Barbara Demick has an article in the LA Times about cockroach farming in China. The preferred species is the American Cockroach, Periplaneta americana. Cockroaches can be fed table scraps or other plant material that humans and livestock do not eat. Millions of cockroaches can be reared in a relatively small space. Cockroaches are harvested by dropping them in boiling water and drying them.
How are they used? A small portion of the cockroaches are served as a human food “delicacy”. Chinese medical and pharmaceutical companies are using cockroaches as an inexpensive source of protein. Cockroaches can be fed to livestock as dried whole cockroaches, or can be processed and blended into feed. One woman in China reports quitting her factory job and making the equivalent of $10,000 selling cockroaches. The startup costs are low and returns on investment can be as high as 300 percent.
Those interested in entering the cockroach rearing business must choose their location carefully. Neighbors might object to living next door to cockroach rearing facilities and the inevitable escapees. One gentleman in China located his operation in a building that was condemned. Authorities knocked down the building not realizing it was used for cockroach rearing. The million cockroaches that poured our of the structure (to the consternation of the neighbors) had to be eradicated.