CONCORD - The fall cankerworm (commonly called inchworms) has become a growing nuisance to trees and property owners in Cabarrus County over the last few years. Feeding larvae can defoliate and build bothersome webs in many tree species. Usually, willow oaks are targeted, but other tree species from dogwoods to maples can be affected.
After many years of infesting trees in Charlotte, cankerworms moved into Harrisburg in 2009 and made their way to Concord and Kannapolis in 2010. Cabarrus cankerworm populations continued to increase in 2011 and 2012. Here are some tips to remember:
- Cankerworms won’t last forever. Past experience in Cabarrus County indicates the larva stage will be present only about 4 to 5 weeks from the time they hatch out in early spring.
- Fall cankerworms will not kill a healthy tree in their spring feeding frenzy. If all the leaves are removed, the tree will wait a few weeks and then put out new leaves. After new leaves form, there still will be enough growing season for a healthy tree to recover.
- The best control for reducing future infestations is tree banding. Place bands on trees in November and monitor them until the larva disappear in April.
- Spraying is less effective. Since the larva stage is short term, the cankerworms won’t kill the tree and spraying a mature tree is difficult or expensive. Most homeowners will ignore the spring infestation on mature shade trees.
- If you wish to control fall cankerworms on understory shrubbery during the spring larva stage, any pesticide that controls caterpillars will work on fall cankerworms.