The diversity of floral temperature patterns, and their use by pollinators

Pollinating insects utilise various sensory cues to identify and learn rewarding flower species. One such cue is floral temperature, created by captured sunlight or plant thermogenesis. Bumblebees, honeybees and stingless bees can distinguish flowers based on differences in overall temperature between flowers. We report here that floral temperature often differs between different parts of the flower creating a temperature structure or pattern. Temperature patterns are common, with 55% of 118 plant species thermographed, showing within-flower temperature differences greater than the 2°C difference that bees are known to be able to detect. Using differential conditioning techniques, we show that bumblebees can distinguish artificial flowers differing in temperature patterns comparable to those seen in real flowers. Thus, bumblebees are able to perceive the shape of these within-flower temperature patterns. Floral temperature patterns may therefore represent a new floral cue that could ass...

传粉昆虫会借助多种感官线索识别并习得具有奖赏性的花卉类群。其中一类关键线索为花部温度，其热源可来自植株捕获的太阳光，或是植物自身的产热作用。熊蜂、蜜蜂与无刺蜂均可依据不同花卉间的整体温度差异区分花朵。本研究报道，花部不同部位间往往存在温度差异，进而形成温度结构或温度模式。此类温度模式十分普遍：在经热成像测温的118种植物中，有55%的物种其花内温度差大于已知蜜蜂可察觉的2℃温差。我们采用差异条件化技术开展实验，结果显示熊蜂能够区分温度模式与真实花卉温度模式相近的人工花朵。由此可见，熊蜂可感知这类花内温度模式的空间形态。因此，花部温度模式或许可作为一类全新的花卉线索，其可能……