Environmental sampling for Dermacentor species (Acari: Ixodidae) in southern British Columbia, Canada in May, 2022

Abstract

Traditionally, the most commonly encountered Dermacentor spp. (Acari: Ixodidae) in southern British Columbia, Canada has been Dermacentor andersoni Stiles. However, with the novel detection of Dermacentor similis Lado in southern British Columbia, environmental sampling for Dermacentor spp. is needed to provide up-to-date information on which ticks are present in this area. Drag sampling was conducted at 33 sites across southern British Columbia, covering 2000 m² per site. Environmental and weather data were recorded at the time of sampling. The only Dermacentor spp. collected was D. andersoni, with these ticks found at 10 sites. Univariable mixed-effect Poisson regression models with a random effect for site were used to investigate the relationship between transect-level environmental variables and the number of D. andersoni collected within a transect. As soil moisture decreased, the number of D. andersoni collected increased. No other relationships were detected. This study suggests that D. andersoni remains present in southern British Columbia and may be affected by the environmental variable of soil moisture. It also provides evidence that coupling different tick collection methods, for example, environmental and host sampling, has benefit in providing a more complete picture of the tick species present in an area.