Our research in the insect toxicology area is focused primarily on plant-derived products that have insecticidal, insect repellent, or antifeedant properties. Current and recent projects have included studies on compounds or extracts from plant essential oils (terpenes), isoflavoids, cyanogenic glycosides, glucosinolates, and conjugated linoleic acid. Insecticidal spectrum of activity, selectivity, mechanisms of action, and metabolism are investigated using insect pests as model organisms. Synthesis of derivatives and analogs provides novel insecticides or repellents and provides series of closely related compounds for use in quantitative structure-activity relationships (QSAR) to help explain their modes of action. Funding has been provided by the U.S. Environmental Protection Agency, U.S. Department of Defense (DoD) through the Deployed War Fighter Protection Program (DWFP), EcoSMART Technologies, the Centers for Disease Control and Prevention (CDC), the Leopold Center for Sustainable Agriculture, the Iowa Soybean Promotion Board, and Valent BioSciences.
Environmental Toxicology and Chemistry
Our studies on the environmental fate and effects of agrochemicals include projects that address the insecticidal protein toxin in transgenic crops (e.g. Bt corn), veterinary antibiotics in soil and water, and phytoremediation of conventional pesticides in soil, water, and plants. We study the movement, degradation, and persistence of the agrochemicals (including natural insecticides) in the environment and develop new bioassays for the evaluation of possible non-target effects. New or improved analytical methods for detection and quantification of residues are also developed in our laboratory. Funding for the research projects has come from the U.S. Department of Agriculture, the U.S. Environmental Protection Agency, the Center for Health Effects of Environmental Contamination at the University of Iowa, Bayer CropSciences, and the Iowa State Water Resources Research Institute.