This bug has been eating leaves of my plants!
Looks just like a firefly, to me! They don't eat leaves, so you've got the wrong culprit. Adult firefly beetles feed on nectar and the larvae are predaceous ground dwellers. Beneficial insects, all the way around.
Fireflies have been all over the place in my yard, too. By the way, there are many species of this insect, each with its own physical characteristics.
Here is a link that might be useful:
I agree with rhizo. Keep looking for the culprit.
Thanks, I suspected it's the firefly but I saw it always at the leaves with holes. Now, I will leave these guys alone.