Billaea steini Brauer et Bergenstamm 1891
Creators: name: Zhang, Chun-Tian
name: Shima, Hiroshi
name: Wang, Qiang
name: Tschorsnig, Hans-Peter
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Tachinidae
Billaea
Billaea steini

description: Billaea steini (Brauer et Bergenstamm, 1891)
Figs. 52–55, 86, 95
Gymnodexia steini Brauer et Bergenstamm, 1891: 364.— Bezzi & Stein 1907: 440 (catalog). — Herting 1974b: 142 (type examination).
Billaea steini.— Stein 1924: 231 (key and notes).— Zimin et al. 1969: 1271 (key).— Herting 1984: 140 (catalog).— Herting & Dely-Draskovits 1993: 360 (catalog).— Tschorsnig & Herting 1994: 80 (key).— Ziegler & Shima 1996: 428 (distribution).— Richter 2004: 352 (key).— Shima 2014: 833 (catalog).
Billaea ringdahli Villeneuve, 1937: 2.— Zimin et al. 1969: 1270 (key).— Mesnil 1970: 122 (as syn. of steini).— Herting 1984: 140 (as syn. of steini; catalog).— Herting & Dely-Draskovits 1993: 360 (as syn. of steini; catalog). Billaea inumbrata Kolomiets, 1966: 97.— Herting 1984: 140 (as syn. of steini; catalog).— Herting & Dely-Draskovits 1993: 360 (as syn. of steini; catalog).
Diagnosis. Gena broad, flagellomere 1 short, arista pubescent, prementum about 5 times as long as wide, 2 katepisternal setae, fore claws of male short, abdominal tergites 3 and 4 each with a pair of trapezoid dark brown markings.
Redescription. Body length 9.2–13.0 mm.
Male. Head (Figs. 86, 95). With dense grayish white pruinosity; frontal vitta black, lunule brown; antenna dark brown except base of flagellomere 1 and pedicel reddish brown; arista dark brown; palpus reddish yellow. Vertex 0.17–0.20 of head width; frontal vitta wider than fronto-orbital plate at narrowest point; the latter with 2–3 rows of fine black hairs; parafacial bare, 2.5–3 times as wide as flagellomere 1; facial carina short and low, indistinct; lower margin of face slightly protruding forward; gena broad, its height 0.43–0.53 of eye height. Inner vertical seta 0.44–0.47 of eye height; 14–16 inclinate frontal setae, which are slightly shorter than ocellar seta and distinctly shorter than inner vertical seta. Flagellomere 1 1.5–2 times as long as pedicel; pedicel with long a seta which is as long as flagellomere 1 and pedicel combined; arista pubescent, the pubescence at most as wide as base of arista. Palpus about as long as prementum, the latter about 5 times as long as wide.
Thorax. Black, with dense gray pruinosity, 5 longitudinal black vittae on scutum, inner vitta about 1/2 width of outer vitta on presutural area; scutellum black, with gray pruinosity. Prosternum about 1.5 times as long as wide; 4 postpronotal setae, 3 basal setae in a straight line; 0–1 presutural and 2–3 postsutural acrostichal setae; 3 presutural and 4 postsutural dorsocentral setae; 2 postsutural intra-alar setae; 3 supra-alar setae; 2 katepisternal setae; katepimeron haired. Wing. Hyaline, brownish; tegula black, basicosta dark brown; calypter yellowish white; halter reddish at base and dark brown at apex. Relative lengths of 2nd, 3rd and 4th costal sectors approximately as 7:13:6; vein M from dm-cu crossvein to its bend about 1.5 times distance between the bend and wing margin, bend approximately right-angled, with a short appendix; cell r4+5 closed or narrowly open. Legs. Black; pulvilli yellowish. Fore claws and pulvilli shorter than 5th tarsomere; fore tibia with a row of short anterodorsal setae on basal 3/5 and 1–2 posterior setae; mid tibia with 1–2 anterodorsal, 2 posterodorsal and 1–2 ventral setae; hind tibia with a row of closely set anterodorsal setae in equal length, 2 posterodorsal and 2 ventral setae.
Abdomen. Wide ovate, reddish brown to dark brown, densely covered with gray pruinosity on most of tergites, with a pair of small to medium dark trapezoid markings on tergites 3 to 5 which are interrupted by a narrow gray pruinose vitta. Dorsum with short and recumbent black hairs on tergites; syntergite 1+2 with 1 lateral marginal seta; tergite 3 with 2 median marginal and 1 lateral marginal setae. Male terminalia (Figs. 52–55). Posterior lobes of sternite 5 blunt. Cerci and surstylus long and narrow, cerci pointed apically in caudal view; postgonite slightly longer than basiphallus; distiphallus long, membranous apical part slightly longer than sclerotized basal part.
Female. Vertex about 0.36 of head width; frontal vitta wider than fronto-orbital plate at narrowest point; parafacial about 3.6 times as wide as flagellomere 1; genal height 0.53 of eye height. Two strong proclinate orbital setae and 1 weak reclinate prevertical seta, proclinate ocellar setae about as strong as frontal setae and stronger than prevertical seta, crossed inclinate inner vertical and outwardly directed outer vertical setae strong. Mid tibia with 2 anterodorsal, 3 posterodorsal and 2 posterior setae and 1 ventral seta; hind tibia with 2–3 strong setae among irregular row of anterodorsal setae, 3–4 posterodorsal and 3 ventral setae.
Type material examined. Holotype ♀ of Gymnodexia steini Brauer et Bergenstamm, HUNGARY (NHMW). Holotype ♂ of Billaea ringdahli Villeneuve, SWEDEN (CNC).
Other material examined. JAPAN. Hokkaidō: 1♂, Iwaobetsu (Mt. Rausu), 5.viii.1967, T. Saigusa; 1♂, Aizankei, Mts. Daisetsu, 10.viii.1967, H. Shima (KUM). 2♂♂, Okapeppu-rindo, Shiretoko, 29.viii.1995, T. Tachi; 1♂, Okepeppu-rindo, Shiretoko, 13.viii.1996, T. Tachi (BLKU). SWEDEN. 1♂, 1♀, Visby, 21.vii.1936 (SMNS).
Distribution. Japan (Hokkaidō), Europe (Austria, Bulgaria, Hungary, Sweden) and Russian Far East (Ussuria).
Remarks. This species is one of five species with bare parafacial, 2 katepisternal setae, fore claws and pulvilli of male short and a pair of triangular black markings on each tergites 3 and 4, the other species being B. robusta, B. triangulifera, B. chinensis and B. atkinsoni. Within these species, B. steini and B. triangulifera are the only two with 5 dark longitudinal vittae on presutural scutum, fore tibia with 2 posterior setae, abdomen dark brown, and tergite 3 with 2 strong median marginal setae. But B. steini differs from the latter in having short flagellomere 1, pubescent arista, longer prementum, and shorter and wholly dark flagellomere 1.
description: Published as part of 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), pp. 1-40 in Zootaxa 3949 (1) on pages 23-24, DOI: 10.11646/zootaxa.3949.1.1, http://zenodo.org/record/288389