Mowing as a strategy to manage nymphal blacklegged ticks

In the Northeastern U.S., blacklegged ticks (Ixodes scapularis) are commonly found along the forested edges of residential yards, making the lawn-forest interface risky for tick bites and the potential transmission of the Lyme disease-causing bacteria. The CDC and other public health agencies commonly recommend mowing as a vegetation management strategy to suppress blacklegged tick populations. However, there are not sufficient field studies evaluating the impact of mowing on blacklegged tick activity at the forest edge. In April 2024, using a randomized block design, we erected three blocks of three 4m X 1m enclosures (N=9) along the lawn-forest interface of a simulated backyard edge to track nymphal blacklegged tick movement and survival across the ecotone and into the lawn. Enclosures in each block received one of three treatments: weekly mowing, mowing every other week, or not mowing at all. In May 2024, each enclosure was infested with 300 lab-reared nymphal blacklegged ticks at the forest edge. Nymphs were sampled weekly using a 0.5m² flag. Nymphs detected in lawn areas were uniquely marked each week. We observed nymphal tick movement >2m into maintained lawn areas as well as multi-week survival of ticks in both maintained and unmaintained lawn areas. The results of this study can help inform future recommendations for mowing as a residential blacklegged tick management practice.