What are Big Green Worms on Tomato Plants?

If you're a gardener or tomato lover, you may have encountered big green worms on your tomato plants. These worms are the larvae of the tomato hornworm, a common garden pest that can cause significant damage to tomato plants.

Identification

The tomato hornworm is a large, bright green worm that grows up to 4 inches in length. It has a distinctive horn on its tail end, which is its namesake. The worm has several white stripes along its body, which can be used to differentiate it from a similar-looking pest, the tobacco hornworm.

Habitat and Lifecycle

The tomato hornworm is native to North America and is most commonly found in the southern and eastern parts of the United States. It prefers to live in warm, humid environments and is most active during the summer months. The adult moth lays its eggs on the underside of tomato leaves, and the larvae emerge within a week. The larvae feed on tomato leaves and fruit for several weeks before pupating in the soil. The adult moth emerges from the pupa after about two weeks.

Damage to Tomato Plants

Tomato hornworms can cause significant damage to tomato plants by eating the leaves, stems, and fruit. The damage can lead to reduced yields and even the death of the plant. If the infestation is severe, it may be necessary to remove the affected plants to prevent the spread of the infestation to other plants in the garden.

Control and Prevention

There are several methods for controlling and preventing infestations of tomato hornworms. One of the most effective is handpicking the worms off the plants and dropping them into a bucket of soapy water. You can also use a biological control method such as introducing parasitic wasps, which lay their eggs inside the hornworms, killing them from the inside out. Additionally, you can use organic pesticides such as neem oil or Bacillus thuringiensis (BT), which are effective against hornworms but won't harm beneficial insects like bees or ladybugs.

Conclusion

If you see big green worms on your tomato plants, don't panic. They are most likely tomato hornworms, a common garden pest that can be controlled and prevented with a combination of methods. By identifying and treating these pests early, you can protect your tomato plants and enjoy a bountiful harvest.