Beginner

Scientific Name
Manduca sexta (tobacco hornworm); Manduca quinquemaculata (tomato hornworm)

Identification

• Large, smooth, green caterpillars
• Mature larvae measure 8 cm (3 ½ in.) in length
• Has seven or eight conspicuous white V-shaped markings down each side and a prominent spike (horn) on its rear end
• Feeds on the leaves, stems and fruit of tomato plants

Often Confused With
N/A

Period of Activity
Hornworm larvae may be present in tomato fields during the mid- to late summer.

Scouting Notes
Look for feeding damage – entire leaves consumed, leaving petioles and stems bare or heavy fruit feeding.  In contrast, cabbage loopers eat relatively small holes in the leaves, while variegated cutworm damage includes holes in leaves and gouges or burrows in the fruit.

Thresholds
One larvae per 30 plants.

Advanced

Scientific Name
Manduca sexta (tobacco hornworm)
Manduca quinquemaculata (tomato hornworm)

Identification
These hornworms are large, smooth, green caterpillars.  Mature larvae measure 8 cm (3 ½ in.) in length.  The hornworm has seven white diagonal markings (tobacco hornworm) or eight white V-shaped markings (tomato hornworm) down each side and a prominent spike (horn) on its rear end.  The hornworm feeds on the leaves, stems and fruit of tomato plants.

Often Confused With
N/A

Biology
The pest overwinters as a pupae in the soil.

Period of Activity
The larvae are present in mid- to late summer.

Scouting Notes
Look for feeding damage – entire leaves consumed, leaving petioles and stems bare or heavy fruit feeding.  In contrast, cabbage loopers eat relatively small holes in the leaves, while variegated cutworm damage includes holes in leaves and gouges or burrows in the fruit.

With experience, the damage from these worms can also be distinguished by their frass.

Thresholds
One larvae per 30 plants.

Management Notes

• Control measures are rarely needed for this pest in tomatoes.