Department of Biology, University of Florence, Via Madonna del Piano, 6, 50019, Sesto Fiorentino, Italy.
Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
Sci Rep. 2020 Nov 16;10(1):19929. doi: 10.1038/s41598-020-76852-2.
The entomopathogenic fungus Beauveria bassiana is a widely used biopesticide that is considered as an effective alternative to classical agrochemicals. B. bassiana is thought to be safe for pollinators although little is known about its side-effects on pollinators' behaviour and cognition. Here, we focused on honey bees and used the proboscis extension response (PER) protocol to assess whether B. bassiana affects individual sucrose responsiveness, non-associative and associative olfactory learning and memory. Fungus-treated bees displayed an enhanced sucrose responsiveness, which could not be explained by metabolic alterations. Strikingly, exposed bees were twice as inconsistent as controls in response to sucrose, showing PER to lower but not to higher sucrose concentrations. Exposed bees habituated less to sucrose and had a better acquisition performance in the conditioning phase than controls. Further, neither mid- nor long-term memory were affected by the fungus. As sucrose responsiveness is the main determinant of division of foraging labour, these changes might unsettle the numerical ratio between the sub-castes of foragers leading to suboptimal foraging. Although the use of biocontrol strategies should be preferred over chemical pesticides, careful assessment of their side-effects is crucial before claiming that they are safe for pollinators.
球孢白僵菌是一种广泛应用的生物农药，被认为是传统农用化学品的有效替代品。尽管人们对球孢白僵菌对传粉者行为和认知的副作用知之甚少，但它被认为对传粉者是安全的。在这里，我们专注于蜜蜂，使用触角延伸反应（PER）协议来评估球孢白僵菌是否会影响个体对蔗糖的反应性、非联想和联想嗅觉学习和记忆。真菌处理过的蜜蜂对蔗糖的反应性增强，这不能用代谢改变来解释。引人注目的是，与对照相比，暴露于真菌的蜜蜂对蔗糖的反应不一致性是对照的两倍，对较低但不是较高的蔗糖浓度有 PER 反应。暴露于真菌的蜜蜂对蔗糖的习惯形成较少，在条件作用阶段的获得性能更好。此外，中期和长期记忆都不受真菌的影响。由于蔗糖反应性是觅食劳动分工的主要决定因素，这些变化可能会破坏觅食者亚群之间的数量比例，导致觅食效果不佳。虽然应该优先使用生物防治策略而不是化学农药，但在声称它们对传粉者安全之前，必须仔细评估它们的副作用。
