Researchers at Bristol's School of Biological Sciences have discovered that flowers are able to communicate with bumblebees and maybe other species, including humans, through electricity.
The study was published in the journal Science, and describes how, whereas bumblebees have a positive electrical charge, flowers tend to have a negative one. Electricity is conducted slowly through plants, which have an electrical connection to the ground.
"We just now have discovered that electrical potentials, an unavoidable by-product of flying in air for bumblebees and being grounded for the flower, are being exploited to benefit both parties," co-author of the study, Daniel Robert, told Discovery News. It's "another example of the beauty of evolution."
Robert and other scientists conducted the study by placing petunia flowers in an area populated by free-flying foraging bees. They then examined changes in the electric fields and the bees' behavior as a result of interactions between the two groups. Results of the experiment indicated that an electrical field was generated by a bee landing on one of the flowers. The resulting force seemingly improves the bee's memory of the flower's pollen and nectar supply, while also leaving the flower with a charge for a short time thereafter.
"This novel communication channel reveals how flowers can potentially inform their pollinators about the honest status of their precious nectar and pollen reserves," Robert said. "The last thing a flower wants is to attract a bee and then fail to provide nectar; a lesson in honest advertising since bees are good learners and would soon lose interest in such an unrewarding flower."
It is well known that flowers use bright colors, patterns and fragrance to attract pollinators, but the idea of electrical communication is a new development. It was also found that bees in the study were able to distinguish colors more quickly in the presence of electrical signals.
"The co-evolution between flowers and bees has been a long and beneficial history," Robert said, "so perhaps it's not entirely surprising that we are still discovering today how remarkably sophisticated their communication is."