Foraging strategies are maintained despite workforce reduction: A multidisciplinary survey on the pollen collected by a social pollinator

Autoři: Paolo Biella aff001;  Nicola Tommasi aff001;  Asma Akter aff002;  Lorenzo Guzzetti aff001;  Jan Klecka aff001;  Anna Sandionigi aff001;  Massimo Labra aff001;  Andrea Galimberti aff001
Působiště autorů: University of Milano-Bicocca, Department of Biotechnology and Biosciences, Milan, Italy aff001;  University of South Bohemia, Faculty of Science, Department of Zoology, České Budějovice, Czech Republic aff002;  Czech Academy of Sciences, Biology Centre, Institute of Entomology, České Budějovice, Czech Republic aff003
Vyšlo v časopise: PLoS ONE 14(11)
Kategorie: Research Article
doi: 10.1371/journal.pone.0224037


The way pollinators gather resources may play a key role for buffering their population declines. Social pollinators like bumblebees could adjust their foraging after significant workforce reductions to keep provisions to the colony optimal, especially in terms of pollen diversity and quantity. To test what effects a workforce reduction causes on the foraging for pollen, commercially-acquired colonies of the bumblebee Bombus terrestris were allowed to forage in the field and they were experimentally manipulated by removing half the number of workers. For each bumblebee, the pollen pellets were taxonomically identified with DNA metabarcoding of the ITS2 region followed by a statistical filtering based on ROC curves to filter out underrepresented OTUs. Video cameras and network analyses were employed to investigate changes in foraging strategies and behaviour. After filtering out the false-positives, HTS metabarcoding yielded a high plant diversity in the pollen pellets; for plant identity and pollen quantity traits no differences emerged between samples from treated and from control colonies, suggesting that plant choice was influenced mainly by external factors such as the plant phenology. The colonies responded to the removal of 50% of their workers by increasing the foraging activity of the remaining workers, while only negligible changes were found in diet breadth and indices describing the structure of the pollen transport network. Therefore, a consistency in the bumblebees’ feeding strategies emerges in the short term despite the lowered workforce.

Klíčová slova:

Biodiversity – Bumblebees – Flowering plants – Foraging – Plants – Pollen – Species interactions – Plant-animal interactions


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