Ticks fighting ticks: Investigating co-feeding dynamics and host responses to native and regionally invasive tick species

Ticks are pervasive ectoparasites that influence ecosystem health through their roles as blood feeders, vectors of pathogens, and influencers of habitat use and movement patterns of their hosts. In the northeastern U.S., Peromyscus leucopus (white-footed mouse), are important reservoir hosts for ticks and are crucial for maintaining tick populations and transmitting pathogens like Borrelia burgdorferi, the agent of Lyme disease. Ixodes scapularis (blacklegged tick), the vector of Lyme disease, is a generalist that feeds on small mammals and birds as juveniles and larger mammals as adults. In many areas of the U.S., native ticks are expanding their geographical range to new areas, driven by anthropogenic changes like climate change. Specifically, Amblyomma maculatum (Gulf Coast tick), has been moving northwards. This tick is also a generalist, feeding on small and large mammals throughout its life stages. The invasion of new species into naïve areas may increase tick competition for hosts, thereby increasing tick burdens, pathogen load, and disease transmission. This research investigates interactions between I. scapularis and A. maculatum on shared hosts, focusing on co-feeding dynamics and host behavioral responses. Using Noldus EthoVision® XT software, I will analyze P. leucopus behavioral responses to infestations by single and co-infested tick species and assess co-feeding competition dynamics. Furthermore, this will provide insights into how host responses and interspecies competition shape tick success and pathogen transmission, offering critical knowledge to predict the ecological and public health impacts of climate-induced tick range expansions.