PhD, Cornell University, 1980
MS, Cornell University, 1976
BA, Carleton College, 1973
Population and community ecology of insects, biological controls of invasive insects
Dr. Evan's research is focused on biological control and biological invasions in insect ecology. His field studies include both agricultural crops and native habitats (e.g., sagebrush communities). He studies interactions among insect species (predators, parasitoids and herbivores) and host plants (including weeds and crops). Dr. Evans seeks to understand how these interactions influence population dynamics of individual species. Ultimate goals include reducing modern reliance on pesticides (insecticides and herbicides), and conserving native species in a world of increasing human population, agricultural and urban intensification, and climate change. Major topics of interest include the effects of predator diversity on prey suppression; the effects of alternative prey and other naturally occurring foods on target prey suppression; intraguild predation and other effects of invasive species on resident natural enemies and their prey; efforts to enhance predator effectiveness (conservation biological control); and effects of weather and climate change on interactions among natural enemies and their hosts. Much of his work on predators has focused on ladybird beetles (aka ladybugs; Coccinellidae), particularly as native species have been affected by spectacular successes of introduced species in colonizing and spreading throughout North America. Dr. Evan's focuses on biological control as a metapopulation process of natural enemies tracking down their pest victims across space and time. This focus highlights that success in biocontrol programs (both classical and conservation) varies widely as natural enemies are better or less able to find and contain the pest at multiple locations across often diverse landscapes. Weather and climate change further influence biocontrol success.