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Ruhland F, Gabant G, Toussaint T, Nemcic M, Cadène M, Lucas C. Reproductives signature revealed by protein profiling and behavioral bioassays in termite. Sci Rep 2023; 13:7070. [PMID: 37127756 PMCID: PMC10151321 DOI: 10.1038/s41598-023-33252-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 04/10/2023] [Indexed: 05/03/2023] Open
Abstract
Proteins are known to be social interaction signals in many species in the animal kingdom. Common mediators in mammals and aquatic species, they have seldom been identified as such in insects' behaviors. Yet, they could represent an important component to support social signals in social insects, as the numerous physical contacts between individuals would tend to favor the use of contact compounds in their interactions. However, their role in social interactions is largely unexplored: are they rare or simply underestimated? In this preliminary study, we show that, in the termite Reticulitermes flavipes, polar extracts from reproductives trigger body-shaking of workers (a vibratory behavior involved in reproductives recognition) while extracts from workers do not. Molecular profiling of these cuticular extracts using MALDI-TOF mass spectrometry reveals higher protein diversity in reproductives than in workers and a sex-specific composition exclusive to reproductives. While the effects observed with extracts are not as strong as with live termites, these results open up the intriguing possibility that social signaling may not be limited to cuticular hydrocarbons or other non-polar, volatile chemicals as classically accepted. Our results suggest that polar compounds, in particular some of the Cuticular Protein Compounds (CPCs) shown here by MALDI to be specific to reproductives, could play a significant role in insect societies. While this study is preliminary and further comprehensive molecular characterization is needed to correlate the body-shaking triggering effects with a given set of polar compounds, this exploratory study opens new perspectives for understanding the role of polar compounds such as proteins in caste discrimination, fertility signaling, or interspecific insect communication.
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Affiliation(s)
- Fanny Ruhland
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261), CNRS - University of Tours, Tours, France
| | - Guillaume Gabant
- Centre de Biophysique Moléculaire (UPR 4301), CNRS - University of Orléans, Orléans, France
| | - Timothée Toussaint
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261), CNRS - University of Tours, Tours, France
| | - Matej Nemcic
- Centre de Biophysique Moléculaire (UPR 4301), CNRS - University of Orléans, Orléans, France
| | - Martine Cadène
- Centre de Biophysique Moléculaire (UPR 4301), CNRS - University of Orléans, Orléans, France
| | - Christophe Lucas
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261), CNRS - University of Tours, Tours, France.
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Watanabe H, Ogata S, Nodomi N, Tateishi K, Nishino H, Matsubara R, Ozaki M, Yokohari F. Cuticular hydrocarbon reception by sensory neurons in basiconic sensilla of the Japanese carpenter ant. Front Cell Neurosci 2023; 17:1084803. [PMID: 36814868 PMCID: PMC9940637 DOI: 10.3389/fncel.2023.1084803] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/17/2023] [Indexed: 02/09/2023] Open
Abstract
To maintain the eusociality of a colony, ants recognize subtle differences in colony-specific sets of cuticular hydrocarbons (CHCs). The CHCs are received by female-specific antennal basiconic sensilla and processed in specific brain regions. However, it is controversial whether a peripheral or central neural mechanism is mainly responsible for discrimination of CHC blends. In the Japanese carpenter ant, Camponotus japonicus, about 140 sensory neurons (SNs) are co-housed in a single basiconic sensillum and receive colony-specific blends of 18 CHCs. The complexity of this CHC sensory process makes the neural basis of peripheral nestmate recognition difficult to understand. Here, we electrophysiologically recorded responses of single basiconic sensilla to each of 18 synthesized CHCs, and identified CHC responses of each SN co-housed in a single sensillum. Each CHC activated different sets of SNs and each SN was broadly tuned to CHCs. Multiple SNs in a given sensillum fired in synchrony, and the synchronicity of spikes was impaired by treatment with a gap junction inhibitor. These results indicated that SNs in single basiconic sensilla were electrically coupled. Quantitative analysis indicated that the Japanese carpenter ants have the potential to discriminate chemical structures of CHCs based on the combinational patterns of activated SNs. SNs of ants from different colonies exhibited different CHC response spectra. In addition, ants collected from the same colony but bred in separate groups also exhibited different CHC response spectra. These results support the hypothesis that the peripheral sensory mechanism is important for discrimination between nestmate and non-nestmate ants.
