During the winter (beekeeper’s vacation time: I think if you keep bees long enough, you are forced into enjoying winter sports), I was reading Bees: Their Vision, Chemical Senses and Language by Karl Von Frisch. Von Frisch was the scientist who discovered how bees communicate through dancing. He also did work with bees and color, and contributed to what is known about what colours bees can perceive. It’s interesting to think about what colours bees can see, and how that relates to their favorite flowers; Von Frisch says that bees can see yellow, blue-green, blue, and ultraviolet. But, there are many great nectar sources that have white flowers (blackberry, horse chesnut, apple etc.). Previously (until five minutes ago, when I cracked the book again), I thought this meant that bees can see white excellently, too. But actually, as Von Frisch points out, “white” coloured light contains all the colours in the spectrum visible to us, because you can split it through a prism into ROY G. BIV. For bees, “white”, then, would be composed of all the colours they can see, (YGBU!). If one component, ultraviolet (which humans cannot see) is taken away, what is leftover would no longer appear white to a bee, and would be a complementary colour to ultraviolet, maybe blue-green, Von Frisch suggest. And it turns out, most white flowers in fact absorb ultraviolet light.
So! All along, I’ve been painting some of my bee boxes white because I think they will be able to see it well, and it turns out that maybe yes, that particular white paint may absorb ultraviolet rays, leaving behind the complementary colour to ultraviolet, which bees can see great. But also, maybe the white paint I select may instead reflect ultraviolet, making it a true “white” to the bee, and therefore uninteresting and not memorable (as discovered by Dr. Mathilde Hertz).
Unfortunately, I can’t see ultraviolet, so there is sadly no way for me to tell the difference when I’m buying my paint from the hardware store!
All this is to say, before I got sidetracked, is that bees cannot see red. They only perceive it as black. So today, when I wanted to open my queen box to check on the queens, and I knew there would be stray loose bees inside, I took it into the bathroom, turned off the lights, and used Liam’s headlamp on the red-light setting (because it is frowned on in our household to release bees inside. It is also apparently not done to set down nucs right next to the front door, no matter how short a time one plans to leave there).
So cool! Bees don’t fly if it’s dark, and it’s the neatest thing to be looking at bees in the red light, and them not being able to see, so they don’t fly up at you.
Here’s a pic of horse chestnut, a fantastic bee tree:
It produces spiky balls for kids to throw at each other, and has an amazing scarlet coloured pollen. Some varieties have pinkish red flowers, but most trees have these massive cones of white flowers: