You can spray BT (bacillus thuringiensis) and it will break down in sunlight/HID within a few days. Extremely deadly to caterpillars, if you can get to them (They like to get in the buds.) The problem is two-fold as well, as where they feed, mold often follows, so you want to try and remove any noticeably fed upon buds, to hopefully delay or prevent that from happening.