School of Life Sciences, Arizona State University, Tempe, Arizona.
Department of Evolutionary Biology, University of California at Los Angeles, Los Angeles, California.
J Anim Ecol. 2019 Feb;88(2):236-246. doi: 10.1111/1365-2656.12911. Epub 2018 Nov 2.
Animals must effectively balance the time they spend exploring the environment for new resources and exploiting them. One way that social animals accomplish this balance is by allocating these two tasks to different individuals. In honeybees, foraging is divided between scouts, which tend to explore the landscape for novel resources, and recruits, which tend to exploit these resources. Exploring the variation in cognitive and physiological mechanisms of foraging behaviour will provide a deeper understanding of how the division of labour is regulated in social insect societies. Here, we uncover how honeybee foraging behaviour may be shaped by predispositions in performance of latent inhibition (LI), which is a form of non-associative learning by which individuals learn to ignore familiar information. We compared LI between scouts and recruits, hypothesizing that differences in learning would correlate with differences in foraging behaviour. Scouts seek out and encounter many new odours while locating novel resources, while recruits continuously forage from the same resource, even as its quality degrades. We found that scouts show stronger LI than recruits, possibly reflecting their need to discriminate forage quality. We also found that scouts have significantly elevated tyramine compared to recruits. Furthermore, after associative odour training, recruits have significantly diminished octopamine in their brains compared to scouts. These results suggest that individual variation in learning behaviour shapes the phenotypic behavioural differences between different types of honeybee foragers. These differences in turn have important consequences for how honeybee colonies interact with their environment. Uncovering the proximate mechanisms that influence individual variation in foraging behaviour is crucial for understanding the ecological context in which societies evolve.
动物必须有效地平衡它们在探索环境中新资源和开发利用这些资源上所花费的时间。社会动物实现这种平衡的一种方法是将这两项任务分配给不同的个体。在蜜蜂中，觅食分为侦察蜂和采集蜂，前者倾向于在景观中探索新的资源，后者倾向于利用这些资源。探索觅食行为的认知和生理机制的变化将深入了解劳动分工在社会昆虫社会中是如何调节的。在这里，我们揭示了蜜蜂觅食行为可能如何受到潜伏抑制（LI）表现的倾向的影响，LI 是一种非联想学习形式，通过这种形式，个体学会忽略熟悉的信息。我们比较了侦察蜂和采集蜂之间的 LI，假设学习的差异与觅食行为的差异相关。侦察蜂在寻找和遇到新资源时会寻找并遇到许多新气味，而采集蜂则不断地从同一资源中觅食，即使其质量下降。我们发现侦察蜂比采集蜂表现出更强的 LI，这可能反映了它们对觅食质量的辨别能力。我们还发现侦察蜂的酪胺水平明显高于采集蜂。此外，在关联气味训练后，与侦察蜂相比，采集蜂大脑中的章鱼胺明显减少。这些结果表明，学习行为的个体差异塑造了不同类型的蜜蜂觅食者之间表型行为差异。这些差异反过来又对蜜蜂群体与环境的相互作用产生重要影响。揭示影响觅食行为个体差异的近似机制对于理解社会进化所处的生态背景至关重要。
