Dexia divergens Walker, 1856

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 : 26-28

Dexia divergens Walker, 1856

Figs. 25−28

Dexia divergens Walker, 1856a: 21 . — Wulp 1896: 138 (catalog). — Crosskey 1976: 178 (catalog). — Zhang & Shima 2004: 54 (Chinese Dexia ). — Zhang et al. 2004: 128 (list). — Zhang et al. 2005: 304 (list). — Hao et al. 2008: 99 (list). — O’Hara et al. 2009: 28 (catalog).

Eomyocera carinata Townsend, 1926: 538 . — Baranov 1932: 216. — Crosskey 1967: 101 (as syn. of D. divergens ).

Diagnosis. Dark inner thoracic vitta 1/2−1/4 as wide as pruinose portion between inner and outer vittae; 3 presutural and 3 postsutural dorsocentral setae; abdominal tergites with whitish pruinosity only on anterior margin; tergites 3 and 4 each with median discal setae in both sexes.

Description. Body length. 7.5−14.3 mm.

Male. Head with grayish white pruinosity, fronto-orbital plate and parafacial slightly pale yellowish; antenna and palpus yellow. Frons 0.15−0.18 times as wide as head width, frontal vitta slightly narrower than fronto-orbital plate at middle, parafacial nearly parallel-sided, 2.0−2.5 times as wide as 1st flagellomere; face rather well concave, facial carina long and sharp on ridge, lower margin of face slightly protruding forward; gena about 0.4 times as wide as eye height, with several fine and long hairs on lower portion. Inner vertical seta 0.35−0.38 times as long as eye height, fine, about twice as long as hair-like outer vertical setae; ocellar seta slightly longer than postocellar seta, as strong as frontal seta; 8−9 inclinate frontal setae, lowest seta nearly level with base of antenna; vibrissa inserted slightly above level of lower of face; fronto-orbital plate with a row of several fine rather long hairs; parafacial nearly bare, several minute hairs visible at high magnifications; gena with several fine and rather long hairs on lower portion; occiput without black hairs behind postocular setae. Antenna falling short of lower margin of face by about length of 1st flagellomere, 1st flagellomere about 3 times as long as pedicel; total width of arista including plumosity 2.5−3 times as wide as 1st flagellomere. Prementum 3 times as long as wide; palpus subequal in length to antenna or premenum.

Thorax black in ground color, postpronotal lobe reddish, with grayish white pruinosity, pruinosity on scutum slightly pale yellowish; scutum with 4 longitudinal black vittae that do not extend back to scutellum, inner vitta 1/2−1/4 as wide as pruinose portion between inner and outer vittae; scutellum darkened on basal 1/ 2. All thoracic hairs black, prosternum about twice as long as wide; usually 1 presutural and 2 postsutural acrostichal setae; 3 presutural and 3 postsutural dorsocentral setae; 2 postsutural intra-alar setae, anterior one smaller; 2 supra-alar setae; 2 katepisternal setae. Wing hyaline, slightly and evenly tinged with pale brown; tegula reddish yellow or pale brown on apical 1/2 and dark on basal half; basicosta brown to dark; halters yellow. Lower calypter pale brown, with long fringe on outer margin. Costal spine 1.0−1.5 times as long as rm crossvein; relative lengths of 2nd, 3rd and 4th costal sectors approximately 1:2:1; vein M from dm-cu crossvein 3−4 times distance between the bend and wing margin, appendix about 1/2 length of r-m crossvein. Legs reddish yellow, tarsi brown-black. Hind leg longest, hind femur distinctly longer than other femora, hind tibia slightly sinuate at basal 1/3. Mid tibia with 2−6 posterodorsal setae; hind tibia with 2−4 anterodorsal, 2 posterodorsal and 1−3 ventral setae

Abdomen long ovate, translucent reddish yellow; black on mid dorsal longitudinal portion of syntergite 1+2 to tergite 5, anterior and posterior margin of syntergite 1+2, posterior 1/6 of tergites 3 and 4 and narrow posterior margin of tergite 5, with rather dense whitish pruinosity on anterior 1/7 of tergite 3, 1/6−1/8 of tergite 4 and 1/3−4/5 of tergite 5. Hairs black, rather dense fine short and suberect, finer on tergite 5 and longer on venter; syntergite 1+2 without median marginal setae, with 1 lateral marginal seta; tergite 3 with 1−2 pairs of median discal, 1 pair of median marginal and 1−2 lateral marginal setae, tergite 4 with 1−2 pairs of median discal, a row of marginal, and 1 laterodiscal setae; tergite 5 with some discal and a row of marginal setae, marginal setae shifted forward on median portion. Male terminalia. Surstylus long, bluntly rounded apically; postgonite shorter than basiphallus; distiphallus long.

Female. Frons about 0.34 times as wide as head width, frontal vitta about 1/2 as wide as fronto-orbital plate; parafacial about 3 times as wide as 1st flagellomere, genal 0.57−0.59 times as wide as eye height; all head setae strong, outer vertical seta more than 3/5 eye height, about 1/2 as long as inner vertical seta, ocellar seta shorter than inner vertical seta, 1 prevertical and 2 strong proclinate orbital setae, 4−6 frontal setae. Basicosta pale. Abdomen reddish yellow, syntergite 1+2 and tergite 3 dark brown on mid dorsal portion and posterior margin; grayish white pruinosity on anterior 1/4−1/2 of tergites; tergites 3 and 4 each with a pair of median discal setae; tergite 5 without discal setae. Other characters almost same as in male.

