Hello Chris,

Thank you for reaching out to Ask Extension with your question!

Do you have a picture of the beetle you are seeing?

Blister Beetles tend to increase in the same years as we have heavy Grasshopper infestations, as the larvae of blister Beetles will feed on Grasshopper eggs. Most of the insecticides that control Blister Beetles are not organic and they can also harm pollinators when used improperly.

For organic options, the best will be to pick off the beetles and drown in soapy water (similar to Japanese Beetle control). You MUST wear gloves when handling these beetles as they contain a toxic blistering agent called cantharidin, that can cause severe blisters if it touches your skin. Hand picking might be your best bet if they are in small numbers. If you have a lot of them, or handpicking is not possible, then Kaolin Clay could work. There are also pyrethrin products that have shown to work on most Blister Beetles.

Here is more information from Oklahoma State about Blister Beetles and their controls:

https://extension.okstate.edu/e-pest-alerts/2024/blister-beetles-activity-in-alfalfa-pasture-and-lawns.html 

https://extension.okstate.edu/e-pest-alerts/site-files/documents/2011/alfalfa-growers-who-market-to-horse-owners-should-watch-for-blister-beetles-july-19-2011.pdf

I hope this helps!

Dawn