
Model Bioinsecticide Aimed at High-Value
CropsBy Ben Hardin January 8, 1999WASHINGTON, Jan. 8--U.S. Department of
Agriculture scientists are fine-tuning a friendly fungus that attacks
silverleaf whiteflies and other pests and could be the foundation of a new
bioinsecticide service industry. Silverleaf whiteflies alone cause
multimillion-dollar crop losses each year to U.S. cotton and many fruits,
vegetables and ornamentals. Work with the environmentally friendly fungus Paecilomyces
fumosoroseus is under way at the National Center for Agricultural Utilization
Research, operated at Peoria, Ill., by USDAs
Agricultural Research Service. The ARS
scientists say factories could produce P. fumosoroseus, dry it and
transport it to small fermentors at field sites. There the fungus would be
rejuvenated, multiplied and applied through spray or irrigation systems. 
It seems fitting that scientists in the
same center that helped launch the antibiotics industry a half-century ago
should partner with industry to harness fermentation technology for our
nations agriculture, said Floyd Horn, ARS Administrator. About 3 years ago, NCAUR microbiologist Mark A. Jackson and his colleagues
applied for a patent on mass-producing the fungus. The invention was a modified
version of deep-tank fermentation developed at the center to mass-produce
penicillin during World War II. In recent years, the researchers have steadily improved P.
fumosoroseus fermentations, doubling the number of spores produced in a
tank and cutting fermentation time from three days to less than two. In the
process, they developed fermentation mixtures that are more economical than the
precisely defined recipes used earlier. For factory-produced fungi to become commercially viable, large and
predictable numbers of healthy spores must be produced and dried months in
advance. In recent laboratory studies, the scientists found about 75 percent of
freeze-dried spores remained alive after five months of storage. To lower bioinsecticide costs, the researchers are defining conditions that
allow the fungus to multiply rapidly in portable fermentors. As the research
progresses, they will inoculate fermentors at several ARS locations and
commercial field sites. The ARS scientists at Peoria are using a portable
fermentor patented by
Eco Soil
Systems, Inc., San Diego, Calif., under a three-year cooperative research
and development agreement (CRADA) begun last summer with the company. Small packages of well-maintained, freeze-dried spores will be mixed with
nutrients in the fermentors. The spores are expected to spring vigorously from
their Rip Van Winkle state and multiply 100- to 1,000-fold. These fresh, active
spores will then be sprayed directly on plants to kill whiteflies. Technologies for P. fumosoroseus may later be adapted to different
fungi suited to protecting turf grasses from insects. Companies that provide
care for lawns and golf courses could then provide more environmentally
friendly pest controls. More information about the research is available on the World Wide Web at: http://www.ars.usda.gov/is/AR/archive/jan99/tank0199.htm
Scientific contact: Mark A. Jackson, ARS
National Center for Agricultural
Utilization Research, Peoria, Ill., phone (309) 681-6283, fax (309)
681-6427, [email protected]. U.S. Department of Agriculture | |