The species of Billaea Robineau-Desvoidy (Diptera, Tachinidae) from the eastern Palearctic and Oriental regions are revised. Ten described species are recognized, viz. B. atkinsoni (Baranov) (new records for Japan, Laos, Malaysia, Pakistan and Thailand), B. ficorum (Townsend), B. fortis (Rondani), B. impigra Kolomiets (new record for China), B. kolomyetzi Mesnil, B. malayana Malloch, B. morosa Mesnil, B. robusta Malloch, B. steini (Brauer et Bergenstamm) and B. triangulifera (Zetterstedt) and nine species are described as new to science, B. brevicauda Zhang et Shima sp. nov. (China), B. carinata Zhang et Shima sp. nov. (China), B. chinensis Zhang et Shima sp. nov. (China and Vietnam), B. flava Zhang et Wang sp. nov. (China), B. kurahashii Zhang et Shima sp. nov. (Laos and Thailand), B. micronychia Zhang et Shima sp. nov. (China and Japan; previously misidentified from China as B. irrorata (Meigen)), B. papei Zhang et Shima sp. nov. (Malaysia), B. setigera Zhang et Shima sp. nov. (China) and B. verticalis Shima et Zhang sp. nov. (China). Billaea fasciata (Townsend, 1928) is treated as a junior synonym of B. ficorum (Townsend, 1916), syn. nov. Billaea irrorata is no longer recorded from the eastern Palearctic. A key to 19 species of Billaea from the eastern Palearctic and Oriental regions and 101 figures of male terminalia, bodies, heads and abdomens are given.
The species of Estheria Robineau-Desvoidy (Diptera: Tachinidae) from the East Palearctic and Oriental regions are reviewed. Eighteen species are recognized: the fourteen previously described, E. acuta (Portschinsky, 1881), E. alticola Mesnil, 1967, E. bucharensis (Kolomiets, 1974), E. cinerella Mesnil, 1967, E. cristata (Meigen, 1826), E. decolor (Pandellé, 1896), E. flavipennis Herting, 1968, E. lacteipennis Mesnil, 1967, E. maculipennis Herting, 1968, E. magna (Baranov, 1935), E. nigripes (Villeneuve, 1920), E. pallicornis (Loew, 1873), E. petiolata (Bonsdorff, 1866) and E. picta (Meigen, 1826), and four species described as new to science, E. hirtinerva Zhang Shima sp. nov. (W China, Nepal), E. prostata Zhang Shima sp. nov. (W China, Nepal), E. tibetensis Zhang Shima sp. nov. (W China, Nepal) and E. wangi Zhang Liang sp. nov. (W China, Pakistan). Estheria acuta and E. decolor are newly recorded for China, E. magna is newly recorded for Malaysia, Pakistan and Vietnam, and E. pallicornis is newly recorded for Nepal. An identification key to the 18 species of Estheria so far known from the East Palearctic and Oriental regions is included, together with 126 figures of heads and habitus of males and females, and male terminalia and known distributions.