Billaea

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 : 36

Key to species of Billaea of the Eastern Palearctic and Oriental Regions

1 Two katepisternal setae; fore claws and pulvilli of male shorter than 5th tarsomere................................. 2

- Three katepisternal setae; fore claws and pulvilli of male longer or shorter than 5th tarsomere....................... 15

2 Abdomen broadly pale yellowish or reddish yellow in ground color, dark brown to black on mid dorsal longitudinal area and tergite 5, with grayish white or yellowish pruinosity on entire dorsum or on narrow anterior margins of tergites 3 and entire tergite 5............................................................................................. 3

- Abdomen broadly black or dark brown in ground color, sides of tergites 3 and 4 sometimes broadly reddish............. 4

3 Legs brown to dark brown; abdomen covered with pale yellowish gray-white pruinosity on anterior 3/5–4/5 of tergites, dark brown on mid dorsal longitudinal area on tergites 3 and 4 and shallow-triangularly brown on posteromedian portion of tergites 3 to 5; tergite 5 brown, with grayish white pruinosity on anterior 3/4........................... B. kurahashii sp. nov.

- Legs reddish yellow except tarsi; abdomen translucent yellow, dark brown on mid dorsal longitudinal area of tergites 3 and 4 and posterior portion of tergites 4 and entire 5, narrow anterior margin of tergites 3 and 4 and entire tergite 5 with grayish white pruinosity.............................................................................. B. flava sp. nov.

4 Fore tibia nearly always with 1 posterior seta; flagellomere 1 at least reddish yellow or brown at base................. 5

- Fore tibia usually with 2 posterior setae; flagellomere 1 dark brown; pedicel reddish yellow........................ 10

5 Postsutural scutum with transverse black band on anterior 3/5; abdomen with grayish pruinosity, posterior portion of each tergite transversely black; wing with distinct brown markings on triangular anteromedian portion between costa and vein M and along vein CuA1, the tinged area contrasting with basal whitish area and lower calypter.......... B. ficorum (Townsend)

- Outer and inner longitudinal vittae always separated on thoracic dorsum; abdominal tergites with triangular black markings or posterior transverse dark band on tergites 3 and 4; wing at most narrowly tinged with brown at base or along veins R1 and R2+3 and along R4+5 and M from base to r-m crossvein, the tinged area not contrasting with wing base or lower calypter........ 6

6 Parafacial with dense black hairs on lower portion along outer margin of eye; vertex of male 0.14–0.17 head width; gena 0.41– 0.49 times as wide as eye height; 5 black thoracic vittae on presutural scutum; abdomen with dark triangular markings on tergites 3 to 5, and markings on tergites 3 and 4 merged on posterior margin............................. B. papei sp. nov.

- Parafacial bare...................................................................................... 7

7 Vertex of male 0.12–0.14 head width; genal height about 0.2 of eye height; 4 longitudinal black vitta on presutural scutum of thorax; abdominal tergite 3 with broad black transverse band which is not interrupted medially with pruinosity, tergites 4 and 5 with black transverse band which is interrupted medially by grayish pruinosity....................... B. morosa Mesnil

- Vertex of male 0.16–0.22 of head width; abdominal tergites 3 to 5 each with a pair of triangular black markings......... 8

8 Thorax with 4 longitudinal black vitta on presutural scutum; abdomen black, broadly reddish brown on sides of tergites 3 and 4, with posterior black band on tergites 4 and 5, which is triangularly extended anteriorly on both sides.. B. robusta Malloch

- Thorax with 5 or 4 longitudinal black vitta on presutural scutum, if median vitta present, 1–1.5 times as wide as inner vitta on presutural scutum; abdomen dark brown or reddish brown, triangular markings on tergites 3 and 4 completely separated from each other.......................................................................................... 9

9 Vibrissa strong, longer than antenna; ocellar seta weak; abdomen dark brown to brown. In lateral view surstylus straight at posterior surface and slightly pointed at apex............................................. B. atkinsoni (Baranov)

- Vibrissa weak, less than antennal length; ocellar seta stronger than upper frontal setae; abdomen brown, sometimes reddish yellow. In lateral view surstylus slightly bent posteriorly and bluntly rounded at apex.............. B. chinensis sp. nov.

10 Facial carina high and long, well developed; arista plumose, including plumosity about twice as wide as flagellomere 1.. 11

- Facial carina usually low and short, or undeveloped; arista pubescent or plumose................................. 12

11 Abdominal tergites 2 to 4 reddish brown on sides, posterior transverse black band of tergites 3 to 5 narrowed laterally and