Abstract
The female and pupa of Simulium siripoomense Takaoka and Saito, 1996, hitherto known only from larval specimens collected from Thailand, are described for the first time. Based upon several diagnostic characters found in the female and pupa, this species, previously placed in the subgenus Byssodon, is transferred to the subgenus Simulium s. str., and is further assigned to the malyschevi-group within this subgenus by the characteristic shape of the female genitalia, the pupal gill with six slender filaments per side, and the fenestrate cocoon. This represents the first record of the malyschevi-group in Thailand.
