Identification

• Tomato hornworms are the larval stage of the sphinx moth, which is also known as the hawk moth or the hummingbird moth. This caterpillar is green in color, with a dark green horn on its head and black sides. The tomato hornworm emerges from pearly eggs placed on tomato leaves, usually in May or June. After emergence, the caterpillar feeds on the leaves of the tomato plant for over a month.
  
  

Effects

• Tomato hornworms chew on tomato plant leaves, causing rapid defoliation of the plant. The fruit of the plant may also suffer from feeding injuries. This pest is especially damaging to tomato plants, but also infests other vegetables such as peppers and potatoes.
  
  

Diagnosis

• Examine your tomato plants for signs of tomato hornworm damage. Tomato hornworm larvae usually feed on the outside of plant leaves when shade is present, which is at dawn and dusk. Tomato hornworm damage will be evident, as the leaves appear chewed or are completely gone. If larva are present, you can remove them by hand and destroy them.
  
  

Control

• Heavy infestations of tomato hornworms often requires chemical controls. Consult your local garden center regarding products recommended in the control of tomato hornworms. Products containing spinosad or carbaryl are often effective in eliminating these pests. Biological control products containing Bacillus thuringiensis or BT are also recommended in the treatment of tomato hornworms. Apply chemical control products according to the directions for best results.