Billaea morosa Mesnil 1963

Billaea morosa Mesnil, 1963

Figs. 40–43, 83, 92

Billaea morosa Mesnil, 1963: 53.— Kolomiets 1966: 87 (key and notes).— Herting 1984: 140 (catalog).—Herting & Dely- Draskovits 1993: 359 (catalog).— Ziegler & Shima 1996: 428 (distribution).— Richter 2004: 352 (key).— Zhang et al. 2004: 127 (checklist).— O’Hara et al. 2009: 28 (catalog).— Shima 2014: 833 (catalog).

Diagnosis. Body small, vertex of male 0.12–0.14 of head width, gena 0.20–0.24 of eye height, arista plumose, 2 katepisternal setae, male claws short, fore tibia with 1 posterior seta, abdominal tergite 3 with broad black transverse band not interrupted medially by pruinosity.

Redescription. Body length 6.3–10.5 mm.

Male. Head (Figs. 83, 92). With dense grayish white pruinosity; frontal vitta black; antenna dark brown except reddish yellow pedicel and base of flagellomere 1; palpus dark brown except reddish yellow apex. Vertex 0.12– 0.14 of head width; frontal vitta at narrowest point slightly wider than fronto-orbital plate; parafacial nearly parallel-sided, 1.5–2 times as wide as flagellomere 1; face rather weakly concave, facial carina very weak and indistinct, lower margin of face weakly warped forward, slightly beyond vibrissal angle; genal height 0.20–0.24 of eye height; occiput flattened. Inner vertical seta 0.38–0.39 of eye height, longer than ocellar seta; ocellar seta as long as upper frontal seta; 8–11 pairs of inclinate frontal setae; fronto-orbital plate with a sparsely set row of short fine black hairs; parafacial bare. Antenna with pedicel having a long seta about as long as flagellomere 1; flagellomere 1 2–2.5 times as long as pedicel; arista including plumosity about twice as wide as flagellomere 1. Prementum 2.5–3 times as long as wide; palpus about as long as antenna.

Thorax. Black, with dense yellowish gray pruinosity; 4 dark longitudinal vittae on scutum, inner vitta slightly narrower than outer one on presutural area, a narrow and obscure median vitta visible on anterior 1/2 of presutural scutum; scutellum black, with gray pruinosity on apical half. Postpronotal lobe with 4 setae, 3 basal setae standing nearly in a straight line; 2 presutural and 3 postsutural acrostichal setae; 3 presutural and 4 postsutural dorsocentral setae; 2 postsutural intra-alar setae; 3 supra-alar setae; 2 katepisternal setae; scutellum with 1–2 pairs of shorter discal setae. Wing. Hyaline, slightly tinged with pale brown; tegula and basicosta black; lower calypter yellowish white. Relative lengths of 2nd, 3rd and 4th costal sectors approximately as 1.3:2.2:1; bend of vein M nearly rightangled, with short appendix, vein M from dm-cu crossvein to its bend about twice the distance between bend and wing margin. Legs. Black, pulvilli dull yellowish. Fore tibia with a row of anterodorsal setae and 1 posterior seta; mid tibia with 2–3 anterodorsal, 2 posterodorsal and 1 ventral setae; hind tibia with a row of anterodorsal setae, no strong seta among them, 2–3 posterodorsal and 1 ventral setae. Fore claws and pulvilli shorter than 5th tarsomere.

Abdomen. Shining black in ground color, with dense grayish white pruinosity on anterior 1/3 of tergites 3, 3/5 of tergite 4 and 3/4 of 5, tergite 3 with broad black transverse band which is not interrupted medially by pruinosity, tergites 4 and 5 with black transverse band which is interrupted medially by grayish pruinosity. Dorsum with dense fine short recumbent black hairs; syntergite 1+2 with 1 lateral marginal seta, without median marginal seta; tergite 3 with 1 lateral marginal and 2 median marginal setae. Male terminalia (Figs. 40–43). Posterior lobe of sternite 5 wide and blunt. Cerci short, narrow and pointed at apex; surstylus long and narrow, weakly pointed at apex in caudal and lateral views; distiphallus slender, apical membranous part about twice as long as sclerotized basal part.

Female. Vertex 0.28–0.33 of head width, parafacial 2–2.5 times as wide as flagellomere 1, gena 0.33–0.36 of eye height; 6 inclinate frontal setae about as long as lateroclinate ocellar seta, 2–3 strong proclinate orbital setae, reclinate prevertical seta weak; inner vertical seta about 2/3 eye height, outer vertical seta about 1/2 as long as inner vertical seta; basal half of antenna and palpus reddish yellow; abdomen ovate, shining black, gray pruinosity on anterior 1/3 of each tergite. Other characters are same as in male.

Type material. Holotype ♂, RUSSIA, Yakovlevka [as “Jakovlevka”] (83°13′E, 71°06′N), Primorskiy Kray (ZIN). Not examined.

Material examined. CHINA. Liaoning: Huanren, Laotuding Mountain, 500–800 m, 2♂♂, 9.vi.1994, D. Wei, 16♂♂, 1♀, 30.v.2006, J.-Y. Liu, Z.-P. Ge, Z.-Q. Yang, J. Lian, L.-Y. Feng; 1♂, Benxi, Sikeshu, Caohecheng, 300– 350 m, 28.v.2009, C. Fu; 2♂♂, 2♀♀, Benxi, Yanghugou, Dongyingfang, 700–800 m, 2–3.vi.1989, 30.v.2009, C.-T. Zhang. Hebei: 1♀, Xiaowutai Mountain, Zhulu, Jinhekou, 800–1500 m, 17.vi.2009, C. Fu (SYNU). JAPAN, Hokkaidō: 1♂, Jozannkei, Sapporo, 21.viii.1996, T. Tachi; Honshu: 1♂, Yamanashi, Kanayama, 1200–1600 m, 24.vii.1986, H. Shima; 1♂, Ishikawa, Tsurugi, ii.1981, K. Togashi. Kyushu: 1♀, Mt. Kuju, Hosenji, 19.viii.1986, H. Shima. RUSSIA: 1♀, Primor’ye Ussuriysk Reserve, 140–160 m, 21.vii.1990, T. Saigusa leg (KUM).

Distribution. China (Hebei, Liaoning), Japan (Hokkaidō, Honshu, Kyushu), Russian Far East (Ussuria, Sakhalin, Kuril Island).

Remarks. We did not examine the type in ZIN, but the specimens we examined fit well with the description of B. morosa by Mesnil (1963) and Kolomiets (1966). Billaea morosa is distinguished from other species of Billaea in having small body, narrow vertex and genal height, and tergites 3 and 4 with transverse black band interrupted medially by pruinosity.