Research Product

Two test methods are described. The first involved the design and field validation of a fully contained test system. This system was used to assess potential adverse effects of microbial pest control agents (MPCAs) on a nontarget invertebrate and determine fates of the MPCAs in the animal. American oysters, Crassostrea virginica, were exposed to various MPCA types represented by the vegetative bacterium, Pseudomonas fluorescens, gram-positive bacterial spores of Bacillus sphaericus, and fungal spores of Colletotrichum gloeosporioides. Each MPCA cleared from the oysters at a different rate. None of the microbes caused infection, pathogenesis or toxicity. Spore germination was not observed in oyster tissue. In the second method, developing embryos of the inland silverside fish, Menidia beryllina, were exposed to spores of the insect pathogenic fungus, Beauveria bassiana. Fungal growth on the chorion surface as well as embryo rupture and death were observed. Spores treated with a dispersant (biological detergent, Triton X-100) showed significantly less binding (p less than or equal to 0.01) to embryos than untreated spores. Neither detergent-treated or heat-killed spores caused significant adverse effects.