What Is The Best Insecticide For Killing Bagworms?

What Is The Best Insecticide For Killing Bagworms? Sprays such as Bacillus thuringiensis, spinosad and any of the pyrethroid insecticides are effective on bagworms, especially early in the season. Late season infestations, when bagworm caterpillars are larger and more difficult to kill, are best treated with pyrethroid sprays. Does the insecticide Sevin kill bagworms? Answer: