Invasive Eastern red cedar provides habitat for A. americanum to invade new areas of Oklahoma

Tick-borne diseases, including Ehrlichiosis and Rocky Mountain spotted fever, are increasing in the United States, with Oklahoma having one of the highest annual incidence rates in the country.  With these two diseases associated with Amblyomma americanum, A. maculatum, and Dermacentor variabilis, recent surveillance studies across the state have demonstrated a western movement of A. americanum (Lone Star ticks) in the last 30 years.  While the habitat for Lone Star ticks in the eastern and central regions have been characterized, the dry, arid, drought prone areas in western Oklahoma are normally thought to be too harsh to support the establishment of the species. This recent change in species distribution in western Oklahoma has been accompanied by increasing reports of tick-borne disease cases.  Eastern red cedar (Juniperus virginiana) is an invasive pine species taking over large portions of the Great Plains region.  Serving as a haven for mammals, birds, and mosquito vectors of West-Nile Virus, we hypothesized that this invasive tree species is also creating conditions which allow for the establishment of Lone Star populations in otherwise improbable areas.  In the spring and summer of 2015, six representative sites were chosen across central and western Oklahoma, each characterized by varying levels of eastern cedar invasion.  Sampling was done using CO₂ traps to focus primarily on Lone Star populations.  Results indicate that Eastern red cedar does indeed support Lone Star tick populations at different levels of invasion.  Additionally, D. variabilis was found in the majority of the sites along with Lone Star ticks, indicating the possibility that competition might be occurring at some level.  Future studies are in place to evaluate the factors which may be involved in providing suitable habitat for Lone Star ticks as well as whether red cedar also provides habitat for Oklahoma tick species which are active in the winter months.