Science-- there's something for everyone

Saturday, July 7, 2012

Flowers provide bees with a grippy surface


Yesterday, we learned that flowers are specifically colored to attract bees, but that's not the only service flowers provide for their favorite pollinators. Most flower petals contain conical cells that make it easier for bees to grip them. That conical shape is determined by a single gene, called MIXTA. Without this gene, the cells in a flower’s petals will be flat and smooth. 

Katrina Alcom and Beverly Glover from the University of Cambridge and Heather Whitney from the University of Bristol were interested in determining under what conditions bees prefer flowers with conical cells. Could they be induced to favor flat-celled flowers? Yes, they could.

The researchers presented bees with a variety of petunias: normal flowers with conical cells, mutant flowers with flat cells, and dark flowers with conical cells. The last group of flowers is harder for the bees to see. Under normal conditions, the bees preferred the normal flowers. If given the choice between flat-celled flowers and dark flowers, the bees usually prefer the flat-celled flowers, presumably because they're easier to fine. There was one exception however. Under windy conditions (simulated with a shaking platform), bees preferred the hard to see flowers with conical cells.

This means that a variety of cues can influence a bee's choice of flower. If there’s no wind, color plays a more important role in flower selection. If it is windy, they prefer the grippy surface provided by flowers with conical cells.