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Cappa F, Petrocelli I, Dani FR, Dapporto L, Giovannini M, Silva-Castellari J, Turillazzi S, Cervo R. Natural biocide disrupts nestmate recognition in honeybees. Sci Rep 2019; 9:3171. [PMID: 30816211 PMCID: PMC6395671 DOI: 10.1038/s41598-019-38963-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 11/27/2018] [Indexed: 12/30/2022] Open
Abstract
Honeybee colonies are under the threat of many stressors, biotic and abiotic factors that strongly affect their survival. Recently, great attention has been directed at chemical pesticides, including their effects at sub-lethal doses on bee behaviour and colony success; whereas the potential side effects of natural biocides largely used in agriculture, such as entomopathogenic fungi, have received only marginal attention. Here, we report the impact of the fungus Beauveria bassiana on honeybee nestmate recognition ability, a crucial feature at the basis of colony integrity. We performed both behavioural assays by recording bee guards’ response towards foragers (nestmate or non-nestmate) either exposed to B. bassiana or unexposed presented at the hive entrance, and GC-MS analyses of the cuticular hydrocarbons (CHCs) of fungus-exposed versus unexposed bees. Our results demonstrated that exposed bees have altered cuticular hydrocarbons and are more easily accepted into foreign colonies than controls. Since CHCs are the main recognition cues in social insects, changes in their composition appear to affect nestmate recognition ability at the colony level. The acceptance of chemically unrecognizable fungus-exposed foragers could therefore favour forager drift and disease spread across colonies.
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Affiliation(s)
- Federico Cappa
- Università degli studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy.
| | - Iacopo Petrocelli
- Università degli studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy
| | - Francesca Romana Dani
- Università degli studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy
| | - Leonardo Dapporto
- Università degli studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy
| | - Michele Giovannini
- Università degli studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy
| | - Jeferson Silva-Castellari
- Università degli studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy
| | - Stefano Turillazzi
- Università degli studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy
| | - Rita Cervo
- Università degli studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy
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Hewlett SE, Wareham DM, Barron AB. Honey bee ( Apis mellifera) sociability and nestmate affiliation are dependent on the social environment experienced post-eclosion. ACTA ACUST UNITED AC 2018; 221:jeb.173054. [PMID: 29361601 DOI: 10.1242/jeb.173054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/13/2017] [Indexed: 10/18/2022]
Abstract
Underpinning the formation of a social group is the motivation of individuals to aggregate and interact with conspecifics, termed sociability. Here, we developed an assay, inspired by vertebrate approaches to evaluate social behaviours, to simultaneously examine the development of honey bee (Apis mellifera) sociability and nestmate affiliation. Focal bees were placed in a testing chamber which was separated from groups of nestmates and conspecific non-nestmates by single-layer mesh screens. Assessing how much time bees spent contacting the two mesh screens allowed us to quantify simultaneously how much bees sought proximity and interaction with other bees and their preference for nestmates over non-nestmates. Both sociability and nestmate affiliation could be detected soon after emergence as an adult. Isolation early in adult life impaired honey bee sociability but there was no evidence for a critical period for the development of the trait, as isolated bees exposed to their hive for 24 h when as old as 6 days still recovered high levels of sociability. Our data show that, even for advanced social insects, sociability is a developmental phenomenon and experience dependent.
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Affiliation(s)
- Susie E Hewlett
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Deborah M Wareham
- Department of Health Professions, Macquarie University, Sydney, NSW 2109, Australia
| | - Andrew B Barron
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
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