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Affiliation(s)
- Hidehiro Watanabe
- Department of Earth System Science, Fukuoka University, Fukuoka, Japan,*Correspondence: Hidehiro Watanabe,
| | - Shoji Ogata
- Department of Earth System Science, Fukuoka University, Fukuoka, Japan
| | - Nonoka Nodomi
- Department of Earth System Science, Fukuoka University, Fukuoka, Japan
| | - Kosuke Tateishi
- Department of Earth System Science, Fukuoka University, Fukuoka, Japan
| | - Hiroshi Nishino
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | - Ryosuke Matsubara
- Department of Chemistry, Graduate School of Science, Kobe University, Kobe, Japan
| | - Mamiko Ozaki
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan,KYOUSEI Science Center for Life and Nature, Nara Women’s University, Nara, Japan
| | - Fumio Yokohari
- Department of Earth System Science, Fukuoka University, Fukuoka, Japan
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Re-Analysis of Abdominal Gland Volatilome Secretions of the African Weaver Ant, Oecophylla longinoda (Hymenoptera: Formicidae). Molecules 2021; 26:molecules26040871. [PMID: 33562181 PMCID: PMC7915463 DOI: 10.3390/molecules26040871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 01/23/2021] [Accepted: 02/02/2021] [Indexed: 11/25/2022] Open
Abstract
The African weaver ant, Oecophylla longinoda, is used as a biological control agent for the management of pests. The ant has several exocrine glands in the abdomen, including Dufour’s, poison, rectal, and sternal glands, which are associated with pheromone secretions for intra-specific communication. Previous studies have analyzed the gland secretions of Dufour’s and poison glands. The chemistry of the rectal and sternal glands is unknown. We re-analyzed the secretions from Dufour’s and poison glands plus the rectal and sternal glands to compare their chemistries and identify additional components. We used the solid-phase microextraction (SPME) technique to collect gland headspace volatiles and solvent extraction for the secretions. Coupled gas chromatography–mass spectrometry (GC-MS) analysis detected a total of 78 components, of which 62 were being reported for the first time. These additional components included 32 hydrocarbons, 12 carboxylic acids, 5 aldehydes, 3 alcohols, 2 ketones, 4 terpenes, 3 sterols, and 1 benzenoid. The chemistry of Dufour’s and poison glands showed a strong overlap and was distinct from that of the rectal and sternal glands. The different gland mixtures may contribute to the different physiological and behavioral functions in this ant species.
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Wagoner KM, Millar JG, Schal C, Rueppell O. Cuticular pheromones stimulate hygienic behavior in the honey bee (Apis mellifera). Sci Rep 2020; 10:7132. [PMID: 32346037 PMCID: PMC7188687 DOI: 10.1038/s41598-020-64144-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 04/08/2020] [Indexed: 11/08/2022] Open
Abstract
The health of western honey bee (Apis mellifera) colonies is challenged by the parasitic mite Varroa destructor and the numerous harmful pathogens it vectors. Selective breeding for the naturally occurring social immune trait "hygienic behavior" has emerged as one sustainable approach to reducing the mites' impact on honey bees. To expand our understanding of hygienic triggers and improve hygienic selection tools, we tested the hypothesis that the cuticular compounds (Z)-10-tritriacontene and (Z)-6-pentadecene, previously associated with unhealthy honey bee brood and/or brood targeted for hygiene, are triggers of honey bee hygienic behavior independent of brood health. In support of our hypothesis, application of synthetic (Z)-10-tritriacontene and (Z)-6-pentadecene onto brood and brood cell caps significantly increased hygienic behavior compared to application of similarly structured hydrocarbon controls (Z)-16-dotriacontene and (Z)-7-pentadecene. Furthermore, we demonstrate a significant positive correlation between colony-level hygienic responses to (Z)-10-tritriacontene and the traditional freeze-killed brood assay for selection of hygienic honey bee stocks. These results confirm biological activity of (Z)-6-pentadecene and reveal (Z)-10-tritriacontene as a novel hygiene trigger. They also support development of improved tools for honey bee colony monitoring and hygienic selection, and thus may accelerate development of honey bee stocks with greater resistance to Varroa and associated pathogens.
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Affiliation(s)
- Kaira M Wagoner
- Biology Department, University of North Carolina at Greensboro, Greensboro, USA.
| | - Jocelyn G Millar
- Department of Entomology, University of California, Riverside, USA
| | - Coby Schal
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, USA
| | - Olav Rueppell
- Biology Department, University of North Carolina at Greensboro, Greensboro, USA
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Cini A, Sumner S, Cervo R. Inquiline social parasites as tools to unlock the secrets of insect sociality. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180193. [PMID: 30967091 PMCID: PMC6388031 DOI: 10.1098/rstb.2018.0193] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2018] [Indexed: 01/07/2023] Open
Abstract
Insect societies play a crucial role in the functioning of most ecosystems and have fascinated both scientists and the lay public for centuries. Despite the long history of study, we are still far from understanding how insect societies have evolved and how social cohesion in their colonies is maintained. Here we suggest inquiline social parasites of insect societies as an under-exploited experimental tool for understanding sociality. We draw on examples from obligate inquiline (permanent) social parasites in wasps, ants and bees to illustrate how these parasites may allow us to better understand societies and learn more about the evolution and functioning of insect societies. We highlight three main features of these social parasite-host systems-namely, close phylogenetic relationships, strong selective pressures arising from coevolution and multiple independent origins-that make inquiline social parasites particularly suited for this aim; we propose a conceptual comparative framework that considers trait losses, gains and modifications in social parasite-host systems. We give examples of how this framework can reveal the more elusive secrets of sociality by focusing on two cornerstones of sociality: communication and reproductive division of labour. Together with social parasites in other taxonomic groups, such as cuckoos in birds, social parasitism has a great potential to reveal the mechanisms and evolution of complex social groups. This article is part of the theme issue 'The coevolutionary biology of brood parasitism: from mechanism to pattern'.
