the story in Agricultural Research magazine.
Last Meal for Colorado Potato Beetle? By
April 24, 2000
A last meal could be in store for Colorado potato beetles in the
form of a new artificial diet cooked up by Agricultural Research Service entomologists
in Beltsville, Md.
But "chef" Dale Gelman and ARS colleagues there aren't trying to
poison the pesky beetles with their new diet. Rather, the scientists are
working to step up the pace of entomological research aimed at testing new
weaponry that farmers eventually can use against the beetles. The pest's larvae
devour the leaves of eggplant, tomato and potato plants, causing $150 million
annually in crop losses and chemical control expenses.
The chemical pesticide Admire is a standard defense, but experts
fear the beetle may soon develop resistance to it. That's why Gelman's team at
ARS' Insect Biocontrol
Laboratory in Beltsville is trying to streamline research aimed at finding
alternatives, particularly biological ones like the parasitic wasp Edovum
puttleri. Female wasps hatch their larvae inside the beetle's eggs,
Until now, rearing lab colonies of the beetles meant feeding them
on a living host--namely potato plants. But growing them is costly and
time-consuming. So, scientists developed a simple artificial diet made of oats,
lettuce, some potato leaf powder and other ingredients. Dried into powder,
lettuce is cheaper, easier to obtain than potato material and--most
important--whets the beetle's appetite.
So far, Gelman's team has reared nine generations of beetles on
the diet. Once perfected to the beetle's taste, the team will transfer the diet
technology to a commercial producer for researchers to use in lab studies.
An article on the work appears in this month's issue of Agricultural
Research magazine and on the
ARS is the U.S. Department of Agriculture's chief scientific arm.
Scientific contact: Dale Gelman, ARS
Laboratory, Beltsville, Md., phone (301) 504-8909, fax (301) 504-8190.