A gardening friend of mine says that I have tomato worms. The ends of the plants are bitten off and some tomatoes have been bitten into and now have concave brown spots on them. I have gone out at dusk and dawn to look for the critters, but to no avail. There is no evidence of worm droppings. I saw the suggestion about using a black light in the evening, but I do not have one as of now. Any other ideas/suggestions? I am broken hearted - the plants have been very healthy up to a few days ago. Does diamataceous earth really work? How do you use it? Sprinkle over the plants? Thank you for your help!!