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Peng T, Kennedy A, Wu Y, Foitzik S, Grüter C. Early life exposure to queen mandibular pheromone mediates persistent transcriptional changes in the brain of honey bee foragers. J Exp Biol 2024; 227:jeb247516. [PMID: 38725404 DOI: 10.1242/jeb.247516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/28/2024] [Indexed: 06/25/2024]
Abstract
Behavioural regulation in insect societies remains a fundamental question in sociobiology. In hymenopteran societies, the queen plays a crucial role in regulating group behaviour by affecting individual behaviour and physiology through modulation of worker gene expression. Honey bee (Apis mellifera) queens signal their presence via queen mandibular pheromone (QMP). While QMP has been shown to influence behaviour and gene expression of young workers, we know little about how these changes translate in older workers. The effects of the queen pheromone could have prolonged molecular impacts on workers that depend on an early sensitive period. We demonstrate that removal of QMP impacts long-term gene expression in the brain and antennae in foragers that were treated early in life (1 day post emergence), but not when treated later in life. Genes important for division of labour, learning, chemosensory perception and ageing were among those differentially expressed in the antennae and brain tissues, suggesting that QMP influences diverse physiological and behavioural processes in workers. Surprisingly, removal of QMP did not have an impact on foraging behaviour. Overall, our study suggests a sensitive period early in the life of workers, where the presence or absence of a queen has potentially life-long effects on transcriptional activity.
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Affiliation(s)
- Tianfei Peng
- Institute of Molecular and Organismic Evolution, Johannes Gutenberg University of Mainz, Biozentrum I, Hanns Dieter Hüsch Weg 15, 55128 Mainz, Germany
- College of Plant Science, Jilin University, Changchun 130062, PR China
| | - Anissa Kennedy
- Institute of Molecular and Organismic Evolution, Johannes Gutenberg University of Mainz, Biozentrum I, Hanns Dieter Hüsch Weg 15, 55128 Mainz, Germany
| | - Yongqiang Wu
- Institute of Molecular and Organismic Evolution, Johannes Gutenberg University of Mainz, Biozentrum I, Hanns Dieter Hüsch Weg 15, 55128 Mainz, Germany
| | - Susanne Foitzik
- Institute of Molecular and Organismic Evolution, Johannes Gutenberg University of Mainz, Biozentrum I, Hanns Dieter Hüsch Weg 15, 55128 Mainz, Germany
| | - Christoph Grüter
- Institute of Molecular and Organismic Evolution, Johannes Gutenberg University of Mainz, Biozentrum I, Hanns Dieter Hüsch Weg 15, 55128 Mainz, Germany
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2
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Ozan M, Helanterä H, d'Ettorre P, Sundström L. Queen fecundity, worker entourage and cuticular chemistry in the ant Formica fusca. Proc Biol Sci 2023; 290:20230861. [PMID: 37554034 PMCID: PMC10410219 DOI: 10.1098/rspb.2023.0861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 07/06/2023] [Indexed: 08/10/2023] Open
Abstract
Cooperative breeding entails conflicts over reproductive shares that may be settled in different ways. In ants, where several queens simultaneously reproduce in a colony, both queens and workers may influence the reproductive apportionment and offspring quality. Queens may vary in their intrinsic fecundity, which may influence the size of the worker entourage attending individual queens, and this may eventually dictate the reproductive output of a queen. We tested whether the reproductive success of queens is affected by the size of their worker entourage, their fecundity at the onset of the reproductive season, and whether the queen cuticular hydrocarbon profile carries information on fecundity. We show that in the ant Formica fusca both queen fecundity and egg hatching success increase with the size of their entourage, and that newly hatched larvae produced by initially highly fecund queens are smaller. Furthermore, higher relatedness among workers increased queen fecundity. Finally, the queens that received a large worker entourage differed in the cuticular chemistry from those that received a small worker entourage. Our results thus show that workers play a pivotal role in determining queen fitness, that high intracolony relatedness among workers enhances the overall reproductive output in the colony, and that queen fecundity is reflected in their cuticular hydrocarbon profile.
