Data of winter weight from different subspecies of honey bee Apis mellifera colonies (Linnaeus, 1758) in southwestern Sweden

Honey bees are currently facing mounting pressures that have resulted in population declines in many parts of the world. In northern climates winter is a bottleneck for honey bees and a thorough understanding of the colonies’ ability to withstand the winter is needed in order to protect the bees from further decline. In this study the influence of weather variables on colony weight loss was studied over one winter (2019-2020) in two apiaries (32 colonies in total) in southwestern Sweden with weather stations recording wind, temperature, humidity and precipitation at 5-min intervals. Three subspecies of honey bees and one hybrid were studied: the native Apis mellifera mellifera, the Italian A. m. ligustica, the Carniolan A. m. carnica and the hybrid Buckfast. Additionally, we recorded Varroa mite infestation. To analyze factors involved in resource consumption, three modelling approaches using weather and weight data were developed: the first links daily consumption rates with environmental variables, the second modelled the cumulative weight change over time, and the third estimated weight change over time taking light intensity and temperature into account. Weight losses were in general low (0.039 ± 0.013kg/day and colony) and comparable to southern locations, likely due to an exceptionally warm winter (average temperature 3.5°C). Weight losses differed only marginally between subspecies with indications that A. m. mellifera was having a more conservative resource consumption, but more studies are needed to confirm this. We did not find any effect of Varroa mite numbers on weight loss. In general, increasing light and temperature increase resource consumption in honey bees and within the temperature ranges of the experiment resource consumption was found to be in accordance with the master equation of metabolic theory of ecology (MTE). The effects of climate change could potentially affect the honey bees’ overwintering strategies and successes since temperature is expected to change but light intensity is expected to remain the same. A dependence on both light and temperature to guide resource consumption could thus potentially limit the honey bees’ ability to adapt to a changing climate.当前，西方蜜蜂（honey bee）正面临日益严峻的生存压力，全球多地已出现其种群数量下降的现象。在北方气候区，冬季是西方蜜蜂生存的关键瓶颈，因此需全面掌握蜂群的越冬能力，方能避免种群进一步衰退。 本研究于2019-2020年的越冬期，在瑞典西南部的两个养蜂场（共32群蜜蜂）开展实验，探究气象变量对蜂群体重下降的影响；实验依托气象站以5分钟为间隔，同步记录风速、气温、相对湿度与降水量数据。 本次研究共涉及西方蜜蜂的3个亚种与1个杂交品系：本土的欧洲黑蜂（Apis mellifera mellifera）、意大利蜂（Apis m. ligustica）、卡尼鄂拉蜂（Apis m. carnica）以及巴克菲特杂交蜂（Buckfast）；此外，研究还记录了瓦螨（Varroa mite）的侵染情况。 为分析蜜蜂资源消耗的相关影响因子，本研究基于气象与体重数据构建了三类建模方案：其一将日资源消耗速率与环境变量相关联，其二模拟随时间推移的累计体重变化，其三结合光照强度与气温，估算随时间变化的体重动态。 总体而言，蜂群的体重下降速率较低，为(0.039±0.013)千克/群·天，与南方区域的观测结果相近，这大概率得益于本次冬季异常偏暖（平均气温3.5℃）。不同亚种间的体重下降速率仅存在细微差异，有迹象表明欧洲黑蜂的资源消耗更为保守，但该结论仍需更多研究予以验证；此外，本研究未发现瓦螨侵染数量对蜂群体重下降存在显著影响。 总体来看，光照强度与气温升高均会提升西方蜜蜂的资源消耗速率；在本实验的温度区间内，蜜蜂的资源消耗模式符合代谢生态学理论（Metabolic Theory of Ecology, MTE）的核心方程。由于气温预计将发生变化而光照强度将保持相对稳定，气候变化或会对西方蜜蜂的越冬策略与越冬成功率产生潜在影响；若蜜蜂的资源消耗同时依赖光照与气温，则可能限制其应对气候变化的适应能力。