This neat looking fellow is the larval stage (caterpillar) of the Carolina Sphinx moth (Manduca sexta) feeding on Eggplant leaves (Solanum melongena). The horn which projects from the rear of this caterpillar cannot sting and is quite harmless.

Larvae of the Manduca sexta grow quickly to a relatively large size of 3 to 5" long, and can devour young dill, eggplant, pepper, potato, tobacco, datura, petunia, and tomato plants in one to two days (the speed at which major damage can occur often takes gardeners by surprise). Tobacco Hornworms can also damage young fruit on eggplant, pepper, and tomato plants causing decay or hard spots which can make the fruit unharvestable.

''Manduca sexta'' adult female taken by Shawn Hanrahan at Texas A&M Collection in College Station, Texas.

Life Cycle

Tobacco Hornworms can be found in all regions of Florida year-round. Because these caterpillars are heavily parasitized and a favorite of birds, moles, skunks, and toads they rarely tend to be a serious pest in Florida gardens.

Tobacco Hornworm eggs are deposited on the upper or lower leaves of plants of the Solanum family and hatch in about seven days. The larvae feed on the plant leaves for about three to four weeks and develop into fat, green caterpillars about 5" long. The full grown larva eventually make their way down the plants and burrow into the soil where they transform into the pupal stage. Depending on weather conditions the moths emerge from the pupa within 2 to 4 weeks. The emerging moth makes its way to the soil surface and mates. The females begin to deposit eggs on the tomato plants for the next brood of hornworms.

Control

Hand picking tobacco hornworms then squishing them is very effective. Controlling breakouts of these and other caterpillars can be achieved by spraying Bacillus thuringiensis (BT) on susceptible plants before caterpillars become a major problem. Do not take any action if you find tobacco hornworms with something that looks like little fuzzy pieces of rice standing upright on the caterpillar's back. These are the cocoons of the braconid wasp pupae. When these parasitic wasps emerge from their cocoons they will not only parasitize this caterpillar, but other insects as well.

 Sources: Rodale's Garden Problem Solver; American Horticultural Society Pests and Diseases