Tomatoes are one of our favorite things to grow in spring; but they sure do come with their fair share of pests. If you know what you’re looking for ahead of time you can stop these pests in their tracks before they inflict too much damage. Early detection is the key to successful pest control. We’ve waited all winter for tomato season, don’t let these little destroyers take it away. Take a look at the top five pests that affect tomatoes and let’s go to battle. The tomato pest control options will be listed in order of least toxicity.

Spider mites on tomatoes

Tomatoes and Spider Mites

Spider mites are tiny, brownish-red pests that feed on the leaves of tomato plants, causing discoloration, wilting, and stunted growth. They are difficult to see with the naked eye but you can test for them if you start to notice a white, stippled discoloration forming on the top of your tomato leaves.

Take a white sheet of paper and hold it under the leaves of your plant. Gently thump the leaves and see if you can now see tiny brownish-red specks zooming around on the white paper. As infestations increase, leaves begin to lose all of their green color, fading into tan, and in later stages, spider mites can be identified by the fine webbing they leave behind. Don’t let them get to any of these stages if you can possibly help it. Observe and inspect your tomato plants and leaves daily; things change quick in the garden.

Control Spider mites by:

  • Spraying them multiple times a week with a blast of water from the hose to displace and discourage them.
  • Spraying with insecticidal soap.
  • Alternately spraying with pyrethrin and spinosad at 14 day intervals as needed. (Try only spraying spinosad after the sun starts to go down so you avoid contact with pollinating bees.)

One other thing to note is that spider mites truly love hot, dry weather and plants that are stressed. Keep your tomato plants well fed and watered; a healthy plant will help with prevention of spider mites.

Tomato Hornworm on stem of tomatoes

Tomatoes and Tomato Hornworms

Tomato Hornworms are large green caterpillars with white stripes on their sides and a horn-like protrusion on their rear end. These caterpillars defoliate tomato plants and cause damage to their fruit. Tomato Hornworms are also hard-to-see pests as they are pretty much the same color as the tomato leaves that they love to munch. You’ll have to really look for them under leaves, along stems, etc…

What you actually might see before you see the hornworm is little black pellets on top of your leaves which is frass (a.k.a. caterpillar poop). Or, even before that, you might see a hummingbird moth flittering around your tomatoes and this could be a sign that tomato hornworms will soon follow as they are the larvae of these moths.

Control by:

  • Handpicking them from the plant
  • Spraying with Bt (Bacillus thuringiensis)

Fun fact about tomato hornmworms, they are phosphorescent. If you have a black light, and go searching for them at night, they will glow purple!

Leaf-footed bug

Tomatoes and Leaf Footed Bugs

Leaf-footed bugs are pests with piercing mouthparts. They are known to feed on the fruit of tomato plants, causing yellow spots, discoloration, and sometimes even fruit drop. Inspect tomato plants often for eggs deposited in a strand on the undersides of leaves or in a row along stems. As nymphs, they are orangish-red with black spots. At this stage you will most likely see a cluster of these juvenile bugs. As adults, leaf-footed bugs have a distinct flattened appearance with leaf-like projections on their hind legs, and are brownish in color with white stripes on their wings.

It’s much easier to control leaf-footed bugs when they are eggs or nymphs, adults have a tough exoskeleton that makes them harder to control. Again, early detection is key.

Control by:

  • Brushing them from your plants into a bowl of soapy water and they’ll meet their demise. (Newspaper on the soil below the plant can capture any bugs that evade the bowl.)
  • Spraying with insecticidal soap, Neem oil, or pyrethrin spray.
  • Vacuuming from plant with a small handheld device (weird, but works).

Keeping your garden debris free, both in and around, helps with prevention of leaf-footed bugs.

Aphids up close.

Tomatoes and Aphids

Aphids, oh we couldn’t forget about aphids. These tiny pests seem to show up on just about any plant, and tomatoes are not excluded. Yellow, green, or brownish-gray, aphids are sucking insects that can drain the vital juices out of leaves on your tomato plants, leaving them yellowed and weakened. You’ll find clusters of them congregating on the tips of new growth underneath leaves and along stems (they’re everywhere). Aphids also excrete a sticky substance (honeydew) that is very attractive to ants. If you aren’t careful, you may two pests in one that you have to deal with.

Aphids are soft bodied insects and while that makes them easier for pest controls to target, they also multiply so fast that multiple sprays will most likely be warranted. You just can’t get them all the first time.

Control by:

  • Spraying a hard blast of water.
  • Squishing with fingers (will most likely stain skin).
  • Releasing beneficial insects (ladybugs and green lacewings) for organic control
  • Spraying with insecticidal soap.
  • Spraying with pyrethrin.
Leafminers on leaves.

Tomatoes and Leafminers

Leafminers are insects that lay their eggs on the leaves of plants. Larvae hatch from these eggs, burrow into the leaves, and feed on the plant tissue. Leafminers cause visible tunnels or trails on the leaves, which can be white, brown, or discolored. This tunneling can cause significant damage to the leaves and affect the overall health of the plant. Other signs may include leaf curling or deformation, reduced plant growth, and decreased fruit production.

Control by:

  • Spraying with Neem Oil (only spray in the cooler early morning or late evening hours to avoid burning plants)
  • Spraying with Bt (Bacillus thuringiensis)

Try preventing leafminers by placing yellow sticky traps around tomato plants; adults are attracted to them.

Don’t be discouraged, just because we listed these pests doesn’t mean that you will have an issue with all of them. We just wanted you to know what to look out for and it’s a reminder to be diligent about checking on your tomatoes and all your plants this spring. Early detection is key; we can’t stress that enough!