R code for: Following regulation, imidacloprid persists and flupyradifurone increases in non-target wildlife

<b>Abstract</b><br/><p>After regulation of pesticides, determination of their persistence in the environment is an important indicator of effectiveness of these measures. We quantified concentrations of two types of systemic insecticides: neonicotinoids (imidacloprid, acetamiprid, clothianidin, thiacloprid, and thiamethoxam) and butenolides (flupyradifurone), in off-crop non-target media of hummingbird cloacal fluid, honey bee (<em>Apis mellifera</em>) nectar and honey, and wildflowers before and after regulation of imidacloprid on highbush blueberries in Canada in April 2021. We found that mean total pesticide load increased in hummingbird cloacal fluid, nectar, and flower samples following imidacloprid regulation. On average, we did not find evidence of a decrease in imidacloprid concentrations after regulation. However, there were some decreases, some increases and other cases with no changes in imidacloprid levels depending on the specific media, time point of sampling and site type. At the same time, we found an overall increase in flupyradifurone, acetamiprid, thiamethoxam and thiacloprid, but no change in clothianidin concentrations. In particular, flupyradifurone concentrations observed in biota sampled near to agricultural areas increased by 2-fold in honey bee nectar, 7-fold in hummingbird cloacal fluid, and 8-fold in flowers after the 2021 imidacloprid regulation. The highest residue detected in this study was flupyradifurone at 665 ng/mL (PPB) in honey bee nectar. Mean total pesticide loads were highest in honey samples (84 ± 10 PPB) followed by nectar (56 ± 7 PPB), then hummingbird cloacal fluid (1.8 ± 0.5 PPB), and least, flowers (0.51 ± 0.06 PPB). Our results highlight that limited regulation of imidacloprid does not immediately reduce residue concentrations while other systemic insecticides, possibly replacement compounds, concurrently increase in wildlife.</p>

<b>摘要</b><br/><p>在农药实施管控后，评估其在环境中的持留性是衡量该类管控措施有效性的重要指标。本研究针对加拿大2021年4月高丛蓝莓田中吡虫啉限用令实施前后的样本开展检测，定量分析了两类内吸性杀虫剂（systemic insecticides）的浓度：新烟碱类（neonicotinoids，涵盖吡虫啉、啶虫脒、噻虫胺、噻虫啉及噻虫嗪）与丁烯内酯类（butenolides，涵盖氟吡呋喃酮），检测基质包括蜂鸟泄殖腔液、西方蜜蜂（<em>Apis mellifera</em>）花蜜与蜂蜜，以及野生花卉这几类农田外非靶标介质。</p><p>研究结果显示，吡虫啉限用令实施后，蜂鸟泄殖腔液、花蜜及花卉样本中的总农药平均残留量有所上升。整体而言，未观测到吡虫啉浓度在限令实施后出现普遍性下降；但根据具体检测基质、采样时点及样地类型的不同，吡虫啉水平分别呈现下降、上升或无变化三种情况。</p><p>与此同时，本研究发现氟吡呋喃酮、啶虫脒、噻虫嗪及噻虫啉的总残留量整体上升，而噻虫胺的浓度未出现明显变化。具体而言，在农业区域附近采集的生物样本中，2021年吡虫啉限用令实施后，氟吡呋喃酮的浓度在西方蜜蜂花蜜中提升2倍，在蜂鸟泄殖腔液中提升7倍，在花卉样本中提升8倍。本研究中检测到的最高残留为西方蜜蜂花蜜中的氟吡呋喃酮，浓度达665 ng/mL（ppb）。</p><p>各类基质的平均总农药残留量由高到低依次为：蜂蜜（84 ± 10 ppb）、花蜜（56 ± 7 ppb）、蜂鸟泄殖腔液（1.8 ± 0.5 ppb），最低为花卉样本（0.51 ± 0.06 ppb）。</p><p>本研究结果表明，仅针对吡虫啉的有限管控无法立即降低环境中的农药残留水平，而其他可能作为替代药剂的内吸性杀虫剂，在野生生物体内的残留量却同步上升。</p>