Effectiveness of tick sampling methods in the field: A systematic scoping review

Climate change is driving the expansion of various tick species in North America. In this context, it is essential to ensure that vector populations can be effectively detected and monitored in both emerging and endemic regions. The objective of this study was to characterize the methods used for sampling questing hard ticks of the family Ixodidae and synthesize current knowledge on their effectiveness. A scoping review was conducted and 56 studies published before October 2024 were included in the analysis. Overall, 63% of the studies were conducted in North America and 9% in Europe. The majority of the studies concerned Ixodes spp. (63%). Most studies on Ixodes spp. and Dermacentor spp. examined cloth-based methods such as dragging, flagging, and sweeping, while CO₂ traps were most frequently studied for Amblyomma spp. Only seven studies quantified the proportion of the estimated tick population sampled using collection methods. Overall, a single dragging passage was estimated to capture only a small proportion of the questing nymph population, approximately 6% (5.9-6.3%). Several technical, environmental, and climatic factors may influence sampling effectiveness, including temperature, sampling period, and cloth type. Methodological variability across studies limited comparability and hindered the establishment of standardized guidelines. Nevertheless, we can conclude that no single collection method emerged as a gold standard, and that a combination of methods may be required. Based on these findings, we provide evidence-based recommendations for the selection of tick sampling methods based on different objectives, tick genus, life stage, and environmental and climatic factors.