Mosquito Control And Its Effects on Wildlife

Home mosquito spraying is gaining popularity thanks to increased advertising by new, specialized businesses that promise to make your yard a ‘no-fly zone’ because ‘what good is your yard if you can’t enjoy it?’

Another mail insert showed up the other day, promising us the freedom to use our yard again. More than the incessant roar of gas-powered blowers, this subject makes me want to stand up and shout: “Stop thinking that humans are the only creature that matters!”

I grew up in the South. We had mosquitoes. We learned how to deal with them. Remember these tips?

• Eliminate standing water: Cover, turn over, or remove any equipment, containers, or toys that might collect water.
• Unclog gutters; they hold water when clogged.
• Check for sagging tarps or other covers that collect water.
• Check for standing water around outdoor faucets or air conditioning drains and correct.
• Ensure that rain barrels don’t have openings.
• Remove English Ivy (The dense nature of ivy allows it to hold in pooled water where mosquitoes can breed, provides a humid area that mosquitoes like, and protects mosquitoes from pesticide sprays.)

We also built screened porches to use, lit citronella candles, bought bug zappers, and applied bug spray. But that was only after we took care of the above issues to ensure they had fewer places to breed. This April 2018 article from Consumer Reports says that the CDC and the EPA still say those are the best and first approaches to try. The article also says “The use of automated spraying systems, which function like automatic water sprinklers, is growing. But the devices are not EPA-approved, and ... you’re better off skipping them.”

Red admiral butterfly

Why does one approach to dealing with mosquitoes matter over the other? There is growing evidence that these chemical sprays do more than kill mosquitoes. They kill other bugs: bees, butterflies, fireflies. As a result, they reduce food for all levels of the wild food chain – for example, birds eat a lot of bugs!

They harm humans that come into contact with them. And improper usage can lead to insecticide resistance. These are powerful reasons to reconsider what one family’s choice means for the rest of us.

Here are some of the articles available on the internet about the serious downsides of using mosquito control companies:

This story from 2016 covered the deaths of millions of bees after aerial spraying in South Carolina. While home spraying would not cover such a large area, it shows that the chemicals are toxic to other insects.

This article from 2015 illustrates how spraying can introduce chemicals into water and onto plants. It also talks about the chemicals used – permethrin, one of the common ones in mosquito misting systems, is toxic to bees.

And this article indicates that lab testing “specifically found that butterflies are being exposed to naled, permethrin, and dichlorvos - insecticides sprayed locally for mosquito control - far more than is acceptable, as it was already known that these chemicals were toxic to many species past a certain concentration.” Permethrin is the one advertised by most of these companies as the one they use.

What about humans? The companies say their products are safe for humans, but has there been enough research? This article in 2016 references a study that found a potential health link: “The authors report that kids living in zip codes where the spraying was done each summer had around a 25% higher risk of an autism diagnosis or developmental problem compared to kids living in areas without the aerial spraying.” Obviously, more studies need to be done but are more studies being done?

Don’t be fooled by assurances from the companies themselves. Remember these companies exist to make a profit, not to do what is right for the environment. All they want is for you to believe their promises and so that you’ll sign up for a regular spray program. Listen carefully to what they say:

• They will tell you that their products are biodegradable and that their systems are EPA approved (but the Consumer Reports article says not all systems are approved). You’d be surprised at what the EPA approves and biodegradable does not mean that the chemicals are not toxic and won’t kill every bug that comes into contact with it (that is their goal after all).

• They will tell you that their systems are safe for children and pets (notice the use of the word ‘system’ not chemical). Ask them if their products are safe for bees, butterflies, and fireflies. They don't know. No one speaks up for the invertebrates (the insects).

Dragonfly = mosquito eater 

For many years humans have assumed that businesses have done their research and are offering safe products. We found that was not always true, usually after some species suffered as a result of our negligence (remember DDT, or the more recent research on neonicotinoids?). These home spraying programs have all the hallmarks of profit-driven, consumer-scare tactics. “It’s YOUR yard – take it back!”

We’ve got to think about our neighbors and the hundreds of other species that depend on us not to poison their world. It’s up to us to make the right decision – for us and for the critters around us.

Need a good resource for dealing with mosquitoes at the community level? Check out this PDF from The Xerces Society.