I have heard Thuricide BT is great for worms and caterpillars. They say you can use it up to the day of harvest. I used it on my plants to kill off leaf miners
Word up....that's exactly what happened to me....I sat there (stoned) inspecting every flipping bud. I caught it before they killed and spread from bud to bud. I ended up harvesting... Maybe you're gonna be luckier than me.