Assistant Professor University of Maine Orono, Maine
The blacklegged tick (Ixodes scapularis) currently is undergoing significant range expansions in North America, increasing human risk of exposure to several important tick-borne pathogens. Among these pathogens is Borrelia burgdorferi, the primary etiological agent of Lyme disease, which has experienced concomitant expansion in range and causes over 300,000 human cases per year in the U.S. This presentation highlights modeling and field studies exploring the ecological drivers of the ongoing invasion of the blacklegged tick in two emerging areas of tick-borne disease transmission, and ecological strategies to reduce or inhibit transmission. First, in the upper Midwest, we conducted spatial-temporal analyses of the concomitant spread of the blacklegged tick and human cases of Lyme disease. Second, in the state of Maine, we conducted manipulative field experiments to test the hypotheses that ambient temperature, snow cover, and ground cover alter overwinter survival of nymphal blacklegged ticks across large-scale climate gradients and thus limit the current geographic distribution of blacklegged ticks in the state. Finally, we carried out an observational field study and a large-scale citizen science project to investigate impacts of forest land management and forest landscape change on tick densities and activity patterns of their key hosts, including white-footed mice and white-tailed deer. Ultimately, this ongoing research effort may enhance our understanding of the distribution of blacklegged ticks and the pathogens they transmit under current and future climate scenarios, enabling us to more effectively target ecological vector management interventions to maximize their public health impact.
