Bees and flowers share a fundamental connection. Flowers rely on bees for pollination, allowing them to reproduce, and bees depend on flowers for vital sustenance in the form of nectar and pollen. Understanding how bees locate and choose flowers offers insights into this essential ecological partnership.
Bee Vision
Bee vision differs significantly from human vision. Like humans, bees possess trichromatic vision, meaning their eyes have three types of photoreceptors that combine to form their color perception. However, while human vision is based on red, green, and blue light, bees perceive colors based on ultraviolet (UV), blue, and green light. This distinction means that bees cannot see the color red; they typically perceive it as black or gray.
Bees can, however, see reddish wavelengths like yellow and orange. Their visual range spans approximately 300 to 650 nanometers (nm), contrasting with the human range of 390 to 750 nm. The ability to detect UV light provides bees with a distinct advantage in locating nectar, as many flowers display patterns visible only under UV light.
Preferred Flower Colors
Given their unique visual capabilities, bees are most attracted to specific flower colors. They primarily favor flowers in the blue, purple, and violet spectrum, with white and yellow flowers also proving highly attractive due to their distinct UV light reflection. Many flowers feature “nectar guides” or “bee guides,” patterns on their petals often only visible in UV light. These patterns act like visual runways, directing bees toward nectar and pollen sources, increasing foraging efficiency. While bees generally do not see red, some red flowers might still attract them if they possess UV markings or reflect UV light.
Beyond Color Signals
While color is a primary attractant, bees rely on a combination of cues to efficiently locate and identify suitable flowers. Floral scent plays a significant role, with bees using their strong sense of smell to find flowers, especially from a distance. Flowers emit complex mixtures of volatile compounds, with scent levels often highest when ready for pollination.
Flower shape also provides important signals, influencing how easily bees can access nectar and pollen. Flowers with open, bowl-shaped structures offer easy access, while others have specialized shapes like tubes or lips for specific bee species. The availability of pollen itself acts as a direct attractant, as pollen provides essential protein for bees and their larvae. These various cues work in concert with color, creating a comprehensive signaling system that guides bees to their floral rewards.
Planting for Pollinators
Understanding bee preferences allows for more effective planting strategies to support these vital pollinators. To create a bee-friendly garden, it is beneficial to include a variety of flowers that appeal to their specific vision and other senses. Focus on planting flowers in shades of blue, purple, and violet. Incorporating white and yellow flowers, especially those known to have UV patterns, will also draw bees.
Beyond color, select flowers with strong, appealing scents and varied shapes that offer easy access to nectar and pollen. Planting a diverse range of species ensures a continuous bloom throughout the growing season, providing a consistent food source for bees from early spring until late autumn. Avoiding pesticides and opting for native plants further enhances the environment for these crucial insects.