Abstract
Ixodes ricinus ticks (Acari: Ixodidae) are the most important vector for Lyme borreliosis in Europe. As environmental and climate changes might affect the distribution and activity of tick populations, this study aimed to determine the effects of environmental factors, i.e., meteorological, bioclimatic, and habitat characteristics on questing activity of I. ricinus nymphs across diverse climatic types in France over an 8-year period. Questing activity was observed using a repeated removal sampling design with a cloth-dragging technique in 11 sampling sites from 7 tick observatories from 2014 to 2021 at approximately 1-month intervals, involving 631 sampling campaigns. Three phenological patterns were observed, potentially following a climatic gradient. The mixed-effects negative binomial regression revealed that observed nymph counts were driven by different interval-average meteorological variables, including one-month average temperature, previous-season average temperature, and half-year average minimum relative humidity. The interaction effects indicated that the phenology in colder climates peaked differently from that of warmer climates. Also, the land cover characteristics that support the highest baseline abundance were moderate forest fragmentation with transition borders with agricultural areas. Finally, our model could potentially be used to predict seasonal human-tick exposure risks in France that could contribute to mitigating Lyme borreliosis risks.
Variable Strength of Forest Stand Attributes and Weather Conditions on the Questing Activity of Ixodes ricinus Ticks over Years in Managed Forests
