EAR TAGGING INCREASES TICK (IXODES-DAMMINI) INFESTATION RATES OF WHITE-FOOTED MICE (PEROMYSCUS-LEUCOPUS)

The white-footed mouse (Peromyscus leucopus) is an important host of t he deer tick (Ixodes dammini), and the principle reservoir for the spi rochete (Borrelia burgdorferi) known to cause Lyme disease. In summer and autumn 1991, we uniquely marked small rodents, including P. leucop us, with metal ear tags. The presence of ear tags increased rates of i nfestation by larval ticks on mice by 50 to 100%, probably because the tags reduced grooming efficiency. Because larval deer ticks acquire t he Lyme disease spirochete more efficiently from P. leucopus than from other mammalian and avian hosts, increasing the numbers of ticks para sitizing mice may cause a higher percentage of ticks to carry Lyme dis ease,