Billaea yintiaoling Zhang, 2023

Li, Yue, Dong, Ruiqing, Hao, Bo & Zhang, Chuntian, 2023, Two new species and one newly recorded species of Tachinidae from Chongqing China (Diptera: Calyptratae), Zootaxa 5257 (1), pp. 160-169 : 161-162

Billaea yintiaoling Zhang sp. nov.

Figs 1–12

Diagnosis. Facial carina long, narrow and high, gena 0.5–0.6 of eye height. Fore tibia with 1 posterior seta, fore claws and pulvilli shorter than fifth tarsomere in male. Abdomen laterally reddish yellow to brown, without a pair of large triangular black markings on tergites 3 and 4, dark brown on posterior margin of tergite 4 and entire tergite 5.

Description. Body length 8.0– 11.5 mm.

Male. Head ( Figs 7–8 ). With whitish pruinosity, frontal vitta dark brown, parafacial with sparsely pruinosity on lower half, lunule reddish brown. Antenna with scape, pedicel and base of postpedicel reddish yellow, 5/6–7/8 postpedicel dark brown, palpi yellow. Vertex about 0.20 of head width; frontal vitta widened anteriorly, about 1.3 times as wide as fronto-orbital plate at narrowest point, fronto-orbital plate with 1–2 rows of fine short black hairs, 11–12 pairs of inclinate frontal setae, lowest setae at level with base of antenna. Parafacial nearly parallel-sided, 2–3 times as wide as postpedicel, nearly bare, only hairy on upper portion. Face rather well concave, facial carina long, narrow and high, visible antenna in lateral view. Gena 0.5–0.6 as high as eye height, lower margin of face protruding forward. Occiput flattened, mostly with yellowish hairs, with 2 rows of black hairs below postocular setae. Inner vertical seta about as long as 2/3 of eye height, ocellar setae usually stronger than upper frontal setae, vibrissa inserted above level of lower margin of face, equal or slightly longer than antenna. Postpedicel about 4 times as long as pedicel.Arista plumose, equal or slightly narrower than postpedicel width. Palpus as long as postpedicel and prementum, prementum 4 times as long as wide, labella large.

Thorax ( Figs 5–6 ). Black with dense yellowish gray pruinosity; dorsum with 2 broad outer and 2 narrow inner dark brown longitudinal vittae and one brown median vitta, which narrower on presutural scutum and wider on postsutural scutum, inner vitta 1/4–1/3 as wide as pruinose portion between inner and outer vittae on presutural scutum, extending to anterior 2/5 of postsutural scutum, 2 broad outer vittae extending to anterior 2/3 of postsutural scutum. Scutellum black in ground color, with gray pruinosity on apical 2/3. Prosternum 1.5–2 times as long as wide, proepisternum hairy, postpronotal lobe with 3 setae nearly standing in a straight line, 2 presutural and 2–4 postsutural acrostichal setae; 3 presutural and 4 postsutural dorsocentral setae, 2 postsutural intra-alar setae; 2–4 supra-alar setae, first and third weak and short or absent. Scutellum with three pairs of marginal setae, apical scutellar setae crossed and 1–3 pairs of short discal scutellar setae. One anepimeral seta, 2 katepisternal setae. Wing hyaline, tinged with brownish; tegula dark brown, and basicosta dark brown on basal 1/2 and reddish brown on apical 1/2. Relative lengths of costal sectors 2nd, 3rd and 4th approximately as 1:2:1, bend of vein M about right-angled, with short appendage, which is shorter than 1/2 length of crossvein r-m or without it; bend of vein M distinctly closer to wing margin than to crossvein dm-cu (2:1), cell r 4+5 narrowly opened. Halter yellow. Lower calypter large, pale yellowish white. Legs dark brown, tibiae brown to reddish brown, pulvilli pale yellowish. Fore tarsi subequal in length to head height, fore claws and pulvilli shorter than 5th tarsomere, fore tibia with a row of short anterodorsal setae on basal 3/5 and usually 1 (seldom 2) posterior seta, preapical anterodorsal slightly longer than preapical dorsal seta. Mid tibia with 2 anterodorsal, 2 posterodorsal and 1 ventral setae. Hind tibia usually with comb-like row of anterodorsal setae of rather uniform length, 1–2 posterodorsal (upper one shorter) and usually 1 ventral seta, 1 preapical anterodorsal and 1 preapical dorsal setae.

