Along with sight and smell, bumblebees can detect flowers via their electric fields. Scientists already knew that as bumblebees fly, their wings generate positively charged static electricity. Flowers usually have a negative charge compared with the air, a difference that helps carry pollen from a flower to a bumblebee pollinating it (shown here). Now, lab tests reveal that bumblebees can learn to distinguish artificial flowers providing a sweet solution and having a certain pattern of electric field from similar artificial blossoms dosed with bitter liquids that sport a distinctly different electric field. These results suggest that the insects can also distinguish among natural flowers by their electric charge, researchers report online in Science. This matters because a flower's charge changes temporarily after a bumblebee visits it, possibly helping other bees avoid a flower that's now low in pollen. Furthermore, the researchers contend, if bumblebees can distinguish among blossoms with a lot or a little nectar, the insects won't be turned off by an entire species of flower after a few low-reward experiences.
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