Electric Signal

Not just colour, fragrance and shape, flowers also use electric field to attract pollinators. Bumblebees can sense this electric field and use it to recognise nectar-rich blooms. Plants are usually negatively charged and emit weak electric fields, while bees gain a positive charge as they fly through the air. Bee’s landing increases the flower’s electrical charge slightly for a short period of time. This change signals to the next bee that the flower has just been visited and its nectar has been depleted. How the bees detect the electric fields is not yet known but it may be that their hair bristle up under the electrostatic force.

Source

Down To Earth, March 2013