Hornworms Hornworms Hornworms are probably the best known of all insects that feed on tobacco. They are bright green in color and when fully grown about the size of the finger and 3 to 4 inches long. Two species damage tobacco.
Damage is caused by the larvae feeding on the leaves.
Hornworms pass the winter in the soil as pupae, which emerge as hawk moths during late spring. Larvae feed for about 4 weeks. The pupal stage lasts about 3 weeks except for the overwintering generations.