Systemic acaricidal treatment of white-footed mice (Peromyscus leucopus) against juvenile blacklegged ticks (Ixodes scapularis) in Connecticut

White-footed mice (Peromyscus leucopus) play a critical role in blacklegged tick (Ixodes scapularis) ecology both in their reproduction and pathogen transfer. While topical acaricide treatment of rodent pathogen reservoirs has been readily explored over the past several decades, orally delivered, systemic acaricidal treatment is recently gaining traction as an approach for management of ticks and tick-borne pathogens. We sought to further advance this research by deploying commercially available fipronil-laced bait targeting P. leucopus to determine bait acceptance and to document levels of active ingredient in the animals shown to be lethal to ticks in previous efforts. Initial efforts showed a reduction in juvenile I. scapularis burdens on P. leucopus (57-94%) compared to control over a two-year period. As a result, a similar bait formulation has been integrated into a multi-town systemic treatment effort targeting both P. leucopus and white-tailed deer (Odocoileus virginianus). The oral delivery of systemic acaricides shows promise in impacting tick burdens on the primary pathogen reservoir host, P. leucopus, and will be further explored as part of an areawide, integrated, systemic strategy for reducing host-seeking I. scapularis abundances, associated pathogen infection, and their subsequent impact on public health.