Coastal salt marshes serve as breeding areas for several species of mosquitoes, primarily Aedes sollicitans, Aedes cantator, and Aedes taeniorhynchus. In the upper regions of a salt marsh, areas such as depressions and neglected ditches can breed millions of mosquitoes during the course of a summer. Adult females deposit their eggs on the marsh surface where the eggs must dry for 24 hours. When the monthly high tides flood the marsh, these egg-laiden depressions fill with water and the larvae hatch and develop rapidly. Adults emerge in one to two weeks following the moon tides. These mosquitoes can be effectively controlled through Open Marsh Water Management (OMWM) practices. The breeding areas can be altered to allow for better fish predation on the larvae and ditches can be connected so that tidal flow is enhanced to these upper marsh areas throughout the month, discouraging egg laying.
Temporary Woodland Pools
Shallow, temporary pools are common in woodland areas during the spring and wet summers. A variety of mosquito species will utilize these areas. Some of the most common are Aedes canadensis, Aedes excrucians and Aedes vexans. These mosquitoes lay their eggs along the edges of the pool and rely on rainwater or melting snow to hatch the larvae.
Roadside ditches are the suitable habitat for many species of Culex mosquitoes. The larvae of Culex pipiens and Culex restuans, for example, can survive in waters with high organic content. Culex mosquitoes will lay their eggs directly on the water's surface; therefore, ditches that hold water for extended periods of time can breed large numbers of mosquitoes.
The larvae of Anopheles are found primarily in small ponds among the emergent vegetation. Typically, ponds clogged with vegetated growth can breed huge numbers of these mosquitoes because fish and other aquatic predators cannot readily feed on the larval mosquitoes. These areas should be maintained to keep vegetative growth to a minimum. Also, they can be stocked with predatory fish, such as Gambusia affinis.
Artificial containers such as tires, bottles and buckets provide an excellent, predator free larval mosquito habitat. Many mosquitoes that prefer natural containers (treeholes) have adapted to using these man made mosquito nurseries. In such instances, the abundance of litter and other debris can allow for the proliferation of millions of mosquitoes during a season. Aedes albopictus, notorious for transmitting several diseases, is one species that has capitalized on using tires and other artificial containers. To control these mosquitoes, all items collecting rainwater should be tipped over, removed or cleaned regularly.
Tree holes and other natural containers, such as pitcher plants, serve as good habitat for larval mosquitoes. Aedes triseriatus, known to transmit several disease agents including dog heartworm, prefers tree holes and can be a very common mosquito in wooded areas. Frequent rainfalls will maintain standing water in these areas and breed mosquitoes throughout an entire summer.
The mosquito Coquilletidia perturbans can be extremely prolific in cattail marshes as well as areas with other emergent freshwater vegetation. The larvae attach themselves to the stems and roots of the emergent vegetation to obtain oxygen. Therefore, they do not need to swim up and down in the water column to feed and breath. Because of this adaptation, the larvae are not exposed to predatory fish making control of this species very difficult.
Hardwood and Coniferous Freshwater Swamps
These swamps can serve as larval habitat for a variety of mosquito species. In particular, they are a primary larval habitat for the mosquito Culiseta melanura, the enzootic vector of EEE virus. Culiseta larvae live deep within the recesses of the root cavities of large trees. Controlling these mosquitoes in such a difficult to reach habitat makes management of this mosquito nearly impossible.
Streams with running water produce few, if any, mosquitoes. In general, mosquitoes need still water to lay their eggs on or near. However, Anopheles and Culex mosquitoes are sometimes found in isolated pockets of water away from the main flow of the stream. The major biting insect produced in running water is the black fly which can hold onto the undersurface of rocks as it filter feeds.