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Affiliation(s)
- Alessandro Cini
- Centre for Biodiversity and Environment Research, University College London, Gower Street, London WC1E 6BT, UK
- Dipartimento di Biologia, Università degli Studi di Firenze, Via Madonna del Piano, 6, 50019 Sesto Fiorentino, Italy
| | - Seirian Sumner
- Centre for Biodiversity and Environment Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Rita Cervo
- Dipartimento di Biologia, Università degli Studi di Firenze, Via Madonna del Piano, 6, 50019 Sesto Fiorentino, Italy
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Brossette L, Meunier J, Dupont S, Bagnères A, Lucas C. Unbalanced biparental care during colony foundation in two subterranean termites. Ecol Evol 2019; 9:192-200. [PMID: 30680106 PMCID: PMC6342128 DOI: 10.1002/ece3.4710] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 10/05/2018] [Accepted: 10/11/2018] [Indexed: 11/11/2022] Open
Abstract
Parental care is a major component of reproduction in social organisms, particularly during the foundation steps. Because investment into parental care is often costly, each parent is predicted to maximize its fitness by providing less care than its partner. However, this sexual conflict is expected to be low in species with lifelong monogamy, because the fitness of each parent is typically tied to the other's input. Somewhat surprisingly, the outcomes of this tug-of-war between maternal and paternal investments have received important attention in vertebrate species, but remain less known in invertebrates. In this study, we investigated how queens and kings share their investment into parental care and other social interactions during colony foundation in two termites with lifelong monogamy: the invasive species Reticulitermes flavipes and the native species R. grassei. Behaviors of royal pairs were recorded during six months using a non-invasive approach. Our results showed that queens and kings exhibit unbalanced investment in terms of grooming, antennation, trophallaxis, and vibration behavior. Moreover, both parents show behavioral differences toward their partner or their descendants. Our results also revealed differences among species, with R. flavipes exhibiting shorter periods of grooming and antennation toward eggs or partners. They also did more stomodeal trophallaxis and less vibration behavior. Overall, this study emphasizes that despite lifelong monogamy, the two parents are not equally involved in the measured forms of parental care and suggests that kings might be specialized in other tasks. It also indicates that males could play a central, yet poorly studied role in the evolution and maintenance of the eusocial organization.
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Affiliation(s)
- Lou Brossette
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261)CNRS – University of ToursToursFrance
| | - Joël Meunier
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261)CNRS – University of ToursToursFrance
| | - Simon Dupont
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261)CNRS – University of ToursToursFrance
| | - Anne‐Geneviève Bagnères
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261)CNRS – University of ToursToursFrance
- CEFE, CNRS UMR5175, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, EPHE, IRDMontpellierFrance
| | - Christophe Lucas
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261)CNRS – University of ToursToursFrance
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Guillem RM, Drijfhout FP, Martin SJ. Species-Specific Cuticular Hydrocarbon Stability within European Myrmica Ants. J Chem Ecol 2016; 42:1052-1062. [PMID: 27832346 PMCID: PMC5119849 DOI: 10.1007/s10886-016-0784-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 05/15/2016] [Accepted: 07/04/2016] [Indexed: 01/14/2023]
Abstract
Recognition is a fundamental process on which all subsequent behaviors are based at every organizational level, from the gene up to the super-organism. At the whole organism level, visual recognition is the best understood. However, chemical communication is far more widespread than visual communication, but despite its importance is much less understood. Ants provide an excellent model system for chemical ecology studies as it is well established that compounds known as cuticular hydrocarbons (CHCs) are used as recognition cues in ants. Therefore, stable species-specific odors should exist, irrespective of geographic locality. We tested this hypothesis by comparing the CHC profiles of workers of twelve species of Myrmica ants from four countries across Europe, from Iberia to the Balkans and from the Mediterranean to Fennoscandia. CHCs remained qualitatively stable within each species, right down to the isomer level. Despite the morphological similarity that occurs within the genus Myrmica, their CHCs were highly diverse but remarkably species-specific and stable across wide geographical areas. This indicates a genetic mechanism under strong selection that produces these species-specific chemical profiles, despite each species encountering different environmental conditions across its range.
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Affiliation(s)
- Rhian M Guillem
- Department of Animal and Plant Sciences, University of Sheffield, S10 2TN, Sheffield, UK. .,Department of Earth & Life Sciences, Gibraltar Botanic Gardens Campus, University of Gibraltar, Gibraltar, GX11 1AA, Gibraltar.
| | - Falko P Drijfhout
- Chemical Ecology Group, School of Physical and Geographical Sciences, Lennard-Jones Laboratory, Keele University, Keele, ST5 5BG, UK
| | - Stephen J Martin
- School of Environment & Life Sciences, University of Salford, Manchester, M5 4WT, UK
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Mothapo NP, Wossler TC. “You are not always what you eat”: diet did not override intrinsic nestmate recognition cues in Argentine ants from two supercolonies in South Africa. AFRICAN ZOOLOGY 2016. [DOI: 10.1080/15627020.2016.1236670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Natasha P Mothapo
- DST-NRF Centre of Excellence for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Theresa C Wossler
- DST-NRF Centre of Excellence for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
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Torres CW, Tsutsui ND. The Effect of Social Parasitism by Polyergus breviceps on the Nestmate Recognition System of Its Host, Formica altipetens. PLoS One 2016; 11:e0147498. [PMID: 26840394 PMCID: PMC4740506 DOI: 10.1371/journal.pone.0147498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 01/04/2016] [Indexed: 11/30/2022] Open
Abstract
Highly social ants, bees and wasps employ sophisticated recognition systems to identify colony members and deny foreign individuals access to their nest. For ants, cuticular hydrocarbons serve as the labels used to ascertain nest membership. Social parasites, however, are capable of breaking the recognition code so that they can thrive unopposed within the colonies of their hosts. Here we examine the influence of the socially parasitic slave-making ant, Polyergus breviceps on the nestmate recognition system of its slaves, Formica altipetens. We compared the chemical, genetic, and behavioral characteristics of colonies of enslaved and free-living F. altipetens. We found that enslaved Formica colonies were more genetically and chemically diverse than their free-living counterparts. These differences are likely caused by the hallmark of slave-making ant ecology: seasonal raids in which pupa are stolen from several adjacent host colonies. The different social environments of enslaved and free-living Formica appear to affect their recognition behaviors: enslaved Formica workers were less aggressive towards non-nestmates than were free-living Formica. Our findings indicate that parasitism by P. breviceps dramatically alters both the chemical and genetic context in which their kidnapped hosts develop, leading to changes in how they recognize nestmates.
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Affiliation(s)
- Candice W. Torres
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, United States of America
- * E-mail:
| | - Neil D. Tsutsui
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, United States of America
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Caliari Oliveira R, Oi CA, do Nascimento MMC, Vollet-Neto A, Alves DA, Campos MC, Nascimento F, Wenseleers T. The origin and evolution of queen and fertility signals in Corbiculate bees. BMC Evol Biol 2015; 15:254. [PMID: 26573687 PMCID: PMC4647589 DOI: 10.1186/s12862-015-0509-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 10/12/2015] [Indexed: 12/13/2022] Open
Abstract
Background In social Hymenoptera (ants, bees and wasps), various chemical compounds present on the cuticle have been shown to act as fertility signals. In addition, specific queen-characteristic hydrocarbons have been implicated as sterility-inducing queen signals in ants, wasps and bumblebees. In Corbiculate bees, however, the chemical nature of queen-characteristic and fertility-linked compounds appears to be more diverse than in ants and wasps. Moreover, it remains unknown how queen signals evolved across this group and how they might have been co-opted from fertility signals in solitary ancestors. Results Here, we perform a phylogenetic analysis of fertility-linked compounds across 16 species of solitary and eusocial bee species, comprising both literature data as well as new primary data from a key solitary outgroup species, the oil-collecting bee Centris analis, and the highly eusocial stingless bee Scaptotrigona depilis. Our results demonstrate the presence of fertility-linked compounds belonging to 12 different chemical classes. In addition, we find that some classes of compounds (linear and branched alkanes, alkenes, esters and fatty acids) were already present as fertility-linked signals in the solitary ancestors of Corbiculate bees, while others appear to be specific to certain species. Conclusion Overall, our results suggest that queen signals in Corbiculate bees are likely derived from ancestral fertility-linked compounds present in solitary bees that lacked reproductive castes. These original fertility-linked cues or signals could have been produced either as a by-product of ovarian activation or could have served other communicative purposes, such as in mate recognition or the regulation of egg-laying. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0509-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ricardo Caliari Oliveira
- Department of Biology, Laboratory of Socioecology & Social Evolution, KU Leuven, Leuven, Belgium.
| | - Cintia Akemi Oi
- Department of Biology, Laboratory of Socioecology & Social Evolution, KU Leuven, Leuven, Belgium.
| | | | - Ayrton Vollet-Neto
- Department of Biology, Laboratory of Behavioral Ecology, FFCLRP, University of São Paulo, Ribeirão Preto, Brazil.
| | - Denise Araujo Alves
- Department of Entomology and Acarology, ESALQ, University of São Paulo, Piracicaba, Brazil.
| | - Maria Claudia Campos
- Department of Biology, Laboratory of Behavioral Ecology, FFCLRP, University of São Paulo, Ribeirão Preto, Brazil.
| | - Fabio Nascimento
- Department of Biology, Laboratory of Behavioral Ecology, FFCLRP, University of São Paulo, Ribeirão Preto, Brazil.
| | - Tom Wenseleers
- Department of Biology, Laboratory of Socioecology & Social Evolution, KU Leuven, Leuven, Belgium.
