Comparing conventional and novel methods of tick collection

Ticks are vectors of disease world-wide. 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. Three tick species, Amblyomma americanum, Amblyomma maculatum, and Dermacentor variabilis, were collected from 20 different sites in western Tennessee from April-August of 2013. Data were log transformed, and analyzed using a mixed-model ANOVA and LSD for mean separation. CO₂ dragging was significantly more effective than flagging or sweep netting, though not different from CO₂ flagging or conventional dragging (P < 0.0001). Significantly more ticks were collected in April/May as numbers declined June-August (P < 0.0001). There was also a significant trap x month interaction effect (P = 0.0253) only for A. americanum; it was not significant for A. maculatum (P = 0.5915) or D. variabilis (P = 0.5235). Knowledge about the diversity of species collected with various methods can help improve sampling and surveillance procedures such as estimates of relative tick densities, disease exposure risks, comparison of habitat use, and evaluation of pathogen prevalence.