Abstract A new aleocharine species, Himalusa thailandensis Pace, Klimaszewski & Center sp. n., found feeding on sewer vine, Paederia pilifera Hook. f., in Thailand, is described and illustrated. This is the first record of the genus Himalusa for Thailand. Himalusa was previously known from the Himalayan region in Nepal where it was originally described. New data on bionomics and distribution are provided, including a discussion on the potential use of this species in the biological control of weeds in the United States. A short diagnosis, description, colour habitus images of adult and larva, and black and white genital images are provided. A key to the world species of Himalusa is also given. A new tribe Himalusini Klimaszewski, Pace & Center, is erected to accommodate Himalusa species.