Persistence studies of Metarhizium acridum under U.S. Northern Plains conditions

The Orthopteran specific fungus, Metarhizium acridum, is under consideration for importation and release in the United States. As part of its evaluation for release, long term persistence studies under the conditions of the U.S. Northern Plains have been conducted. When applied in the Fall, the fungus did not persist to the following year on foliage, in the soil or under leaf litter. When applied in the late Spring-early Summer the fungus did not persist to any measurable degree beyond one month, as measured by bioassay by confining Melanoplus sanguinipes with treated substrates.