Our major pest species belong to the previously mentioned summer hatching species, characterized by the highly successful Aedes vexans. In this species, flooded eggs hatch when the water temperature exceeds a critical point (about 10°C). Larval development may take as little as 5 days, allowing this species to exploit extremely temporary bodies of water.
Adult females are persistent biters, capable of multiple summer generations and are known to disperse over great distances. Edmonton's heavy summer rainfall, combined with its gently rolling topography of poorly draining, clay-rich soils, creates perfect conditions for the widespread development of huge populations of this particular species.
The other 4 groups of mosquitoes, Anopheles, Coquillettidia, Culex, and Culiseta exhibit a variety of life strategies. For the most part, eggs are laid directly on the surface of open water in the form of floating egg rafts. Hatching stimuli are of little significance.
Over-wintering in Anopheles, Culex and Culiseta mainly takes place in the adult stage by fertilized, non blood-fed females. This occurs mostly in animal burrows, rock piles and root cellars. In Coquillettidia, larval stages over-winter restrict development to very permanent water bodies.