Big bees do a better job: intraspecific size variation influences pollination effectiveness.

By P. Willmer, Kathryn Finlayson. 2014

97 citations recorded by the source corpus.

Bumblebees (Bombus spp.) are efficient pollinators of many flowering plants, yet the pollen deposition performance of individual bees has not been investigated. Worker bumblebees exhibit large intraspecific and intra-nest size variation, in contrast with other eusocial bees; and their size influences collection and deposition of pollen grains. 2. Laboratory studies with B. terrestris workers and Vinca minor flowers showed that pollination effectiveness PE, as measured from pollen grains deposited on stigmas in single visits (SVD), was significantly positively related to bee size; larger bees deposited more grains, while the smallest individuals, with proportionally shorter tongues, were unable to collect or deposit pollen in these flowers. Individuals did not increase their pollen deposition over time, so handling experience does not influence SVD in Vinca minor. 3. Field studies using Geranium sanguineum and Echium vulgare, and multiple visiting species, confirmed that individual size affects SVD. All bumblebee species showed positive SVD/size effects, though even the smallest individuals did deposit pollen. Apis with its limited size variation showed no such detectable effect when visiting Geranium flowers. Two abundant hoverfly species also showed size effects, particularly when feeding for nectar on Echium. 4. Mean size of foragers also varied diurnally, with larger individuals active earlier and later, so that pollination effectiveness varies through a day; flowers routinely pollinated by bees may best be served by early morning dehiscence and visits from larger individuals. 5. Thus, while there are well-documented species-level variations in pollination effectiveness, the fine-scale individual differences between foragers should also be taken into account when assessing the reproductive outputs of biotically-pollinated plants.

Subfields: Ecology, Evolution, Behavior and Systematics, Insect Science, Plant Science

View Paper: https://www.semanticscholar.org/paper/fc43e23aa906b82e8e0db824a441f601f481694a

How researchers see this paper

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In Ecology, Evolution, Behavior and Systematics

1. Rita Földesi
2. I. Grass
3. P. Batáry
4. J. Ollerton
5. B. Howlett

In Insect Science

1. P. Batáry
2. J. Ollerton
3. B. Howlett

In Plant Science

1. P. Batáry
2. J. Ollerton
3. B. Howlett

Citations in the corpus

• Pollinator Diversity: Distribution, Ecological Function, and Conservation (2017, background): “There is also the added complication of intraspecific variation in pollination ability—for example, large Bombus terrestris individuals deposit more pollen on stigmas per visit, and are also active for longer in the day, than smaller conspecifics (Willmer & Finlayson 2014).”
• Larger pollinators deposit more pollen on stigmas across multiple plant species—A meta‐analysis (2020, background): “This result is in accordance with previous studies which have also shown that larger pollinator species can deposit more pollen onto stigmas than smaller pollinators hence they were found to be more likely to contact the sexual organs of flowers (Ramalho et al., 1998; Willmer & Finlayson, 2014).”