Environmental factors affecting the range expansion of Ixodes scapularis in Illinois

Transmission of tick-borne pathogens relies on complex interactions between humans, animal hosts, and arthropod vectors. Ixodes scapularis, commonly called the black-legged tick, has undergone a dramatic range expansion over the past decades and is the main vector of a number of tick-borne illnesses of public health concern, including Lyme disease, relapsing fever borreliosis, and Babesiosis. Many environmental factors affect how receptive an area is to colonization by an invading tick species. For instance, habitat fragmentation and landscape composition may affect tick reproductive success by limiting what hosts are present. Illinois is currently witnessing the southward range expansion of this species. Starting in 2019, the INHS Medical Entomology Lab statewide tick surveillance program, in partnership with the Illinois Department of Public Health has documented the presence and abundance of I. scapularis across Northern and Central Illinois. The objectives of my research were to improve our understanding of the landscape and environmental drivers of I. scapularis abundance on an invasion front. I also compared whether these drivers differ for areas with a longer history of establishment (Northern sites) compared to more recently invaded, and lower abundance (Central Illinois) sites.