Tobacco Hornworms (Manduca sexta) are closely related to and often confused with the very similar tomato hornworms. The larvae of both feed on the foliage of various plants in the nightshade family, such as tomato and tobacco. The tobacco hornworm can be distinguished by its seven diagonal lines on its sides; tomato hornworms have V-shaped markings. An easy way to remember the markings is tobacco hornworms have straight white lines like cigarettes, while tomato hornworms have V-shaped markings as in V8 juice. They are found in open areas, particularly those under cultivation located in the eastern half of the United States and southeastern Canada. The hornworm caterpillars, although they are called tobacco worms, also attack the foliage of potatoes, eggplants, green peppers, and various weeds. Persistent rumors that caterpillars can sting with their horns are totally false. The larvae of the species are the damaging stage, leaving dark green or black droppings called frass. In the adult moth stage, it is also known as the Carolina Sphinx and Six-spotted Sphinx. In the southern tobacco-growing states the adult is called a Tobacco Fly. Orange, MA. USA. Summer. Wild.