Tobacco Hornworm

By William T. Hathaway

Three Stages of the Tobacco Hornworm

The adult Carolina Sphinx Moths (Manduca sexta) fly at dusk. Females lay eggs on the upperside of host plant leaves in the lower regions of the plant. Eggs hatch in 2-8 days and the larvae (hornworms) emerge. These caterpillars eat and grow for about 20 days and then molt into a pupating stage, dropping to the ground. They then burrow into the soil, where a pupal cell is constructed. A brown cocoon-like structure, measuring up to 2 inches long, is formed. This cocoon overwinters in burrows in the soil.

With the arrival of warmer summertime temperatures, adult moths emerge from the cocoons. The developmental cycle starts over again as the adults mate and the females again lay eggs. Because of their large size, these caterpillar hornworms are capable of removing all foliage on a plant in a short period of time. Farmers have learned to control this insect attack. However, a more damaging attack is ongoing from out-of-state politicians who would sweeten their coffers by robbing the tobacco industry.