Abstract: Investigating the Relationship between Amblyomma americanum Abundance, Temperature, and Moisture in the Virginia Peninsula

As tick-borne diseases are on the rise across the United States it becomes more important to understand and predict their distribution. There is a lot of talk, but little empirical evidence, regarding the effect of human land use on the distribution of ticks and tick-borne diseases, especially outside of the Lyme-disease system. Here in Virginia, there is growing concern about Ehrlichia chaffeensis, a pathogenic bacterium transmitted by the lone star tick (Amblyomma americanum) and carried by the white-tailed deer (Odocoileus virginianus). Over the course of my 10 week Freshman Monroe Project, I will investigate how the interaction of human land use, white-tailed deer habitat use, and moisture availability (a key factor determining tick survival) influences the distribution of adult lone star ticks and E. chaffeensis. My Monroe research is a collaboration with Dr. Matthias Leu and graduate student Dylan Simpson (both landscape ecologists/conservation biologists), and Dr. Kerscher (molecular biologist).


My research has two goals. First, I will collect adult lone star ticks from the Virginia and Middle Peninsulas and determine the prevalence of E. chaffeensis based on molecular techniques. The Virginia peninsula is an ideal location to conduct tick research as it contains a variety of land cover types (forest, agricultural, marsh, urban, and rural), which affect the distribution of white-tailed deer. The Virginia peninsula is also varied in topography, which determines humidity gradients and therefore tick distributions; tick prefer humid areas. Human land use increases white-tailed deer populations via conversion of rural land into low-density housing areas, which tends to increase deer habitat quality by creating more forest edges, and by reducing hunting in low-density housing areas. Second, to explore long-term effects of land use and moisture availability on adult lone star tick populations and disease prevalence, I will determine prevalence of E. chaffeensis in adult ticks collected in 2013, 2014, and 2015, from the same sites that I will sample this summer, by members of the Applied Conservation and Ecological Research (ACER) lab.