mosquito repellent effect on pollinators - Ask Extension
I'm a master gardener trying to educate my community on avoiding mosquito spraying in favor of dunks and was asked an interesting question. This pers...
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mosquito repellent effect on pollinators #792916
Asked May 27, 2022, 8:12 AM EDT
I'm a master gardener trying to educate my community on avoiding mosquito spraying in favor of dunks and was asked an interesting question. This person uses a product that is all essential oils (produced by "Ranger") and includes cedar wood, peppermint, Citronella and garlic, which is sprayed on shrubs and vegetation. He wondered if this product would have a detrimental effect on pollinators. I did not have an answer. Can you assist? Thanks in advance.
Anne Arundel County Maryland
Expert Response
Thank you for reaching out to us with your question. Entomologist Emily Zobel wrote an article on the use of essential oils for mosquito control, which you can use for reference. Cornell University has published profiles on essential oils and their efficacy/side effects as minimum-risk pesticides. You can find those here: https://nysipm.cornell.edu/environment/active-ingredients-eligible-minimum-risk-pesticide-use/
When it comes to assessing pesticide side-effects on non-target insects, research is typically done only on honey bees and not on the vast array of pollinators and other beneficial insects in the environment. You will find in Cornell's profile pages that some of these essential oils do have some level of toxicity to honey bees. It will depend on the dose and amount of exposure. These ingredients are considered "minimum risk" pesticides, so, not as bad as some broad-spectrum insecticides, but also they are still considered pesticides, they are not "harmless."
As for using essential oils to control adult mosquitoes: garlic oil, lemongrass oil, and citronella oil are some of the commonly used essential oils in barrier sprays, but there is little to no research on them showing their effectiveness on mosquitoes in the United States. Also, sprays may not reach adult mosquitoes and others can fly in from nearby locations after the product is applied.
The more targeted and cost-effective way to control mosquitoes is to focus on killing them in the larval stage (e.g., using Mosquito Dunks) as you are recommending. Here is our main page on controlling mosquitoes.
I hope this information helps. Please do reach back to us if you have any further questions.
Christa
When it comes to assessing pesticide side-effects on non-target insects, research is typically done only on honey bees and not on the vast array of pollinators and other beneficial insects in the environment. You will find in Cornell's profile pages that some of these essential oils do have some level of toxicity to honey bees. It will depend on the dose and amount of exposure. These ingredients are considered "minimum risk" pesticides, so, not as bad as some broad-spectrum insecticides, but also they are still considered pesticides, they are not "harmless."
As for using essential oils to control adult mosquitoes: garlic oil, lemongrass oil, and citronella oil are some of the commonly used essential oils in barrier sprays, but there is little to no research on them showing their effectiveness on mosquitoes in the United States. Also, sprays may not reach adult mosquitoes and others can fly in from nearby locations after the product is applied.
The more targeted and cost-effective way to control mosquitoes is to focus on killing them in the larval stage (e.g., using Mosquito Dunks) as you are recommending. Here is our main page on controlling mosquitoes.
I hope this information helps. Please do reach back to us if you have any further questions.
Christa
