AVRDC International Cooperators'
Tomato Insect Pests
Found in North America and Southeast Asia
Feeding scars on the fruit surface are shallow and dry. The
inside of the fruit is often hollowed out. This cavity is usually
dry and may have frass and decay.
Chewing mouthparts. Caterpillars are dull green with many
light stripes along their backs and a broader stripe down
each side. The undersides are usually yellow. Adult moths
are grayish and active at night.
Where To Look
Caterpillars are commonly found in two places. Groups of
newly hatched larvae can skeletonize tomato leaves and
typically feed under a webbing of silk. Look for the webbing
of the feeding damage. Older caterpillars become more
independent and can be found gouging the surface of the
External fruit damage
Larva entering a stem
Populations develop continually throughout the year. Adult moths lay their eggs in off-
white scale-covered clusters on the leaves. When feeding is complete caterpillars
pupate in the soil. The population can develop on some weeds. This pest also
commonly feeds on onion, soybean, chili pepper, and sugar beets.
Spraying of chemical insecticides has been the major approach to combating
armyworm. But the pest is developing resistance to many chemicals. In response,
farmers sometimes mix several insecticides together in hope that one of them will be
effective. These strategies are not sustainable.
The use of alternative, biological control measures are very useful. Parasitic wasps and
nuclear polyhedrosis viruses (NPVs) that target armyworm are commercially available.
Strains of Bacillus thuringiensis (Bt) are useful for killing armyworm larvae.
Pheromones for armyworm are commercially available. They are useful for monitoring,
and especially to determine the entry of the pest into the field. Pheromones by