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van Wilgenburg E, Elgar MA. Confirmation bias in studies of nestmate recognition: a cautionary note for research into the behaviour of animals. PLoS One 2013; 8:e53548. [PMID: 23372659 PMCID: PMC3553103 DOI: 10.1371/journal.pone.0053548] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 12/03/2012] [Indexed: 11/30/2022] Open
Abstract
Confirmation bias is a tendency of people to interpret information in a way that confirms their expectations. A long recognized phenomenon in human psychology, confirmation bias can distort the results of a study and thus reduce its reliability. While confirmation bias can be avoided by conducting studies blind to treatment groups, this practice is not always used. Surprisingly, this is true of research in animal behaviour, and the extent to which confirmation bias influences research outcomes in this field is rarely investigated. Here we conducted a meta-analysis, using studies on nestmate recognition in ants, to compare the outcomes of studies that were conducted blind with those that were not. Nestmate recognition studies typically perform intra- and inter colony aggression assays, with the a priori expectation that there should be little or no aggression among nestmates. Aggressive interactions between ants can include subtle behaviours such as mandible flaring and recoil, which can be hard to quantify, making these types of assays prone to confirmation bias. Our survey revealed that only 29% of our sample of 79 studies were conducted blind. These studies were more likely to report aggression among nestmates if they were conducted blind (73%) than if they were not (21%). Moreover, we found that the effect size between nestmate and non-nestmate treatment means is significantly lower in experiments conducted blind than those in which colony identity is known (1.38 versus 2.76). We discuss the implications of the impact of confirmation bias for research that attempts to obtain quantitative synthesises of data from different studies.
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12
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Endo S, Itino T. Myrmecophilous aphids produce cuticular hydrocarbons that resemble those of their tending ants. POPUL ECOL 2012. [DOI: 10.1007/s10144-012-0355-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bos N, Dreier S, Jørgensen CG, Nielsen J, Guerrieri FJ, d'Ettorre P. Learning and perceptual similarity among cuticular hydrocarbons in ants. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:138-146. [PMID: 22067290 DOI: 10.1016/j.jinsphys.2011.10.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 10/24/2011] [Accepted: 10/25/2011] [Indexed: 05/31/2023]
Abstract
Nestmate recognition in ants is based on perceived differences in a multi-component blend of hydrocarbons that are present on the insect cuticle. Although supplementation experiments have shown that some classes of hydrocarbons, such as methyl branched alkanes and alkenes, have a salient role in nestmate recognition, there was basically no information available on how ants detect and perceive these molecules. We used a new conditioning procedure to investigate whether individual carpenter ants could associate a given hydrocarbon (linear or methyl-branched alkane) to sugar reward. We then studied perceptual similarity between a hydrocarbon previously associated with sugar and a novel hydrocarbon. Ants learnt all hydrocarbon-reward associations rapidly and with the same efficiency, regardless of the structure of the molecules. Ants could discriminate among a large number of pairs of hydrocarbons, but also generalised. Generalisation depended both on the structure of the molecule and the animal's experience. For linear alkanes, generalisation was observed when the novel molecule was smaller than the conditioned one. Generalisation between pairs of methyl-alkanes was high, while generalisation between hydrocarbons that differed in the presence or absence of a methyl group was low, suggesting that chain length and functional group might be coded independently by the ant olfactory system. Understanding variations in perception of recognition cues in ants is necessary for the general understanding of the mechanisms involved in social recognition processes based on chemical cues.
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Affiliation(s)
- Nick Bos
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
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15
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Meunier J, Delémont O, Lucas C. Recognition in ants: social origin matters. PLoS One 2011; 6:e19347. [PMID: 21573235 PMCID: PMC3087756 DOI: 10.1371/journal.pone.0019347] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 03/28/2011] [Indexed: 11/28/2022] Open
Abstract
The ability of group members to discriminate against foreigners is a keystone in the evolution of sociality. In social insects, colony social structure (number of queens) is generally thought to influence abilities of resident workers to discriminate between nestmates and non-nestmates. However, whether social origin of introduced individuals has an effect on their acceptance in conspecific colonies remains poorly explored. Using egg-acceptance bioassays, we tested the influence of social origin of queen-laid eggs on their acceptance by foreign workers in the ant Formica selysi. We showed that workers from both single- and multiple-queen colonies discriminated against foreign eggs from single-queen colonies, whereas they surprisingly accepted foreign eggs from multiple-queen colonies. Chemical analyses then demonstrated that social origins of eggs and workers could be discriminated on the basis of their chemical profiles, a signal generally involved in nestmate discrimination. These findings provide the first evidence in social insects that social origins of eggs interfere with nestmate discrimination and are encoded by chemical signatures.
