What's Eating My Tomato Plant?

I purchased a tomato plant, about a foot tall, put it in potting soil and even added ground eggshells. This happens every year. Something just eats away at the leaves (like a moth eats at fabric). I put Sevin dust one year, that just killed the plant. This year I put marigolds around it. I did see two caterpillars, dark brown with white stripes, on the ground a few mornings ago.

I brought it into the patio (screened in) yesterday. What seems to be the problem? Since I don't have bees/insects to pollinate it will it produce tomatoes? The leaves do have a brown black outer color. I use rainwater and Miracle Gro. It gets at least 5 hours of sun. Help for the 5th year in a row.

By monroe95 from Kissimmee, FL