Gardens Alive! & Supplies
Tomato Pests
That Will Destroy Your Tomatoes
Tomatoes are one of the most-loved plants in the vegetable garden. Unfortunately, not just gardeners love them. Pests love them, too. They nibble on their leaves, stems and fruits—sometimes reducing yields, sometimes destroying crops. The good news, though, is that many tomato pests can be controlled—and you can enjoy bountiful harvests of sun-ripened tomatoes.
Here's a list of the top 10 bugs on tomato plants and how you can control them.
Aphids
Aphids are common garden pests that feed on many types of plants, including tomatoes, and can ruin a garden quickly. They can also transmit viruses as they move from plant to plant. When aphids infest tomato plants, they remove sap from the leaves. While tomato plants can survive aphid attacks, severe infestations will cause the leaves to curl and stunt the plant's growth.
Identification:
Aphids usually appear on tomato plants early in the growing season. These tiny insects are about 1/8-inch long and may be pinkish-green to yellow-green in color. They have two cornicles that look like tailpipes and extend from the end of their abdomens. Aphids are usually found on the tomato plant's stems or under its leaves.
Getting rid of Aphids:
Gardeners have lots of pest control methods that get rid of aphids. One option is to spray your plants with a heavy stream of water and knock the aphids off the plants. If aphids are a serious problem in the garden beneficial insects, like Green Lacewings and Sta-Home™ Lady Beetles, are great ways to reduce heavy populations. Another option is to use Pyola® Insect Spray or Shield-All Plus™ Insect, Disease and Mite Control. When using pesticides, always make sure you read and follow the directions and on the label.
Whiteflies
More common on tomatoes growing in greenhouses or in the southeastern areas of the United States, these tiny tomato bugs suck sap from tomato plants. Whitefly attacks can lead to sooty and sunscald, and whiteflies can also transmit diseases to tomato plants.
Identification:
Whiteflies are tiny—about 2mm long—with yellow bodies and white wings. If you rustle the tomato plant's leaves and see a cloud of insects, it could be whiteflies. Another way to monitor for whiteflies is to use a sticky trap, like Pot Stickers Insect Glue Traps.
Getting rid of Whiteflies:
To get rid of whiteflies, you can use an horticultural oil that smothers the insect. Spraying the plants may also be effective. If whiteflies are a persistent problem, then releasing beneficial insects can also control their populations. Insecticides, like Shield-All Plus™ Insect, Disease and Mite Control, are also an option. If using an insecticide, make sure the insecticide is labeled for whitefly control and follow the label instructions.
Cutworms
If you've ever gone to the garden and found your recently transplanted tomato plant cut off near the ground, chances are cutworm caterpillars are to blame. These tomato pests like to chew tender young seedlings and transplants. Fortunately, if you take a few preventative measures, cutworms are easy to control.
Identification:
Either gray, brown, black or variegated in color, cutworm caterpillars are usually 1-2 inches long. When touched or disturbed, they curl up into a c-shape.
Getting rid of Cutworms:
One way to control cutworms is to till the soil in the fall or spring. This can expose cutworms to cold weather or predators. When transplanting tomato seedlings into the garden, apply beneficial insects, like nematodes. Another easy and effective method to control cutworms is to place cardboard or plastic collars around the transplants. Make sure you push the collars at least 2-3 inches into the soil. The collars can be removed once the tomato plants have set several leaves.
Hornworms
One of the most recognizable tomato pests, the large and destructive tomato hornworm can defoliate a tomato plant—and nibble on the fruits as well. Hornworm moths lay eggs on the underside of tomato plant leaves in early to midsummer. The hornworm caterpillars emerge and start eating the foliage. Because they're green, they camouflage well with the foliage.
Identification:
The adult tomato hornworm moth is a mottled gray-brown color and up to 5 inches across. The hornworm caterpillar is green with white, v-shaped markings on its side and a black projection on its last segment. They can grow up to 4 inches long.
Getting rid of Hornworms:
To deter hornworms, plant marigolds around your tomato plants. The marigold scent acts as a natural repellent. To get rid of tomato hornworms, most gardeners inspect their plants regularly and handpick the worms from the plants. To kill them, drop them in soapy water.
Parasitic wasps control hornworms naturally. If you find a hornworm that has white, rice-like projections on its back, leave it. These are pupal cases of parasitic wasps. When the adult wasps emerge, they will look for other hornworm caterpillars to parasitize.
If using pesticides, choose lower-risk options like containing bacillius thuringiensis (Bt) or spinosad. Follow label instructions. Shield-All Plus™ Insect, Disease and Mite Control is another option.
Stink Bugs
Stink bugs are a nuisance in the house and the garden. These bugs can kill tomato plants by sucking the liquid out of them—and they can damage the fruits, leaving yellow, uneven spots on ripening tomatoes.
Identification:
Adult stink bugs are up to 3/4-inch long and either green or brown with a shield shape. When squished, they emit a very unpleasant odor.
Getting rid of Stink Bugs:
Of all the types of tomato pests, stink bugs are some of the most challenging to control. Some pesticides, such as Shield-All Plus™ Insect, Disease and Mite Control, may reduce their damage. If using pesticides, read and follow label instructions.
