Crop Protection Guides
Soybean Insect Pests
Chewed holes are present on the leaves. Leaves are
damaged to the point that they are not recognizable as those
of soybean. In severe infestations, leaves are completely
gone causing the plant to die. Occasionally this insect also
cuts plant stems at the soil line and feeds directly on the
Chewing mouthparts. Very young caterpillars are blackish-
green and have a distinct black band across the back of their
heads. Older ones are slightly darker with yellow bands along
their backs and sides of their bodies. Their heads are
prominent and black and along their backs are rows of
crescent-shaped black spots. Adult moths are active only at
Where to look
They are easy to detect. The young larvae feed together on the surface of the leaves.
Larger caterpillars tend to feed along. Search the entire plant to locate them. Look
carefully at the upper and lower surfaces of the leaves.
The behavior of this species is variable (Note above paragraph). Females lay their
eggs in hair-covered clusters. Mature caterpillars pupate in earthen cells in the soil.
Generations may be continual in warm climates. This insect attacks many species of
crops. Among them are tomato, cauliflower, potato, onion, eggplant, chili pepper,
lettuce, pea, and maize.
Insecticides are used to control this pest. Defoliation during the mid-flowering stage is
most damaging to yields. Pheromones may be used to monitor pest populations.
Resistant lines are being developed.
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.
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