The evolution of flower-visiting behaviour in pollen wasps remains poorly investigated. The females of oligolectic Celonites species show two fundamentally different behavioural patterns for pollen uptake from Heliotropium flowers with a narrow corolla tube. They remove pollen from the concealed anthers either with their forelegs or with their proboscis. Single-frame video analysis revealed that pollen collection with the proboscis consists of a hitherto unknown, unique, and stereotypic behavioural pattern. The first phylogenetic reconstruction of Celonites based on ultra-conserved elements demonstrates that this highly complex behaviour is presumably homologous and evolved only once. It probably derived from accidental consumption of pollen adhering to the proboscis during nectar uptake and is associated with morphological adaptations of the foretarsi and mouthparts. Pollen uptake with the forelegs evolved independently. Morphological adaptations to this type of pollen uptake are the elongation of the forelegs and a tarsal pollen brush formed by hooked setae. These results confirm for pollen wasps a view that has been developed in studies of bee–flower relationships, namely that pollen collection, contrary to nectar collection, is a specific and stereotypic behaviour that often requires morphological and behavioural adaptations, possibly underlying the high rate of specialization observed in pollen-collecting Hymenoptera.

中文翻译：

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Celonites属（膜翅目：Vespidae：Masarinae）花粉中花粉吸收花粉的不同适应进化


花粉蜂访花行为的演变仍然研究不足。寡聚 Celonites 物种的雌性表现出两种根本不同的行为模式，用于从具有窄花冠管的 Heliotropium 花中吸收花粉。它们用前腿或长鼻从隐藏的花药中去除花粉。单帧视频分析显示，带有喙的花粉收集由迄今为止未知的、独特的和刻板的行为模式组成。基于超保守元素的 Celonites 的首次系统发育重建表明，这种高度复杂的行为可能是同源的，并且只进化了一次。它可能源于在花蜜吸收过程中意外食用粘附在喙上的花粉，并且与前跗骨和口器的形态适应有关。前腿的花粉吸收是独立进化的。对这种花粉吸收的形态适应是前腿的伸长和由钩状花序形成的跗花粉刷。这些结果证实了花粉蜂在蜜蜂-花关系研究中形成的观点，即花粉收集，与花蜜收集相反，是一种特定的刻板行为，通常需要形态和行为适应，这可能是在花粉收集膜翅目中观察到的高专业化率的基础。