Flea Beetles
Flea beetles feed on tomato plant foliage as well as a variety of vegetable plants. They usually do the most damage in the spring when tomato seedlings are just getting started and don't have lots of foliage. Heavy infestations this tomato beetle can kill a tomato plant. Signs of flea beetle damage are tiny holes in the leaves.
Identification:
Flea beetles are so small, usually less than an 1/8 inch long, that they're difficult to spot. However, if you disturb an infested plant, you may see them jumping. They may be brown, black, gray or striped.
Getting rid of Flea Beetles:
Placing lightweight row covers over young plants will protect them from insect damage. The row covers must be removed when the plants start to flower so that pollination can occur. Products with kaolin clay, such as Surround® At Home® Crop Protectant, can protect young plants. Another option is using beneficial nematodes. If these methods don't work, use Pyola® Insect Spray.
Nematodes
Nematodes are microscopic worms that live under the soil. Some nematodes are beneficial to plant growth and pest control. Others, like the root-knot nematode, can leave tomato plants weak and stunted.
Identification:
Because the nematodes live underground and are microscopic, you probably won't see them. You can, though, see the damage to root systems. Plant roots may have galls or a knotted appearance. Above ground, tomato plants attacked by the root-knot nematode may look stunted or wilted. Yields will be reduced.
Getting rid of Nematodes:
If root-knot nematodes are a problem in your area, consider planting tomato varieties resistant to the root-knot nematode. Rotating crops may help, but is difficult because this nematode affects a host of other plants. Also, sterilize garden equipment so that you don't spread the nematodes to other areas.
Tomato Fruitworms
Tomato fruitworms are some of the most damaging pests for tomato plants. The fruitworm caterpillar will feed on the tomato plant's stems and leaves. If fruits are present, it will feed on the fruits. A single caterpillar may damage up to four tomatoes.
Identification:
The adult tomato fruitworm moth usually flies at night and is light yellow-green. The fruitworm larvae or caterpillars grow up to 1 1/2 inch long and are yellow-green, green-brown or black. They may have stripes.
Getting rid of Tomato Fruitworms:
Check your tomato plants for signs of the fruitworm. In some cases, handpicking the caterpillars is effective. Spinosad and Bt-containing products, including Bull's-Eye Bioinsecticide and Green Step™ Caterpillar Control, can also be used. If using, read and follow label directions. Beneficial nematodes may also be effective.
Spider Mites
Spider mites feed on foliage, piercing the leaves and sucking the sap. A severe infestation of these tiny tomato bugs can stunt a tomato plant's growth and even kill it. Spider mites infestation is more likely to occur during hot dry summers. Evidence of spider mites may be webbing or tiny white or yellow spots on the leaves.
Identification:
Spider mites are tiny, about the size of a period. Evidence of spider mites may be webbing or tiny white or yellow spots on the leaves. One way to check for them is to hold a white piece of paper under the tomato plant foliage and rustle the leaves. The mites will fall to the paper, creating black specks.
Getting rid of Spider Mites:
Because spider mites do the most damage to stressed plants, keep your plants healthy and well-watered during hot, dry spells. To remove them, you can spray water on the tomato plants. Horticultural oils, such as Pyola Insect Spray, also work well. When using, follow label instructions. Another option is introducing beneficial insects, like lady beetles.
Slugs and Snails
Slugs and snails are common garden pests. They thrive in moist conditions and will feed on the foliage of young plants as well as tomato plant foliage and fruits. They can stunt plant growth and damage fruits.
Identification:
Slugs, which look like snails without hard shells, are gray-brown in color, soft-bodied and can be up to 2 inches long. When they feed on plants, snails leave a trail of slime behind. Usually snails feed at night.
Getting rid of Slugs and Snails:
To prevent slugs from attacking your tomatoes, prune the bottom branches and make sure they receive lots of air circulation and light. Avoid overhead watering. Controlling slugs is fairly easy. You can hand pick them off of the plants. Placing beer traps, or shallow pans of beer, in the garden is also effective.
How to Protect Tomatoes From Pests: General Tips
Following some basic preventative measures will help protect your tomato plants from pest damage. Here are some tips on how to protect tomato plants from pests:
- Keep your tomato plants healthy by mulching, regular watering, pruning and not over-fertilizing them. Healthy plants are better able to withstand some pest pressure.
- Practice crop rotation. Avoid planting tomato or other nightshade plants in the same place year after year.
- Remove plant debris and weeds from the garden. In the fall, pull up and remove plants from the garden. Weed your garden regularly to keep it as weed-free as possible.
- Inspect your tomato plants regularly for pests. Managing pests when populations are small and they haven't done much plant damage is more effective than waiting until you have damaged plants and huge pest populations.
- Clean and sanitize garden equipment. This helps prevent the spread of pests and disease.
- Keep notes about your garden. Note when pests appear and what pests appear. Over time you can be more proactive about the common pests in your garden.
Conclusion
Unfortunately, garden pests are part of gardening. However, learning about the pests most likely to attack your tomatoes can help you be proactive. Many gardeners keep their favorite Garden Insect Control on hand, so they are ready for when pests strike.
