Billaea, Robineau-Desvoidy, 1830

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

Key to species of Billaea of East Asia [Couplets 1–7 and 10–18 as in Zhang et al. (2015)]

8 Thorax with 4 longitudinal black vitta on presutural scutum; abdomen broadly reddish brown or reddish yellow on sides of tergites 3 and 4.......................................................................................9ʹ

- 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 Zhang et Shima

9ʹ Abdomen dark, covered with white pruinosity, posterior black band on tergites 3 to 5, which is triangularly extended anteriorly on both sides, syntergite 1+2 and tergite 3 without lateral marginal and median marginal setae........ .. B. robusta Malloch

- Abdomen reddish yellow with posterior black band on tergite 4, and entire tergite 5 dark brown with yellowish white pruinosity on both sides, tergites 3 and 4 without triangular markings in male. Syntergite 1+2 and tergite 3 each with a pair of lateral marginal setae, tergite 3 with 2 median marginal setae....................................... B. yintiaoling sp. nov.