Knowledge of host species that maintain populations of Ixodes scapularis, the vector of Lyme disease in the eastern U.S., is needed to improve preventative strategies. The prevailing dogma of Lyme disease ecology is that the white-footed mouse (Peromyscus leucopus) is the most important host for juvenile ticks (i.e., larvae and nymphs; 1). The white-tailed deer (Odocoileus virginanus) is the primary host for adult ticks, however its role as a host for juveniles has not been rigorously studied. Here we provide both DNA and visual evidence that juveniles feed on O. virginanus. Our DNA-based host detection system may be more broadly applied in future studies to identify other important hosts of I. scapularis
