School of Life Sciences, Arizona State University, Tempe, AZ, USA.
Sci Rep. 2023 Nov 9;13(1):19458. doi: 10.1038/s41598-023-46948-6.
Managed honey bees have experienced high rates of colony loss recently, with pesticide exposure as a major cause. While pesticides can be lethal at high doses, lower doses can produce sublethal effects, which may substantially weaken colonies. Impaired learning performance is a behavioral sublethal effect, and is often present in bees exposed to insecticides. However, the effects of other pesticides (such as fungicides) on honey bee learning are understudied, as are the effects of pesticide formulations versus active ingredients. Here, we investigated the effects of acute exposure to the fungicide formulation Pristine (active ingredients: 25.2% boscalid, 12.8% pyraclostrobin) on honey bee olfactory learning performance in the proboscis extension reflex (PER) assay. We also exposed a subset of bees to only the active ingredients to test which formulation component(s) were driving the learning effects. We found that the formulation produced negative effects on memory, but this effect was not present in bees fed only boscalid and pyraclostrobin. This suggests that the trade secret "other ingredients" in the formulation mediated the learning effects, either through exerting their own toxic effects or by increasing the toxicities of the active ingredients. These results show that pesticide co-formulants should not be assumed inert and should instead be included when assessing pesticide risks.
管理的蜜蜂最近经历了很高的蜂群损失率，而农药暴露是一个主要原因。虽然高剂量的农药可能是致命的，但低剂量的农药可以产生亚致死效应，这可能会严重削弱蜂群。学习能力下降是一种行为亚致死效应，经常出现在接触杀虫剂的蜜蜂中。然而，其他农药（如杀菌剂）对蜜蜂学习的影响研究较少，农药制剂与有效成分的影响也研究较少。在这里，我们研究了杀菌剂制剂 Pristine（有效成分：25.2%肟菌酯，12.8%吡唑醚菌酯）急性暴露对蜜蜂嗅觉学习能力的影响，在探鼻反射（PER）试验中。我们还使一部分蜜蜂只接触有效成分，以测试是哪种制剂成分（或成分组合）导致了学习效果。我们发现，该制剂对记忆产生了负面影响，但只接触肟菌酯和吡唑醚菌酯的蜜蜂没有这种影响。这表明制剂中的商业秘密“其他成分”通过发挥其自身的毒性作用或增加有效成分的毒性来调节学习效果。这些结果表明，不应假设农药共制剂是惰性的，在评估农药风险时应将其包括在内。
