Tissue-damaging marking methods do not affect tick burdens on field captured Peromyscus spp

Authors: ROBERTS, CHLOE - Pennsylvania State University; BURGESS, EDWIN - University Of Florida; MILLER, TAYLOR - Pennsylvania State University; WISE, ANNA-MARIE - Pennsylvania State University; DICKERSON, CERA - Pennsylvania State University; SKVARLA, MICHAEL - Pennsylvania State University; Li, Andrew; MACHTINGER, ERIKA - Pennsylvania State University

Submitted to: Wildlife Society Bulletin
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2022
Publication Date: 11/11/2022
Citation: Roberts, C.E., Burgess, E.R., Miller, T.M., Wise, A., Dickerson, C.J., Skvarla, M.J., Li, A.Y., Machtinger, E.T. 2022. Tissue-damaging marking methods do not affect tick burdens on field captured Peromyscus spp. Wildlife Society Bulletin. https://doi.org/10.1002/wsb.1385.
DOI: https://doi.org/10.1002/wsb.1385

Interpretive Summary: White-footed mice are important reservoir hosts for the pathogen that causes Lyme disease in people. Studies of host-targeted tick control and disease ecology, including interactions among mice, ticks and tick-borne pathogens in nature require proper methods for marking of wild white-footed mice. The USDA ARS scientists teamed up with university researchers in evaluation of multiple mouse-marking methods in a field study conducted in Pennsylvania. Results indicate Bait boxes are among few commercially available host-targeted tick control tools that are intended for use to control immature deer ticks feeding on white-footed mice in the environment. It is unknown how these bait boxes are used by the target species or potential risks associated with supplemental baiting. This study was designed to understand bait consumption by mice in relation to vegetation cover classes and the nutritional value of baits in comparison to native acorn species. Results indicated the ear punch marking method resulted in significantly more ticks than the blue dye control. This could potentially lead to bias in tick load estimates. Ear tagging method did not significantly alter tick load estimate, therefore is recommended for use in marking Peromyscus spp. for tick ecology studies along with personal preferences, cost, ease of use, and durability. The study provides useful information regarding mouse-marking methodology that can be used by wildlife biologists, researchers who study ticks and tick-borne disease epidemiology, as well as vector control professionals.

Technical Abstract: The blacklegged tick, Ixodes scapularis, is the vector of Borrelia burgdorferi, the etiological agent that causes Lyme disease in the United States. Studies investigating host-parasite interactions are valuable in understanding Ix. scapularis ecology, and, by extension, the transmission of the Lyme disease pathogen. Small mammals are important hosts for Ix. scapularis, particularly white-footed mice and deer mice from the genus Peromyscus. These animals have also been used as model organisms in several fields and are frequently trapped to evaluate broad ecological concepts. Previous studies have suggested that methods that result in tissue damage result in increased tick burdens, which may have consequences in ecological studies. The present study was designed to further evaluate four mouse-marking methods, namely blue dye (non-tissue damage control), lab tags, round tags, or ear punches, to determine if any method affects the tick burden on captured mice. Mice were captured biweekly using Sherman traps from May through September in 2020. The overall tick burden fluctuated between months, and no significant difference in total tick burden was found between captured male and female mice. Results also indicate there were no significant differences in tick burden on captured mice among the two ear tagging marking methods and the blue dye control. However, the ear punch marking method resulted in significantly more ticks than the blue dye control. Therefore, ear tagging and blue dye should be considered for use in marking Peromyscus spp. for tick ecology studies along with personal preferences, cost, ease of use, and durability.