Are you concerned about mosquito control chemicals negatively impacting pollinators? You are not alone! And, if you’re confused about how to talk about the impact of mosquito control on pollinators in your community, you are also not alone!
The DuPage Monarch Project has prepared this handout to help you. Read on to learn the basics about mosquito control chemicals and what you can do to work within your community to lessen the impact of these chemicals on pollinators.
Chemical Control: The Basics
- Larvicides target mosquitoes in the aquatic larval stage and do not harm pollinators.
- Adulticides kill adult mosquitoes and are typically sprayed into the air or directly onto plant leaves. Because some species of pollinators like monarchs, have chemical receptors on their legs and feet, adulticides applied directly to the plant leaf can kill a pollinator.
- The use of adulticides – but not the use of larvicides – has been shown to have a negative impact on pollinators.
Mosquitoes and the diseases that they bring with them, such as West Nile virus, are not going away. Communities are correct to place a high priority on protecting humans from illnesses caused by mosquitoes. Consequently, chemical control of mosquitoes can be an unwelcome, but sometimes necessary, fact of urban life. But we can take steps to lessen the negative impact of chemical mosquito control on pollinators in our own communities.
Preventing the hatching of mosquito larvae is the easiest, cheapest and most effective way to reduce chemical use for controlling adult mosquitoes. You can do this by routinely checking your property for sources of standing water, where mosquitoes lay their eggs. Keep buckets, gutters, birdbaths, trash cans, pools, pool covers, and other sources of standing water clean and dry. You can help pollinators in your community by talking with your neighbors and your community leaders about doing this too.
Knowing What’s Happening
Home gardeners and bee-keepers often ask about mosquito management in their area: When does it happen and what products are used? Typically, there is no single organization responsible for mosquito management in any state or county. Finding this information will require some outreach on the part of an interested homeowner. As a concerned citizen, your goal should be to gather information on adult mosquito management, as larval management has no known impact on pollinators.
- Contact your local government (city, township or county) to ask if spraying for adult mosquitoes is performed in your area. Ask if the spraying is performed by government employees or by an outside contractor. Generally municipalities and their contractors spray (fog) from the street using trucks or handheld sprayers, or will apply residual barrier treatments directly onto plants using handheld sprayers.
- If your property is adjacent to a park or forest preserve, contact the appropriate Park District or Forest Preserve District to gather information on their mosquito program, if one exists. Many Park or Forest Preserve Districts do not have in-house mosquito management programs.
- If adult spraying is performed by a contractor, ask for a point-person you can contact within that company to gather the necessary information.
- Because all current mosquito adulticide products have some effect on pollinators, the most important question is when, and how, they spray in your area.
- Keep in mind, adult mosquito treatments are fairly localized. Aerial spraying (fogging) generally only affects the immediate treatment area. Therefore, treatments even just a street over may not have an effect on your property. Barrier treatments are even more localized, as they should only affect the vegetation that was directly sprayed.
Remember Your Neighbors
Keep in mind that your neighbors, apartment complexes, private businesses, condo associations and other local residents can hire private mosquito control companies themselves without needing to notify the municipality or anyone else nearby.
What Can You Do?
While mosquito adulticides are known to have potential negative impacts on butterflies and moths, if these products are applied at the labelled rates, at the correct time of day, and follow all labelled instructions, the impact on pollinators can be minimized.
Maintaining a friendly, respectful ongoing relationship with local government, contractors and neighbors is the single most important thing you can do to reduce the impact of mosquito control chemicals on pollinators.
- Encourage the applicator to research and use the most ecological-responsible products available.
- Encourage the applicator to apply products following all labelled guidelines, paying particular attention to label rates and application instructions. Inform them that there are sensitive pollinators in the area.
- Encourage the applicator to spray after dusk, when many pollinators are not actively foraging.
- If they do not already do so, ask if you can receive notification prior to any nearby treatments, so that you can take appropriate measures to cover your garden or other sensitive areas like decorative ponds. If this is not possible, encourage them to develop a notification system for future treatments.
- If possible, opt out of treatments around your home. However, understand that this may not be possible, especially if the mosquitoes targeted carry human diseases (Culex mosquitoes, for example).
- Make sure you do not have standing, stagnant water around your property. Dumping these containers will reduce the local mosquito population, and therefore help reduce any need to spray for adult mosquitoes. Encourage your neighbors to do the same.
- Where possible, cover sensitive areas with tarps to reduce the amount of pesticide contacting plants that attract pollinators. This will not provide complete protection, and in the case of honeybee colonies, may lead to overheating. Tarps should be removed the morning after pesticide application.