Mosquito Misting Myths

Why mosquito misting systems are a bad choice for insect control

The mosquito has always been a nuisance. People were trying to come up with ways to combat the spread of the pesky little insect long before they'd even heard of the West Nile virus. Mosquito misting systems have become a popular mosquito-fighting solution in the last few years, but that isn't necessarily a good thing. Many entomologists and mosquito experts agree that mosquito misting systems are not only harmful to the environment, they aren't even effective at properly combating mosquitoes.

How mosquito misting systems work

Mosquito misting systems are professionally installed and automated devices consisting of spray nozzles connected to a pump and a reservoir of pesticide. At several set times throughout the day, mosquito misting systems spray this insecticide into the air for periods ranging from 20 to 60 seconds. The intended effect is to kill and drive off mosquitoes and other insects.

Insecticides: natural or toxic?

Many companies that install mosquito misting systems claim that the insecticides they use are natural and biodegradable. A product commonly cited is pyrethrum, a natural derivative of chrysanthemum flowers. However, this claim can be misleading.

While pyrethrum itself is a natural product, the pesticides in which it is used may be potentially toxic. Some pesticides that use pyrethrum even feature labels that state "hazardous to humans and domestic animals." Nor is pyrethrum even considered the best way to combat mosquitoes.

The American Mosquito Control Association has warned that the frequent use of pyrethrum in mosquito misting systems could lead to resistance in mosquitoes, which, in the words of the AMCA, "would seriously compromise our capability to control adult mosquito populations."

Because mosquito misting systems are automated, the chances of spraying insecticides when people or animals are present are increased. Rain and wind can also cause insecticides to drift into neighboring areas.

If you are looking at installing a mosquito misting system, be extremely thorough and request full disclosure of all information pertaining to the pesticides your system will use. And don't just ask. Read the labels for yourself.

Do mosquito misting systems work?

Yes and no. Even those opposed to mosquito misting systems acknowledge that they are effective at reducing adult mosquito populations, but this effectiveness comes at a potentially much higher cost.

First, there is the monetary cost. Mosquito misting systems typically cost several thousand dollars to purchase and install, plus the cost of insecticide used every month. A simple and cost-efficient alternative is handheld or hose applicators, which cost around 20 dollars and can be used as needed.

Then there is the potential of developed resistance, as the AMCA has warned. The AMCA is joined in that belief by the American Association of Pesticide Safety Educators and many state regulatory boards.

If you have outdoor pets, the regular and indiscriminate spraying of insecticides may also cause health problems for them.

Weighing the costs and potential hazards of mosquito misting systems against their benefits, a cheaper and better focused attack on mosquito populations seems best. Apply a handheld insect spray as needed to areas of potential mosquito proliferation. Eliminate puddles and sources of longstanding water that can contribute to mosquito breeding, or add larvicide to standing water.

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