i had the same problem when i was growing recently, ironicly it look like they were getting stuck to tri's on the plant. I recently harvested and had to pick them all off with twissors ( i dont want to smoke them, lol), before hanging them to dry. I inquired about them before on here and found that alot of growers use the yellow fly traps. Next time i will set them out before flower, so i dont have the same problem. It might be your best bet.