Dealing with bagworms on evergreen trees plants

Asked May 2, 2013, 3:58 PM EDT

I've got a significant bagworm problem over the last few years, on Douglas Fir and arborvita. I've tried to control by picking off the bags and burning them. I also pulled out a heavily infested evergreen ornamental and burned it. I understand May-June is the best time to spray. I've got an air blast sprayer on a tractor (farm use). The trees are 15-25' tall. Are there some formulations eg of Sevin or permethrin that could be used? And how do I know when to spray? It would be good if the pesticide were not toxic to bees. Lots of bumblebees in the yard nearby. Thanks.

Lehigh County Pennsylvania

1 Response

Hello, and thanks for using the Ask an Expert system.
Ohio State University offers a good fact sheet on the biology and control of evergreen bagworms that should answer your questions. You can access the fact sheet at It provides invormatiion on various control methods as well as methods for figuring the timing of sprays.