Tomato Hornworms are really big green caterpillars that can devastate your pepper garden. Giant brown moths lay pearl-like eggs on your pepper leaves, from which the monsters will hatch and start to eat voraciously. They can decimate all the leaves on a plant overnight.
We've also heard growing a patch of dill near tomatoes works like a trap crop, because hornworms will attack the dill over the tomatoes. Dill grows like a weed and is easy to direct sow from seed, so if you grow enough of it you won't likely miss the dill. You could pick off the hornworm caterpillar off the dill if desired and squish and throw into the compost, or let nature run it's course - more than likely they may become bird food or wasp food before they mature. And when they do mature, these hornworm caterpillars turn into what we call "hummingbird moths" also known as sphinx or hawk moths, which are fun to watch – they are frequently mistaken for small hummingbird as they zip about in the garden.
We also have Swallowtail butterflies lay their eggs on Dill, and we see the caterpillars, but they often seem to disappear before they get very large – probably due to the wasps and other beneficial insect predators that are attracted to the flowers. We hope these little guys made it, the Black Swallowtails they transform to are gorgeous and lovely to see in the garden.