Scout Conifer Windbreaks for Bagworms Now

David Owens, Extension Entomologist;

Last year we received a few complaints of bagworms defoliating windbreak trees. Right now, bagworms are still small enough that they should be susceptible to B.t. or a spinosad. The oldie goodies (carbaryl, acephate) are also effective, though harder on beneficials. Be looking for small, leafy looking pyramids hanging down from the tips of leaves. Bagworms attach their bags to twigs when they pupate, and the old bags do not come off. Check to make sure that what you see on your windbreaks are young, active bagworms, not yesteryear’s worms.

Small bagworm indicated by arrow. Larvae of this size can be controlled by insecticide sprays.