Simulium (Gomphostilbia) dhangi sp. nov., S. (G.) sumbaense sp. nov. and S. (Nevermannia) wayani sp. nov. are described from the Lesser Sunda Archipelago, Indonesia. Simulium (G.) sumbaense sp. nov. is placed in the S. varicorne species-group and is characterized by the pupal gill with eight filaments arranged as (1+1+1+1+2)+2 from dorsal to ventral, while S. (G.) dhangi sp. nov., unplaced to group, is characterized by the pupal gill composed of two inflated trunks and four slender filaments all arising basally, and the short larval antenna as long as the stem of the labral fan. Simulium (N.) wayani sp. nov. belongs to the S. ruficorne species-group and is characterized by the female spermatheca with an unsclerotized neck, and pupal gill with four inflated filaments. The number of species of black flies from the archipelago increases from 19 to 22.

Simulium (Simulium) contractum Takaoka from Sulawesi, Indonesia was known only as the pupa. Its female, male and mature larva are described for the first time. The tentative assignment of this species in the Simulium dumogaense species-group is confirmed by the adult characters including the female and male genitalia. The female and male of this species are similar to those of Simulium (Simulium) tumpaense Takaoka & Roberts but are distinguished by the yellowish femora.

Ovitrap surveillance was conducted to determine the infestation patterns of dengue vectors in fourteen study sites across eight provinces located in the Sunda Islands, Indonesia. High ovitrap indices up to 70% and 90% were obtained from indoor and outdoor areas, respectively. Mean numbers of Ae. aegypti and Ae. albopictus larvae ranged from 0.13 to 14.50 and 0.10 to 18.60, respectively. Mixed infestation (<10%) and interchange of breeding habitat preferences of Ae. albopictus and Ae. aegypti were also observed in the present study.