Visible light to bees, when compared to humans, is more towards the short waved lengths.
That is, they see more yellow, blue, violet and ultraviolet. They don’t generally see red (see Fig. 1). Therefore, what they see in your garden is different from what you see. Because flowering plants co-evolved with bees they are designed to be attractive to bees and not humans. Therefore UV photography often shows much prettier flowers (see Fig. 2).
Here is a challenge to some of our great photographers. What about posting on Candide, South Africa’s floral biodiversity as bees see it? #UVphoto
What flowers do bees like best?
I have spent over 40 years collecting bees, mostly in South Africa but also in other southern African and East African countries. My opinion is that yellow flowers are most attractive to bees. Larger bees, like large carpenter bees and leafcutter bees, like big yellow legumes, small carpenter bees like little yellow daisies.
My favourite bee tree is the PWeeping Wattle. On a hot summer day in Limpopo, one can hear the bees buzzing around the tree before one sees the tree. As the colour wheel suggests blue and purple flowers are attractive, but large carpenter bees also like purple legumes, like Virgilia Blossom Tree. White is also attractive.
As always there are exceptions and here they are worth pointing out. Some Diascia are red and pink, and they are only pollinated by the Oil-Collecting Bees. Aloe is commonly visited by many different species of bees and cellophane bees frequently visit red lilies and proteas. I do not know if some bees see red, because the bee colour spectrum is that of the honeybee, or that UV patterns emerge from the red and pink petals. I think the bottom line is that we can be sure that bees are not seeing what we see.
That said, what do male bees see? Because some male carpenter bees have big eyes and all they do is look for female bees, I photographed black female carpenter bees with a UV filter. They did not show any UV patterns, unfortunately.