Measurement of electric charges on foraging bumblebees (Bombus terrestris)

Abstract

Bumblebees carry electric charge. Almost always positive, this charge facilitates pollen transfer between bumblebee and flower during pollination and is likely to play a role in the detection of electric fields. Models of the Coulomb forces acting on pollen grains during pollination are predominantly based upon laboratory measurements of bumblebee charge. Using a novel method, the charges on bumblebees are measured outdoors for the first time. Outdoor bumblebees are found to carry similar positive charges to those previously measured in the laboratory. Bee charge is affected by local weather conditions, with the most positive charges being found on bees flying in warm, dry conditions. Results show that bee charges used in previous models of pollen transfer are representative of wild foraging bumblebees, and that pollen transfer between bee and flower is likely to be affected by local weather conditions.