i had a huge problem with white flies once and gnats. the organic answer is LADYBUGS, theyre carniverous insects and wont eat your plants.
you can get them at nurserys pretty cheap somwhere or probably off the internet for a lil bit extra (+shipping) if you cant find them
they work wonders, i got a pack of like 300 and they last all season. kind of seem to go away but they go in search of all the bugs to eat them
but i guess this only works outdoors. you dont want 300 ladybugs in your house, a warehouse wouldnt really matter tho. =/
ive heard of this sandy glass type stuff for the soil bugs. you put it on top of the soil and leave it dry, it cuts the bugs up when they walk through it lol. i forgot what its called tho.