Hey i had two healthy beautiful tomato plants. At first those ugly looking green caterpillars were coming around but i got rid of them and now i have this other species of caterpillar that at ground level burrows into the stem of your tomato plant and hollows the inside as it goes. I pulled one of the tomat plants out of the ground and it was like a twig all brown and fully hollow in the inside. I know what the problem is but how do i stop them from getting to the plant?