AVRDC International Cooperators'
Fact Sheet

Sweet Potato Insect Pests
 

Hawk Moth
Agrius convolvuliis

Found throughout Africa and Asia

 caterpillar


Damage symptoms

Leaves have large holes. Extensive defoliation generally occurs in the plant. In severe cases, the plant is completely devoid of leaves and dies.


Insect characteristics

Chewing mouthparts. The caterpillar is large, often with a diameter the size of your thumb. Its color varies from green to brown. It has a horn arising form the upper end of its body. The sleek adult moth has a streamlined spindle-shaped body built for rapid, strong flying.

caterpillar causing severe damage
Caterpillar causing severe damage


Where to look

Because of the large size of the caterpillar and its prominent horn, you should have little difficulty finding it on the leaves. However, its color may blend with the foliage so inspect the entire plant carefully.


Technical information

The full grown larva pupates in the soil. After several seeks, the adult surfaces and lays eggs singly on the foliage. The eggs are about 1 mm in diameter. Adult activities only occur at night. The adult is often attracted to lights. This insect is also occasionally found on beans.


Control

Collect and destroy larvae. Plow fields soon after harvest to expose the pupae. If insecticide application becomes necessary, a safer and cheaper chemical, like malathion, will control this pest. Hawk moth larvae are external feeders and will easily come into contact with the pesticide.
 
Last updated: 2001. 
Information from: Field Guide: Insect Pests of Selected Vegetables in Tropical and Subtropical Asia. 1995. B.L. Parker, N.S. Talekar and M. Skinner. Publication 94-427. Pesticide and other control recommendations should be adapted to local conditions. 

AVRDC Home | Extension Materials Home | Sweet Potato Home