Abstract
The female and male of Simulium (Simulium) beludense sp. nov. are described based on reared adult specimens collected from Sabah, Malaysia. This new species was previously misidentified as S. (S.) nigripilosum Edwards of the melanopus-group because of a great similarity of their external morphology. The female genitalia examined in this study easily separate this new species from S. (S.) nigripilosum. It is also indicated that S. (S.) beludense sp. nov. is not assignable to the melanopus-group, but is rather closely related to S. (S.) argentipes Edwards from Peninsular Malaysia, S. (S.) bidentatum (Shiraki) from Japan and China, and S. (S.) canlaonense Delfinado from the Philippines, all of which belong to the different group so far undetermined.
