抄録
Two more new black-fly species of the rare subgenus Simulium (Montisimulium) were discovered in Doi Inthanon National Park, Chiang Mai, Thailand, where S. (M.) merga Takaoka and Choochote was known as the only named species. These two new species, S. (M.) angkaense sp. nov. and S. (M.) laoleense sp. nov., are described on the basis of the pupal and⁄or mature larvae. Both new species are easily distinguished from S. (M.) merga by the pupal gill with 12 slender filaments, and from all the 16 known species with 12 pupal gill filaments in other countries by the long and very long common basal stalk of the gill, respectively.
