Caterpillars on Tomato Plants

Tomato plants are a favorite food not only for humans but also for some caterpillars.

Tomatoes are attacked by many different types of caterpillars. Some chew on leaves while others feast on the stems and still others enjoy the fruit. Knowing what type of caterpillar you are dealing with will help you choose the correct treatment.

Leaf Miner

Chlorophyll is the favorite food of the leaf miner.

Larvae of the leaf miner tunnel through the tomato leaf eating chlorophyll-filled mesophyll cells. When the chlorophyll is eaten, it leaves behind dead tissue or feeding scars called stipples. If the feeding continues, tomato growth is stunted and yield is reduced.

Cutworm

Cutworms attack the tomato plant at ground level only.

The cutworm caterpillar cuts off young plants at ground level and feeds on them during the night. To prevent this, wrap young tomato stems with a strip of newspaper before planting in the ground.

Beet Armyworm

Beet armyworms, depending on age, either graze together or alone.

Young larvae of the beet armyworm are found grazing together on the outer part of the underside of leaves. Older larvae graze alone and eat the whole leaf, which will eventually lead to complete defoliation.

Pinworm

If tomato fruit is cut open from the bottom, this worm may be found inside. But evidence of this caterpillar is also present by a blackened cavity near the stem scar. This is created by the pinworm tunneling into the fruit.

Tomato Fruitworm

Young caterpillars eat their own eggshells when they hatch and then move on to young leaves. Older caterpillars eat older leaves and tunnel through fruit. They will produce a web around their feeding area.

Tomato Hornworm

Tomato hornworms love tomato leaves.

The tomato hornworm is about 4 inches long. During the day, the tomato hornworm is found on the interior of the tomato plant. During dawn and dusk, the tomato hornworm moves to outer leaves. This caterpillar is very destructive and is capable of completely consuming all leaves and stems from a tomato plant.

References

• Tomato Gardening Guru: Tomato Problems & Prevention
• Texas A&M Agrilife Extension: Common Insect Pests of Tomatoes
• Colorado State University Cooperative Extension, Denver County: The Tomato Hornworms