Hello: I'm not sure if they are actually bagworms (I haven't seen any bags hanging) but something is eating my arborvitae plants. I just noticed that foliage was starting to disappear at the end of May, which leads me to believe it may be bagworms. The foliage is missing on the bottom area of the plant. It started on one plant and is spreading. The plants aren't anywhere near dead, so I need to find a solution soon. Can you recommend a certain pesticide? Thanks!! Robin Goman