Lotsa good info here to get rid of them little mother fukers but the one bit of info & the easiest fix of all is missing.
Air flow,air flow,air flow ,air flow, air flow,did i mention air flow ?
The best way to naturally guard against them & to speed their death is to have excellent air flow to ALL AREAS OF THE GROW,increase air flow DIRECTLY on the plants & you'll create an enviroment they hate.