Type material examined. Holotype male of Eomyocera carinata Townsend , Island of Penang, MALAYSIA, Baker ( USNM) . Lectotype male of Dexia divergens Walker (by fixation of Crosskey 1976: 178), MALAYSIA, Mt. Ophir , Johore, Malay Peninsula, 68, A.R. Wallace ( BMNH) .

Additional material examined. CHINA. Formosa (= Taiwan) : 1 female, Gebiet des Shisha –stammes, v– vi.1912, H. Sauter ( USNM). Fujian : 6 males, 5 females, Zhangpu , 23−28.v.1962, G.-T. Jin leg. 3 males, 1 female, Ninghua , 17−24.v.1959, G.-T. Jin, Y.-M. Lin . 1 male, Chongan, Xing village , 7.vi.1960, G.-T. Jin, Y.- M. Lin . 1 male, Jianyang, Huangkeng , 5.vii.1960, G.-T. Jin, Y.-M. Lin. Jiangxi : 1 male, Jinggang Shan, Ciping , 28.iv.1981, X.-W. Liu, G.-T. Jin ( SEMC). Guangdong : 351 males, Huguang, Zhanjiang , 7.iv.1981, 11.vii.1981, 20.viii.1981, Z. Liang ( IZCAS) . 10 males, 3 females, Lingnan Univ. campus, Guangzhou , 6.viii.1927, K.-S. Chan . 5 males, Honam Island, Panyu District, 1931 ( SYU). Guangxi : 1 male, Longsheng , 140 m, 1.v.1963, Y.-S. Shi . 1 male, Longzhou , 640 m, 1.v.1963, Y.-S. Shi ( IZCAS) . 1 male, Jinxiu, 10.xi.1981, G.-T. Jin leg ( SEMC). Shaanxi: Hua Shan , 4.viii.1978, G.-T. Jin ( SEMC). Sichuan : 1 male, Emei Shan , 16.v.1955, K.-R. Huang, and G. Jin. Xizang : 2 males, Médong , 23.x.1979, J.-W. Wu ( SEMC). Yunnan : 1 male, Dongbiguan, 1200−1400m, Dehong , 15−16.ix.1996, H. Shima . 1 male, Wuliang Shan, Jingdong , 24.viii.1990, H. Shima . 1 female, Haishuihe, 2700 m, Lijiang , 28.viii.1996, H. Shima ( BLKU) . 1 male, Damenglong, Xishuangbanna , 17.iv.1955, S.-Y. Wang . 1 male, Baoshan, Mt. NE. 1200−1800 m, 28.v.1955.1 male, Jingdong , 1170 m, 28.v.1956, Kelexiangnovski . 1 male, Mt. Kongming, 2200 m, Xishuangbannan , 23.ix.1957, L.-C. Zang . 2 males, Xiaomengyang , 800 m, 3-4.v.1957, Bangfelov, S.-Y. Wang . 1 male, Pianma, 2100 m, Lushui , 29.v.1981, C.-M. Chao . 1 male, Adong, 2700 m, Deqin , 5.ix.1981, X.-Z. Zhang ( IZCAS) . 9 males, Menglun-Jincang, Xishuangbanna , 11.v−9.vi.1983, J.-M. Fang. Zhejiang : 1 male, Qingyuan, Baishanzu , 23.vii.1963, G.-T. Jin ( SEMC) . INDONESIA. 1 male, Mt. Pusuk. 300 m, Lombok , 23.xii.1973, S. Shinonaga . 3 males, Suranad, 100 m, Lombok , 19−21.xii.1973, H. Kurahashi and S. Shinonaga . 1 male, Mt. Tjemere, 400−1400 m, Grebon , Java, 19−25.xi.1973, R. Kano . 3 males, Kupang, 20 m, Timor , 15−18.xii.1973, S. Shinonaga ( BLKU) . MALAYSIA. 1 male, Malaya, Island of Penang, 1916, Baker . INDIA. 1 male, Ammatti , S. Coorg., 3100 ft, v.1951, P. S. Nathan . 1 female, Naduvatam, Nilgiri Hills , 6000 ft, v.1958, P. S. Nathan . 1 female, Anamalai Hills, Cinonona , 3500 ft, v.1959, P. S. Nathan ( USNM) .

Distribution. China (Fujian, Guangdong, Guangxi, Hainan, Jiangxi, Shaanxi, Sichuan, Xizang, Yunnan, Zhejiang), India, Indonesia (Java, Lombok, Timor), Malaysia (Pen. Malaysia).

Remarks. This species is similar to D. subnuda , but is distinguished from it in having reddish yellow tibiae, abdominal tergite 5 reddish yellow in male, at least on basal 1/ 2 in female, with whitish pruinosity on anterior 1/3−4/5, and female with 1 pair of median discal setae on tergite 4.