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Affiliation(s)
- Joël Meunier
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.
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Abstract
The cuticular hydrocarbons (CHCs) of ants provide important cues for nest-mate and caste recognition. There is enormous diversity in the composition of these CHCs, but the manner in which this diversity has evolved is poorly understood. We gathered data on CHC profiles for 56 ant species, relating this information to their phylogeny. We deduced the mode of evolution of CHC profiles by reconstructing character evolution and then relating the number of changes in CHC components along each branch of the phylogeny to the length of the branch. There was a strong correlation between branch length and number of component changes, with fewer changes occurring on short branches. Our analysis thereby indicated a gradual mode of evolution. Different ant species tend to use specific CHC structural types that are exclusive of other structural types, indicating that species differences may be generated in part by switching particular biosynthetic pathways on or off in different lineages. We found limited, and contradictory, evidence for abiotic factors (temperature and rainfall) driving change in CHC profiles.
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Affiliation(s)
- E van Wilgenburg
- Department of Zoology, University of Melbourne, Melbourne, Vic., Australia.
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17
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Bos N, Guerrieri FJ, d’Ettorre P. Significance of chemical recognition cues is context dependent in ants. Anim Behav 2010. [DOI: 10.1016/j.anbehav.2010.08.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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18
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Witte V, Schliessmann D, Hashim R. Attack or call for help? Rapid individual decisions in a group-hunting ant. Behav Ecol 2010. [DOI: 10.1093/beheco/arq100] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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van Wilgenburg E, Sulc R, Shea KJ, Tsutsui ND. Deciphering the chemical basis of nestmate recognition. J Chem Ecol 2010; 36:751-8. [PMID: 20556636 PMCID: PMC2895867 DOI: 10.1007/s10886-010-9812-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 05/19/2010] [Accepted: 06/01/2010] [Indexed: 11/28/2022]
Abstract
Social insects maintain colony cohesion by recognizing and, if necessary, discriminating against conspecifics that are not part of the colony. This recognition ability is encoded by a complex mixture of cuticular hydrocarbons (CHCs), although it is largely unclear how social insects interpret such a multifaceted signal. CHC profiles often contain several series of homologous hydrocarbons, possessing the same methyl branch position but differing in chain length (e.g., 15-methyl-pentatriacontane, 15-methyl-heptatriacontane, 15-methyl-nonatriacontane). Recent studies have revealed that within species these homologs can occur in correlated concentrations. In such cases, single compounds may convey the same information as the homologs. In this study, we used behavioral bioassays to explore how social insects perceive and interpret different hydrocarbons. We tested the aggressive response of Argentine ants, Linepithema humile, toward nest-mate CHC profiles that were augmented with one of eight synthetic hydrocarbons that differed in branch position, chain length, or both. We found that Argentine ants showed similar levels of aggression toward nest-mate CHC profiles augmented with compounds that had the same branch position but differed in chain length. Conversely, Argentine ants displayed different levels of aggression toward nest-mate CHC profiles augmented with compounds that had different branch positions but the same chain length. While this was true in almost all cases, one CHC we tested elicited a greater aggressive response than its homologs. Interestingly, this was the only compound that did not occur naturally in correlated concentrations with its homologs in CHC profiles. Combined, these data suggest that CHCs of a homologous series elicit the same aggressive response because they convey the same information, rather than Argentine ants being unable to discriminate between different homologs. This study contributes to our understanding of the chemical basis of nestmate recognition by showing that, similar to spoken language, the chemical language of social insects contains “synonyms,” chemicals that differ in structure, but not meaning.
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Affiliation(s)
- Ellen van Wilgenburg
- Department of Environmental Science, Policy and Management, University of California, 137 Mulford Hall, #3114, Berkeley, CA 94720-3114, USA.
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20
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Yusuf AA, Pirk CWW, Crewe RM, Njagi PGN, Gordon I, Torto B. Nestmate recognition and the role of cuticular hydrocarbons in the African termite raiding ant Pachycondyla analis. J Chem Ecol 2010; 36:441-8. [PMID: 20349337 DOI: 10.1007/s10886-010-9774-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Revised: 11/17/2009] [Accepted: 01/11/2010] [Indexed: 11/30/2022]
Abstract
Cuticular hydrocarbons (CHCs) are used for chemical communication among nestmates in many ant species, and they may play a role in the discrimination of nestmates and non-nestmates. Using the mandible opening response (MOR) bioassay, we tested the response of the African termite raiding ant, Pachycondyla analis, to CHC extracts of nestmates and non-nestmates. The ants were able to distinguish control chemical cues, from nestmate CHCs, and from non-nestmate CHCs, and, based on a CHC recognition threshold, aggression was demonstrated toward non-nestmates. Gas chromatography (GC) and GC-mass spectrometric analyses showed that CHC components of different ant colonies had chain lengths ranging from C(8) to C(31), comprising mainly n-alkanes, alkenes, and methyl branched alkanes, with the n-alkanes occurring in the same proportions among all colonies. The ants were grouped successfully according to their colonies of origin by using discriminant analysis of CHCs. We demonstrate that nestmate recognition occurs in P. analis, and that some of the cues involved are evidently alkenes and methyl-branched alkanes.
