Programa de Pós-Graduação em Entomologia, Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
Departamento de Fisiologia, Universidade de São Paulo, São Paulo, SP, Brazil.
Sci Total Environ. 2024 Nov 20;952:175892. doi: 10.1016/j.scitotenv.2024.175892. Epub 2024 Aug 31.
The global decline of pollinators has become a major concern for the scientific community, policymakers, and the general public. Among the main drivers of diminishing bee populations is the widespread use of agrochemicals. To gain a comprehensive understanding of the foraging dynamics of bees at agrochemical-contaminated areas, it is essential to consider both environmental conditions and the specific foraging ecology of bee species. For the first time, we conducted a semi-field study to investigate whether stingless bees exhibit a preference for food contaminated with agrochemicals compared to non- contaminated food, under natural weather conditions. Colonies of Plebeia lucii Moure, 2004 were placed in a greenhouse and subjected to a preference test, where bees were given the freedom to choose between contaminated or non-contaminated food sources following a preliminary training period. Within the greenhouse, we placed feeders containing realistic concentrations of an insecticide (acephate: 2 mg a.i./L), a herbicide (glyphosate: 31.3 mg a.i./L), or a mixture of both, alongside non-contaminated food. Environmental variables (temperature, humidity, and light intensity) were monitored throughout the experiment. At higher temperatures, the foragers preferred food containing the mixture of both agrochemicals or uncontaminated food over the other treatments. At lower temperatures, by contrast, the bees preferred food laced with a single agrochemical (acephate or glyphosate) over uncontaminated food or the agrochemical mixture. Our findings indicate that agrochemical residues in nectar pose a significant threat to P. lucii colonies, as foragers do not actively avoid contaminated food, despite the detrimental effects of acephate and glyphosate on bees. Furthermore, we demonstrate that even minor, natural fluctuations in environmental conditions can alter the colony exposure risk. Despite the interplay between temperature and bees' preference for contaminated food, foragers consistently collected contaminated food containing both agrochemicals, whether isolated or in combination, throughout the whole experiment.
传粉媒介的全球减少已成为科学界、政策制定者和公众的主要关注点。蜜蜂数量减少的主要原因之一是农用化学品的广泛使用。为了全面了解受农用化学品污染地区蜜蜂的觅食动态，必须考虑环境条件和蜜蜂物种的特定觅食生态。我们首次进行了半野外研究，以调查在自然天气条件下，无刺蜜蜂是否会对受农用化学品污染的食物表现出偏好，而不是非污染食物。我们将 Plebeia lucii Moure, 2004 的殖民地放在温室中，并进行了偏好测试，在初步培训期后，蜜蜂可以自由选择受污染或未受污染的食物来源。在温室中，我们放置了含有真实浓度杀虫剂（乙酰甲胺磷：2 毫克有效成分/升）、除草剂（草甘膦：31.3 毫克有效成分/升）或两者混合物的饲养器，以及未受污染的食物。整个实验过程中监测环境变量（温度、湿度和光照强度）。在较高温度下，觅食者更喜欢含有两种农用化学品混合物或未受污染的食物，而不是其他处理方式。相比之下，在较低温度下，蜜蜂更喜欢含有单一农用化学品（乙酰甲胺磷或草甘膦）的食物，而不是未受污染的食物或农用化学品混合物。我们的研究结果表明，花蜜中的农用化学品残留对 P. lucii 殖民地构成了重大威胁，因为觅食者并没有主动避免受污染的食物，尽管乙酰甲胺磷和草甘膦对蜜蜂有有害影响。此外，我们还证明，即使环境条件发生微小的自然波动，也会改变殖民地的暴露风险。尽管温度和蜜蜂对受污染食物的偏好之间存在相互作用，但在整个实验过程中，觅食者始终一致地收集含有两种农用化学品的受污染食物，无论是单独存在还是组合存在。
