Just this week discovered bagworms on my arbivitae, some damage has been...

Asked July 27, 2013, 5:45 PM EDT

Just this week discovered bagworms on my arbivitae, some damage has been done, have picked off all that we saw, each day going back and relooking, what do we need to do at this point and later to prevent another infestation next year...and the timing please. Also, will these plants rebound, they are not at all severely damaged, but noticeable gaps. PS really prefer the most environmentally safe method.

Talbot County Maryland

1 Response

Bagworms are a common problem in the landscape, and luckily, there are some options that might appeal to you. The bagworm eggs hatch in early June, and the caterpillars begin feeding and spinning the bag where they will pupate in late summer. They will emerge as moths and mate/lay eggs that will overwinter until early the next summer.

For control, look for existing bags on the target tree or shrub- for light infestations, hand-picking and destroying the bags is a viable option. For larger infestations, Bacillus thuringiensis can be sprayed between June 15- July 15 (before they pupate). B. thuringiensis is an organic, environmentally friendly option that should have no effect on people, animals, or beneficial insects. You may continue to hand-pick and destroy through fall and winter to eliminate overwintering eggs.