Fall and Spring Cankerworm
Identification
Caterpillars of these two similar species reach one inch long; color varies from light green to dark brown with yellow stripes on their sides. Fall cankerworm caterpillars have three pairs of abdominal legs; spring cankerworms have two.
Hosts
Caterpillars of both species feed on oaks, maples and hickories.
Biology
Both species hatch in the spring. While young larvae only make holes in leaves, older caterpillars consume most of the leaf. After feeding for about six weeks, caterpillars burrow into the soil to pupate. Fall cankerworm adults emerge and lay eggs in the fall; spring cankerworms overwinter in the soil and adults emerge in the early spring.
Control
Natural enemies usually limit outbreaks to 1-2 years with little tree mortality. Sticky bands placed around tree trunks can trap females as they ascend trees to lay eggs. High use areas or high value tree may require insecticidal control.