![Grasshoppers that have been killed by a fungus: Link to photo information](/peth04/20041031225719im_/http://ars.usda.gov/is/graphics/photos/oct04/k11446-1i.jpg) Melanoplus
grasshoppers that have been killed by the fungus Beauveria bassiana.
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magazine
story to find out more. |
Beneficial Fungi Could Halt Hopper
Hordes By Erin
Peabody October 7, 2004
Two fungi may represent a natural solution to the problem of
millions of grasshoppers leaping across parts of the western United States each
summer. Both are like a fatal case of athlete's foot to insects, producing
infectious spores that hoppers can pick up on their feet.
Stefan T. Jaronski, an insect pathologist with the
Agricultural Research Service, is
studying these fungi and other microbes in hopes of keeping soaring hopper
populations in check. He works at the agency's
Northern Plains Agricultural Research
Laboratory in Sidney, Mont.
During outbreaks, which are often driven by droughts,
grasshoppers can gobble up valuable crops, forage and ornamental plants,
costing millions of dollars in damage.
One fungus, Beauveria bassiana, is already registered in the
United States for the control of a variety of insects. Once grasshoppers pick
up its spores on their feet and other body parts, the fungus grows quickly
inside their bodies, usually killing them within a week.
Recently, Jaronski found that an effective way to deliver the B.
bassiana spores and make them attractive to grasshoppers is to mix them with
raw canola oil. Black and strong-smelling, the raw oil contains higher
concentrations of the fatty acids that the insects find irresistible. It's also
cheaper than using refined, store-bought canola oil.
Jaronski envisions the mixture of canola oil and fungal spores
being sprayed on targeted strips of rangelands from the air or on the ground.
Because the oil attractant lures hoppers to the strips from a wide distance,
only small amounts of the fungal spores are needed.
The other fungus, Metarhizium anisopliae var. acridum, is much
more host-specific than Beauveria, affecting just grasshoppers and their close
relatives. Jaronski's lab has found that Metarhizium is very infectious in most
American grasshoppers and the Mormon cricket, which also causes destructive
outbreaks. Coupled with the raw canola oil carrier, it could also become a
valuable tool for controlling grasshoppers.
Read more
about this research in the October 2004 issue of Agricultural Research
magazine.
ARS is the U.S. Department of
Agriculture's chief scientific research agency. |