times as wide as head width; parafacial slightly more than twice width of 1st flagellomere; gena 0.4−0.44 times as wide as eye height. Inner vertical seta slightly more than 1/3 eye height, and twice as long as outer vertical seta; ocellar seta stronger than inner vertical seta. 1st flagellomere 3.5−4 times as long as pedicel. Prementum 2.5−3 times as long as wide; palpus about as long as antenna. Thorax black in ground color, postpronotal lobe and apical half of scutellum reddish yellow, covered with with thin pale yellowish pruinosity; scutum with 4 longitudinal black vittae, inner vitta about 1/4 as wide as pruinose portion between inner and outer vittae. Proepisternum bare. All thoracic hairs black; postpronotal lobe with 3−4 setae (2 strong), 3 basal setae standing nearly in a straight line; 3 presutural and 3 postsutural dorsocentral setae; 2 postsutural intra-alar setae; 2 supra-alar setae; 2 katepisternal setae. Wing pale brownish hyaline; tegula and basicosta dark brown, tegula sometimes reddish yellow on base. Costal spine about as long as crossvein r-m; relative lengths of 2nd, 3rd and 4th costal sectors approximately 1:2.2:1.2; vein M from dm-cu crossvein to its bend 4−6 times distance between the bend and wing margin. Lower calypter with long fringe on outer margin. Legs reddish yellow. Mid tibia with 2 posterodorsal setae; hind tibia with 4−5 anterodorsal, 2−5 posterodorsal and 2 ventral setae. Abdomen translucent yellow, black on mid-dorsal longitudinal area and posterior margin of syntergite 1+2 to tergite 5, with rather dense whitish pruinosity on anterior 1/6−1/5 of tergites 3 to 5. Syntergite 1+2 with 1 lateral marginal seta, without median marginal setae; tergites 3 and 4 each with 2 pairs of median discal and a row of marginal setae; tergite 5 with rows of discal and marginal setae. Male terminalia. Cerci slender and apically pointed; surstylus about 3 times as long as wide, apex blunt or weakly pointed; postgonite slightly shorter than basiphallus; distiphallus long, scleoritzed basal part about 3 times as long as membranous apical part.

Female. Frons 0.3−0.4 times as wide as head width; gena about 0.52 times as wide as eye height; inner vertical seta about 2/3 eye height; outer vertical seta slightly less than 1/2 length of inner vertical seta; ocellar seta as long as inner vertical seta; 1 weak outwardly directed prevertical and 2 strong proclinate orbital setae; 6−8 frontal setae. Lower calypter yellowish, with short fringe on outer margin. Abdomen yellow, dark brown on posterior margin of syntergite 1+2, posterior 1/3 of tergite 3 and posterior 2/3 of tergites 4 and 5; grayish white pruinosity on anterior 1/4−1/5 of tergite 3 and anterior 1/3 of tergites 4 and 5; tergite 3 with 1−2 pairs of median discal setae and tergite 4 with a pair of median discal setae. Other characters almost same as in male.

Type material examined. Holotype male of Dexia hainanensis Zhang , CHINA, Jianfengling , 800 m, Hainan, 20.v.1993, Y.-S. Cui . Paratypes. Hainan: 1 male, 1 female, same data as holotype ; 1 male, Wuzhi Shan, 1200 m, 14.v.1993, Y.-S. Cui ( SNU) .

Additional material examined. CHINA. Hainan: 1 male, Jianfengling, 20.vi.1981, Z.-Q. Chen ( IZCAS) . 2 females, Diaoluo Shan , 500−950 m, 22−24.v.2003, C.-T. Zhang ( SNU) .

Distribution. China (Hainan).

Remarks. This species appears to be close to D. divergens , but differs from it in having narrow inner thoracic vitta, abdominal tergite 3 with a complete row of marginal setae in both sexes, and narrower cerci.