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22
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Green PWC. The Effects of Insect Extracts and Some Insect-Derived Compounds on the Settling Behavior of Liposcelis bostrychophila. J Chem Ecol 2009; 35:1096-107. [DOI: 10.1007/s10886-009-9688-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 09/02/2009] [Accepted: 09/04/2009] [Indexed: 11/30/2022]
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23
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Sex-specific antennal sensory system in the ant Camponotus japonicus: structure and distribution of sensilla on the flagellum. Cell Tissue Res 2009; 338:79-97. [DOI: 10.1007/s00441-009-0863-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 08/12/2009] [Indexed: 11/26/2022]
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24
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Molecular basis for changes in behavioral state in ant social behaviors. Proc Natl Acad Sci U S A 2009; 106:6351-6. [PMID: 19332792 DOI: 10.1073/pnas.0809463106] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A hallmark of behavior is that animals respond to environmental change by switching from one behavioral state to another. However, information on the molecular underpinnings of these behavioral shifts and how they are mediated by the environment is lacking. The ant Pheidole pallidula with its morphologically and behaviorally distinct major and minor workers is an ideal system to investigate behavioral shifts. The physically larger majors are predisposed to defend the ant nest, whereas the smaller minors are the foragers. Despite this predisposition, majors are able to shift to foraging according to the needs of the colony. We show that the ant foraging (ppfor) gene, which encodes a cGMP-dependent protein kinase (PKG), mediates this shift. Majors have higher brain PKG activities than minors, and the spatial distribution of the PPFOR protein differs in these workers. Specifically, majors express the PPFOR protein in 5 cells in the anterior face of the ant brain, whereas minors do not. Environmental manipulations show that PKG is lower in the presence of a foraging stimulus and higher when defense is required. Finally, pharmacological activation of PKG increases defense and reduces foraging behavior. Thus, PKG signaling plays a critical role in P. pallidula behavioral shifts.
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Kroiss J, Bordon S, Strohm E. Hydrocarbons in the nest material of a solitary digger wasp represent a kairomone for a specialized cuckoo wasp. Anim Behav 2008. [DOI: 10.1016/j.anbehav.2008.07.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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Guerrieri FJ, d'Ettorre P. The mandible opening response: quantifying aggression elicited by chemical cues in ants. ACTA ACUST UNITED AC 2008; 211:1109-13. [PMID: 18344485 DOI: 10.1242/jeb.008508] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Social insects have evolved efficient recognition systems guaranteeing social cohesion and protection from enemies. To defend their territories and threaten non-nestmate intruders, ants open their mandibles as a first aggressive display. Albeit chemical cues play a major role in discrimination between nestmates and non-nestmates, classical bioassays based on aggressive behaviour were not particularly effective in disentangling chemical perception and behavioural components of nestmate recognition by means of categorical variables. We therefore developed a novel bioassay that accurately isolates chemical perception from other cues. We studied four ant species: Camponotus herculeanus, C. vagus, Formica rufibarbis and F. cunicularia. Chemical analyses of cuticular extracts of workers of these four species showed that they varied in the number and identity of compounds and that species of the same genus have more similar profiles. The antennae of harnessed ants were touched with a glass rod coated with the cuticular extract of (a) nestmates, (b) non-nestmates of the same species, (c) another species of the same genus and (d) a species of a different genus. The mandible opening response (MOR) was recorded as the aggressive response. In all assayed species, MOR significantly differed among stimuli, being weakest towards nestmate odour and strongest towards odours originating from ants of a different genus. We thus introduce here a new procedure suitable for studying the chemical basis of aggression in ants.
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Affiliation(s)
- Fernando J Guerrieri
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark.
