Entomopathogenic fungi are highly susceptible to the effects of solar radiation, particularly UVB, thereby limiting their environmental-persistence and efficacy in environments of high insolation. Strategies for protecting microbial biopesticides have historically focused on either water-soluble UV-protectants for aqueous carriers, or oil soluble UV-protectants for oil carriers. The current research involves coating spores with a water soluble UV-protectant and then applying the coated spores in an oil carrier. Potential advantages of this strategy include the following: 1) the ability to apply a dry formulation of the spores, thereby reducing the effects of thermohydric stress and the formation of reactive oxygen molecules, 2) the ability to maintain a coating around the spores when the oil carrier spreads over a hydrophobic surface (i.e. plant surfaces), and 3) the ability of coated spores to become biologically active in the presence of moisture. Metarhizium anisopliae var. acridum (Gams and Rozyspal) isolate IMI 330189 spores from liquid and aerial culture were coated with a water soluble lignin derivative during an air drying process. These coated spores showed significantly higher tolerance to simulated sunlight than non-coated aerial conidia. The coated liquid-culture and aerial-culture spores remained virulent to Schistocerca americana ((Drury) with some reduction in virulence when compared to non-coated aerial conidia.
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA