About: johnson

Website

http://www.biosci.ohiou.edu/faculty/johnson

Profile

Plant-Herbivore Coevolution, Insect-Plant Interaction, Physiology My research interests include the chemical ecology of plant-herbivore interactions, comparative aspects of digestive strategies in insects and more recently, responses of aquatic insects to water pollutants. Ongoing projects that students could contribute to fall into two broad categories: Aquatic Insect Ecology - Our laboratory has biomonitoring sites in three local watersheds impacted by acid mine drainage. In addition to sorting and identifying macroinvertebrates from field samples, there are opportunities to for independent projects to investigate effects of specific pollutants (pH, heavy metals) on feeding behavior and growth, test sediments for residual effects of contaminants on colonization and other processes, or investigate physiological mechanisms for tolerating acidity or toxins. Chemical Ecology of Insect-Plant interactions. A focus in my lab is on the metabolic fate of plant defensive compounds after they are ingested by caterpillars, and the effects of compounds on growth and performance. I am investigating the role of oxygen availability in the caterpillar midgut for activating plant antiherbivore defenses (primarily phenolics). Students could assist in maintaining laboratory colony insects, performing microelectrode measurements of O2 in dissected caterpillars, or conducting experiments to better characterize oxidases in gut fluid that deplete O2.