This is the third of ten short news articles written by students, during the professional development class of Fall 2022, about each other's research.

Student Research Spotlight - Jesse Evans

By Sukhman Singh

To maintain the forest health, controlled forest burns are scheduled at regular intervals to manage populations of insects and invasive plants, and reproduction of native plants. Controlled forest burning also drives animals to move to new habitats in unburned forest areas to escape the flames. This is where the forest-dwelling white-footed mouse comes into play. This mouse species can carry disease-causing pathogens inside their body and is also a host to the blacklegged tick. Blacklegged ticks are the only vector of the pathogen that causes Lyme disease in humans, dogs, and horses. The CDC estimates around 400,000 people get Lyme disease every year in the US.

Jesse Evans, an entomology master's student in Erika T. Machtinger's lab at Penn State, is interested in studying the potential effect of large-scale controlled fire on white-footed mouse populations and blacklegged tick abundance and feeding success on these mice. “Lack of management strategies to control tick presence makes it essential to search for new strategies to control tick abundance and spread,” Jesse said.

According to Jesse, controlled burning of forest will cause food and water scarcity and will force mice to shift from to unburned locations where other mice are well established. He hypothesizes that this will create competition among mice populations, leading to stress. Jesse hypothesizes that stressed mice population will support more ticks as they move into unburned areas, the total mouse population in these areas will increase. To answer his questions, he will conduct field studies where he will be trapping white-footed mice using Sherman traps in recently burned and unburned forest and counting ticks on each animal. He will then collect mice feces and hair to estimate the amount of corticosteroids (a hormone in mice's body that activates a stress response and indicates that mice are under stress). He will also investigate the effects of tick feeding on mice by introducing different biotic and abiotic stresses such as food and water scarcity, and competition in laboratory setting.

“Understanding how these large-scale landscape changes effect tick-mouse interactions can help us understand tick-borne disease risk across Pennsylvania,” Jesse stated. If we knew that controlled forest burns would decrease tick abundance and ultimately Lyme occurrence, we can better use controlled burns to help to reduce Lyme disease risk to human population. In addition, understanding how landscape alteration increases parasite abundance can aid development planning to include tick mitigation efforts during and following these activities.

This research is supported by funding from the United States Department of Agriculture.