Abstract
Three new black fly species, i.e., Simulium (Gomphostilbia) padangense sp. nov., S. (Simulium) sumatraense sp. nov. and S. (S.) minangkabaum sp. nov. are described based on females, males, pupae and mature larvae collected from West Sumatra, Indonesia. S. (G.) padangense is unique within the subgenus Gomphostilbia in having the pupal gill with one much inflated and seven slender filaments. S. (S.) sumatraense and S. (S.) minangkabaum are most closely related to S. (S.) celsum from Java and S. (S.) argentipes from Peninsular Malaysia, respectively.
