Hi -- I'm a gardening newbie, but I killed one of these and then discovered (if I'm right) that it's a young wheel bug (beneficial). I thought it was a juvenile squash bug, but they appear to be green. I'm not positive -- perhaps someone else out there knows more than I do... [If I'm right, stay away from the adults -- they're supposed to have a nasty bite if bothered...]

Here is a link that might be useful: True bugs with pictures

I am not an expert, but I had a bunch of these on dying plants, so I would advise you try to relocate them and watch them from a safe distance to see if they harm other plants. Good luck :)