A combination of the frequent fungicides boscalid and dimoxystrobin with the neonicotinoid acetamiprid in field-realistic concentrations does not affect sucrose responsiveness and learning behavior of honeybees

The effect of the fungicide Cantus Gold and the neonicotinoid insecticide Mospilan on the mortality, the responsiveness to sucrose and the learning performance of honeybees was tested. Mortality studies were performed for a low and a high concentration to determine two suitable sublethal doses for behavioral experiments. PER (proboscis extension response) tests and olfactory conditioning were conducted to investigate possible negative synergistic effects of the plant protection products. During the PER tests, a series of sucrose concentrations was presented to the bees and the response was noted (1/0). During conditioning, a rewarded (Nonanol) and a punished odor (Eugenol) were used, which were interchanged during reversal learning. Only bees that reacted to the highest concentration of sucrose water and showed no spontaneous reaction for both odors were conditioned. It was noted when the bee showed a conditioned response. There were no treatment effects on the responsiveness to sucrose and the learning performance.本研究测试了杀菌剂Cantus Gold与新烟碱类杀虫剂Mospilan对蜜蜂死亡率、蔗糖响应能力及学习表现的影响。为筛选出适用于行为实验的两种适宜亚致死剂量，本研究设置低、高两种浓度梯度开展死亡率试验。随后开展喙伸长反应（Proboscis Extension Response, PER）试验与嗅觉条件反射实验，以探究这两类植保产品是否存在潜在负面协同效应。在喙伸长反应试验中，研究人员向蜜蜂依次施加系列梯度蔗糖溶液，并记录其反应（1代表产生反应，0代表无反应）。在条件反射训练阶段，实验采用奖赏性气味（壬醇，Nonanol）与惩罚性气味（丁香酚，Eugenol），并在反转学习环节交换二者的奖惩属性。仅选取对最高浓度蔗糖水溶液产生响应、且对两种气味均无自发反应的蜜蜂开展训练，并记录蜜蜂出现条件反射反应的时刻。本实验结果显示，两种植保药剂对蜜蜂的蔗糖响应能力与学习表现无显著影响。