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Affiliation(s)
- Martina Ozan
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014, Finland
- Tvärminne Zoological Station, University of Helsinki, J.A. Palménintie 260, 10900 Hanko, Finland
| | - Heikki Helanterä
- Tvärminne Zoological Station, University of Helsinki, J.A. Palménintie 260, 10900 Hanko, Finland
- Faculty of Science, Ecology and Genetics Research Unit, University of Oulu, 90014, Finland
| | - Patrizia d'Ettorre
- Laboratoire d'Ethologie Expérimentale et Comparée, UR 4443, Université Sorbonne Paris Nord, Villetaneuse, France
- Institut Universitaire de France (IUF), Paris, France
| | - Liselotte Sundström
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014, Finland
- Tvärminne Zoological Station, University of Helsinki, J.A. Palménintie 260, 10900 Hanko, Finland
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3
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Helanterä H, Ozan M, Sundström L. Relatedness modulates reproductive competition among queens in ant societies with multiple queens. Behav Ecol 2023; 34:340-345. [PMID: 37192926 PMCID: PMC10183207 DOI: 10.1093/beheco/arad004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 10/05/2022] [Accepted: 01/09/2023] [Indexed: 03/03/2023] Open
Abstract
Reproductive sharing in animal groups with multiple breeders, insects and vertebrates alike, contains elements of both conflict and cooperation, and depends on both relatedness between co-breeders, as well as their internal and external conditions. We studied how queens of the ant Formica fusca adjust their reproductive efforts in response to experimental manipulations of the kin competition regime in their nest. Queens respond to the presence of competitors by increasing their egg laying efforts, but only if the competitors are highly fecund and distantly related. Such a mechanism is likely to decrease harmful competition among close relatives. We demonstrate that queens of Formica fusca fine-tune their cooperative breeding behaviors in response to kinship and fecundity of others in a remarkably precise and flexible manner.
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Affiliation(s)
- Heikki Helanterä
- Faculty of Biological and Environmental Sciences, Organismal and Evolutionary Biology Research Programme, P.O.BOX 65, FI 00014, Helsinki University, Finland
- Tvärminne Zoological station, J.A. Palménintie 260, FI 10900 Hanko, Finland
- Faculty of Science, Ecology and Genetics Research Unit, FI 90014, University of Oulu, Finland
| | - Martina Ozan
- Faculty of Biological and Environmental Sciences, Organismal and Evolutionary Biology Research Programme, P.O.BOX 65, FI 00014, Helsinki University, Finland
- Tvärminne Zoological station, J.A. Palménintie 260, FI 10900 Hanko, Finland
| | - Liselotte Sundström
- Faculty of Biological and Environmental Sciences, Organismal and Evolutionary Biology Research Programme, P.O.BOX 65, FI 00014, Helsinki University, Finland
- Tvärminne Zoological station, J.A. Palménintie 260, FI 10900 Hanko, Finland
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4
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A fluid role in ant society as adults give larvae 'milk' from pupae. Nature 2022; 612:405-406. [PMID: 36450952 DOI: 10.1038/d41586-022-03722-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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5
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Reproductive inhibition among nestmate queens in the invasive Argentine ant. Sci Rep 2020; 10:20484. [PMID: 33235272 PMCID: PMC7687882 DOI: 10.1038/s41598-020-77574-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 11/11/2020] [Indexed: 11/23/2022] Open
Abstract
In social species, the presence of several reproductive individuals can generate conflict. In social insects, as queen number increases, individual oviposition rate may decrease because of direct and indirect behavioural and/or chemical interactions. Understanding the factors that mediate differences in queen fecundity should provide insight into the regulation and maintenance of highly polygynous insect societies, such as those of the invasive Argentine ant (Linepithema humile). In this study, we investigated (1) whether differences in the oviposition rates of Argentine ant queens exposed to polygynous conditions could result from interactions among them; (2) whether such differences in fecundity stemmed from differences in worker attention; and (3) whether polygynous conditions affected the cuticular hydrocarbon profiles of queens (CHCs). We found that differences in queen fecundity and CHC profiles observed under polygynous conditions disappeared when queens were exposed to monogynous conditions, suggesting some form of reproductive inhibition may exist when queens cohabit. These differences did not seem to arise from variation in worker attention because more fecund queens were not more attractive to workers. Levels of some CHCs were higher in more fecund queens. These CHCs are associated with greater queen productivity and survival. Our findings indicate that such compounds could be multifunctional queen pheromones.
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Oliveira RC, Warson J, Sillam-Dussès D, Herrera-Malaver B, Verstrepen K, Millar JG, Wenseleers T. Identification of a queen pheromone mediating the rearing of adult sexuals in the pharaoh ant Monomorium pharaonis. Biol Lett 2020; 16:20200348. [PMID: 32810428 DOI: 10.1098/rsbl.2020.0348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The division of labour between reproductive queens and mostly sterile workers is among the defining characteristics of social insects. Queen-produced chemical signals advertising her presence and fertility status, i.e. queen pheromones, are normally used to assert the queen's reproductive dominance in the colony. Most queen pheromones identified to date are chemicals that stop the daughter workers from reproducing. Nevertheless, it has long been suggested that queen pheromones could also regulate reproduction in different ways. In some multiple-queen ants with obligately sterile workers, for example-such as fire ants and pharaoh ants-queen pheromones are thought to regulate reproduction by inhibiting the rearing of new sexuals. Here, we identify the first such queen pheromone in the pharaoh ant Monomorium pharaonis and demonstrate its mode of action via bioassays with the pure biosynthesized compound. In particular, we show that the monocyclic diterpene neocembrene, which in different Monomorium species is produced solely by fertile, egg-laying queens, strongly inhibits the rearing of new sexuals (queens and males) and also exerts a weakly attractive 'queen retinue' effect on the workers. This is the first time that a queen pheromone with such a dual function has been identified in a social insect species with obligately sterile workers.