Abdomen. Long ovate, reddish yellow to brown in ground color, densely covered with pale yellowish white pruinosity on anterior 2/3 to 4/5 of tergites 3 to 5, and a wide dark brown longitudinal median vitta on tergites, and dark brown on posterior margins of tergite 4 and entire tergite 5. Syntergite 1+2 and tergite 3 each with 1–2 pairs of lateral marginal setae, median marginal setae absent on syntergite 1+2, 2 median marginal on setae tergite 3, a row of strong marginal setae on tergites 4 and 5. Tergites 3 to 5 without discal seta, with dense fine and recumbent hairs, sparser on venter. Sternite 5 and male terminalia as the figures ( Figs 9–12 ). In ventral view, sternite 5 rectangular, V-shaped median cleft about 5/9 of the sternite length, lateral lobe bluntly round apically. In caudal view, cerci short, narrowed on distal half, pointed apically, and surstylus long and wide, and bluntly round apically. In lateral view cerci bent ventrally and surstylus broad, bluntly round, slightly bent posteriorly. Pregonite long and bent posteriorly, postgonite nearly as long as basiphallus, distiphallus long, membranous apical part slightly longer than sclerotized basal part.

Female ( Figs 1–4 ). Vertex about 1/3 of head width and strongly widened anteriorly, parafacial about 3 times as wide as antenna, gena about 1/2 as high as eye height, 9–10 frontal setae, upper two smaller, 2 proclinate orbital setae, 1 upwardly directed prevertical seta, ocellar seta proclinate, about as long as inner vertical seta, longer than upper frontal setae, outer vertical seta about 1/2 as long as inner vertical seta. Thorax with 3 supar-alar setae, 4th and 5th tarsomere of legs flattened.Abdomen ovate, dark brown, yellow on lateral surface of syntergite 1+2 and tergite3, grayish white pruinosity on anterior 2/3 of tergites 3 and 4 and anterior 4/5 of tergites 5. A pair of large triangular brown markings on posterior 1/2 of tergite 3, posterior 3/5 of tergite 4, and a trapezoid marking on tergite 5. Other characters are same as in male.

Type material. Holotype male: CHINA, Chongqing, Wuxi, Yintiaoling Natural Reserve, Lanying to Huangcaoping , 31.24°N, 109.53°E, elev. 1780–2070 m, 14.VIII.2022, C. T. Zhang . Paratype: 1 female, Yintiaoling Nature Reserve , Guanshan Forestry Station, 31.28°N, 109.45°E, elev. 1800–2100 m, 17.VIII.2022, C. T. Zhang .

Etymology. The specific name is taken from the country of the type locality, Yintiaoling Nature Reserve, Wuxi County, Chongqing, China.

Distribution. China (Chongqing).

Remarks. This species is similar to B. robusta Malloch from Malaysia, but differs from the latter by a pair of lateral marginal setae on abdominal syntergite 1+2 and tergite 3, and 2 median marginal setae on tergite 3, tergites 3 and 4 without dark triangular markings. The species is also close to B. chinensis Zhang et Shima from China (Shaanxi, Shanxi, Sichuan, Tibet, Yunnan) and Vietnam, but distinguished by the broader genal height, long, narrow and high facial carina, longer prementum and vibrissae, hind tibia with 1–2 posterodorsal (upper one shorter), 2 median marginal setae on tergite 3, without a pair of triangular dark brown markings on tergites 3 and 4.

Figures

FIGURES 1–12. Billaea yintiaoling Zhang sp. nov., 1–4, female, 5–12, male. 1–2, 5–6. Body in lateral and dorsal views. 3–4, 7–8. Heads in lateral and anterior views, 9–10. Epandrium, cerci and surstyli in caudal and lateral views. 11. Phallus: Aedeagal apodeme, ejaculatory apodeme, hypandrium, pregonite, postgonite, basiphallus, distiphallus in lateral view. 12. Sternite 5.