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27
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Johnston RE. Chapter 9 Individual Odors and Social Communication. ADVANCES IN THE STUDY OF BEHAVIOR 2008. [DOI: 10.1016/s0065-3454(08)00009-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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DAPPORTO LEONARDO. Cuticular lipid diversification in Lasiommata megera and Lasiommata paramegaera: the influence of species, sex, and population (Lepidoptera: Nymphalidae). Biol J Linn Soc Lond 2007. [DOI: 10.1111/j.1095-8312.2007.00833.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Leonhardt SD, Brandstaetter AS, Kleineidam CJ. Reformation process of the neuronal template for nestmate-recognition cues in the carpenter ant Camponotus floridanus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2007; 193:993-1000. [PMID: 17639411 DOI: 10.1007/s00359-007-0252-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 06/22/2007] [Accepted: 06/23/2007] [Indexed: 11/24/2022]
Abstract
Ants use cuticular hydrocarbons (CHC-profiles) as multicomponent recognition cues to identify colony members (nestmates). Recognition cues (label) are thought to be perceived during ant-ant encounters and compared to a neuronal template that represents the colony label. Over time, the CHC-profile may change, and the template is adjusted accordingly. A phenotype mismatch between label and template, as happens with CHC-profiles of foreign workers (non-nestmates), frequently leads to aggressive behavior. We investigated the template reformation in workers of the carpenter ant Camponotus floridanus by masking their antennae with postpharyngeal gland (PPG) extracts from nestmates or non-nestmates. The behavioral response of manipulated workers encountering unmanipulated workers was measured independently after 2 and after 15 h. After 2 h of incubation, workers treated with either of the two PPG-extracts showed low aggression towards nestmates and high aggression towards non-nestmates. In contrast, after 15 h of incubation, workers treated with non-nestmate PPG-extract showed low aggression towards both nestmates and non-nestmates. The slow (>2 h) adjustment of the template indicates a reformation localized in the central nervous system rather than in chemosensory neurons. In addition, our data show that template adjustment to a new CHC-profile does not impair the assessment of the old CHC-profile as nestmate label.
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Affiliation(s)
- Sara Diana Leonhardt
- Department of Sociobiology and Behavioral Physiology, Biozentrum, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
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Greene MJ, Gordon DM. Structural complexity of chemical recognition cues affects the perception of group membership in the ants Linephithema humile and Aphaenogaster cockerelli. J Exp Biol 2007; 210:897-905. [PMID: 17297148 DOI: 10.1242/jeb.02706] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Hydrocarbon profiles on the cuticle of social insects act as multi-component recognition cues used to identify membership in a species, a colony or, within colonies, cues about its reproductive status or task group. To examine the role of structural complexity in ant hydrocarbon recognition cues, we studied the species recognition response of two ant species, Linepithema humile and Aphaenogaster cockerelli, and the recognition of conspecifics by L. humile. The cuticular hydrocarbons of ants are composed of molecules of varying chain lengths from three structural classes, n-alkanes, methyl-branched alkanes and n-alkenes. We employed species recognition bioassays that measured the aggressive response of both species of ants to mixtures of hydrocarbon classes, single structural classes of hydrocarbons (n-alkanes,methyl-branched alkanes and n-alkenes), and controls. The results showed that a combination of at least two hydrocarbon structural classes was necessary to elicit an aggressive species recognition response. Moreover, no single class of hydrocarbons was more important than the others in eliciting a response. Similarly, in the recognition of conspecifics, Linepithema humile did not respond to a mixture of n-alkane cuticular hydrocarbons presented alone, but supplementation of nestmate hydrocarbon profiles with the n-alkanes did elicit high levels of aggression. Thus both L. humile and A. cockerelli required mixtures of hydrocarbons of different structural classes to recognize species and colony membership. It appears that information on species and colony membership is not in isolated components of the profile, but instead in the mixture of structural classes found in cuticular hydrocarbon profiles.
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Affiliation(s)
- Michael J Greene
- Department of Biology, University of Colorado at Denver and Health Sciences Center, Campus Box 171, PO Box 173364, Denver, CO 80217-3364 USA.
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Lengyel F, Westerlund SA, Kaib M. Juvenile Hormone III Influences Task-Specific Cuticular Hydrocarbon Profile Changes in the Ant Myrmicaria eumenoides. J Chem Ecol 2006; 33:167-81. [PMID: 17146723 DOI: 10.1007/s10886-006-9185-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We investigated the influence of juvenile hormones (JH) on the composition of cuticular hydrocarbons (CHCs) and the division of labor in colonies of the African ant Myrmicaria eumenoides. CHCs have long been implicated in nestmate recognition in social insect colonies. In M. eumenoides, the CHC profiles also vary with the task performed from brood-tender-type to forager type. The endocrine factors regulating the task allocation as well as the intracolonial recognition cues are not well understood, but JHs are prime candidates. Only JH III was identified in the hemolymph of M. eumenoides workers. Foragers had significantly higher JH III titers than brood tenders. The application of exogenous JH III and a JH analogue (methoprene) to M. eumenoides workers did not result in an observable acceleration of task change in our study. However, longevity of the focus workers, and thus the observational period, was reduced by the applications. Changes from a brood-tender-type to a forager-type CHC profile were accelerated by the application of JH III and methoprene, resulting in brood-tending workers that displayed forager-type CHC profiles. We present the first data supporting that recognition cues of an eusocial Hymenopteran are influenced by JH III, which could thus play a major role in the regulation of the dynamic nature of social insect colonies. JH III is connected to at least two key processes: the acceleration of CHC changes and the more long-term modulation of task shifting. Moreover, this indicates that changes in CHC recognition cues do not trigger task allocation in social insect colonies.
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Affiliation(s)
- F Lengyel
- Department of Animal Physiology, University of Bayreuth, 95447, Bayreuth, Germany
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