The European honey bee (Apis mellifera) is a highly valuable, semi-free-ranging managed agricultural species. While the number of managed hives has been increasing, declines in overwinter survival, and the onset of colony collapse disorder in 2006, precipitated a large amount of research on bees’ health in an effort to isolate the causative factors. A workshop was convened during which bee experts were introduced to a formal causal analysis approach to compare 39 candidate causes against specified criteria to evaluate their relationship to the reduced overwinter survivability observed since 2006 of commercial bees used in the California almond industry. Candidate causes were categorized as probable, possible, or unlikely; several candidate causes were categorized as indeterminate due to lack of information. Due to time limitations, a full causal analysis was not completed at the workshop. In this article, examples are provided to illustrate the process and provide preliminary findings, using three candidate causes. Varroa mites plus viruses were judged to be a “probable cause” of the reduced survival, while nutrient deficiency was judged to be a “possible cause.” Neonicotinoid pesticides were judged to be “unlikely” as the sole cause of this reduced survival, although they could possibly be a contributing factor.

欧洲蜜蜂（Apis mellifera) 是一种非常有价值的半自由放养管理的农业物种。虽然管理蜂箱的数量一直在增加，但越冬存活率下降，以及 2006 年蜂群崩溃紊乱的发生，促使对蜜蜂健康进行大量研究，以期分离出致病因素。召开了一次研讨会，向蜜蜂专家介绍了正式的因果分析方法，将 39 种候选原因与指定标准进行比较，以评估它们与自 2006 年以来观察到的加州杏仁行业使用的商业蜜蜂越冬生存能力降低的关系。候选原因被分类为可能的、可能的或不太可能的；由于缺乏信息，一些可能的原因被归类为不确定的。由于时间限制，研讨会没有完成完整的因果分析。在本文中，使用三个可能的原因提供了示例来说明该过程并提供初步结果。瓦螨加病毒被认为是导致存活率降低的“可能原因”，而营养缺乏被认为是“可能的原因”。新烟碱类杀虫剂被认为“不太可能”是导致存活率下降的唯一原因，尽管它们可能是一个促成因素。