Tick community composition in Midwestern US habitats in relation to sampling method and environmental conditions

The ranges of many tick species are changing due to climate change and human alteration of the landscape. Understanding tick responses to environmental conditions and how sampling method influences measurement of tick communities will improve our assessment of human disease risk. We compared tick sampling by three collection methods (dragging, CO2 trapping and rodent surveys) in adjacent forested and grassland habitats in the lower Midwest, USA, and analyzed the relationship between tick abundance and microclimate conditions. The study areas were within the overlapping ranges of three tick species, which may provide conditions for pathogen exchange and spread into new vectors. Dermacentor variabilis (American dog tick) was found using all methods, Amblyomma americanum (lonestar tick) was found by dragging and CO2 trapping and Ixodes scapularis (blacklegged deer tick) was found only on rodents. Proportion of each species differed significantly among sampling methods. More ticks were found in forests compared to open habitats. Further, more ticks were collected by dragging and from rodents in hotter, drier conditions. Our results demonstrate that multiple sampling methodologies better measure the tick community and that microclimate conditions strongly influence the abundance and activity of individual tick species.