Bagworms on Arborvitae
Hello. We just noticed a few weeks ago that one of our 10 arborvitaes appears to be dying - it happened very quickly. After some online research, we discovered the tree is infested with bagworms. I have read a lot about them & now that it's August, it appears it is too late to spray them. We have hand-picked over 200 of these bagworms & it appears we have gotten most of them. They have moved to the adjoining arborvitaes & we, hopefully, have gotten them all off of those as well. What else can we do at this point? Anything? We have to spray in early May/June correct? Can the arborvitae be saved? It has some growth, but looks over 75% dead.
Certified GKH Gardening Expert
It sounds like you have done about all you can thus far. Bt (Bacillus thuringiensis) products sprayed in the spring can be successful in the control of bagworms. In addition to hand pulling, power washing the 'bags' off the plant may be an adequate form of control. Here is an article that you may find helpful: https://www.gardeningknowhow.com/plant-problems/pests/insects/treatment-bagworms.htm