Tobacco hornworm on tobacco
This is the hornworm the crop is named after, and the one tobacco growers scout for. NC State counts plants in the field and treats at one clean hornworm over an inch long per ten plants. A parasitised hornworm counts as a fifth of one, because it eats far less and will die. Adults begin to emerge in early June in North Carolina, and most of the damage comes in July and later, over two to three generations.
At a glance
- Damage
- Whole leaves eaten, green fruit gouged
- Type
- Chewing
- Settings
- Field, Garden
- Threshold
- 1 or more hornworms over 1 inch without white cocoons per 10 plants checked (NC State); five cocooned worms count as one
- Ally
- Bacillus thuringiensis kurstaki
- Rate
- Label rate. DiPel DF lists tobacco hornworm and gives 0.5–1.0 lb per acre on tobacco
How to confirm it
A large green caterpillar, up to about 4 inches (10 cm), with seven white diagonal stripes on each side and a red horn on the tail. The tomato hornworm has V-shaped marks and a black or dark blue horn. Dark green or black droppings on the leaves below show where it is feeding.
Identification, lifecycle, degree days and every control option are on the full Tobacco hornworm profile. Not sure it is this pest? Answer four questions about the damage.