Harmful or healthy? Studying how chemicals in nectar and pollen affect bees

Can diseased bees take advantage of antimicrobial chemicals found in plant nectar and pollen and self-medicate?

Bombus terrestris feeds on nectar from purple flowers of Calluna vulgaris (heather)

There is strong evidence of wild pollinator declines in the UK and around the world, with potentially severe impacts on agricultural productivity and ecosystem function, and ultimately, on human health and welfare.

Both man-made and natural pressures impact pollinator health, abundance, and diversity.

These pressures include loss of habitat, pesticide application, and parasites amongst others.

Understanding these factors is increasingly urgent, given the recent emergence of new parasites and diseases in wild and managed pollinators.

Emergent diseases are believed to be behind rapid and dramatic declines in managed honeybees and wild bumblebee populations in North and South America.

Recent work in the UK has shown that honeybee diseases are rapidly emerging in wild bumblebee populations, with potentially devastating implications.

Plant chemicals serve as a defence mechanism to reduce herbivore damage and plant pathogens but can also be stored and used by herbivores to reduce parasitism or control predators.

These plant-produced compounds are also present in nectar and pollen, the food of adult and larval bees, but are relatively poorly studied in terms of their effects on pollinators.  

This project is revealing important antimicrobial effects of nectar metabolites against pathogens and parasites of bees and helping to highlight benefits of floral landscapes for pollinator health rather than simply as food for pollinators. 

  • Background data on the chemical compounds of pollen and nectar in UK plants.
  • Recommendations of plant species that can promote pollinator health in agricultural and urban environments in the UK.

Prof. Mark J.F. Brown, Royal Holloway, University of London

McArt, S. H., Koch, H., Irwin, R. E. & Adler, L. S. (2014)

Arranging the bouquet of disease: floral traits and the transmission of plant and animal pathogens.

Ecology Letters 17: 624-636

Koch, H., Abrol, D. P., Li, J. & Schmid-Hempel, P. (2013)

Diversity and evolutionary patterns of bacterial gut associates of corbiculate bees.

Molecular Ecology 22: 2028-2044

Arnold, S. E. J., Peralta Idrovo, M. E., Lomas Arias, L. J., Belmain, S. R. & Stevenson, P. C. (2014)

Herbivore defence compounds occur in pollen and reduce bumblebee colony fitness.

Journal of Chemical Ecology 40(8): 878-881

Tiedeken, E-J., Egan, P. A., Stevenson, P. C., Wright, G. A., Brown, M. J. F., Power, E. F., Farrell, I., Matthews, S. M. & Stout, J. C. (2015)

Nectar chemistry modulates the impact of invasive plant species on native pollinators.

Functional Ecology (online) DOI: 10.1111/1365-2435.12588