ForumTeaming Up Against the
Although it may be one of today's favorite buzzwords,
"cooperation" is the best word to describe how scientists, growers,
and industry have managed to advance against the silverleaf whitefly. This
month's cover story describes many technologies being delivered to those who
need them to cope with this physically tiny but agriculturally monstrous pest.
Since 1986, the silverleaf whitefly, also known as biotype B of the
sweetpotato whitefly, has inflicted massive losses on crops from alfalfa to
zucchini. In 1992, it became the target of a national 5-year plan.
"The plan was a blueprint, a flexible one, that helped us decide what
needed doing and who would do it," says Robert M. Faust. At the
Agricultural Research Service, Faust is national program leader for field and
horticultural crop entomology.
ARS led the plan's development along with the U.S. Department of
Agriculture's Animal and Plant Health
Inspection Service; USDA's Cooperative
State Research, Education, and Extension Service; and state agricultural
experiment stations and cooperative extension services at universities.
Whitefly troubles still abound but technologies and management in some areas
are reducing the damage.
"Most of the progress can be traced to new information from
researchers, who have built a solid foundation for long-term management of this
pest," Faust says.
Scientists presented about 575 summaries of studies during annual reviews of
the plan from 1993 to 1996. To help researchers find existing information,
scientists at ARS' Western Cotton
Research Laboratory in Phoenix, Arizona, compiled a bibliography of nearly
Scientists are exploring new ways to turn information from studies into
blueprints for action.
For example, Jon Allen and Carlyle Brewster at the University of Florida
have come up with new tools for studying regional cropping systems. From
satellite images, they built crop maps of key whitefly areas in California and
Texas. This allows them to design and simulate experimental crop systems. Such
systems could be a basis for recommending anti-whitefly strategies.
To disseminate study findings quickly and widely, several agencies and
organizations established Internet sites. There,
growers, industry, and the public have access to scientific projects, results,
But growers can't settle for just reading about progress. They have today
and tomorrow to worry about. Early on, researchers and others with USDA,
universities, and extension services formed local committees to advise growers
in hard-hit areas.
One of these regional efforts shows how cooperation has glued together the
elements of research, information delivery, and technology application. The
effort began in 1993, when ARS, the University of Arizona, Arizona Department
of Agriculture (ADA), Cotton Incorporated, and the Arizona Cotton Growers
Association began producing whitefly-control guidelines. Commodity groups
mailed these to growers.
In 1995, the guidelines led to a plan to slow the whitefly's notorious
capacity to develop resistance to insecticides. The plan relied heavily on
research, especially on findings needed to estimate whitefly numbers and set
thresholds for crop damage.
The same year, a 200-acre trial was conducted by the ARS lab in Phoenix, the
University of Arizona, and ARS' Southern
Crops Research Laboratory in College Station, Texas. The trial revealed the
need for additional controls, because of the pest's increasing resistance to
In response, the ADAin cooperation with ARS, industry and grower
groups, university scientists, Cotton Incorporated, and othersapplied to
the U.S. Environmental Protection Agency (EPA) for an emergency exemption to
allow use of two insect growth regulators on Arizona cotton.
IGR's don't kill pests by poisoning them. Instead, they halt the immature
pest's development, rendering it "forever young"unable to
mature and reproduce. IGR's typically have less impact on a pest's natural
biological controls and wildlife than do conventional insecticides.
Data sources for the EPA application also included the University of
California, Texas A&M University, University of Florida, and Arizona Cotton
Research and Protection Council. EPA approved the application in time for the
Last season, Arizona growers widely used the IGR'sbuprofezin (Applaud)
and pyriproxyfen (Knack). Most growers were able to manage whiteflies while
reducing insecticide sprays. In tests, IGR's allowed 60 percent reductions in
whitefly insecticides compared to 1995.
"The effort that culminated in the availability of the IGR's for
1996," says Thomas Henneberry, director of ARS' Phoenix laboratory,
"led Arizona cotton growers to greatly change their whitefly management
practices. It's likely to evolve to address new challenges growers face in the
A new, national cooperative action plan on whiteflies will be put in place
this year. It will have a strong emphasis on technology transfer.
Jim De Quattro, ARS Information
Staff, phone (301) 344-2756.