...From the pages of Agricultural Research magazine
Fungus Set To
At the ARS National Center
for Agricultural Utilization
Research, microbiologist Mark
Jackson and technician Angela
Payne evaluate the fermentation
progress of the bioinsecticidal
fungus Paecilomyces fumosoroseus, destined for use in field trials.
Trouble is brewing for silverleaf whiteflies and other
The Agricultural Research
Service (ARS) and Encore Technologies, LLC, are considering a licensing
agreement to commercialize ARS' patented (No. 5,968,808) new method
of mass-producing the fungus Paecilomyces fumosoroseus as a bioinsecticide.
Microbiologist Mark Jackson developed the method, which
uses deep-tank liquid culture fermentation, based on his fungal nutrition
studies at ARS' National Center for Agricultural Utilization Research,
Peoria, Illinois. There, Jackson combined the method with an Encore
procedure for formulating Paecilomyces spores into an air-dried
powder that can be wetted and sprayed onto plants.
"I see this being used in greenhouses, out in the
crop field, for organic uses, and the home pest control market,"
says David A. Goulet, Encore's president. "Anyplace where chemical
use is a concern, this would fit the bill."
Thrips and aphids are just a couple of the pests that
Paecilomyces could see action against.
Jackson has his sights on the silverleaf whitefly, a sap-sucking
pest of 600 plant species, including cotton, tomatoes, and poinsettias.
Whitefly infestations in these and other U.S. crops cause multimillion-dollar
Paecilomyces kills whiteflies by snaking tiny filaments
into their bodies to feed and grow. Jackson compares the sight to "Gulliver's
Travels, when the Lilliputians tie down the giant." People
and other animals face no such danger, but infected whiteflies die within
several days. New spores then emerge to infect other whiteflies, sparing
nonhost insects as they spread.
Despite such advantages over chemical controls, past attempts
to formulate Paecilomyces have stumbled on high production costs
and other problems, Jackson says. Only one U.S. companyCertis
USA, LLChas registered it as a biopesticide (Apoka Strain 97).
"The big problem with biocontrol agents is producing
them cost-effectively and keeping them stable once produced," says
Jackson. "We've overcome this problem by developing new technologies
for spore production and stabilization." These involve feeding
a Paecilomyces cultureany of 35 known strainsa diet
of carbon, nitrogen, and other nutrients inside fermentation tanks.
Combining the fermentation culture with appropriate temperature and
aeration stimulates the fungus to produce highly infectious blastospores,
which are ideal for bioinsecticide uses.
"We can do a 2-day fermentation run and obtain a
yield of a billion blastospores per milliliter," Jackson reports.
What's more, the blastospores can survive 1 to 2 years of cold storage.
Both features are expected to revive prospects for the
fungus as a commercial bioinsecticide that can compete with, or complement,
conventional chemical controls. In poinsettias, for example, the fungus
might prove useful against whiteflies that threaten the crop 6 to 8
weeks before harvest, when insecticides aren't applied for fear of mottling
the plants' coloring.
"Technically," says Goulet, "this material
is 2 years from being ready to go" to market as a bioinsecticide
product. First, though, it would require EPA registration. Encore also
wants to find commercial partners to help market it.By Jan
Suszkiw, Agricultural Research Service Information Staff.
This research is part of Crop Production, Product Value,
and Safety, an ARS National Program (#304) described on the World Wide
Web at www.nps.ars.usda.gov.
Mark A. Jackson
is with the USDA-ARS National Center
for Agricultural Utilization Research, 1815 N. University St., Peoria,
IL 61604; phone (309) 681-6283, fax (309) 681-6693.
"Fungus Set To Fight Insect Pests" was published in the August 2003 issue of Agricultural Research magazine.