All mosquitoes require standing water or moist soil to breed, but the type of water they prefer depends on the species. Some prefer containers, such as tires, tree holes, buckets, and water troughs. Others prefer water with lots of organic material (leaves, grass) that is very stagnant. Still others breed primarily in swamps and marshes, some fresh water, and some salt water. Which species are most important in disease transmission depends on the location, virus, and other animals (amplification hosts) involved. Control of these different types of mosquitoes obviously requires different approaches. Some can be affected by measures taken at individual stables, such as reducing or cleaning water holding containers. Other species require more extensive management, such as impoundments, truck or aerial sprays, and treatment of ditches or other large bodies of water.
Figure 2. Life cycle of a mosquito: eggs, larvae, pupa, and adult.
Female mosquitoes bite animals, using the blood as a protein source to develop eggs. The eggs are laid in or near water, hatch (some require flooding, others hatch immediately), and begin larval development. Development from egg to adult can be completed in as little as 6-7 days in the summer.
Some species will bite almost any type of animal, while others are very specific. Different species vary in their preferred time to feed, but many feed during dawn or dusk. Mosquitoes tend to bite anywhere on the horse, unlike some other flies which concentrate on the midline, face or legs.