Comparison of conventional and novel trapping methods for tick collection

Ticks are the primary vectors of arthropod-borne diseases in the United States, and the current distribution of some species is uncertain.  One such tick, Amblyomma maculatum, (Gulf Coast tick), is spreading northward from its historical range and is of medical and veterinary concern because of its competence as a vector of both Rickettsia parkeri and Ehrlichia ruminantium.   Identifying optimal collection methods for specific species is essential as methods often vary in effectiveness, target species, and associated biases. The purpose of this study was to compare conventional trapping methods (dragging, flagging, sweep netting, and CO₂ trapping) with novel approaches (CO₂ flagging and CO₂ dragging) for collecting questing ticks. We specifically targeted A. maculatum to determine optimal methods for collection to determine the spatial distribution of these ticks and their associated pathogens.  Consequently, we will be collecting ticks from 20 different sites in western Tennessee known to have A. americanum, A. maculatum, and Dermacentor variabilis from May-September of 2013. Preliminary results from April and May suggest that overnight CO₂ trapping collected significantly more ticks (16.2±4.96) than sweep netting (5.55±1.94) (P <0.001); and CO₂-flagging collected significantly more A. maculatum than both CO₂ dragging and conventional flagging (P < 0.001). Additional results will be presented.  Knowledge about the numbers of ticks and the diversity of species collected with each method can help to improve sampling procedures and surveillance techniques with goals such as estimates of relative tick densities or disease exposure risks, comparison of habitat use, and evaluation of pathogen prevalence.