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 expenses.
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 a 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
planned.
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 insecticides.
