A New Defense Against Insect Pests
December 24, 2003
A new biological control developed by
Agricultural Research Service scientists
may provide an important defense against some of the most destructive insect
pests that farmers face.
A bacterium called Chromobacterium suttsuga has been
found to be effective against Colorado potato beetles, corn rootworms,
diamondback moths, silverleaf whiteflies and green stinkbugs. These pests
collectively cost farmers almost $3 billion annually in crop losses and control
The team of ARS scientists involved in the research includes
microbiologist Phyllis Martin, laboratory technician Ashaki Shropshire,
molecular biologist Dawn Gundersen-Rindal and entomologists Dale Gelman,
Michael Blackburn and Robert Farrar--all at the
Insect Biocontrol Laboratory in
Beltsville, Md.--plus entomologist Jeffrey Aldrich and visiting scientist Edson
Hirose at the Chemicals Affecting
Insect Behavior Laboratory, also in Beltsville. A patent application for
the discovery has been filed.
In lab tests, the scientists found that C. suttsuga seems
to produce multiple toxins that deliver a lethal blow to the pests. Preliminary
results from field tests have confirmed lab results, and more field tests are
The bacterium's toxins can be combined with chemical compounds
and then applied to soil, plants or seeds. To control soil-dwelling pests, rice
grains can be treated with the toxins and applied to the soil, where pests will
feed on the treated grains.
Insect pests often develop resistance to chemical insecticides,
so biological compounds are regularly investigated for insecticidal properties.
Biological control agents can be an important addition or alternative to
synthetic chemical pesticides, and important in integrated pest management.
Other advantages of C. suttsuga are that it's stable in
the environment, and insects readily ingest it.
The discovery may ultimately provide a new control for
agriculturally important insect pests and give growers alternatives to chemical
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.