Behavioural evidence for self-medication in bumblebees? [v2; ref status: indexed, http://f1000r.es/5ep]
The presence of antimicrobial secondary metabolites in nectar suggests that pollinators, which are threatened globally by emergent disease, may benefit from the consumption of nectars rich in these metabolites. We tested whether nicotine, a nectar secondary metabolite common in Solanaceae and Tilia...
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| Format: | Article |
| Language: | English |
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F1000 Research Ltd
2015-05-01
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| Online Access: | http://f1000research.com/articles/4-73/v2 |
| _version_ | 1818011379457589248 |
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| author | David Baracchi Mark J. F. Brown Lars Chittka |
| author_facet | David Baracchi Mark J. F. Brown Lars Chittka |
| author_sort | David Baracchi |
| collection | DOAJ |
| description | The presence of antimicrobial secondary metabolites in nectar suggests that pollinators, which are threatened globally by emergent disease, may benefit from the consumption of nectars rich in these metabolites. We tested whether nicotine, a nectar secondary metabolite common in Solanaceae and Tilia species, is used by parasitized bumblebees as a source of self-medication, using a series of toxicological, microbiological and behavioural experiments. Caged bees infected with Crithidia bombi had a slight preference for sucrose solution laced with the alkaloid and behavioural tests showed that the parasite infection induced an increased consumption of nicotine during foraging activity, though nicotine had an appetite-reducing effect overall. When ingested, nicotine delayed the progression of a gut infection in bumblebees by a few days, but dietary nicotine did not clear the infection, and after 10 days the parasite load approached that of control bees. Moreover, when pathogens were exposed to the alkaloid prior to host ingestion, the protozoan’s viability was not directly affected, suggesting that anti-parasite effects were relatively weak. Nicotine consumption in a single dose did not impose any cost even in starved bees but the alkaloid had detrimental effects on healthy bees if consistently consumed for weeks. These toxic effects disappeared in infected bees, suggesting that detoxification costs might have been counterbalanced by the advantages in slowing the progression of the infection. Nicotine consumption did not affect bee lifespan but the reduction in the parasite load may have other likely unexplored subtle benefits both for individual bees and their colony. Potential evidence for self-medication is discussed. The contention that secondary metabolites in nectar may be under selection from pollinators, or used by plants to enhance their own reproductive success, remains to be confirmed. |
| first_indexed | 2024-04-14T06:07:58Z |
| format | Article |
| id | doaj.art-db7cf97821724f50aa56edfc55f2e6c3 |
| institution | Directory Open Access Journal |
| issn | 2046-1402 |
| language | English |
| last_indexed | 2024-04-14T06:07:58Z |
| publishDate | 2015-05-01 |
| publisher | F1000 Research Ltd |
| record_format | Article |
| series | F1000Research |
| spelling | doaj.art-db7cf97821724f50aa56edfc55f2e6c32022-12-22T02:08:29ZengF1000 Research LtdF1000Research2046-14022015-05-01410.12688/f1000research.6262.27009Behavioural evidence for self-medication in bumblebees? [v2; ref status: indexed, http://f1000r.es/5ep]David Baracchi0Mark J. F. Brown1Lars Chittka2Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UKSchool of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UKDepartment of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UKThe presence of antimicrobial secondary metabolites in nectar suggests that pollinators, which are threatened globally by emergent disease, may benefit from the consumption of nectars rich in these metabolites. We tested whether nicotine, a nectar secondary metabolite common in Solanaceae and Tilia species, is used by parasitized bumblebees as a source of self-medication, using a series of toxicological, microbiological and behavioural experiments. Caged bees infected with Crithidia bombi had a slight preference for sucrose solution laced with the alkaloid and behavioural tests showed that the parasite infection induced an increased consumption of nicotine during foraging activity, though nicotine had an appetite-reducing effect overall. When ingested, nicotine delayed the progression of a gut infection in bumblebees by a few days, but dietary nicotine did not clear the infection, and after 10 days the parasite load approached that of control bees. Moreover, when pathogens were exposed to the alkaloid prior to host ingestion, the protozoan’s viability was not directly affected, suggesting that anti-parasite effects were relatively weak. Nicotine consumption in a single dose did not impose any cost even in starved bees but the alkaloid had detrimental effects on healthy bees if consistently consumed for weeks. These toxic effects disappeared in infected bees, suggesting that detoxification costs might have been counterbalanced by the advantages in slowing the progression of the infection. Nicotine consumption did not affect bee lifespan but the reduction in the parasite load may have other likely unexplored subtle benefits both for individual bees and their colony. Potential evidence for self-medication is discussed. The contention that secondary metabolites in nectar may be under selection from pollinators, or used by plants to enhance their own reproductive success, remains to be confirmed.http://f1000research.com/articles/4-73/v2Antimicrobials & Drug ResistanceBehavioral EcologyBehavioral NeuroscienceParasitologyPlant-Biotic InteractionsSensory Systems |
| spellingShingle | David Baracchi Mark J. F. Brown Lars Chittka Behavioural evidence for self-medication in bumblebees? [v2; ref status: indexed, http://f1000r.es/5ep] F1000Research Antimicrobials & Drug Resistance Behavioral Ecology Behavioral Neuroscience Parasitology Plant-Biotic Interactions Sensory Systems |
| title | Behavioural evidence for self-medication in bumblebees? [v2; ref status: indexed, http://f1000r.es/5ep] |
| title_full | Behavioural evidence for self-medication in bumblebees? [v2; ref status: indexed, http://f1000r.es/5ep] |
| title_fullStr | Behavioural evidence for self-medication in bumblebees? [v2; ref status: indexed, http://f1000r.es/5ep] |
| title_full_unstemmed | Behavioural evidence for self-medication in bumblebees? [v2; ref status: indexed, http://f1000r.es/5ep] |
| title_short | Behavioural evidence for self-medication in bumblebees? [v2; ref status: indexed, http://f1000r.es/5ep] |
| title_sort | behavioural evidence for self medication in bumblebees v2 ref status indexed http f1000r es 5ep |
| topic | Antimicrobials & Drug Resistance Behavioral Ecology Behavioral Neuroscience Parasitology Plant-Biotic Interactions Sensory Systems |
| url | http://f1000research.com/articles/4-73/v2 |
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