The most suitable temperature for larval development of Aedes vexans Meigen was found to be 25 °C. At this temperature 86% of the larvae survived and pupated in 7 days. At 10°, 15°, 20°, and 30 °C larval development time was 46, 22, 10, and 8 days and survival rates were 17, 56, 74, and 71%, respectively. At 5 °C mortality was 100% in the first-instar stage, the last larva dying 12 days after hatching. Adults emerged in 2 to 5 days after being transferred into water at 25 °C, males emerging 2 days before the females.