How Many Hornworms on a Tomato Plant

Tomatoes are a popular crop for home gardeners and commercial growers alike. While they can be relatively easy to grow, tomato plants are susceptible to a number of pests and diseases. One common pest that tomato growers may encounter is the hornworm. These large, green caterpillars can do significant damage to tomato plants if left unchecked. In this article, we will discuss how many hornworms you can expect to find on a tomato plant and what you can do to keep them under control.

What are Hornworms?

Hornworms are the larval stage of the Sphinx moth, also known as the hawk moth. There are two species of hornworms that commonly attack tomato plants: the tomato hornworm and the tobacco hornworm. The tomato hornworm is slightly smaller than the tobacco hornworm and has eight V-shaped markings on its sides, while the tobacco hornworm has seven diagonal stripes. Both species can cause significant damage to tomato plants, as they feed on the leaves, stems, and fruit of the plant.

How Many Hornworms Can You Expect?

The number of hornworms you can expect to find on a tomato plant will depend on a number of factors, including the size of the plant, the degree of infestation, and the time of year. Hornworms typically lay their eggs on the undersides of tomato plant leaves, and the eggs hatch in 5-10 days. Once the caterpillars emerge, they will begin feeding on the leaves and stems of the plant. In about 3-4 weeks, they will pupate and emerge as adult moths.

It is not uncommon to find several hornworms feeding on a single tomato plant, especially if the plant is small or if the population of hornworms in the area is high. In severe infestations, it is possible to find dozens of hornworms on a single plant, which can cause significant damage to the plant and decrease its yield.

Controlling Hornworms

If you notice hornworms on your tomato plants, it is important to take action to control the infestation before it gets out of hand. There are several methods you can use to control hornworms:

Handpicking: If you have only a few hornworms on your tomato plants, you can handpick them off the plant and dispose of them. Be sure to wear gloves when handling hornworms, as they can be covered in spines that can cause skin irritation.

Bt Spray: Bt, or Bacillus thuringiensis, is a natural bacteria that is toxic to many types of caterpillars, including hornworms. Bt spray can be applied to tomato plants to kill hornworms and other caterpillars. Be sure to follow the package instructions when using Bt spray.

Insecticides: Insecticides can be used to control hornworm infestations, but they should be used with caution. Many insecticides can be harmful to beneficial insects, such as bees and butterflies, as well as to humans and pets. If you choose to use insecticides, use them sparingly and only as directed.

In Conclusion

Hornworms can be a nuisance for tomato growers, but with proper control measures, they can be kept under control. Regular inspection of your tomato plants, handpicking, and the use of natural or chemical control methods can all be effective in managing hornworm infestations. By taking steps to control hornworms, you can help ensure a healthy, productive tomato harvest.