Sheri, I also found this info:
"The least expensive way to control bagworms is to pick them off the plant
and destroy them. If there is a large population this may not be practical. There are several insecticides labeled for bagworm control. A biological control is Bt, which stands for Bacillus thuringiensis. Bt is a bacteria that causes the worms to get sick, stop feeding and die. For best control the bagworms need to be treated early in their life. They generally start hatching in mid to late May and hatch through mid June. For more information on bagworm control contact your county Extension office, Master Gardener hotline or local nursery."
I also read this:
Although Bt is organic and safe to use, it will kill all types of caterpillars, including butterfly larvae. Spray only the plants
that are affected by the bagworms and mix only the amount of spray you will use at one time."
<sigh> Not an easy decision - and probably not a cheap remedy either. Sorry I couldn't find anything more encouraging