Botany, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland.
School of Chemical Sciences, DCU Water Institute, Dublin City University, Dublin 9, Ireland.
Sci Total Environ. 2023 Oct 20;896:166214. doi: 10.1016/j.scitotenv.2023.166214. Epub 2023 Aug 9.
In an agricultural environment, where crops are treated with pesticides, bees are likely to be exposed to a range of chemical compounds in a variety of ways. The extent to which different bee species are affected by these chemicals, largely depends on the concentrations and type of exposure. We quantified the presence of selected pesticide compounds in the pollen of two different entomophilous crops; oilseed rape (Brassica napus) and broad bean (Vicia faba). Sampling was performed in 12 sites in Ireland and our results were compared with the pollen loads of honey bees and bumble bees actively foraging on those crops in those same sites. Detections were compound specific, and the timing of pesticide application in relation to sampling likely influenced the final residue contamination levels. Most detections originated from compounds that were not recently applied on the fields, and samples from B. napus fields were more contaminated compared to those from V. faba fields. Crop pollen was contaminated only with fungicides, honey bee pollen loads contained mainly fungicides, while more insecticides were detected in bumble bee pollen loads. The highest number of compounds and most detections were observed in bumble bee pollen loads, where notably, all five neonicotinoids assessed (acetamiprid, clothianidin, imidacloprid, thiacloprid, and thiamethoxam) were detected despite the no recent application of these compounds on the fields where samples were collected. The concentrations of neonicotinoid insecticides were positively correlated with the number of wild plant species present in the bumble bee-collected pollen samples, but this relationship could not be verified for honey bees. The compounds azoxystrobin, boscalid and thiamethoxam formed the most common pesticide combination in pollen. Our results raise concerns about potential long-term bee exposure to multiple residues and question whether honey bees are suitable surrogates for pesticide risk assessments for all bee species.
在农业环境中，农作物会使用杀虫剂，因此蜜蜂可能会通过多种途径接触到一系列化学物质。不同蜜蜂物种受到这些化学物质影响的程度，在很大程度上取决于接触的浓度和类型。我们定量检测了两种不同传粉作物（油菜和蚕豆）花粉中的选定农药化合物。在爱尔兰的 12 个地点进行了采样，我们的结果与在这些地点采集的采集这些作物的蜜蜂和熊蜂的花粉负荷进行了比较。检测是特定化合物的检测，与采样相关的农药施用时间可能会影响最终的残留污染水平。大多数检测结果都来自于最近未在田间使用的化合物，而油菜田的样本比蚕豆田的样本污染更为严重。作物花粉仅受到杀菌剂的污染，蜂蜜蜂花粉负荷主要含有杀菌剂，而熊蜂花粉负荷中则检测到更多的杀虫剂。在熊蜂花粉负荷中观察到了最高数量的化合物和最多的检测结果，其中特别值得注意的是，尽管最近没有在采集样本的田间使用这些化合物，但评估的五种新烟碱类杀虫剂（噻虫胺、噻虫啉、吡虫啉、噻虫嗪和噻虫酰胺）均有检出。新烟碱类杀虫剂的浓度与熊蜂采集的花粉样本中野生植物物种的数量呈正相关，但这种关系不能用蜜蜂来验证。嘧菌酯、苯甲酰菌胺和噻虫嗪是花粉中最常见的农药组合。我们的研究结果表明，蜜蜂可能长期接触多种残留农药，这引发了人们对蜜蜂潜在风险的担忧，并且质疑蜜蜂是否适合作为所有蜜蜂物种的农药风险评估的替代物。
