Pollen Foraging Strategies in Solitary Bees

Solitary bees display a remarkable diversity of pollen foraging strategies that balance the nutritional requirements of larvae with the morphological and chemical defences of pollen sources. Individual females collect pollen on specialised hairs (scopae) or in abdominal brushes, employing behaviours such as scraping, buzzing, rubbing and tapping to dislodge grains. Foraging ranges and floral fidelity vary from strict specialists that harvest pollen from a single host genus to broad generalists that exploit dozens of plant families. Specialisation often reflects adaptations to host pollen chemistry—such as tolerance to defensive compounds or spines—while generalists exhibit behavioural plasticity, combining multiple collection techniques in response to flower morphology. These strategies have broad ecological implications, affecting plant–pollinator networks, larval development, habitat management and the resilience of wild bee communities to environmental change. Understanding the interplay of behavioural repertoire, pollen traits and host‐plant availability is essential for conserving solitary bees and for designing agri-environment schemes that support diverse pollinator assemblages.

Research from Nature Portfolio

Seminal work on pollen chemistry has shown that evolutionary host-shifts in solitary bee lineages are mediated by primary nutritional content rather than floral scent or colour, indicating that shared amino acid and sterol profiles can guide saltation between unrelated hosts. Complementary investigations into specialist solitary bees foraging on economically important crops have revealed that these bees tolerate mechanical and chemical pollen defences of their hosts, while generalist social bees avoid such pollen due to physiological costs. Together, these studies underscore the role of intrinsic adaptations in determining host fidelity, larval performance and the co-evolutionary dynamics of bee–plant interactions.

Pollen Foraging Strategies in Solitary Bees publication trend

The graph below shows the total number of articles in pollen foraging strategies in solitary bees across all publications each year (not limited to Nature Index journals).

Technical terms

Scopa: specialised hairs or brushes on a bee’s body for transporting pollen.
Oligolecty: foraging strategy in which a bee collects pollen from a narrow range of related plant taxa.
Polylecty: foraging strategy in which a bee collects pollen from a wide range of unrelated plant species.
Buzz pollination: vibrational pollen-release method using thoracic muscle contractions to extract pollen from poricidal anthers.
Host‐saltation: evolutionary shift between unrelated host plants driven by shared pollen nutritional traits.

References

1. Pollen chemical and mechanical defences restrict host-plant use by bees. Proceedings of the Royal Society B (2024).
2. A review and updated classification of pollen gathering behavior in bees (Hymenoptera, Apoidea). Journal of Hymenoptera Research (2019).
3. How wild bees find a way in European cities: Pollen metabarcoding unravels multiple feeding strategies and their effects on distribution patterns in four wild bee species. Journal of Applied Ecology (2021).
4. The importance of pollen chemistry in evolutionary host shifts of bees. Scientific Reports (2017).
5. Pollen defenses negatively impact foraging and fitness in a generalist bee (Bombus impatiens: Apidae). Scientific Reports (2020).