Insect identification - Ask Extension
Found at night mostly on my cone flowers - thought they were Japanese beetles but no green and isn’t it early for them? Only visible damage is limit...
Knowledgebase
Insect identification #640700
Asked May 25, 2020, 2:20 PM EDT
Found at night mostly on my cone flowers - thought they were Japanese beetles but no green and isn’t it early for them? Only visible damage is limited to the pictures
Fillmore County Minnesota
Expert Response
No Japanese beetle yet, thank goodness, and the damage looks more like that from a caterpillar. Beetles usually don't eat so much. Japanese beetles do the kind of damage you do but the arrive in hordes. I think more looking is necessary to find the pest.
Thank you for the reply. I picked hundreds of these beetles off of my plants over two nights - with the biggest "infestation" on the plant pictured. they covered the whole plant. And in 3 nights of looking these are the only pests found - i also laid earwig traps (rolled newspaper) and nothing. What is the beetle in the picture i can't find it on any of the identification sites.
It is probably a chafer/scarab beetle. They are active now. See:
1. http://minnesotaseasons.com/Insects/May_beetle_(Phyllophaga_sp).html
2. https://www.insectidentification.org/insect-description.asp?identification=May-Beetle
Hello
I sent your question to the University entomologist and he has identified your bug and would like a sample if you would please send him some. Pack them so they don’t crush and please let me know when you see this post.
I sent your question to the University entomologist and he has identified your bug and would like a sample if you would please send him some. Pack them so they don’t crush and please let me know when you see this post.
This is an unusual one. It turns out these are May/June beetles. We typically find May/June beetles attacking oaks and other hardwood trees and not perennials in gardens. These beetles are also a smaller sized species than we normally encounter.
As far as what to do, there isn't anything special. Handpicking is the best nonchemical method. If that is getting to be too much, then a garden residual insecticide, like permethrin, bifenthrin, lambda cyhalothrin. Usually May/June beetle activity is short lived so it should not be a long-term problem.
I also have a request. Some colleagues and myself are quite interested to learn what species this is (can't tell from the pictures). Ask the resident if they would be willing to send a sample of these beetles to me. If yes, the address is: Jeff Hahn 1980 Folwell Ave., 219 Hodson Hall, Dept. of Entomology, University of Minnesota, St. Paul, MN 55108
will absolutely be happy to send a sample. I did hand pick for two nights and on the second night also sprinkled Diatomaceous earth and around the base of the plants most affected - i have sedum plants blooming nearby and while they were also on those I didn't want to affect the pollinators :( . Went out last night and there were none on the coneflowers so not sure if they just had a very short adult life or if it was the Diatomaceous earth because when i originally found these plants were literally covered - but there were a few on the sedum and rockcress so i left them be. I'll go back out tonight and grab a couple of fresh ones and get in the mail tomorrow.
Thank you, when I get more information I will send it to you.
Any update since i sent in my sample?
Judi
Judi
Jeff Hahn just sent me a note that he is back in the office and your samples arrived in good condition and that he will share them with a couple colleagues to identify them.
Thanks! Thanks too for contacting me with the original question. It makes it much easier for me to reply. The repository of questions is huge and the search feature is not very good.
Thanks! Thanks too for contacting me with the original question. It makes it much easier for me to reply. The repository of questions is huge and the search feature is not very good.
