Mass Rearing Beneficial Bugs to Control Pest Insects

Ingredients from the supermarket form the basis for new, cheap lab rations for raising millions of beneficial bugs that will attack other, crop-eating insects. An Agricultural Research Service scientist first developed the new rations, called artificial diets, for big-eyed bugs and lacewings. These two predators devour a range of pests including whiteflies, aphids, scale insects, moth eggs and larvae, and mealybugs.

Good-guy predators have long been used as six-legged alternatives to pesticides. Without a suitable artificial diet, however, the cost of mass-rearing limits a good bug’s market potential. The new lacewing diet costs $2.50 a pound; a commercial diet of insect eggs can cost $300 a pound. The new diets were developed by Allen Cohen at ARS’ Western Cotton Research Laboratory, Phoenix, Ariz. The agency has applied for a patent on the diets.

The main ingredients include ground beef and beef liver. Fish innards, oysters and meat and liver from other animals can be substituted. Chicken eggs are added for stickiness, to hold together the diet’s other components and nutrients. Lacewings and big-eyed bugs reared on the new diets produce more offspring, often mature faster, and are up to 50 percent larger than wild ones, according to the scientists’ studies. And with slight modification, the diets work for other predators including a lady beetle and a minute pirate bug.

The new diet’s first large-scale use may be to rear big-eyed bugs and lacewings to combat silverleaf whiteflies. Since 1986 they have been major pests of U.S. cotton, vegetables and other crops especially in Arizona, California, Florida and Texas. Experimental field testing may begin as early as next year. A feature story about the new diets is in the June issue of ARS’ Agricultural Research magazine. The story is on the World Wide Web at:

/is/AR/archive/jun97/bugdiets0697.htm

Scientific contacts: Allen C. Cohen and Thomas J. Henneberry, ARS Western Cotton Research Laboratory, Phoenix, Ariz., phone (602) 379-3524, fax 379-4509, acohen@ix.netcom.com and henneb@asrr.arsusda.gov.