story to find out more.
Manual montage image (a technique pioneered by Klaus
Bolte of Canada) of a Balcha wasp, a potentially beneficial insect that
attacks the ash borer. To create this image, the wasp specimen was
dissectedlegs, antennae, wings and other body parts separatedthen
the parts were digitally captured and reassembled in Photoshop. This technique
allows exquisite detail to be shown. Contact
Klaus Bolte for high-resolution
Work to Identify Possible Foes of Ash-Killing
Beetle By Luis
Pons January 31, 2005
Since its discovery near Detroit in 2002, the emerald ash borer has
devastated ash tree populations in Michigan, Ohio and Ontario and has been
Now Agricultural Research Service scientists, including those at the
ARS Systematic Entomology Laboratory (SEL)
in Washington, D.C., and Beltsville, Md., are working to precisely identify
parasitic wasps that seem to be natural enemies of this imported metallic-green
beetle, Agrilus planipennis Fairmaire. Thought to have arrived here
about six years ago, hidden in wooden packing material, the borer is
threatening to become a major U.S. pest.
U.S. Forest Service and
Michigan State University researchers found
the potentially beneficial wasps in a study plot in Livonia, Mich., and sent
them to the SEL for identification. There, entomologists
Schauff identified them as species in the genus Balcha, which like
to snack on emerald ash borer larvae, and in the genus Pediobius, which
attack the borer's eggs.
According to Schauff, it is suspected that at least one of the wasp
species found was unknown to science up to this point. Schauff works at SEL's
Beltsville location, while Gates is based at its Washington facilities.
Precisely pinpointing the wasps' identities will entail much work, as
the genus Pediobius alone contains about 215 known species worldwide, 32
of which are found in North America. But knowing their exact identities will be
key if the wasps are to be used to control the emerald ash borer.
SEL's work is just part of ARS' emerald ash borer campaign.
Schaefer and colleagues in the agency's
Insects Introduction Research Unit at Newark, Del., hope to analyze the
borers' DNA. They've also traveled to South Korea, Japan and Mongolia in search
of the insect's origin, hoping to also find its natural enemies.
Ash is a valuable hardwood that provides habitat for wildlife,
ornamentals for landscapes, and wood for various products.
about the research in the February 2005 issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief scientific research agency.