
New Diet Could Help Trim Crop Pest PopulationsBy Jesús
García May 16, 2000Agricultural Research
Service scientists have now applied for a patent on a new insect diet that
will make plant bugs and other crop pests unwitting accomplices to their own
destruction. The key to mass-rearing these ravenous insects in sufficient
numbers is developing a replacement for the plants they feed on. Without these
special diets, the rearing of these insects becomes cost prohibitive. The new diet, which consists of cooked chicken eggs, lima bean
meal, wheat germ, soy flour, yeast, sugar, vitamins and preservatives, was
developed by scientists at ARS
Biological Control and
Mass Rearing Research Unit in Mississippi State, Miss. This diet enables
researchers to propagate destructive plant bugs as hosts for the production of
parasitoids that may eventually help reduce insect pest numbers in the wild.
One of these pests, the western tarnished plant bug, Lygus
hesperus, accounted for about $71 million worth of cotton crop losses in
1998. One parasitoid, a tiny wasp called Amaphes iole, deposits
its own egg into Lygus bug eggs, where it develops into an adult while
consuming the Lygus eggs contents. Once the adult wasp emerges, it
is ready to mate. Any female offspring is capable of parasitizing up to 60
Lygus eggs in its 2-4 days of life as an adult. Two other wasps, Peristenus spp. and Leiophron
uniformis, deposit their eggs inside Lygus nymphs, where they
commence to feed. When the parasitoids reach their prepupal stage, they chew
their way out of their devastated hosts. The new diet-fed insects are also used for research on sterile
release programs which had never before included Lygus bugs because they
could not be reared in sufficient numbers. Sterilized plant bugs reared on the
diet may mate and produce sterile eggs in the wild. Most important, the new diet has been found to be an inexpensive
and effective way to mass rear insect pests and their natural enemies for
biologically based pest management. This technology enhances the agricultural communitys ability
to mass-produce natural enemies of pests and decreases its dependence on
chemicals. ARS is the chief research arm of the
USDA. Scientific contact: Allen C. Cohen,
ARS Biological Control and
Mass Rearing Research Unit, Mississippi State, Miss.; phone (662) 320-7560,
fax (662) 320-7571, [email protected]. U.S. Department of Agriculture |