Seasonal flooding and environmental variation decrease blacklegged tick (Acari: Ixodidae; Ixodes scapularis ) survival in a wetland ecosystem

Abstract

Increased volatility in precipitation can result in higher levels of rainfall and contribute to flooding events. Ticks spend the majority of their life in the environment, and this volatility may impact their survival and long-term occupancy in certain habitat types. While underwater survival has been assessed in some tick species, the effect of water inundation on blacklegged ticks (Ixodes scapularis Say) is not well understood. Here, we elucidated the survival of blacklegged tick nymphs in a wetland ecosystem by creating microcosms called tickaria (n = 48) and deploying these tickaria in “dry” and “wet” sites within an experimental wetland research station in Ohio. Nymphs (n = 10) were contained for the duration of the nymphal season in Ohio, and tickaria were destructively sampled periodically between May and August to assess survival. We found that ticks in the wet sites that experienced flooding had a higher risk of death compared to ticks in dry sites without flooding (P < 0.001). High volumetric water content in soil also contributed to a higher risk of death (P < 0.001). This work suggests that blacklegged tick nymphs are unable to withstand flooding events or saturated soil for long periods of time and expands our understanding of tick survival while inundated in an ecologically relevant system.