We have 200+ blue spruce on the west side of our property. Bagworms love them. Last summer we drenched the trees with Thuricide. We sprayed around the 1st of July. Now, it seems they have mulitplied! Never seen so many bags! Was last summer a late summer for bagworms? Should we have sprayed earlier or later. Is there something else to use that won't hurt the birds? Too many questions, I know. We need to thin the trees as they are crowding each other. But, the bagworms have us worried.

Hi Kent, I know bagworms can be a major problem. they love blue spruce and seem to have done very well the past few years. BT products such as Thuricide, or cyfluthrin or spinosad should work and first of July should have been a pretty good time. Bt products when used according lable directions are specific to caterpillars so are pretty safe for everything else. it does require that the caterpillars eat the product and works better when the caterpillars are small but we do recommend a second spray; first spray late June and second spray 1 week later. Unfortunately with cool springs egg hatch can be delayed so scouting even after spraying is a good idea in case another spray is needed. also what is confusing is even though the caterpillars may be dead the bags do not fall from the trees. so sounds like you are on the right track. just look for the moving bags a few days after you spray to see if an additional spray is needed. good luck, sandy