Tobacco Hornworms

Tobacco Hornworm on Datura

Barb identified these dreaded tobacco hornworms on a Datura "Moonflower" plant we acquired from Larry Wegman.  These and their near kin, tomato hornworms, are frequently described with scorn by visitors to the Butterfly House.  Both varieties are major pests on tomato plants but I think they deserve a little better press.

In spite of the tobacco in its name, Datura species plants are also a hornworm favorite.  The genus Datura includes Jimson weed and various thorn-apples (see the thorn-apple in the picture).  Datura are members of the Solanaceae family, which includes tomatoes, potatoes, eggplant, tobacco, petunia and even the deadly nightshade. 

Carolina Sphinx Moth- Wikimedia

The tobacco hornworm, Manduca sexta is the caterpillar of an attractive moth of the Sphingidae family that includes hawk moths, sphinx moths and hornworms. Its adult form is called the Carolina Sphinx Moth. They are rapid fliers and hover while feeding like a hummingbird.

Because of their large size, short life cycle and ease of feeding they are used in research settings as well as classrooms. Research includes neurobiology, flight mechanisms and larval nicotine resistance. Given their contributions to research and their habit of eating tobacco, I can almost forgive them for chewing the occasional tomato.

Read more: Datura and Hornworms | eHow.com http://entomology.unl.edu/k12/caterpillars/hornworm/hornwormpage.html