story to find out more.
beneficial fungus Metarhizium anisopliae sporulating on a sugar beet
root maggot. Below, microscopic image of the fungus, exhibiting a fluorescent
green protein as it grows on the surface of a young sugar beet root. The
fluorescence allows scientists to see how the fungus interacts with other soil
microorganisms. Click the images for more information about
Friendly Fungus Could Help Sugar Beet Fields Go
"Green" By Erin
Peabody September 19, 2006
How sweet it is! Scientists with the Agricultural Research Service in Sidney,
Mont., may have found a natural alternative to the copious pesticides that
sugar beet growers must spray on fields to fend off their biggest enemy: the
sugar beet root maggot.
Jaronski, an insect pathologist who works at the ARS
Plains Agricultural Research Laboratory in Sidney, has discovered that a
strain of the biocontrol fungus Metarhizium anisopliae is not only
effective at killing the maggot, but is also a vigorous colonizer that can
adapt quickly to its new environment. Jaronski's research builds on initial
biocontrol efforts by ARS scientists at Fargo, N.D., during the 1990s.
Even though the fungus is a newcomer to sugar beet soils, it's quite
capable of holding its own among the hundreds of other microbes already
The maggot is certainly worthy of a unique control strategy. This
subterranean pest gnaws on young sugar beet roots, inflicting deep wounds that
leave the plants vulnerable to disease. It's these destructive feeding habits
that make the maggot the most important insect pest on the 1.4 million acres of
sugar beets grown in the western United States.
Right now, unfortunately, the only tools available to growers battling
it are chemical sprays, such as terbufos, phorate and chlorpyrifos. Without
them, farmers in some beet-growing regionslike the Red River Valley of
North Dakotawould lose up to 40 percent of their beet crop.
Jaronski, who's been studying biocontrol microbes for more than 25
years, puts a lot of stock in Metarhizium. He considers them the fatal
"athlete's foot" of insects, since the fungus first penetrates a vulnerable
insect's cuticle, or "skin," using just a few spores. After that, it grows
steadily inside the insect until finally overwhelming the host's entire body.
Jaronski's next step is to develop an optimal delivery system for the
about the research in the September 2006 issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief scientific research agency.