
Fungi Thwart Two Major Insect PestsBy Hank Becker September 7, 1999Natural fungi may help rein in
important insect pests of vegetable and cereal crops like broccoli and wheat.
Agricultural Research Serviceentomologist John D. Vandenberg has been focusing on whether two parasitic
fungi--Beauveria bassiana and Paecilomyces fumosoroseus--could
become biological controls for diamondback moths and Russian wheat aphids. The aphid is a major pest of U.S. winter wheat and barley. Since invading
the United States about 1986, the green, 1/16-inch-long pests have cost growers
more than $850 million in insecticide treatments, crop yield losses and other
costs. The diamondback moth is a worldwide pest of cabbage, broccoli, canola and
other crucifers. Each year, farmers worldwide spend more than $1 billion to
control it--primarily with chemical insecticides. But in many areas the moth
has become resistant to conventional insecticides as well as natural bacterial
controls like Bacillus thuringiensis (Bt). Vandenberg has conducted laboratory and field tests that show the moth
succumbs to both fungi. But only Beauveria had consistent impact on the
aphid in the field. Vandenberg works at the
U.S. Plant, Soil, and
Nutrition Laboratory operated in Ithaca, N.Y., by ARS, the chief research
agency of the U.S. Department of
Agriculture. Vanderberg and colleagues were the first to field test Mycotrol, a
commercial formulation of B. bassiana, against the diamondback moth.
Weekly or twice-weekly applications significantly reduced insect populations
and damage to seedlings compared to chemical controls. Other scientists have shown that different strains of B. bassianawork against the Russian wheat aphid in the lab. But this is the first report
of Mycotrol's effectiveness against this aphid in the field. Mycotrol was first
developed to combat silverleaf whiteflies through a cooperative research and
development agreement between ARS and Mycotech Corp. of Butte, Mont. For more details, see the story in the September issue of Agricultural Research magazine
and on the web at: http://www.ars.usda.gov/is/AR/archive/sep99/fungi0999.htm Scientific contact: John D. Vandenberg, ARS U.S. Plant, Soil, and
Nutrition Laboratory, Ithaca, N.Y., phone (607) 255-2456, fax (607) 255-1132,
[email protected]. U.S. Department of Agriculture | |