Methods details.

In this study, we intensively measured the longitudinal productivity and survival of 362 commercially managed honey bee colonies in Canada, over a two-year period. A full factorial experimental design was used, whereby two treatments were repeated across apiaries situated in three distinct geographic regions: Northern Alberta, Southern Alberta and Prince Edward Island, each having unique bee management strategies. In the protein supplemented treatment, colonies were continuously provided a commercial protein supplement containing 25% w/w pollen, in addition to any feed normally provided by beekeepers in that region. In the fumagillin treatment, colonies were treated with the label dose of Fumagilin-B® each year during the fall. Neither treatment provided consistent benefits across all sites and dates. Fumagillin was associated with a large increase in honey production only at the Northern Alberta site, while protein supplementation produced an early season increase in brood production only at the Southern Alberta site. The protein supplement provided no long-lasting benefit at any site and was also associated with an increased risk of death and decreased colony size later in the study. Differences in colony survival and productivity among regions, and among colonies within beekeeping operations, were far larger than the effects of either treatment, suggesting that returns from extra feed supplements and fumagillin were highly contextually dependent. We conclude that use of fumagillin is safe and sometimes beneficial, but that beekeepers should only consider excess protein supplementation when natural forage is limiting.

本研究于两年周期内，对加拿大境内362群商业化饲养的蜜蜂蜂群的长期生产力与存活状况开展了系统性密集观测。本研究采用全因子实验设计，在阿尔伯塔省北部、阿尔伯塔省南部与爱德华王子岛三个各具特色的地理区域的养蜂场中，重复开展两项处理实验，每个区域均采用专属的蜜蜂饲养管理方案。在蛋白质补充处理组中，除该区域养蜂人常规提供的饲料外，所有蜂群均持续饲喂一款含25%重量比花粉的商业化蛋白质补充剂。在烟曲霉素（Fumagillin）处理组中，每年秋季均按标签推荐剂量为蜂群施用Fumagilin-B®药剂。两项处理均未在所有观测位点与观测时段中展现出一致的增益效果。仅在阿尔伯塔省北部位点，烟曲霉素处理与蜂蜜产量的大幅提升呈显著关联；而蛋白质补充仅在阿尔伯塔省南部位点实现了季初育虫量的增长。蛋白质补充剂在任何位点均未产生持久益处，且在研究后期与蜂群死亡风险升高、群势下降呈显著关联。不同区域间以及同一养蜂场内部蜂群的存活状况与生产力差异，远大于两项处理各自带来的影响，这表明额外饲喂蛋白质补充剂与烟曲霉素的收益高度依赖于具体环境条件。本研究最终得出结论：烟曲霉素的使用安全且有时可带来收益，但养蜂人仅应在天然蜜粉源匮乏时考虑额外补充蛋白质饲料。