Chemical ecology of pollen: understanding the impacts of plant secondary metabolism on the health, behaviour and fitness of bee pollinators

Grantham Scholar Upuli I Wickramaarachchi’s research explores the impact of pollen metabolites on the foraging health, fitness and survival of bees.

The project

Most flowering plant species depend on insect pollinators for reproduction. And pollination is also of critical concern for the production of fruit, vegetable and seed crops for human consumption. Recent meta-analyses indicate that over 70% of the top world crops are at least moderately dependent on animal pollinators.

Our dependence on this ‘ecosystem service’, has led to growing concern over declines in the abundance and diversity of wild pollinators, and alarm at the recent collapse of managed pollinators (honeybees, Apis mellifera, and bumblebees, Bombus species).

Pollen is a reward for most bee pollinators and is the main source of primary nutrients for the adults as well as developing larvae. In the wild, a loss of habitat and the homogenisation of plant communities threaten to limit the abundance and diversity of pollen available. Bees forage widely but are known to discriminate among different plants. This discrimination could be due to differences in macronutrient levels (protein, fat) or due to the presence of secondary metabolites: the suite of natural chemical compounds used in a plant’s interactions with other species. Plants produce secondary metabolites as defences against insect herbivores (pests), but there is a growing appreciation that these compounds often occur in flowers, including pollen and nectar used by bees. However, the chemical ecology of pollen is poorly understood. 

My research project is mainly focused on exploring the impact of pollen metabolites on the foraging health, fitness and survival of bees. 

Research groups

Upuli is part of the Campbell Lab: Ecology and evolution of species interactions.

Social media

You can find Upuli on LinkedIn.


Upuli won the award for best presentation at the School of Biosciences Annual 3rd Year Postgraduate Symposium on 9th June. The presentation on her latest research findings was titled ‘Herbivory-inducible pollen defences reduce bee fitness’.