Billaea impigra Kolomiets, 1966

Zhang, Chun-Tian, Shima, Hiroshi, Wang, Qiang & Tschorsnig, Hans-Peter, 2015, A review of Billaea Robineau-Desvoidy of the eastern Palearctic and Oriental regions (Diptera: Tachinidae), Zootaxa 3949 (1), pp. 1-40 : 14

Billaea impigra Kolomiets, 1966

Billaea impigra Kolomiets, 1966: 96 .— Herting 1984: 139 (catalog).— Herting & Dely-Draskovits 1993: 358 (catalog).— Ziegler & Shima 1996: 428 (distribution).— Richter 2004: 352 (key).

Redescription. Body length 10.0– 12.5 mm.

Male. Head. Palpus reddish yellow. Vertex of male about 2.5 times as wide as ocellar triangle. Frontal vitta about 3 times as wide as anterior ocellus. Parafacial bare, about 2.5 times as wide as flagellomere 1. Facial carina distinct and wide on top. Genal height slightly more than 1/2 eye height. Occiput slightly inflated. Antenna reddish yellow to brown. Flagellomere 1 2.8 times as long as pedicel and 3.5 times as long as wide; arista thickened at basal 1/4, plumose, length of aristal hairs about twice the width of aristal base. Palpus about 3/4 of genal height.

Thorax. Scutum with 3 presutural and 5 postsutural dark longitudinal vittae, median vitta wider, about as wide as the pruinose distance between median and lateral vittae; scutellum black. Five postpronotal setae, 1–2 presutural and 2 postsutural acrostichal setae, 4 postsutural dorsocentral setae, 3 postsutural intra-alar setae, 3 katepisternal setae. Wing. Hyaline, brownish, basicosta brownish yellow; cell R4+5 open, and vein r4+5 with 5 setose at base. Legs. Fore claws and pulvilli longer than 5th tarsomere in male, 5th tarsomere about 8/9 length of fore claws. Hind tibia with 2 strong setae among a sparse row of anterodorsal setae in equal length.

Abdomen. Bluish black, covered with gray pruinosity, intermediate tergites without a pair of dark triangular spots or distinct dark transverse band, discal setae absent. syntergite 1+2 with 2 median marginal setae (after Kolomiets 1966 and personal letter from V. Richter). V. Richter warmly gave us a description of some important characters, and a figure of the male terminalia of the type specimens of B. impigra in lateral view.

Female. Antenna dark brown except reddish brown pedicel. Vertex about 0.33 of head width; frontal vitta wider than fronto-orbital plate; genal height about 0.5 of eye height; facial carina indistinct, not developed; flagellomere 1 2.5–2.8 times as long as wide and as pedicel; 8 inclinate frontal setae; inner vertical setae about 0.7 times as long as eye height; outer vertical seta 1/2 as long as inner vertical seta; ocellar seta about as long as frontal setae; 2 proclinate orbital setae; 1 outwardly directed prevertical seta; arista short plumose, longest aristal hairs about 1/2 width of flagellomere 1; prementum about 4 times as long as wide. Thoracic scutum with 5 presutural and 5 postsutural dark longitudinal vittae, 4 supra-alar (including prealar) setae; fore claws and pulvilli shorter than 5th tarsomere; mid tibia with 3 anterodorsal, 3 posterodorsal setae; hind tibia with 3–5 strong setae among row of anterodorsal setae, 2 posterodorsal and 2 ventral setae; abdomen dark brown in ground color, tergites 3 to 5 densely covered with sparse grayish white pruinosity; syntergite 1+2 and tergite 3 each with 2 median marginal setae and 1 lateral marginal seta. Other characters are same as in male.

Type material. Holotype ♂, RUSSIA, Primor’ye Peninsula (Primorskij), Far East (131°40′E, 43°10′N), 17.vii.1963 ( ZIN). Paratypes. RUSSIA: 1♂, same as holotype; 1♂, Durming, Habarovskij Kraj, 27.vii.1959 ( ZIN). Not examined.

Material examined. CHINA: 1♀, Yanggetai, Fangshan, 24.vi.1990, Shaanxi, M.-F. Wang ( SYNU).

Distribution. China (Shanxi) (new record for China), Russian Far East (Ussuria), S Siberia.

Remarks. We did not examine the holotype of this species. Above brief description was made after Richter’s personal communication and following Richter (2004). This species appears to be similar to B. fortis and may be distinguished from it in having long flagellomere 1, hind tibia with 2–5 strong setae among a sparse row of anterodorsal setae in equal length, and abdominal syntergite 1+2 with 2 median marginal setae.