Health Protection, Southern Region
VARIABLE OAKLEAF CATERPILLAR,
Heterocampa manteo (Doubleday)
Importance. - This defoliator is common throughout eastern North America. It attacks a wide variety of
hardwoods, including all species of oaks, but prefers the white oaks. Some infestations have covered millions of acres, retarding tree
growth and reducing vigor. Outbreaks occur periodically and usually subside after 2 to 3 years, before serious tree mortality occurs.
Identifying the Insect. - The larval color is variable, but is generally yellowish green, with a narrow white stripe down the center of
the back, and one or two yellowish stripes on the sides. The head is amber, with one dark and one light band on each side of
the head. Mature larvae may reach I 1/2inches (37 mm) long. The adult moth is ashy gray, with three dark wavy lines across each
forewing. The wingspan is approximately 1 1/2 inches (37 mm).
Larva and feeding damage. (Click for detail. JPG 20K)
Identifying the Injury. - Young larvae skeltonize the leaf, while older larvae devour the entire leaf except the leaf stalks and main veins. There
are two periods of defoliation-early May to late June and mid-August to late September.
Biology. - There are two generations in the South and one generation in the North. In the South, the larvae feed from early May until
late June and pupate in the soil. Second generation larvae feed from midAugust until late September, then move to the ground to
spin cocoons and over winter. Adult moths emerge from cocoons by early spring.
Control. - Insect parasites and predators destroy eggs, larvae, and pupae. Winter mortality also helps keep most infestations in
check. Chemical control is occasionally needed to protect high value trees.