Some flowers create blue halo to attract bees
Some flowers have found a nifty way to get the blues.
They create a blue halo to attract bees. That's what scientists reported last Wednesday. Flowers need bees for pollination. Bees are drawn to the color blue. But it's hard for flowers to make that color in their petals.
Instead, some flowers use a trick of physics. They produce a blue halo when sunlight strikes a series of tiny ridges in their thin waxy surfaces. The ridges alter how the light bounces back. This affects the color that one sees.
The halos appear over pigmented areas of a flower. People can see them over darkly colored areas if they look from certain angles.
The halo trick is uncommon among flowers. But many tulip species are among those that can do it. Some kinds of daisy and peony species can do it, too. That’s according to Edwige Moyroud. She works at Cambridge University in England.
Moyroud and others analyzed the flower surfaces and used artificial flowers to show that bumblebees can see the halos. The study was published last Wednesday by the journal Nature.
An accompanying commentary said the paper shows how flowers that aren't blue can still use that color to attract bees. Further work should see whether the halo also attracts other insects, wrote Dimitri Deheyn. He is with the Scripps Institution of Oceanography. It is in La Jolla, California.
CRITICAL THINKING QUESTION
Why don’t all flowers do this?
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