Bumblebees can Identify Flowers with Good Quality Nectar Even Before Landing

Bumblebees assess pollen quality using floral characteristics such as petal color and shape, a new study reveals.

Bees don't eat pollen while foraging, so researchers weren't sure if bumblebees actually form associative relationships between quality of pollen and flowers.

The study by researchers at the University of Exeter and colleagues shows that bumblebees don't just mindlessly move from one flower to another collecting pollen and nectar, but actually spot flowers that will provide good quality nectar even before they land on them.

"There is still very little known about how bees decide which flowers to visit for pollen collection. Easily learning floral features based on pollen rewards, without needing any nectar rewards, is a fast and effective way to recognise those flower species which bees have previously experienced to be the best ones," said Dr Elizabeth Nicholls, a Post Doctoral Research Fellow at the University of Sussex, according to a news release.

For the study, researchers conducted lab experiments to find how well the bees recognize good-quality pollen. The experiments were based on bumblebees kept under control conditions.

The team manipulated pollen quality by diluting the samples. The researchers wanted to find whether bees could differentiate between pollen quality just by seeing and smelling the samples or not. The team placed the pollen samples on brightly colored discs to see if the bees learn to pick good quality pollen by looking at the color of the disc.

The research shows that bumblebees make quick, informed decisions about pollen quality. The ability to learn and assess nectar reward based on pollen quality helps the bees forage efficiently.

The study is also important because it shows that bees rely on their learning abilities to assess floral characteristics. Pesticides such as neonicotinoids could affect bees' foraging behavior and lead to long-term damage to bumblebee population.

The study is published in the Journal of Experimental Biology.