Billaea flava Zhang et Wang

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 : 11-12

Billaea flava Zhang et Wang sp. nov.

Figs. 20–23, 69, 78

Diagnosis. Upper parafacial with fine black hairs, thoracic dorsum with 5 distinct black longitudinal vittae on presutural scutum, legs yellow, fore claws and pulvilli short in male, abdomen translucent yellow except black middle longitudinal portions of tergites, posterior margin of tergite 4 and entire tergite 5.

Description. Body length 9.2–12.5 mm.

Male. Head ( Figs. 69 , 78 ). Frontal vitta dark brown; fronto-orbital plate, parafacial, face and gena brownish yellow in ground color, fronto-orbital plate and gena with thin grayish white pruinosity, parafacial and face with grayish white pruinosity; lunule brown; occiput with dense yellowish gray pruinosity. Antenna reddish yellow except for brown to dark brown outer surface of apical half of flagellomere 1, arista reddish brown. Palpus reddish yellow. Vertex 0.17–0.20 of head width; frontal vitta evenly widened anteriorly, 2.0–2.2 times as wide as frontoorbital plate at middle; parafacial about twice as wide as flagellomere 1; facial carina low, invisible in lateral view, lower margin of face well protruding forward; genal height 0.29–0.35 of eye height. Inner side of fronto-orbital plate and upper 1/3 of parafacial with short, fine black hairs; inner vertical seta strong, about 3/5 eye height; outer vertical seta hair-like but distinct; ocellar seta strong, about 2/5 as long as inner vertical seta; 11–12 inclinate frontal setae. Flagellomere 1 about 3 times as long as pedicel; pedicel with a long seta which is as long as antenna; arista about as long as antenna, arista including plumosity about twice as wide as flagellomere 1. Prementum 3–4 times as long as wide; palpus longer than antenna.

Thorax. Black in ground color, with grayish yellow pruinosity, 5 distinct black longitudinal vittae on scutum, outer vitta broad, about 1/3 as wide as pruinose portion between inner and outer vittae on presutural area, inner vitta extending to anterior 2/5 of postsutural scutum, median vitta extending to posterior margin of postsutural scutum; scutellum black, with grayish yellow pruinosity on outer margin; pleura with grayish white pruinosity. Postpronotal lobe with three setae, arranged nearly in a straight line; 1 presutural and 2 postsutural acrostichal setae; 3 presutural and 4 postsutural dorsocentral setae; 2 postsutural intra-alar setae; 3 supra-alar setae, anteriormost seta weak, about 1/2 as long as notopleural seta; 2 katepisternal setae; scutellum with 2–4 discal setae, crossed apical setae subequal in length to scutellum, subapical seta strong, 1.5–1.8 times as long as apical seta. Wing. Hyaline, evenly tinged with pale yellowish brown; tegula brownish black, basicosta yellow; lower calypter brownish yellow; halter yellow. Relative lengths of 2nd, 3rd and 4th costal sectors approximately as 4:6:3; bend of vein M with a short appendix, which is about 1/2 as long as crossvein r-m; vein M from dm-cu crossvein to its bend 1.6–1.8 times distance between the bend and wing margin. Legs. Coxa, femora and tibiae yellow, tarsi and claws black, pulvilli pale yellow. Fore claws and pulvilli shorter than 5th tarsomere in male; fore tibia with a row of short anterodorsal setae on basal 2/5 and 1 posterior seta; mid tibia with 2 anterodorsal, 2 posterior and 1 ventral setae; hind tibia with a row of regularly set anterodorsal setae in equal length, 1 posterodorsal and 1–3 ventral setae.

Abdomen. Long ovate, translucent yellow, with a narrow median black vitta on syntergite 1+2 to tergite 4, dark brown nearly triangular on posterior portion of tergite 4 and entire tergite 5, gray white pruinosity on anterior margin of tergites 3 and 4 and entire tergite 5. Dorsum with dense and recumbent black hairs, without discal setae; syntergite 1+2 with a pair of lateral marginal setae; tergite 3 without median marginal setae, with a pair of lateral marginal setae; tergites 4 and 5 each with a row of marginal setae. Male terminalia (Figs. 20–23). V-shaped median cleft of sternite 5 wide and about 2/5 length of the sternite. Cerci short, in caudal view narrowed at apical 1/ 2 and pointed at apex; surstylus long and narrowed apically in caudal and lateral views; postgonite about as long as basiphallus; distiphallus slender, sclerotized basal part about as long as membranous apical part.

Female. Vertex 0.28–0.33 of head width; frontal vitta reddish brown to dark brown, 1.8–2 times as wide as fronto-orbital plate; parafacial about twice as wide as antenna; genal height 0.33–0.34 of eye height; flagellomere 1 3–3.5 times as long as wide and as pedicel; inner vertical setae 0.67–0.75 as long as eye height; outer vertical seta 2/3 as long as inner vertical seta; ocellar seta about as long as frontal setae; 2 proclinate orbital setae, stronger than frontal setae; 1 outwardly directed prevertical seta; fore claws and pulvilli shorter than 5th tarsomere; hind tibia with 2 strong submedian setae among row of anterodorsal setae; abdomen yellow except black median longitudinal portion and posterior 1/2–2/3 of tergite 4 and entire tergite 5, grayish white pruinosity only on anterior margin of tergites 4 and and anterolateral tergite 5. Other characters are same as in male.

Type material. Holotype ♂, CHINA, Guangxi, Shangsi, Shiwandashan Mountain (107°53′E, 21°52′N), 300– 500 m, 28–29.iv.2011, Q. Wang ( SYNU). Paratypes. CHINA. Guangxi: 68♂♂, 2♀♀, same locality and date as holotype, C.-T. Zhang & Q. Wang; 1♂, Dayaoshan Mountain (110°19′E, 24°01′N), 1200 m, Jinxiu, 13–18.v.2011, C.-T. Zhang. Hainan: 1♂, Mt. Bawangling (19°50′N, 109°05′E), 800 m, Changjiang, 15.ix.2007, S.-C. Bai ( SYNU).

Etymology. The specific name is taken from a diagnostic character of this species (the translucent yellow abdomen); it is derived from the Latin adjective flavus (yellow).

Distribution. China (Guangxi, Hainan).

Remarks. This species is distinguished from other species of Billaea in having fine black hairs on upper parafacial, 5 distinct black longitudinal vittae on presutural scutum, reddish yellow femora and tibiae, abdomen translucent yellow, and gray white pruinosity only on anterior margin of tergites 3 and 4.

Figures

FIGURES 64 – 72. Billaea spp., heads of male in lateral view. 64. B. atkinsoni (Baranov). 65. B. brevicauda sp. nov. 66. B. carinata sp. nov. 67. B. chinensis sp. nov. 68. B. ficorum (Townsend). 69. B. flava sp. nov. 70. B. fortis (Rondani). 71. B. kolomyetzi Mesnil. 72. B. kurahashii sp. nov. Scale bars = 0.5 mm.

FIGURES 73 – 81. Billaea spp., heads of male in anterior view. 73. B. atkinsoni (Baranov). 74. B. brevicauda sp. nov. 75. B. carinata sp. nov. 76. B. chinensis sp. nov. 77. B. ficorum (Townsend). 78. B. flava sp. nov. 79. B. fortis (Rondani). 80. B. kolomyetzi Mesnil. 81. B. kurahashii sp. nov. Scale bars = 0.5 mm.