I have small russet brown colored bugs (perhaps beetles?). They are mostly...

Asked July 2, 2020, 1:07 PM EDT

I have small russet brown colored bugs (perhaps beetles?). They are mostly rectangular but a bit tapered with grooves in the carapace running the length of the abdomen. About the size of a grain of rice. They are heavily feeding in my runner beans. They seem notably less interested in the purple prodded pole beans next to them. No amount of searching has helped me identify what these are. I’ve resorted to trying to pick them by hand. Help identifying and advice about prevention or control would be greatly appreciated.

St. Joseph County Indiana

3 Responses

The beetle in your picture seems a bit squished, so it is difficult to know what its shape is. You are welcome to take and submit more pictures. If you put a coin in the picture, it will be easier to gauge the size. First guess is that this is an Asian garden beetle, although the shape is somewhat different..

https://www.canr.msu.edu/news/two_new_turf_and_garden_pests_asiatic_garden_beetle_and_oriental_beetle_fou

Sorry it was water logged. Here is another. I don’t have macros so can’t get a crisper close picture.

I had some help by MSU entomologist Mike Reinke on this. He says:

It is called a leaf miner beetle. It belongs to the the same group as many of the other leaf beetles. This one likes various legumes and black locust trees, among others. The larvae are leafminers. They are occasional pests at best. If the owner is seeing a lot of them, they could potentially cause stress and low bean set. A general pesticide could be in order if they feel it is necessary.