Dipartimento di Scienze e Tecnologie Agro-Alimentari, Alma Mater Studiorum Università di Bologna, Bologna, Italy
CREAF, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Proc Biol Sci. 2018 Aug 22;285(1885):20180887. doi: 10.1098/rspb.2018.0887.
Pollinators in agroecosystems are often exposed to pesticide mixtures. Even at low concentrations, the effects of these mixtures on bee populations are difficult to predict due to potential synergistic interactions. In this paper, we orally exposed newly emerged females of the solitary bee to environmentally realistic levels of clothianidin (neonicotinoid insecticide) and propiconazole (fungicide), singly and in combination. The amount of feeding solution consumed was highest in bees exposed to the neonicotinoid, and lowest in bees exposed to the pesticide mixture. Ovary maturation and longevity of bees of the neonicotinoid and the fungicide treatments did not differ from those of control bees. By contrast, bees exposed to the pesticide mixture showed slow ovary maturation and decreased longevity. We found a synergistic interaction between the neonicotinoid and the fungicide on survival probability. We also found an interaction between treatment and emergence time (an indicator of physiological condition) on longevity. Longevity was negatively correlated to physiological condition only in the fungicide and the mixture treatments. Delayed ovary maturation and premature death imply a shortened nesting period (highly correlated to fecundity in ). Our findings provide a mechanism to explain the observed dynamics of solitary bee populations exposed to multiple chemical residues in agricultural environments.
传粉媒介在农业生态系统中经常会接触到农药混合物。即使在低浓度下，由于潜在的协同作用，这些混合物对蜜蜂种群的影响也难以预测。在本文中，我们对新出现的独居蜜蜂雌蜂进行了口服暴露实验，使其接触到环境现实水平的噻虫嗪（新烟碱类杀虫剂）和丙环唑（杀菌剂），单独和混合接触。接触新烟碱类杀虫剂的蜜蜂摄入的喂食溶液量最高，而接触农药混合物的蜜蜂摄入的喂食溶液量最低。新烟碱类杀虫剂和杀菌剂处理组的蜜蜂的卵巢成熟度和寿命与对照组的蜜蜂没有差异。相比之下，接触农药混合物的蜜蜂的卵巢成熟度较慢，寿命降低。我们发现新烟碱类杀虫剂和杀菌剂在生存概率上存在协同作用。我们还发现处理和出蜂时间（生理状况的一个指标）之间存在相互作用对寿命的影响。只有在杀菌剂和混合物处理组中，寿命与生理状况呈负相关。卵巢成熟延迟和过早死亡意味着筑巢期缩短（与 的繁殖力高度相关）。我们的研究结果提供了一种机制，可以解释在农业环境中接触多种化学残留的独居蜜蜂种群中观察到的动态变化。
