Figure 3

Paenibacillus larvae spore concentrations in extracted honey of large-scale (L) beekeepers sampled in both 2019 and 2020. Orange dots indicate spore concentrations in honey samples collected in 2019 and green dots for 2020. L beekeepers are separated from one another by vertical dashed lines. Beekeepers highlighted in light red are those that reported AFB in 2021. Beekeepers highlighted in light blue are those that reported a historical occurrence of AFB within the previous four years (2017–2020). L beekeepers were selected for repeat (2020) sampling by meeting one of the following subset criteria: A = maximum 2019 spore concentration greater than or equal to five spores per gram of honey; B = at least one case of AFB within the previous 10 years; C = select beekeepers with a maximum 2019 spore concentration less than five spores per gram of honey currently using antibiotics as a part of AFB management; D = select beekeepers with a maximum 2019 spore concentration less than five spores per gram of honey not currently using antibiotics; E = select beekeepers with a maximum 2019 spore concentration less than five spores per gram managing very large commercial beekeeping operations (approximately 5000 hives). 1 = L beekeepers that provided follow-up regarding decrease in spore concentrations between sampling years. 2 = L beekeeper with apiaries within flying distance of reported case of AFB between 2019 and 2020 sampling years.