Two species of mosquitoes, Aedes (Verrallina) iriomotensis and Ae. (Ver.) atriisimilis have been colonized for the first time in the laboratory. These colonies have been maintained since 1978, during which time they have undergone approximately 30 generations. The eggs of Ae. iriomotensis apparently withstood desiccation for a period of up to one month. The eggs of Ae. atriisimilis did not withstand complete desiccation but they may be stored under high humidity for 2 months. Larval development of both species was completed within 10 days and 90% of the larvae pupated by the 8th day. Larval mortality was low and appeared to be directly related to amounts of food and rearing density. The pupal stage lasted 1 to 2 days. Males of Ae. iriomotensis mated readily 10 hours after emergence with just emerged females on the water surface. Aedes atriisimilis males mated most readily 3 to 4 days emergence. Copulation with usually initiated on the wing and was completed on the ground.