Billaea setigera Zhang et Shima

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 : 22-23

Billaea setigera Zhang et Shima sp. nov.

Figs. 48–51 , 85 , 94 , 98

Diagnosis. Facial carina developed, lower margin of face strongly protruding forward, hind tibia with a row of anterodorsal setae in irregular length, fore claws of male short, abdomen evenly covered with grayish yellow pruinosity, tergite 3 with a row of 6–8 median marginal setae.

Description. Body length 11.0–14.0 mm.

Male. Head ( Figs. 85 , 94 ). Black in ground color, gena and face reddish brown, with grayish white pruinosity; frontal vitta, antenna and palpus dark brown; lunule yellowish brown. Vertex 0.14–0.18 of head width; frontal vitta strongly widened anteriorly, about twice as wide as fronto-orbital plate at middle; parafacial nearly parallel-sided, 1.5–2 times as wide as flagellomere 1; facial carina well developed, pointed at top and arced in profile; lower margin of face strongly protruding forward; genal height 0.43–0.5 of eye height; lower occiput swollen. Frontoorbital plate with 2–3 irregular rows of long black hairs; parafacial bare; inner vertical seta strong, 0.60–0.65 of eye height, outer vertical seta indistinguishable from upper occipital setae; 9–13 pairs of long and strong inclinate frontal setae, only slightly shorter than ocellar seta and inner vertical seta; vibrissa inserted above lower margin of face by about length of pedicel, 6–8 subvibrissae. Flagellomere 1 2.0–2.5 times as long as pedicel; pedicel with a seta which is slightly longer than flagellomere 1; arista rather short plumose, total width including plumosity 1.4– 1.6 times as wide as flagellomere 1. Prementum 6–7 times as long as wide; palpus slightly longer than pedicel and flagellomere 1 together.

Thorax. Black in ground color, with rather thin grayish pruinosity; 4 rather broad longitudinal vittae distinct on scutum when seen from behind, inner vittae slightly narrower than outer vittae, an additional median vitta visible on postsutural scutum; scutellum reddish brown to dark brown on apical 1/2, with gray pruinosity. Five or six postpronotal setae, 3 strong basal setae in a triangle; dorsum with dense fine black hairs; 2–3 presutural and 2– 3 postsutural acrostichal setae; 3–4 presutural and 4 postsutural dorsocentral setae; 3 postsutural intra-alar setae; 4 supra-alar setae, 1st and 3rd setae weak, sometimes an additional fine seta present between 2nd and 3rd setae; 3 katepisternal setae; scutellum with 6 short discal setae. Wing. Hyaline, weakly tinged with pale brown; tegula dark brown and basicosta brown; calypter yellowish to milky white; halter brown, yellow at apex. Relative lengths of 2nd, 3rd and 4th costal sectors approximately as 1.1:2.3:1; vein M from dm-cu crossvein to its bend about 3 times distance between the bend and wing margin. Legs. Black, pulvilli yellowish. Fore tarsi slightly longer than head height; fore tibia with a row of anterodorsal setae on basal 2/3, 2–3 posterodorsal and 2 posterior setae; mid tibia with 2–5 anterodorsal, 4–5 posterodorsal and 1 strong and 1 fine ventral setae; hind tibia with a rather sparsely set row of anterodorsal setae of irregular length, 3–5 posterodorsal and 3 ventral setae, 3 preapical dorsal setae, of which posterodorsal seta is fine and less than 1/2 length of dorsal seta; fore claws and pulvilli slightly shorter than 5th tarsomere.

Abdomen (Fig. 98). Ovate, dark reddish brown, evenly covered with grayish yellow pruinosity, a dark broad median longitudinal vitta on anterior 1/2–2/3 of tergite 3. Dorsum with dense short recumbent black hairs; syntergite 1+2 with 1–2 lateral marginal setae; tergite 3 with a row of 6–8 strong median marginal setae and 1–2 lateral marginal setae; marginal setae of tergite 5 shifted on posterior 1/5 of the tergite. Male terminalia ( Figs. 48– 51 ). Sternite 5 subsquare, posterior lobe wide and blunt apically, V-shaped median cleft wide and deep. Cerci short, narrowed at apical 2/ 5 in caudal view; surstylus wide and rounded apically; postgonite shorter than basiphallus; distiphallus long, membranous apical part distinctly longer than sclerotized basal part.

Female. Vertex about 0.3 of head width, frontal vitta at narrowest point wider than frontal orbital plate, gena about 0.6 of eye height; 7–8 pairs of inclinate frontal setae, 2 strong proclinate orbital setae, 1 outwardly directed prevertical seta, outer vertical seta about 1/2 as long as inner vertical seta. Mid tibia with 4–6 anterodorsal, 3–4 posterodorsal, 2 posterior and 2 ventral setae; hind tibia with 2–3 strong setae among row of anterodorsal setae rather irregular in length, 3–4 posterodorsal and 2–3 ventral setae. Abdomen shorter and wider, black, with thin grayish white pruinosity on dorsum. Other characters are same as in male.

