Japanese Beetles that appear parasitized - Ask Extension
It looks like about 40-50% of the JB in my garden this year are infected by parasitoid wasps (1-3 white spots on their head area). Do I kill them in ...
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Japanese Beetles that appear parasitized #878518
Asked July 24, 2024, 12:31 AM EDT
It looks like about 40-50% of the JB in my garden this year are infected by parasitoid wasps (1-3 white spots on their head area). Do I kill them in soapy water like I do the others, or is there benefit in leaving them alive to kill the JB? Would that help to propagate the wasp population to hopefully infect more JB this year or next? Or maybe I should crush them to kill them, in hopes that the wasps continue to use the JB body to propagate/reproduce?
Washington County Minnesota
Expert Response
According to the following publication, it's best to spare parasitized beetles.
https://www.maine.gov/dacf/php/gotpests/bugs/factsheets/THE%20FLY%20THAT%20ATTACKS%20JAPANESE.pdf
https://www.maine.gov/dacf/php/gotpests/bugs/factsheets/THE%20FLY%20THAT%20ATTACKS%20JAPANESE.pdf
