Tobacco Hornworm

Manduca sexta — the tobacco hornworm — is one of the most-studied insects in modern science, alongside Drosophila melanogaster, Tribolium castaneum, and the honey bee Apis mellifera. The species is the dominant model organism for insect physiology, neurobiology, host-plant chemistry, immunity, flight biomechanics, and many other research areas because of the large size of the larva (mature at 10 cm and 8 grams), the easily-cultured laboratory life cycle, and the rich neurochemistry of the species. The caterpillar is bright green with seven white diagonal stripes and a distinctive red dorsal 'horn' projecting from the rear (the 'hornworm' name is for this structure, which is purely defensive coloration and not a sting). Caterpillars feed exclusively on Solanaceae — primarily tomato, tobacco, eggplant, and pepper plants — and can defoliate a tomato plant overnight in heavy infestations. The adult is the Carolina sphinx moth, one of the largest North American hawkmoths at 12 cm wingspan, with cryptic gray-brown wings and orange-and-black abdominal banding. Adults are nocturnal, fly at dusk, and pollinate long-tubed white flowers (especially Datura, Nicotiana, and other night-blooming Solanaceae) using a 5-7 cm proboscis. The species is heavily parasitized by the braconid wasp Cotesia congregata, which lays eggs inside the hornworm and the wasp larvae develop within the host before erupting through the skin in 50-100 white silk cocoons attached to the hornworm's exterior — a textbook example of parasitoid biology.