Know the Enemy: Different Virginia Mosquito Species Require Different Approaches to Control
By Dr. David Gaines
A message from Dr. David Gaines. (2.2mg)
Most people think that a mosquito is just a mosquito. Actually about 57 different kinds of mosquitoes live in Virginia. Each species’ lifestyle is unique and can be very different from species to species. If you were to compare mosquitoes to birds, one species could be as different from another as a hawk from a hummingbird. For example, some species only lay their eggs in containers of water, others only lay their eggs in shallow puddles, whereas others only lay eggs in grassy marsh water. Some species feed only on the blood of birds; other species feed only on the blood of frogs and amphibians, while still others specialize in feeding upon the blood of livestock, deer or other large mammals. Some mosquitoes prefer to feed on humans, and quite a few species feed on whatever person or kind of animal is present and bite-able at the time.
Another characteristic that differentiates the many mosquito species found in Virginia is the time of day at which they bite, or feed. Several mosquito species bite only during daylight hours. Other mosquito species feed largely during the hours after dusk, but some do not even begin to search for a blood meal until much later at night. A number of species bite both during the day and night, but their daytime feeding is only done in the shade of trees.
People often think that if mosquitoes are biting them, that they are coming from a nearby creek or pond. In reality, most of the “people biters” in residential areas come from artificial containers of water, or temporary, shallow puddles of water and water left standing in ditches that are located within, or right next to the neighborhood. Very few species come from permanent bodies of water such as ponds or creeks. Those that do mostly come from areas of water with emergent or floating vegetation, floating debris, or areas where the water has become stagnant.
Most of the species that lay eggs in ditches or puddles bite only at dusk or at night. The same is true for the mosquito species that come from permanent bodies of water. Many of the species that breed in leaf-choked, forest pools or puddles bite during both day and night time, but their daytime feeding is only done in the shade of forest. Among the mosquito species that only come from containers of water, several, including the Asian tiger mosquito, only bite during the day and are a major nuisance problem around residential areas where man-made containers are common. Most of the species that breed in containers have been associated with the transmission of several diseases to humans, including West Nile virus, La Crosse encephalitis and St. Louis encephalitis.
Large numbers of several mosquito species can come from pools of flood water or salt marshes, and these species can fly several miles to reach a neighborhood. Therefore, people often think that they are powerless to eliminate a mosquito problem. However, in most neighborhoods, the mosquito problem originates from habitats inside the neighborhood and there are many things that a person can do to help reduce the mosquito population.
If you have a mosquito problem around your home, the first place to check is your own property. Look to see if there are containers of water (e.g., buckets, flower pot trays, toys, trash cans, tarps, wading pools, old tires, roof gutters, etc.) that are holding water and are a source of mosquitoes on your own property. Look for containers of water hidden under bushes, under decks or in the shade of trees. Shaded containers of water are particularly attractive places for certain mosquito species to lay eggs. Also, look for depressions in poorly drained ground, and/or ditches that hold water for more than a week. You can eliminate mosquito breeding habitats on your property by draining them or by treating them with a mosquito larvicide, sold at hardware or garden stores. Mosquito larvicides effectively kill mosquito larvae in water while posing little or no danger to the people that use them or pets that drink the treated water.
Working together with neighbors or forming a neighborhood association to look-out for other potential mosquito breeding habitats around the neighborhood amplifies the efforts of each resident and makes mosquito control more affective. Alert property owners of any standing water in puddles, ditches, or in containers on private property. An association of neighbors may also have more influence than a single citizen when it informs your local government officials about potential mosquito habitats that occur on public land around your neighborhood.
If you and your neighbors work together to eliminate or treat the standing water that is a source of mosquitoes, your may significantly diminish or eliminate your neighborhood mosquito problems. The responsibility for keeping localities safe and healthy falls not only on municipal governments, but also on citizens. Each of us is responsible for helping manage mosquitoes in our own neighborhoods, whether individually or together with our neighbors.
For more information about mosquito control contact your local mosquito control agency, health department or the Virginia Mosquito Control Association (VMCA). You can also contact the American Mosquito Control Association (AMCA) for additional information on mosquitoes and their control. The AMCA is the promoter of National Mosquito Awareness Week. The Virginia Department of Health supports surveillance for mosquito-borne diseases in Virginia and works with local organizations to educate citizens and local officials statewide about mosquito-borne disease prevention and control. The VMCA is a nonprofit organization founded in 1947 and dedicated to helping Virginia’s mosquito control professionals serve the public more effectively. The AMCA is an international organization of over 2,000 pest management and public health professionals dedicated to preserving the public’s comfort, health and well being through safe, environmentally sound mosquito control programs since 1935.