Bumblebees are among the most important wild bees for pollination of crops and securing wildflower diversity. However, their abundance and diversity have been on a steady decrease in the last decades. One of the most important factors leading to their decline is the frequent use of plant protection products (PPPs) in agriculture, which spread into forests and natural reserves. Mixtures of different PPPs pose a particular threat because of possible synergistic effects. While there is a comparatively large body of studies on the effects of PPPs on honeybees, we still lack data on wild bees. We here investigated the influence of the frequent fungicide Cantus® Gold (boscalid/dimoxystrobin), the neonicotinoid insecticide Mospilan® (acetamiprid) and their combination on bumblebees. Cognitive performance and foraging flights of bumblebees were studied. They are essential for the provisioning and survival of the colony. We introduce a novel method for testing four treatments simultaneously on the same colony, minimizing inter-colony differences. For this, we successfully quartered the colony and moved the queen daily between compartments. Bumblebees appeared astonishingly resilient to the PPPs tested or they have developed mechanisms for detoxification. Neither learning capacity nor flight activity were inhibited by treatment with the single PPPs or their combination.

中文翻译：

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熊蜂对新烟碱类杀菌剂组合具有抵抗力

熊蜂是农作物授粉和确保野花多样性最重要的野生蜜蜂之一。然而，在过去的几十年里，它们的丰富度和多样性一直在稳步下降。导致其下降的最重要因素之一是农业中植物保护产品（PPP）的频繁使用，并蔓延到森林和自然保护区。由于可能产生协同效应，不同 PPP 的混合构成了特殊的威胁。虽然关于 PPP 对蜜蜂影响的研究相对较多，但我们仍然缺乏有关野生蜜蜂的数据。我们在此研究了常用杀菌剂 Cantus® Gold（啶酰菌胺/丁氧菌酯）、新烟碱类杀虫剂 Mospilan®（啶虫脒）及其组合对熊蜂的影响。研究了熊蜂的认知表现和觅食飞行。它们对于殖民地的供给和生存至关重要。我们引入了一种新方法，可以在同一菌落上同时测试四种处理方法，最大限度地减少菌落间差异。为此，我们成功地将蜂群分成四份，并每天在隔间之间移动蜂王。大黄蜂对所测试的 PPP 表现出惊人的抵抗力，或者说它们已经开发出了解毒机制。单一 PPP 或其组合的治疗不会抑制学习能力和飞行活动。