Threat posed by 'pollen thief' bees uncovered

Date:October 9, 2015

Source:University of Stirling

A new University of Stirling study has uncovered the secrets of 'pollen thief' bees -- which take pollen from flowers but fail to act as effective pollinators -- and the threat they pose to certain plant species.

Flowers often need pollinators, such as bees, to collect and transport pollen to fertilise other flowers and trigger fruit and seed production. In order to attract pollinators, flowers offer resources such as nectar, oils, and pollen in return.

However some bees act as thieves by taking the pollen -- a vital protein source for young bees -- without providing pollination services.

Even plants which have adapted to the threat they pose can suffer from extremely high levels of pollen theft, according to the study.

Dr Mario Vallejo-Marin, an evolutionary biologist at the University of Stirling and senior author of the study, said: "It's a co-evolutionary arms race between plants and bees. Some plants have fortified structures called anthers, where pollen is locked up behind a thick wall. The only way to open these 'pollen vaults' is through small pores at the tips.

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