Ixodes ricinus ticks survive flooding

Abstract

Climate-change induced weather extremes like floods are increasing in frequency and intensity, with potential consequences for disease vector ecology. We report on a flooding event during the winter of 2023/2024 in Hanover city, Germany. Our observations demonstrate that I. ricinus, the most important vector of tick-borne diseases in Europe, can survive prolonged periods under water and quickly resume host-seeking activity once conditions normalize. Despite being submerged for a total of 25 days, nymphal and adult ticks were observed questing four weeks of the water receding, with densities comparable to pre-flood levels. These findings underscore the resilience of I. ricinus and highlight the potential of ticks to pose infection risks even after extreme weather events.

Keywords: Climate change; Flooding; Hard ticks; Ixodes ricinus; Tick-borne diseases, Transmission risk.