Bureau of Plant Industry, Pennsylvania Department of Agriculture, 2301 North Cameron St., Harrisburg PA 17110, USA.
J Econ Entomol. 2010 Oct;103(5):1517-23. doi: 10.1603/ec09429.
Colony collapse disorder (CCD), a syndrome whose defining trait is the rapid loss of adult worker honey bees, Apis mellifera L., is thought to be responsible for a minority of the large overwintering losses experienced by U.S. beekeepers since the winter 2006-2007. Using the same data set developed to perform a monofactorial analysis (PloS ONE 4: e6481, 2009), we conducted a classification and regression tree (CART) analysis in an attempt to better understand the relative importance and interrelations among different risk variables in explaining CCD. Fifty-five exploratory variables were used to construct two CART models: one model with and one model without a cost of misclassifying a CCD-diagnosed colony as a non-CCD colony. The resulting model tree that permitted for misclassification had a sensitivity and specificity of 85 and 74%, respectively. Although factors measuring colony stress (e.g., adult bee physiological measures, such as fluctuating asymmetry or mass of head) were important discriminating values, six of the 19 variables having the greatest discriminatory value were pesticide levels in different hive matrices. Notably, coumaphos levels in brood (a miticide commonly used by beekeepers) had the highest discriminatory value and were highest in control (healthy) colonies. Our CART analysis provides evidence that CCD is probably the result of several factors acting in concert, making afflicted colonies more susceptible to disease. This analysis highlights several areas that warrant further attention, including the effect of sublethal pesticide exposure on pathogen prevalence and the role of variability in bee tolerance to pesticides on colony survivorship.
蜂群崩溃失调症（CCD），一种以成年工蜂迅速大量死亡为特征的综合征，被认为是美国养蜂人在 2006-2007 年冬季经历的大量越冬损失的少数原因之一。使用相同的数据集进行单因素分析（PLoS ONE 4：e6481，2009 年），我们进行了分类和回归树（CART）分析，试图更好地理解不同风险变量在解释 CCD 方面的相对重要性和相互关系。使用 55 个探索性变量来构建两个 CART 模型：一个带有和一个不带有将 CCD 诊断殖民地错误分类为非 CCD 殖民地的成本的模型。允许错误分类的结果模型树的灵敏度和特异性分别为 85%和 74%。尽管衡量殖民地压力的因素（例如，成年蜜蜂的生理测量，如波动不对称或头部质量）是重要的区分值，但在具有最大区分值的 19 个变量中有 6 个是不同蜂箱基质中的农药水平。值得注意的是，幼虫中的氯菊酯水平（养蜂人常用的一种杀螨剂）具有最高的区分值，且在对照（健康）群体中最高。我们的 CART 分析提供了证据，表明 CCD 可能是几个因素协同作用的结果，使受影响的殖民地更容易患病。该分析突出了几个值得进一步关注的领域，包括亚致死农药暴露对病原体流行率的影响以及蜜蜂对农药耐受性的变异性对殖民地存活率的作用。
