I found several small holes in my strawberry leaves. Upon further investigation, I found these creatures on the bottom of the leaves, curled up. They are very small, 3-4 mm maybe. Yellowish-green body and brown head. I don't know if they are caterpillars or larvae. I attached a picture.
I also found holes on the leaves of my hazelnut tree, so it's possible the same thing is eating them but I am not sure.

Does anyone have a clue what they are? Are they dangerous to the fruit or just the leaves? How do I get rid of them?