O. Biström 1999: Hydrovatus wewalkai n.sp described from Thailand (Coleoptera, Dytiscidae). - Entomologica Fennica 10: 179-181.
Hydrovatus wewalkai n.sp. is described on the basis of two specimens from Thailand. Diagnostic characters for separation of the new species from closely related species are given. A brief description of the collecting site is provided.