DALY: Annoying mosquitoes can be controlled but not eliminated

Timothy Daly

Timothy Daly

Mosquitoes are a constant menace throughout the summer and interfere with outdoor activities. They are more than just an irritating annoyance because they can spread diseases.

In tropical regions of the world, they are vectors for malaria, yellow fever, dengue fever and several others. In the southeastern United States, although uncommon, West Nile virus and eastern equine encephalitis are the primary diseases spread by mosquitoes.

Mosquitoes require a source of water to reproduce. These sources include natural bodies of water like wetlands, ditches, lakes and man-made sources like old tires, containers left outside, and gutters on homes. Rapidly moving waters like creeks and rivers are not suitable as breeding sites. The female lays her eggs in the water. The larvae, which are the immature forms of the mosquitoes, hatch and appear as small “wigglers.” In time they emerge from the water as adult mosquitoes. Only the females bite to suck blood to obtain proteins necessary for their eggs. The mosquitoes secrete saliva that causes the development of an itchy welt.

Mosquitoes cannot be totally eradicated from a site. However, steps can be taken to reduce the infestation of mosquitoes around your home. Eliminate their breeding sites wherever possible. Clean out your gutters. Remove any containers and other items that may have standing water. Ornamental water gardens can be treated with a “larvicide,” which is a tablet containing bacteria that specifically targets the mosquito larvae. It is sold under various brand names such as Bactimos Briquettes, Mosquito Dunks and Mosquito Bits. The doughnut-shaped dunks will slowly dissolve and provide control for up to a month.

Several methods can keep adult mosquitoes under control. Apply insect repellants containing a chemical called DEET when outside or in high risk areas. Wear light colored protective clothing, long pants, shoes and socks in areas where the mosquito populations are bothersome. Also keep screened doors and windows in good repair to exclude them from homes.

Chemical mosquito control should be used only as a supplement to source reduction. The chemicals can be applied by a number of methods, but an outdoor aerosol fogger is the most common. Fogging the air around your home during the evening and nighttime hours is the most effective since mosquitoes are most active at this time.

Residual insecticides, such as malathion and ones containing permethrin, can be applied to shrubbery, ground covers, underbrush and other places where mosquitoes rest during the heat of the day. However, relief is only temporary and repeat applications will be necessary over time. Burning mosquito coils can give relief from the insects, but only in the immediate area. Some of the products on sale for mosquito control are not always as effective as they claim to be. Mosquito plants do not repel mosquitoes, and neither does garlic, herbal remedies or ultrasonic devices. Traps using light or carbon dioxide to lure in insects will attract more mosquitoes than they kill, thus increasing the mosquito population.

A few simple actions can help reduce the nuisance effects of mosquitoes. While they cannot be totally eradicated from an area, their impact can be minimized.

Timothy Daly is an Agricultural and Natural Resource Extension Agent with Gwinnett County. He can be called at 678-377-4010 or e-mailed at tdaly@uga.edu.