Seeing red

Several sorts of bee were enthusiastically buzzing around this crimson Weigelia on another sunny morning. These carder bees, somewhat smaller than the big bumbles, were forcing themselves into the floral trumpets so tightly that I half expected them to emerge, like a champagne cork, with an audible pop.

The pink version of this shrub is uninspiring but I love the red. I wondered if bees prefer it too.  Well, I checked and found that bees, with their colour vision geared to the ultra-violet end of the spectrum, can't see red at all - they see it as black. However, flower petals can carry UV patterns, visible to bees but not normally to us,  which guide them on to the landing strip and towards the drinking fountain, their fuzzy bottoms collecting pollen grains en route.

Last summer in Amsterdam I bought a packet of tulip bulbs labelled Queen of the Night - they were supposed to be black or as near as dammit (actually deep purple). However it was a complete scam because the flowers turned out red. I should have known better than to buy from a street market. If I were going back to Amsterdam I'd take the label from the packet and complain, demand the genuine article. But the market trader might defend theirself by telling me that the tulips were black - to a bee. 
And they would bee right.

Extra: more flower, more bee.