Data from: Honey bees and neonicotinoid-treated corn seed: contamination, exposure, and effects

Most corn (Zea mays) seeds planted in the US in recent years are coated with a seed treatment containing neonicotinoid insecticides. Abrasion of the seed coating generates insecticide-laden planter dust that disperses through the landscape during corn planting and has resulted in many ‘bee-kill’ incidents in North America and Europe. We investigated the linkage between corn planting and honey bee colony success in a region dominated by corn agriculture. Over three years we consistently observed an increased presence of corn seed treatment insecticides in bee-collected pollen and elevated worker bee mortality during corn planting. Residues of seed treatment neonicotinoids, clothianidin and thiamethoxam, detected in pollen positively correlated with cornfield area surrounding the apiaries. Elevated worker mortality was also observed in experimental colonies fed field-collected pollen containing known concentrations of corn seed treatment insecticides. We monitored colony growth throughout the subsequent year in 2015 and found that colonies exposed to higher insecticide concentrations exhibited slower population growth during the month of corn planting, but demonstrated more rapid growth in the month following, though this difference may be related to forage availability. Exposure to seed treatment neonicotinoids during corn planting has clear short-term detrimental effects on honey bee colonies and may affect the viability of beekeeping operations that are dependent on maximizing colony size in the springtime.近年来美国种植的绝大多数玉米（Zea mays）种子，均经含有新烟碱类杀虫剂（neonicotinoid insecticides）的种子处理剂包衣。种衣剂在播种作业的机械摩擦过程中会产生附着杀虫剂的播种粉尘，此类粉尘会在玉米播种季扩散至周边环境，进而在北美与欧洲引发多起“杀蜂”事件。本研究以玉米种植占主导的区域为对象，探究了玉米播种活动与蜜蜂蜂群生存状况之间的关联。在为期三年的观测周期内，我们持续观测到：蜜蜂采集的花粉中玉米种子处理剂杀虫剂的残留量显著升高，且玉米播种季工蜂的死亡率亦有所上升。在花粉中检出的种子处理剂用新烟碱类杀虫剂残留，包括噻虫胺（clothianidin）与噻虫嗪（thiamethoxam），与蜂箱周边玉米田的种植面积呈显著正相关。在饲喂了田间采集的、含已知浓度玉米种子处理剂杀虫剂花粉的试验蜂群中，同样观测到工蜂死亡率升高的现象。我们于2015年对后续全年的蜂群生长情况进行了监测，结果显示：暴露于较高杀虫剂浓度的蜂群，在玉米播种当月的种群增长速度较慢，但在次月的增长速度更快，不过这一差异可能与蜜源的可获得性有关。玉米播种季暴露于种子处理剂新烟碱类杀虫剂，会对蜜蜂蜂群造成明确的短期有害影响，且可能威胁到依赖春季最大化蜂群规模的养蜂生产的存续能力。