Floral resources can be recognized by visitors through attractants that signal their presence. However, besides petals, it is still unclear how floral elements in heterantherous species are perceived by visiting bees. In this study, we aim to understand the role of stamens and petals of Pleroma granulosum and P. raddianum in attracting pollination bees, mainly by evaluating whether pollinator behaviour differs in response to different sized stamens between which there is no apparent colour contrast. Using colour visual models, we estimated bee colour discrimination between stamen sets and corolla in both species and carried out preference experiments among floral elements, using the bees Bombus morio and Xylocopa frontalis as models in the field. Pollination and feeding stamens are not discriminable by bees in both plant species. Bees only preferred flowers with petals, indicating that they are essential to long-distance attraction. During preferential tests, bees seemed to better respond to visual stimuli on the right side, suggesting lateralization. We also demonstrate that tactile stimulation by the anthers is necessary to trigger bee buzzing behaviour. Thus, since bees were not specifically attracted to any stamen set, heteranthery without colour differences between stamens is not enough to determine bee choice behaviour.

访客可以通过表明其存在的吸引剂来识别花卉资源。然而，除花瓣外，尚不清楚如何通过拜访蜂来感知异花科物种中的花卉元素。在这项研究中，我们旨在通过评估传粉媒介的行为是否因不同大小的雄蕊的响应而不同（两者之间没有明显的颜色对比）来理解颗粒毛虫和radradum的雄蕊和花瓣在吸引授粉蜜蜂中的作用。使用彩色视觉模型，我们估计了两个物种的雄蕊集和花冠之间的蜜蜂颜色区分，并使用蜜蜂Bombus morio和Xylocopa frontalis进行了花艺元素之间的偏好实验。作为该领域的模型。在这两种植物中，蜜蜂都无法区分授粉和觅食雄蕊。蜜蜂只喜欢带有花瓣的花朵，这表明它们对于长距离吸引至关重要。在优先测试中，蜜蜂似乎对右侧的视觉刺激有更好的反应，提示其侧向化。我们还证明了花药的触觉刺激对于触发蜂鸣声行为是必要的。因此，由于蜜蜂没有被特定的雄蕊所吸引，因此没有雄蕊间颜色差异的杂种动物的养育方法不足以决定蜜蜂的选择行为。