If you’ve been outside in the past week or so, you’ve probably noticed little green inchworms. While my 9 year old daughter thinks they’re adorable, they are actually pests called cankerworms. Two species, spring and fall cankerworms, hatch in early spring. The larvae (those inchworms we’re seeing) feed on young leaves before dropping to the ground on a silk thread. The larvae then pupate in leaf litter through the summer. When the adults emerge, the females climb trees and deposit eggs on twigs. Fall cankerworm adults climb in October – November, while spring cankerworm adults emerge in early spring.
While these cankerworms will generally not kill a tree, they can defoliate enough branches to cause the tree to be unsightly, and could potentially weaken trees.
While control of these pests would be difficult and costly at this time of year, banding your trees and applying a sticky substance called Tanglefoot (TM) in the fall can trap the adult females and prevent them from laying eggs. This video from NCSU shows how to apply the bands to a tree. Workshops have been held in Durham during previous fall months, and will be publicized here when scheduled in the coming autumn.