This article presents managed honey bee colony loss rates over winter 2018/19 resulting from using the standardised COLOSS questionnaire in 35 countries (31 in Europe). In total, 28,629 beekeepers supplying valid loss data wintered 738,233 colonies, and reported 29,912 (4.1%, 95% confidence interval (CI) 4.0–4.1%) colonies with unsolvable queen problems, 79,146 (10.7%, 95% CI 10.5–10.9%) dead colonies after winter and 13,895 colonies (1.9%, 95% CI 1.8–2.0%) lost through natural disaster. This gave an overall colony winter loss rate of 16.7% (95% CI 16.4–16.9%), varying greatly between countries, from 5.8% to 32.0%. We modelled the risk of loss as a dead/empty colony or from unresolvable queen problems, and found that, overall, larger beekeeping operations with more than 150 colonies experienced significantly lower losses (p < 0.001), consistent with earlier studies. Additionally, beekeepers included in this survey who did not migrate their colonies at least once in 2018 had significantly lower losses than those migrating (p < 0.001). The percentage of new queens from 2018 in wintered colonies was also examined as a potential risk factor. The percentage of colonies going into winter with a new queen was estimated as 55.0% over all countries. Higher percentages of young queens corresponded to lower overall losses (excluding losses from natural disaster), but also lower losses from unresolvable queen problems, and lower losses from winter mortality (p < 0.001). Detailed results for each country and overall are given in a table, and a map shows relative risks of winter loss at regional level.

本文介绍了在35个国家/地区（欧洲为31个）使用标准化COLOSS调查表得出的2018/19冬季受控蜂群损失率。提供有效损失数据的28,629位养蜂人越冬了738,233个菌落，报告了有无法解决的皇后问题的29,912个（4.1％，95％置信区间（CI）4.0-4.1％），79,146个（10.7％，95％CI 10.5-10.9％） ）死后的殖民地，并在自然灾害后损失了13,895个殖民地（1.9％，95％CI为1.8–2.0％）。这样一来，整个殖民地冬季总损失率为16.7％（95％CI为16.4–16.9％），各国之间差异很大，从5.8％到32.0％。我们将损失的风险建模为死/空的殖民地或无法解决的女王问题，发现总体上，拥有150多个殖民地的大型养蜂场损失显着降低（p  <0.001），与早期研究一致。此外，这项调查中包括的养蜂人在2018年至少没有一次迁移其殖民地，其损失明显低于那些迁移的人（p  <0.001）。还检查了2018年冬季过冬的殖民地中新女王的百分比作为潜在的危险因素。在所有国家/地区，进入新女王后进入冬季的殖民地比例估计为55.0％。年轻皇后的百分比越高，相应的总损失就越少（不包括自然灾害造成的损失），但皇后问题无法解决，损失也就越小，冬季死亡率造成的损失就越少（p  <0.001）。表格中列出了每个国家/地区和整体的详细结果，而一张地图则显示了区域级冬季损失的相对风险。