Tobacco hornworm

Definition

The larval stage of the hawkmoth Manduca sexta (Lepidoptera: Sphingidae), a large, bright-green caterpillar with seven diagonal white stripes and a curved red terminal horn. Native to the Americas, it feeds primarily on Solanaceae including tobacco, tomato, and Datura, and is a significant agricultural pest as well as a premier model organism for insect physiology, neurobiology, and developmental studies due to its large size, rapid growth, and ease of laboratory rearing.

Etymology

From the host plant association with tobacco (Nicotiana spp.) and the distinctive curved horn on the terminal abdominal segment.

Example

Researchers inject baculovirus into fifth-instar tobacco hornworms to study host-pathogen interactions, while tobacco growers in the southeastern United States monitor for hornworm damage characterized by defoliation and dark frass on leaf surfaces.

Synonyms

• Manduca sexta larva

Related Terms

• tomato hornworm
• Sphingidae
• Manduca
• instar
• horn
• Frass
• baculovirus
• model organism
• Solanaceae

Usage Notes

Often confused with the tomato hornworm (Manduca quinquemaculata), which has V-shaped markings rather than diagonal stripes and a black horn. In laboratory contexts, 'tobacco hornworm' frequently refers specifically to the larval stage, whereas 'M. sexta' encompasses the full life cycle. The name is sometimes applied loosely to any Manduca larva found on tobacco, though specialists restrict it to M. sexta.