Can you suggest a time frame to spray arborvitae in Macomb township? Thank you!
Macomb County Michigan
July and August are the periods when bagworms are active. The following resource offers recommendations for insecticides that control bagworms. https://extension.entm.purdue.edu/publications/E-27/E-27.html
If you only find a few bagworms on the plants, hand removal and drowning in a bucket of soapy water would be easier than chemical control.