Up to 5 inches long, hornworms are the larvae of large brown moths that fly like hummingbirds. Both tomato and tobacco hornworms are green with diagonal white stripes; the horn, at the pest’s rear, is black on the tomato hornworm, red on the tobacco hornworm. The caterpillars feed upside down on leaf undersides. Since they blend into the foliage, they can be hard to spot, although the black pellets they excrete are plainly visible.
Hornworms
