Fig. 4

The proportions of diapausing Cx. pipiens (A) and Cx. erraticus (B) collected from culverts in fall 2021 through spring 2022. The size of each point is proportional to the number of culverts where Culex were collected. Gray shading highlights dates between March 1, 2022, and April 21, 2022, when there was a rapid decrease in the proportion of mosquitoes in diapause. Although all nine culverts were sampled during each collection event, Cx. pipiens and/or Cx. erraticus were not necessarily collected from every culvert on every collection date