UF/IFAS Vegetable Arthropod Pest Photographs CD-ROM III

Tobacco Hornworm, Manduca sexta
Tomato Hornworm, Manduca quinquemaculata
(Lepidoptera: Sphingidae)

The tobacco hornworm is a serious pest of tomatoes. Because of its large size and rapid growth rate it can defoliate plants quickly. It is found primarily in the southern United States and along the Gulf Coast States, whereas the tomato hornworm is found in northern states. The eggs are spherical in shape and vary from white to green in color. The larva is cylindrical and has five pair of prolegs and three pairs of thoracic legs. The most noticeable characteristic is a large black horn on the back end of the larva, hence the name hornworm. The larva will also have seven oblique lines on the sides that are white in color. The pupa is found approximately 15 cm below the soil surface. The adult is a large moth that is grayish in color with orange spots on the sides of the abdomen. There are usually two to four generations per year. The insect overwinters by entering diapause in the pupal stage. The tomato hornworm is similar in appearance and biology to the tobacco hornworm and is easily distinguished by the presence of eight white or yellowish "V" shaped marks on the side of the larvae instead of oblique lines.

The host range consists of only solanaceous (tomato and its relatives) plants, most commonly tomato and tobacco. Many solanaceous weeds serve as alternate hosts. Insecticides may be used to manage the pest population, but large larvae are difficult to kill. Bacillus thuringiensis may also be used to control the larvae. Cultural control practices include deep tillage to disturb diapausing pupae. Hand picking and destroying the larvae is a practical control method in a small garden. Polistes wasps are good predators of hornworms but may not provide adequate control due to the ability of the larvae to cause a large amount of damage in a short time. Management recommendations are the same for both species.

Images

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Defoliation of a tomato leaflet caused by tobacco hornworm,
Manduca sexta.
(Photographer: J. Castner, University of Florida)
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Damage to tomato fruit caused by tobacco hornworm,
Manduca sexta.
(Photographer: J. Castner, University of Florida)
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Tobacco hornworm, Manduca sexta, larva. This is the
common "tomato hornworm" of southern states. Note the
diagonal white lines along the side of the larva.
(Photographer: J. Castner, University of Florida)
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Tobacco hornworm, Manduca sexta, adult.
(Photographer: J. Capinera, University of Florida)
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Tobacco hornworm, Manduca sexta, pupa.
(Photographer: J. Capinera, University of Florida)
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Newly hatched tobacco hornworm, Manduca sexta, larva and
egg.
(Photographer: J. Castner, University of Florida)
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Tomato hornworm, Manduca quinquemaculata, adult.
(Photographer: J. Capinera, University of Florida)
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Tomato hornworm, Manduca quinquemaculata, larva. This
"true" tomato hornworm is the common tomato pest of
northern states. Note the "V" shaped lines on the side of the
caterpillar, pointing toward the head.
(Photographer: P. Choate, University of Florida)
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