Type material. Holotype ♂, CHINA, Xizang (= Tibet): Qiuxi, Jitang (97°29′E, 30°40′N), 3500 m, Chaya, 15.vii.1982, X.-Z. Zhang ( IZCAS). Paratypes. CHINA. Qinghai: 1♂, Nangqian, 5.viii.1975; 3♂♂, Gelong, 3700 m, Yushu, 10.vii.1984, S.-Y. Wang ( IZCAS). 1♂, Qinghai, 5.vii.1975, Z.-Z. Chen ( SEMC). Sichuan: 1♂, Daocheng to Yading, 3600–4100 m, 10.vii.2006, J.-Y. Liu. 1♂, Geka to Echushan, 2260–4100 m, Daocheng, 14.vii.2006, L.-Y. Feng ( SYNU). 1♂, Zhongrewu, 3500 m, Xiangcheng, 5.vii.1982, X.-Z. Zhang. 1♂, Yidun, 3500–3600 m, Batang, 16.viii.1982, H.-C. Chai. 1♂, Markang, 2700 m, 26.viii.1983, H.-C. Cai ( IZCAS). Xizang: 25♂♂, same data as holotype, 2♂♂, same locality as holotype, 7.vii.1976, 20.viii.1976, Y.-H. Han; 6♂♂, Haitong, 3250 m, Mangkang, 8.viii.1982, 10.viii.1983, X.-Z. Zhang, S.-Y. Wang ( IZCAS); 1♀, GongbuJiangda, 4000 m, 21.viii.2003, M.-F. Wang; 1♂, Bayi Town, 2900–3000 m, Linzhi, 4.viii.2013, C.-T. Zhang; 2♂♂, Lulang, 3300– 3400 m, Linzhi, 7, 11.viii.2013, C.-T. Zhang; 2♂♂, Linzhi Town, 3000 m, Linzhi, 12.viii.2013, Q. Wang; 1♂, Xuekagou, 2850–2900 m, Milin, 17.viii.2013, C.-T. Zhang; 2♂♂, nearby Niyang River, 2800–3400 m, Linzhi, 8.vii.2014, Q. Wang ( SYNU). Yunnan: 43♂♂, Deqin, 10 km N. Deqin, 2800 m, 21.vii.1996, H. Shima (KUM); 1♂, 50 km SE Deqin, 3400 m, 22.viii.1996, H. Shima ( BLKU); 1♂, Deqin, 15.vii.1980, X.-Z. Zhang; 41♂♂, Meilixueshan Mountain, 3180–4500 m, 23–25.vii.1982, X.-Z. Zhang, H.-C. Cai ( IZCAS); 1♂, Meilixueshan Mountain, 2900–3200 m, Deqin, 6.vii.2006, M.-F. Wang; 8♂♂, 3♀♀, Baimaxueshan Mountain, 4250 m, Deqin, 26.vii.2008, S.-C. Bai, X.-D. Fei, S. Wang; 16♂♂, 1♀, Pudacuo, 3700 m, Shangri-la (=Zhongdian), 29.vi.2010, C. Fu, Y.-Y. Zhou ( SYNU).

Etymology. The specific epithet is taken from a diagnostic character of this species (abdominal tergite 3 with 6–8 strong median marginal setae); it is composed from the Latin noun seta (bristle) plus the suffix gero (bear, carry).

Distribution. China (Qinghai, Sichuan, Xizang, Yunnan).

Remarks. This new species is characteristic and distinguished from other species of Billaea in having long prementum, abdominal tergites densely covered with grayish yellow pruinosity, 6–8 strong marginal setae on tergite 3, developed facial carina, and hind tibia with a row of anterodorsal setae in irregular length. The last two characters are common to diagnostic features of Dinera .

Figures

FIGURES 48 – 63. 48 – 51. Billaea setigera sp. nov. 52 – 55. B. steini (Brauer et Bergenstamm). 56 – 59. B. triangulifera (Zetterstedt). 60 – 63. B. verticalis sp. nov. 48 – 49, 52 – 53, 56 – 57, 60 – 61. Cerci, surstyli and epandrium of male in lateral and caudal views. 50, 54, 58, 62. Ejaculatory apodeme (except 50), aedeagal apodeme, hypandrium, pregonite, postgonite, basiphallus, distiphallus. 51, 55, 59, 63. Sternite 5. Scale bars = 0.25 mm.

FIGURES 82 – 88. Billaea spp., heads of male in lateral view. 89 – 90. Abdomens in dorsal view. 82. B. micronychia sp. nov. 83. B. morosa Mesnil. 84. B. papei sp. nov. 85. B. setigera sp. nov. 86. B. steini (Brauer et Bergenstamm). 87. B. triangulifera (Zetterstedt). 88. B. verticalis sp. nov. 89. B. atkinsoni sp. nov. 90. B. chinensis sp. nov. Scale bars = 0.5 mm.

FIGURES 91 – 97. Billaea spp., heads of male in anterior view. 98 – 99. Abdomens in dorsal view. 91. B. micronychia sp. nov. 92. B. morosa Mesnil. 93. B. papei sp. nov. 94, 98. B. setigera sp. nov. 95. B. steini (Brauer et Bergenstamm). 96, 99. B. triangulifera (Zetterstedt). 97. B. verticalis sp. nov. Scale bars = 0.5 mm.