Chronic oral exposure to field-realistic pesticide combinations via pollen and nectar: effects on feeding and thermal performance in a solitary bee
Chronic oral exposure to field-realistic pesticide combinations via pollen and nectar: effects on feeding and thermal performance in a solitary bee
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DOI：
10.1038/s41598-019-50255-4
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发表时间：
2019-09-24
影响因子：
4.6
通讯作者：
Sgolastra, Fabio
中科院分区：
文献类型：
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作者：
Azpiazu, Celeste;Bosch, Jordi;Sgolastra, Fabio
农药的使用是农业生态系统中授粉昆虫减少的主要原因之一。传统上，大多数蜜蜂生态毒理学实验室研究都测试单一化合物的急性暴露。然而，在野外条件下，蜜蜂经常长期接触多种化学物质，具有潜在的协同效应。我们研究了在商业瓜田的花粉和花蜜中测量的三种农药的田间实际浓度对独居蜂 Osmia bicornis L 的影响。我们通过花粉和糖浆，在该物种的雌性蜂的整个生命周期中，口服暴露于 8 种结合了两种新烟碱类杀虫剂（啶虫脒、吡虫啉）和三唑类杀菌剂（腈菌唑）的治疗方法。我们测量了花粉和糖浆的消耗、寿命、卵巢成熟和产热作用。通过糖浆摄入的农药比花粉摄入量高三个数量级。在测试浓度下，没有出现协同效应，我们发现对寿命和卵巢成熟没有影响。然而，所有含有吡虫啉的处理都会导致糖浆消耗受到抑制，胸腔温度和蜜蜂活动急剧下降。我们的结果对农药监管具有重要意义。如果我们只测量致死效应，我们就会错误地得出结论：含有吡虫啉的农药组合对双角螟是安全的。当务之急是在蜜蜂风险评估计划中纳入专门用于检测亚致死效应的测试。通过这种方式，可以更好地评估农药暴露对农业生态系统中蜜蜂种群动态的影响。
Pesticide use is one of the main causes of pollinator declines in agricultural ecosystems. Traditionally, most laboratory studies on bee ecotoxicology test acute exposure to single compounds. However, under field conditions, bees are often chronically exposed to a variety of chemicals, with potential synergistic effects. We studied the effects of field-realistic concentrations of three pesticides measured in pollen and nectar of commercial melon fields on the solitary bee Osmia bicornis L. We orally exposed females of this species throughout their life span to 8 treatments combining two neonicotinoid insecticides (acetamiprid, imidacloprid) and a triazole fungicide (myclobutanil) via pollen and sugar syrup. We measured pollen and syrup consumption, longevity, ovary maturation and thermogenesis. Pesticide intake was three orders of magnitude higher via syrup than pollen. At the tested concentrations, no synergistic effects emerged, and we found no effects on longevity and ovary maturation. However, all treatments containing imidacloprid resulted in suppressed syrup consumption and drastic decreases in thoracic temperature and bee activity. Our results have important implications for pesticide regulation. If we had measured only lethal effects we would have wrongly concluded that the pesticide combinations containing imidacloprid were safe to O. bicornis. The incorporation of tests specifically intended to detect sublethal effects in bee risk assessment schemes should be an urgent priority. In this way, the effects of pesticide exposure on the dynamics of bee populations in agroecosystems will be better assessed.