Help! Japanese beetles - Ask Extension
Hi there,
Yesterday we noticed large numbers of what we think are Japanese beetles flying around. They really weren't still long enough to get a go...
Knowledgebase
Help! Japanese beetles #875430
Asked July 01, 2024, 8:42 AM EDT
Hi there,
Yesterday we noticed large numbers of what we think are Japanese beetles flying around. They really weren't still long enough to get a good look, but that's what we suspect. We have never had these before. We have rose bushes, which I know they attack, but I'm most concerned about our vegetables that they might be attracted to, including asparagus, rhubarb, bush beans, and potatoes. We haven't seen heavy feeding yet but I'm sure it's coming. What's the best way to handle the adults? And is there anything we can do to prevent/kill the grubs later? We have a lot of lawn, which I'm sure is where they came from.
Thanks for your help!
Baltimore County Maryland
Expert Response
Holly, a picture of the critters would be very helpful in indentifying what you have. It's essential to know what you're dealing with in order to treat them effectively.
If they are Japanese beetles, here is some good advice from UME which also has links to controlling grubs: https://extension.umd.edu/resource/japanese-beetles-trees-shrubs-and-flowers/
Also from the USDA: https://www.aphis.usda.gov/sites/default/files/JBhandbook.pdf
Thanks for contacting Ask Extension.
If they are Japanese beetles, here is some good advice from UME which also has links to controlling grubs: https://extension.umd.edu/resource/japanese-beetles-trees-shrubs-and-flowers/
Also from the USDA: https://www.aphis.usda.gov/sites/default/files/JBhandbook.pdf
Thanks for contacting Ask Extension.
You’re so right about a photo being necessary. The problem was that the insects weren’t landing anywhere that we could easily snap a photo. They just zipped around the yard starting in late morning. But finally my husband took this one, and it looks more like maybe a June beetle? Whatever it is, what should we expect? Thanks!
Attaching photo this time!
Kind of hard to distinguish characteristics from the picture.
June bugs (actually beetles) and Japanese beetles are similar in what they eat and the damage they can do to grass and plants.
Both the Japanese beetle and june bugs lay their eggs under the surface of lawns and grassy areas. The larvae (grubs) feed on the grass roots until they are forced below the frost line, then emerge in the summer as adults.
June bug are nocturnal and are attracted to light. Japanese beetles do most of their feeding during the day. Japanese beetles are metallic green with bronze elytra (wing covers). June bugs have maroon and brown elytra. They also can be green but not as shiny.
Here is more info from Kansas State Extension:
https://blogs.k-state.edu/kansasbugs/2018/06/22/green-june-beetles-vs-japanese-beetles/
Thanks for your question!
June bugs (actually beetles) and Japanese beetles are similar in what they eat and the damage they can do to grass and plants.
Both the Japanese beetle and june bugs lay their eggs under the surface of lawns and grassy areas. The larvae (grubs) feed on the grass roots until they are forced below the frost line, then emerge in the summer as adults.
June bug are nocturnal and are attracted to light. Japanese beetles do most of their feeding during the day. Japanese beetles are metallic green with bronze elytra (wing covers). June bugs have maroon and brown elytra. They also can be green but not as shiny.
Here is more info from Kansas State Extension:
https://blogs.k-state.edu/kansasbugs/2018/06/22/green-june-beetles-vs-japanese-beetles/
Thanks for your question!
