Hornworm's Diet

Tomato Hornworms

• Tomato hornworms (Manduca quinquemaculata) are most active during the evening and nighttime hours, avoiding direct sunlight. As their name implies, tomato hornworms feed upon tomato plants (or, indeed, any member of the plant family solanaceae) but will eat virtually any vegetation present in a garden, including peppers, potatoes and other vegetation. If an infestation is serious, entire plants can be stripped of its leaves in only a day's time.

Tobacco Hornworms

• Like the tomato hornworm (Manduca sexta), the tobacco hornworm also avoids sun exposure. Like its name suggests, the tobacco hornworm feeds heavily upon tobacco plants. However, it also feeds on nightshade plants such as eggplants, and more than 1,700 species comprise the tobacco hornworm's diet. Not all elements of the tobacco hornworm's diet is agricultural, though: jimson weed, henbane, ground cherry and sand bur are all components of the tobacco hornworm's diet.

Physical Capabilities

• Hornworms quickly become quite large: reaching up to five inches in as little as a month. The hornworm's body is hairless, except near its front legs. The body of the hornworm is divided into eight subsections; its length and size allows the hornworm to lift up its body to access plant matter and food otherwise out of reach. The deep, vibrant green color of the hornworm's body allows it to blend in with its environment, avoiding detection by predators (usually birds).

Hornworm Presence

• The presence of hornworms is evident by their destructive tendencies: trees and plants will be eaten. Small numbers of hornworms aren't particularly damaging or destructive, but an out-of-control or large population can quickly defoliate a garden. Most gardeners are familiar with hornworms because their presence is so common in the garden environment. Tomato hornworms eat holes in leaves, and both species will also feed on tomatoes and eggplants. Hornworms are most active from the midsummer onward.

Maturity and Diet

• Hornworms eventually mature into moths toward the end of the summer season: the tomato hornworm is the caterpillar form of the five-spotted hawk moth, while the tobacco hornworm is the caterpillar form of the sphinx moth. Both moths are active during both night and day for feeding and mating. The moths are physically adapted, with an elongated mouth and proboscis to access a flower's nectar.