Those bright, green-striped caterpillars nibbling on your tomato plants are called hornworms. You can recognize one by the apparently sharp horn on its tail. Actually, the horns aren't sharp -- and they aren't stingers -- but deterrents against head-eating insects. These large caterpillars may be in the larvae stage, but they are usually around five-inches long. They love to eat like most babies -- these young'uns can decimate your tomato plant in just a couple of days!
Gardeners either love them or hate them. They love them because they make great chicken food and fish bait. Most hate them because your entire crop of tomatoes can be wiped out before you even realize the pests are feasting.
Hornworms, Be Gone!
Hornworms eventually become beautiful hummingbird moths. Despite their adult beauty, the larvae must go if you want to save your tomato plants. You can try to pick them off the leaves or tomatoes. You may recoil when you touch them, as your fingers may feel like they can go right through their soft bodies. But if you choose to physically remove them, simply drop them in a large bucket and drown them with water.
If you choose not to pick them off your plant, you can wait for nature to do it for you. However, you risk losing your tomatoes. You can buy ladybugs to eat them. Often you will notice that there are little white eggs sitting on the backs of the hornworms. These were laid by wasps. Wasps love to eat them or use them for feeding their eggs. The eggs eat the caterpillars by burrowing into them and feasting on their insides until the hornworm dies and the eggs hatch into baby wasps. You can liken their demise to nature's payback for the hornworm decimating your tomato plants.
Some gardeners prefer to spray their tomato plants with an organic recipe of water, dish-washing liquid, and vinegar. This organic pest control concoction will often keep the caterpillars at bay. Diatomaceous earth is another good alternative. Both the spray and the earth will clog up the little air holes on the sides of the hornworm's body that allow it to breathe, rendering it incapable of getting air. It may not kill them all; but, it will work if you don't want to pick them off your plant or allow nature to take its course.
Don't fret that the hornworm's demise won't allow it to evolve into the beautiful hummingbird moth. These voracious insects are quite numerous and often go unnoticed, so many will live to lap up plenty of nectar from flowers, especially in fields of wildflowers, another day. For more information, contact a company like Carroll Exterminating Company.