Mosquito Insecticide

Insecticides are a quick, powerful way to get rid of mosquitoes around the yard, but, unfortunately, they are only temporary. The effect usually lasts only as long as the insecticide is present, so as soon as it drifts away or dries out, the mosquitoes are back.

Mosquito control officials use insecticides only when mosquitoes are especially thick and only in combination with other form of mosquito control. The same should apply to use around the house. By itself, insecticide is not a long-term solution.

Insecticides are commonly dispensed through a fog or ultra-low volume mist. They are available at most home and garden stores and come in hand-held applicators or devices that can be attached to a lawn mower.

Two popular insecticides are:

  • Malathion – an organophosphate often used to treat crops against a wide array of insects. It can be sprayed directly onto vegetation, such as the bushes where mosquitoes like to rest, or used in a 5 percent solution to fog the yard. In the small amounts used for mosquito control, it poses no threat to humans or wildlife. In fact, malathion is also used to kill head lice.
  • Permethrin – one of a group of chemicals called pyrethroids, it is a synthetic form of a natural insecticide found in chrysanthemum flowers. It usually is mixed with oil or water and applied as a mist, about 1/100th of a pound per acre. Like malathion, permethrin kills mosquitoes by disrupting their central nervous systems. Not harmful to people and animals in small amounts, but it is toxic to fish and bees.

Both malathion and permethrin are also available in sprays for use inside the home.

The insecticides will work for several days when applied to shrubbery or grass, but will break down over time, especially in rain. When released into the air through fog or mist, they usually are good only for a few hours before they become too dissipated to be effective.