A Technical Report from The Bartlett Tree Research Laboratories
Cankerworm caterpillars are inchworms or loopers common on shade trees in late spring. Two species of cankerworms are landscape pests: Fall Cankerworm is found in eastern North America and as far west as Montana. Spring Cankerworm is found over most of North America, including Texas and California. Regular landscape inspections should be implemented to monitor for outbreaks. Since most eggs hatch high in trees in early spring, the first signs of an outbreak are easily missed. Tree protection can be achieved with injections, spray treatments and tree banding.