Figure 1. Pollination schedule of the three commercial beekeeping operations tracked over time.

Multiple bee bread samples were collected at each of the above time points for pesticide analysis. At the end of the study, samples for each time point were retrospectively pooled from 3–4 colonies within the same operation that perished at similar times or survived the season. For each available time point, samples were always pooled from the same 3–4 colonies and each time point was represented by at least four pooled samples.