Mosquitoes

Mosquitoes are responsible for more human deaths worldwide than any other animal, and while the risk in the United States is lower than in tropical regions, they remain a genuine public health concern. In the continental U.S., mosquitoes can transmit West Nile virus (approximately 2,000 cases reported annually), Eastern Equine Encephalitis (EEE), and in southern border states, occasional cases of Zika virus and dengue fever.

There are over 200 species of mosquitoes in the United States, but two genera cause most residential problems. Aedes mosquitoes (including the Asian tiger mosquito) are aggressive daytime biters, have distinctive black-and-white striped legs, and can transmit Zika and dengue. Culex mosquitoes are the primary carriers of West Nile virus and are most active at dawn and dusk.

Mosquitoes require standing water to breed, and they need surprisingly little — a bottle cap full of water is enough for a female to lay 100-200 eggs. Common breeding sites that homeowners overlook include clogged gutters, plant saucers, tire swings, children's toys left outside, birdbaths, and even puddles that persist for more than a week. A single neglected rain barrel can produce thousands of mosquitoes per week.

Female mosquitoes locate hosts primarily through carbon dioxide detection — they can sense CO2 from over 150 feet away. They are also attracted to body heat, lactic acid in sweat, and dark clothing. This is why some people seem to attract mosquitoes more than others.

Professional barrier spray treatments using bifenthrin or similar residual insecticides can reduce mosquito activity by 75-90% for 2-3 weeks. These treatments work best as part of a regular program during peak season (typically April through October). However, even the best treatments will be undermined if standing water breeding sites are not eliminated on your property and, ideally, on neighboring properties as well.