Caterpillars of all kinds can do lots of damage to your garden, your yard, and your landscape. How do I hate caterpillars? Let me count the ways. For starters cutworms can chop off plant seedlings. If you like to grow your own food, then you've probably done battle with the tomato hornworm (left). The trouble with the hornworm is that it is the same color as tomato leaves and that makes it nearly impossible to see them and pluck them from the plant. We had hornworms in our garden last year, and they just decimated our tomato plants. There are sprays you can buy to combat caterpillars, such as bacillus thuringiensis or BT.