budworms

so this is only my second outdoor grow. My first went great. This one was awesome until I noticed the buds at the base of all the branches started turning brown. I didn't think anything of it... i wish I knew then what I know now. I lost all the lower bud. I cut 2 of my plants down yesterday because these little bastards were eating at an alarming rate. If I wpuld have waited two more days to see if the bt kicked in i think i would have lost almost all of it. So on that note, I drenched the other plants as well with bt... should I give it five more days or should I just cut my losses and pull remaining plants???