IF A PERSON HAD .. SAY 3500 SQ FT TO GROW FREELY.... AND DEVELOPED A PROBLEM ... A SERIOUS PROBLEM WITH INSECTS..white flies, those pesky little prple/black gnats, AND spider mites.... could a person get a "bag o butterflies" or those praying mantis to erradicate the pests without doing any further harm to the crop?? DOES either insect feed off vegetation?? the ladybug ?
I think butterflies might be nectar-feeders. Not quite sure about the praying mantis but google has always been helpful to me in the past. I think ladybugs like aphids..not sure what else they eat. As a side note, check what our genius US gov't is spending funds on: http://news.bbc.co.uk/1/hi/world/americas/4808342.stm