[ContainerTed]

Alan, to any aspiring tomato plant, the only good hornworm is a dead hornworm. You can spray the plants and kill them that way or you can search thru the plants looking for them and then physically remove them. Missing leaves and small stems are the hornworm trademark. The "black stuff" is their droppings and are made of your former tomato plants leaves and stems.

Here's a picture of what you're looking for. Don't wait around. They can destroy a plant in just a few days. Also, if you see the droppings, the hornworm will be somewhere just above.

Here's the tomato plant version of the devil himself.