Control

The Grand River Mosquito Control District has the distinction of operating one of the most environmentally friendly programs by almost exclusively relying on larval control which results in the long-term elimination of mosquitoes before they bite. The process involves the continuous identification and monitoring of accessible mosquito breeding sites for larvicide application. Breeding sites consist of permanent or temporary bodies of standing water. Flood irrigated fields, ponds left behind receding river currents, marshes, swamps, woodland pools, ditches, storm water retention ponds, catch basin, storm drains, tire piles and sewage ponds make up the numerous mosquito breeding sites. Some breeding sites escape control because of the lack of safe ground access or because they are difficult to detect.
The District uses ecologically-friendly microbial larvicides and growth regulators that are applied directly to breeding sites. Microbial larvicides contain protein toxins that are eaten by mosquito larvae causing them to die within two days. Microbial larvicides are naturally occurring soil bacteria and DO NOT pose risk to humans, wildlife, non-target species or the environment. Methoprene is a compound that mimics the action of an insect growth regulating hormone and prevents adult mosquito emergence. Methoprene degrades quickly in water and does not bio-accumulate.

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 to remove all sources of standing water from the yard.

Once a yard becomes infested with adult mosquitoes it is possible to apply a residual application of insecticide to the vegetation. Most mosquitoes rest below five feet above the ground surface so there is no need to mist the upper canopy of trees. Misting provides the best method of applying an appropriate insecticide that in addition to covering all the surfaces of plants also results in direct insecticide contact with mosquitoes at the time of application. This leads to a quick reduction of mosquitoes and the residual insecticide will continue killing adult mosquitoes that may attempt to re-infest 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 that depending on individual preference can hold from one to five 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 1-5 gallon tanks eliminate the work of pumping while spraying for those who are unable or do not want to pump 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 need to be removed before any application on the lawn.

Numerous insecticides are registered for adult mosquito control and 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 that are sold under different brand names 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 that appear in the product label. Fish in ornamental ponds are very susceptible to insecticides and can easily die form small amounts of exposure.