Classification of Black Flies in the Oriental Region

Crosskey (1973) first classified 78 species of black flies in the Oriental Region into three subgenera of the genus Simulium Latreille s. l.: eight species in Eusimulium Roubaud s. l., 14 species in Gomphostilbia Enderlein, 53 species in Simulium Latreille s. str., and 3 species in Simulium s. l. species unplaced to subgenus. Lewis (1973) proposed a new subgenus Himalayum for S. (S.) indicum Becher. However, it was sunk as a synonym of the subgenus Simulium s. str. by Otsuka et al. (2003). The number of the subgenera in the Oriental Region increased to five since the subgenus Eusimulium s. l. was split into Eusimulium s. str., Montisimulium Rubtsov and Nevermannia Enderlein, until Takaoka (1983) created a new subgenus Wallacellum and added the subgenus Morops Enderlein for some of black flies in the Philippines. Takaoka (2003) reviewed the definition of the two subgenera Gomphostilbia and Morops when working on black flies in Sulawesi, Maluku, and Irian Jaya, and subsequently all species previously placed in the subgenus Morops in the Oriental Region were transferred to the subgenus Gomphostilbia. Davies and Györkös (1988a) and Chen and Zhang (1998) recorded the subgenus Byssodon Enderlein from Sri Lanka, and the subgenus Wilhelmia Enderlein from South China, respectively. Takaoka and Davies (1995a) recorded the genus Sulcicnephia Rubtsov for a single species from Peninsular Malaysia. However, Takaoka and Adler (1997) reevaluated the species placed in the genus Sulcicnephia and transferred it to a newly created subgenus Daviesellum within the genus Simulium s. l. Takaoka and Choochote (2005b) created a new subgenus Asiosimulium based on specimens collected from Thailand. Chen (2016) recorded the subgenus Boophthora Enderlein from Guizhou, China. Thus, all species of black flies in the Oriental Region are placed in 11 subgenera in the genus Simulium s. l. (Table 1).