Hello Thedoobabides,
Yes use BT spray! This biological insecticide contains the bacillus thuringiensis (BT) bacteria which kills larva and prevents caterpillars from being able to eat. This is one of the most effective ways to kill caterpillars, and won’t hurt most beneficial insects. As a bonus, it also kills other cannabis pests like fungus gnats, worms and moths.
Happy Growing Buddy! 💚