Fig. 1

Land cover, aerial sprays and mosquito collections (2006–2017) in Sacramento and Yolo counties, California. a Distribution of cultivated crops (primarily rice), urban, and other natural land cover types across the study area. Land cover categories were derived from the 2011 National Land Cover database [34]. Inset highlights the location of these counties in the state of California. b, c Location of zones targeted for aerial treatment applications (b) and of CO₂-baited mosquito traps (c) during 2006–2017 in Sacramento and Yolo counties. Each polygon (b) and point (c) represents a single spray or trapping event, respectively. A random shift of ≤ 1 km was applied to trap locations for visualization of repeated trapping at the same location across time