Survey Results of Honey Bee Colony Losses in Winter in China (2009–2021)

SIMPLE SUMMARY: Honey bees are of great importance because of their roles in pollination and the supply of bee products. However, the number of honey bee colonies is declining worldwide, and these colony losses mainly occur in winter. Colony loss surveys have been regarded as an efficient measure to protect managed honey bees, as they help identify potential risk factors for colony loss. They may also make beekeepers pay more attention to overwinter beekeeping management and thus reduce colony losses. We conducted surveys on the overwinter mortality of managed honey bee colonies in China from 2009 to 2021. The aim of the present study was to evaluate the health status of honey bee colonies in China and describe the risk factors for winter colony losses. We reported that colony losses were low, with variations among years, provinces, species (Apis mellifera and Apis cerana), and types of apiaries. The results showed that the queen problems (queenless colonies or drone-laying queens), operation size, migration, migration×species interaction, and species significantly affected winter colony losses. Our study contributes to improving the health of managed honey bees and provides useful strategies for colony overwintering. ABSTRACT: There is growing concern that massive loss of honey bees can cause serious negative effects on biodiversity and ecosystems. Surveys of colony losses have been performed worldwide to monitor the dynamic changes and health status of honey bee colonies. Here, we present the results of surveys regarding winter colony losses from 21 provinces in China from 2009 to 2021, with a total of 1,744,324 colonies managed by 13,704 beekeepers. The total colony losses were low (9.84%; 95% Confidence Interval (CI): 9.60–10.08%) but varied among years, provinces, and scales of apiaries. As little is known about the overwintering mortality of Apis cerana, in this study, we surveyed and compared the loss rates between Apis mellifera and A. cerana in China. We found colonies of A. mellifera suffered significantly lower losses than A. cerana in China. Larger apiaries resulted in higher losses in A. mellifera, whereas the opposite was observed in A. cerana. Furthermore, we used generalized linear mixed-effects models (GLMMs) to evaluate the effects of potential risk factors on winter colony losses and found that the operation size, species, migration, migration×species interaction, and queen problems were significantly related to the loss rates. New queens can increase their colony overwintering survival. Migratory beekeepers and large operations reported lower loss rates.