ID

3104-1551

Authors as Published

Eric Day, Department of Entomology, Virginia Tech

Two species of hornworm damage tomato plants in Virginia, the tobacco hornworm, Manduca sexta (Linnaeus) and the tomato hornworm Manduca quinquemaculata (Haworth) (Insecta: Lepidoptera: Sphingidae).

 

figure 1 hornworms
Figure 1, Left: tomato hornworm, Whitney Cranshaw, Colorado State University, Bugwood.org Center: Tobacco hornworm, Sturgis McKeever, Georgia Southern University, Bugwood.org Right: Hornworms with cocoons of wasp parasites, Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org

Description

Both species are green with diagonal lines on sides and prominent horn on rear end. They can be up to 4 inches long.

Common Host Plant(s)

Tomato, eggplant, tobacco, and pepper.

Damage

Theses caterpillars feed on leaves and green fruit. They are typically found on the upper portions of the plant. Since they consume 90% of the foliage just before they pupate they seem to appear “overnight”. This is not actually true; the smaller stages of the caterpillars did limited feeding that was quickly covered by regrowth. They in fact were on the same plant all along.

Distribution

Throughout Virginia and the United States.

Cultural Control

Hand pick worms, but do not destroy caterpillars with cocoons, leave in garden to continue biological control.

Organic/Biological Control

Bacillus thuringiensis, Bt, will control the caterpillars but must be applied when they are less then ½ inch long.

Chemical Control

Apply a labeled insecticide, following all instructions and precautions. Insecticides must also be applied when the caterpillars are less then ½ inch long.

References

University of Florida fact sheet: common name: tobacco hornworm scientific name: Manduca sexta (Linnaeus) (Insecta: Lepidoptera: Sphingidae), common name: tomato hornworm scientific name: Manduca quinquemaculata (Haworth) (Insecta: Lepidoptera: Sphingidae), 
http://entomology.ifas.ufl. du/creatures/field/hornworm.htm


Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.

Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.

Publication Date

April 25, 2011

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