HI Karen, yes there are several: Btk sold as Dipel, Thuricide; cyfluthrin sold asBayer Insect Killer, and spinosad sold as Conserve and Fertilome bagworm spray. The big thing for any sprays to be effective is they must be applied while the caterpillars are still feeding. Late June is best time to apply when caterpillars are small. If they are not feeding then the bags will have to be removed physically. Be sure to read and follow all label directions. You may also want to check with your Purdue Extension. You can find the office nearest you at
http://www.ces.purdue.edu/horticulture.htm Good luck, Sandy