The following information was provided by the West Chicago Mosquito Abatement District.
One of the most-frequently asked questions about community mosquito control applications is about their safety of pollinators. The answers can be found in understanding the products and the practices used.
- The droplet and the dose.
- The products used are formulated and applied with a method specifically optimized for the control of adult mosquitoes. This results in less than an ounce per acre being applied as very fine aerosol droplets which must impinged upon a mosquito in flight to be controlled. These droplets are so small that 15 would fit on the head of a pin.
- This dose is specific to mosquitoes and their weight. For reference, mosquitoes weigh between 2 and 10 mg each. A firefly weighs at least 20 mg, and the average honeybee around 100 mg. Thus even if exposed, the droplets have significantly less ability to negatively impact these and other insects.
- In a 2016 Louisiana State University study of several public health mosquito control products applied by typical ULV (ultra-low volume) sprayers found no harm to bees, even with direct exposure at a 50 foot distance from the sprayer and at the highest possible label rate.
- The protocol.
- Before there can be risk or impact, there must be exposure. Fortunately, mosquitoes are active at night when pollinators are not. This mitigates potential for exposure.
- Those who choose to cover hives, milkweed habitat for monarch caterpillars, gardens may do so, but are not required.
- The day after.
- Droplets from an application either dissipate in the air or dry rapidly if deposited. So it does not leave appreciable residues on foliage, and any trace levels of residues detected are not toxic to sensitive insects within three hours of treatment. Further, incidental residues are rapidly broken down by sunlight.
- Checks and balances.
- All public health mosquito control products are reviewed and registered by the EPA and are labeled for residential use. When the EPA decides to register a product, it determines that when used according to the dose and application directions on the product label, it should not cause undue harm to any non-target insects, animals, humans, or the environment at large.
- Other references.
- You may also find this post on Clarke’s website useful, which answers the Top 10 questions about mosquito control programs, according to Clarke’s Customer Care team: https://www.clarke.com/blog/top-10-resident-questions/.
- The Effect of Insecticides on Butterflies
- What You Need to Know About Truck Spraying – CDC