Roaches ARE good for something!

Biological control, in fact:
….In the summer of 2006, [Pfannenstiel] discovered a new predator that feeds on lepidopteran eggs—the Asian cockroach, Blattella asahinai. This roach was observed in large numbers—up to 100 or more per square meter—in soybean fields at Weslaco, yet it causes no damage to the soybeans.it was the most frequently observed predator of [...]