Grand River Mosquito Control District 970-257-0191

Grand River Mosquito District


Adult Control

Unlike larval control, the District does not control adult mosquitoes on private property. Numerous species of adult mosquitoes seek harborage in humid and shady areas. These include frequently watered lawns, bushes and vegetative ground cover. It becomes obvious that a yard may have a mosquito problem, when mosquito bites start occurring during the day time. These mosquitoes could either have migrated into the yard from mosquito producing sites from blocks or even miles away or could have emerged locally. The first step is prevention, to remove all sources of standing water from the yard.

When a yard becomes infested with adult mosquitoes, it is possible to apply a residual application of insecticide to the vegetation. Since most mosquitoes rest below five feet above the ground surface, there is no need to mist the upper canopy of trees. The best method of applying an appropriate insecticide is to mist, covering all the surfaces of plants. The direct insecticide contact with mosquitoes leads to a quick reduction of mosquitoes, and continues to kill adult mosquitoes attempting to re-infest in the vegetation. The length of time of residual benefits depends on the initial concentration of the applied insecticide and on other environmental factors; such as the frequency of rainfall and exposure to sunlight. By eliminating the mosquito infestation within a yard’s vegetation, daytime biting will also be greatly reduced. Unfortunately numerous mosquitoes become airborne during the evening hours, and yard spraying will not protect against evening and night time mosquito bites.

The best way to mist is to use a compressed, air tank sprayer, which can hold from 1 to 5 gallons of liquid, with a long wand with an adjustable nozzle. The sprayer may be carried by hand, over the shoulder, or mounted on a caddy. Cordless electric models, with 1 to 5 gallon tanks, eliminate the work of pumping, like a conventional sprayer.

Insecticides, like all pesticides, must be used as directed on the label. Protective gear, as directed in the label, must be worn. Misting should be done when it is not windy; and different angles of application, should be used to cover the underside of the leaves, where mosquitoes rest. Children’s toys and pet toys must be removed, before any application on the lawn.

Registered insecticides, for adult mosquito control, can be purchased in local stores that sell lawn and garden products. BIFENTHRIN, PERMETHRIN and LAMDA-CYHALOTHRIN are among the effective active ingredients found in various formulations sold for lawn and garden pest control. Many of these products have to be diluted with proper amounts of water before use. These products are effective against numerous insect pests, and it is important to ascertain that mosquitoes are on the list of insects, appearing in the product label. Fish in ornamental ponds are very susceptible to insecticides, and can easily die from a small amount of exposure.