Dexia longipennis (Townsend)

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 : 49-50

Dexia longipennis (Townsend)

Eomyoceropsis longipennis Townsend, 1926a: 29 . — Baranov 1932: 216. — Crosskey 1969: 94 (type material). — Shima 1989: 869 (list).

Dexilla longipennis (Townsend) : Crosskey 1967: 106.

Dexia longipennis (Townsend) : Crosskey 1976: 179.

Diagnosis. Thorax with 2 presutural and 3 postsutural dorsocentral setae; tibiae reddish yellow, mid and hind tibiae slightly darkened; lower calypter with short fringe.

Description. Body length. 7.9−11.1 mm.

Male. Head with dense pale yellowish white pruinosity; fronto-orbital plate more whitish; antenna orange yellow, with reddish yellow arista; palpus reddish yellow. Frons 0.16−0.17 times as wide as head width; frontal vitta about twice as wide as fronto-orbital plate; parafacial about 2.5 times as wide as 1st flagellomere at middle height; facial carina curved, sharp at apex; lower margin of face slightly produced forward; gena about 0.4 times as wide as eye height. Inner vertical seta fine, about 2/5 eye height; outer vertical seta about 3/ 5 as long as inner seta; ocellar seta stronger than inner vertical seta; 10−12 frontal setae, lowest seta nearly level with base of antenna; fronto-orbital plate almost bare; vibrissa inserted slightly above level of lower margin of face; gena with 1−2 rows of several fine hairs. Antenna falling short of lower margin of face by about 1/2 length of pedicel and 1st flagellomere combined; 1st flagellomere about 4.8 times as long as pedicel. Total width of arista including plumosity about 3 times as wide as 1st flagellomere. Prementum about 1/3 as long as eye height; palpus slightly shorter than 1st flagellomere.

Thorax black in ground color, scutum with rather dense yellowish white pruinosity, 2 broad outer and 2 narrow inner vittae, outer vitta about twice as wide as inner one and inner vitta subequal in width to pruinose portion between outer and inner vittae on presutural scutum; posteromedian portion of postsutural scutum slightly brownish; scutellum with yellowish gray pruinosity, dark on basal 1/3; pleura with rather dense grayish white pruinosity. Hairs black; 2–3 postpronotal setae; 1 presutural and 2 postsutural acrostichal setae; 2 presutural and 3 postsutural dorsocentral setae; 2 postsutural intra-alar setae; 2 supra-alar setae; 2 katepisternal setae, katepisternum with dense hairs. Wing evenly pale brownish tinged; tegula dark brown, basal portion slightly pale; basicosta black; lower calypter translucent pale brown, with long fringe on outer margin. Costal spine as long as r-m crossvein; relative lengths of 2nd, 3rd and 4th costal sectors approximately 1.1:2.6:1.3; vein M from dm-cu crossvein to its bend about 3 times distance between the bend and wing margin, appendix short. Legs reddish yellow; tarsi and claws brown-black; pulvilli brown. Mid and hind legs subequal in length and slightly longer than fore leg; hind tibia nearly straight. Mid tibia with 2 posterodorsal setae; hind tibia with 4 anterodorsal, upper 3 fine, 1 posterodorsal and 1 ventral setae. Claws and pulvilli slightly shorter than tarsomere 5.

Abdomen translucent reddish yellow, brownish-black on mid-dorsal longitudinal portion of syntergite 1+2 to tergite 4, posterior margin of syntergite 1+2, posterior 1/5 of tergites 3 and 4 and entire tergite 5; rather dense yellowish white pruinosity on anterior portion of tergites 3 and 4 (about anterior 1/8−1/10) and anterior 1/3 of tergite 5, the pruinosity band on tergite 5 narrowed on mid dorsal portion. Hairs dense fine short erect and black; syntergite 1+2 with 1 lateral margina seta, without median marginal setae; tergite 3 with 1 pair of median discal, 1 pair of median marginal and 2 lateral marginal setae; tergite 4 with 1 pair of median discal and a row of marginal setae; tergite 5 with 2 pairs of median discal and a row of marginal setae; all setae strong.

Female. Frons about 0.29 times as wide as head width; frontal vitta narrower than fronto-orbital plate at middle; gena about 0.52 times as wide as eye height; all head setae strong, outer vertical seta slightly shorter than 4/5 eye height, about 2/5 as long as inner vertical seta; ocellar seta 5/7 as long as inner vertical seta; prevertical seta subequal in length to ocellar seta; 2 strong proclinate orbital setae, anterior seta stronger and slightly longer than inner vertical seta; 5−6 frontal setae; 1st flagellomere about 6 times as long as pedicel. Thoracic scutum more brownish; legs short, claws and pulvilli short. Abdomen broadly black on mid dorsal longitudinal portion of tergites, and on posterior 1/3−1/4 of tergite 3, posterior 3/4 of tergite 4 and 4/5 of tergite 5; tergites 3 to 5 without discal setae. Other characters almost same as in male.

Type material examined. Lectotype male of Eomyoceropsis longipennis Townsend (by designation of Crosskey 1969: 94), INDONESIA, Tjibodas , Java, ii.1916, E. Jacobson ( USNM).

Additional material examined. MALAYSIA. 1 male and 11 females, Pahang ( BMNH) .

Distribution. Japan (Irimote Is.), Indonesia (Java), Malaysia (Pen. Malaysia)*.

Remarks. This species was described from two males. Crosskey (1969: 94) examined the “ Lectotype male [by fixation of Townsend, 1938: 331]” in USNM, and this is here accepted as the lectotype of Eomyoceropsis longipennis Townsend. Following O’Hara et al. (2009: 11) , lectotype fixation by Townsend (1928: 331) is not accepted.

This species is similar to D. monticola , but differs from it in having short fringe on outer margin of lower calypter, and abdominal tergites 3 and 4 each with a pair of discal setae in male and without them in female.