Bacteria in flowers repellent for bumblebees
Flowers are colonized by bacteria and yeasts, which can also be found in the nectar of the flowers. A German and Austrian team now found indications that bumblebees may avoid nectar with high densities of bacteria (doi: 10.1007/s13592-013-0262-1). In laboratory experiments, a sugar solution was accepted so much the less, the higher the density of bacteria was. The authors assume that high bacteria densities in flowers can negatively influence the pollinator visitation frequency and, hence, also the reproduction of the flowers.