Can you help me out?
I have found these insects in my garden. When I dig down a couple of inches, they started moving around. I did see small yellow grub like bugs as well.. I think it might have been where I had trouble with the yellow squash...but not 100% on that.
The gray bug looks like a squash bug in the nymph stage. They are very common pests of squash. Here is helpful information: http://extension.umd.edu/growit/insects/squash-bug
We don't know what the grub-like bug is, based on your description. Please send photos.