How to Kill Tomato Hornworms

Tomato hornworms are large, but hard to spot unless you examine your plants closely.

Tomato hornworms, also known as Manduca quinquemaculata, are fat green worms with V-shaped designs on their backs. Like the name implies, tomato hornworms feast on tomato plants. In order to keep your tomato plants from being destroyed by these 4-inch creatures, you must take action to kill them. This can be done naturally, or by taking advantage of chemical pesticides.

Things You'll Need

• Bucket
• Soapy water
• Bacillus thuringiensis
• Chickens
• Chemical pesticide

Instructions

1. Prepare a bucket of soapy water, and pick the tomato hornworms off of the tomato plants one at a time. Drop the hornworms in the bucket of soapy water. The worms will eventually drown.

2. Spray Bacillus thuringiensis, Bt, on your tomato plants. Bt is an all-natural bacteria that when ingested, will cause the tomato hornworms to die. You will not see results for several days, but it is a better option than handpicking when the infestation is on the larger side or you're feeling squeamish.

3. Introduce chickens in to your tomato garden. Chickens eat hornworms without harming your tomato plants. Not only will this kill the tomato hornworms, but it is an excellent way to control the hornworms for the future.

4. Spray a product with either the active ingredient spinosad or permethrin on your tomato plants. Follow the product label for safety, and to ensure it is as effective as possible.

Tips & Warnings

• Observe your tomato hornworms before killing them. If they have white cotton-like sacs on them, the hornworms are already being killed by parasitic wasps.

• Till the soil each year before you plant the tomatoes to kill any eggs the tomato hornworms may have laid.

References

• University of Minnesota Extension: Tomato Hornworm - Manduca Quinquemaculata
• Colorado State University; The Tomato Hornworms; Judy Sedbrook

Resources

• Tammy's Recipes: Garden Pests: Tomato Hornworms & Tobacco Hornworms