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Affiliation(s)
- Ricardo Caliari Oliveira
- Laboratory of Socioecology and Social Evolution, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - Jonas Warson
- Laboratory of Socioecology and Social Evolution, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - David Sillam-Dussès
- Laboratory of Experimental and Comparative Ethology UR 4443, University Sorbonne Paris Nord, 93430 Villetaneuse, France
| | - Beatriz Herrera-Malaver
- Laboratory of Systems Biology, VIB-KU Leuven Center for Microbiology, Leuven, Belgium.,Laboratory for Genetics and Genomics, Center of Microbial and Plant Genetics, Department M2S, KU Leuven, Gaston Geenslaan 1, 3001, Heverlee, Belgium
| | - Kevin Verstrepen
- Laboratory of Systems Biology, VIB-KU Leuven Center for Microbiology, Leuven, Belgium.,Laboratory for Genetics and Genomics, Center of Microbial and Plant Genetics, Department M2S, KU Leuven, Gaston Geenslaan 1, 3001, Heverlee, Belgium
| | - Jocelyn G Millar
- Department of Entomology, University of California, Riverside, CA 92521, USA.,Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Tom Wenseleers
- Laboratory of Socioecology and Social Evolution, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
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7
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Princen SA, Van Oystaeyen A, Petit C, van Zweden JS, Wenseleers T. Cross-activity of honeybee queen mandibular pheromone in bumblebees provides evidence for sensory exploitation. Behav Ecol 2019. [DOI: 10.1093/beheco/arz191] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
AbstractThe evolutionary origin of queen pheromones (QPs), which regulate reproductive division of labor in insect societies, has been explained by two evolutionary scenarios: the sender-precursor hypothesis and the sensory exploitation hypothesis. These scenarios differ in terms of whether the signaling system was built on preadaptations on the part of either the sender queens or the receiver workers. While some social insect QPs—such as cuticular hydrocarbons—were likely derived from ancestral fertility cues and evolved according to the former theory, the honeybee’s queen mandibular pheromone (QMP) has been suggested to act directly on preexisting gene-regulatory networks linked with reproduction. This is evidenced by the fact that QMP has been shown to also inhibit ovary activation in fruit flies, thereby implying exploitation of conserved physiological pathways. To verify whether QMP has similar effects on more closely related eusocial species, we here tested for QMP cross-activity in the bumblebee Bombus terrestris. Interestingly, we found that the non-native QMP blend significantly inhibited egg laying in both worker and queen bumblebees and caused accompanying shifts in ovary activation. The native bumblebee QP pentacosane, by contrast, only inhibited the reproduction of the workers. Overall, these findings support the hypothesis that honeybee QMP likely evolved via a route of sensory exploitation. We argue that such exploitation could allow social insect queens to produce compounds that manipulate the workers to remain sterile, but that a major hurdle would be that the queens themselves would have to be immune to such compounds.
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Affiliation(s)
- Sarah A Princen
- Department of Biology, KU Leuven, Laboratory of Socioecology and Social Evolution, Naamsestraat, Leuven, Belgium
| | - Annette Van Oystaeyen
- Department of Biology, KU Leuven, Laboratory of Socioecology and Social Evolution, Naamsestraat, Leuven, Belgium
- Biobest Group NV, Westerlo, Belgium
| | - Clément Petit
- Biobest Group NV, Westerlo, Belgium
- Montpellier SupAgro, Montpellier, France
| | - Jelle S van Zweden
- Department of Biology, KU Leuven, Laboratory of Socioecology and Social Evolution, Naamsestraat, Leuven, Belgium
| | - Tom Wenseleers
- Department of Biology, KU Leuven, Laboratory of Socioecology and Social Evolution, Naamsestraat, Leuven, Belgium
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Almond EJ, Huggins TJ, Crowther LP, Parker JD, Bourke AFG. Queen Longevity and Fecundity Affect Conflict with Workers over Resource Inheritance in a Social Insect. Am Nat 2018; 193:256-266. [PMID: 30720369 DOI: 10.1086/701299] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Resource inheritance is a major source of conflict in animal societies. However, the assumptions and predictions of models of conflict over resource inheritance have not been systematically tested within a single system. We developed an inclusive fitness model for annual eusocial Hymenoptera that predicts a zone of conflict in which future reproductive workers are selected to enforce nest inheritance before the queen is selected to cede the nest. We experimentally tested key elements of this model in the bumblebee Bombus terrestris. In colonies from which queens were sequentially removed, queen tenure was significantly negatively associated with worker male production, confirming that workers gain direct fitness by usurping the queen. In unmanipulated colonies, queen fecundity decreased significantly over the latter part of the colony cycle, confirming that workers' indirect fitness from maintaining queens declines over time. Finally, in an experiment simulating loss of queen fecundity by removal of queens' eggs, worker-to-queen aggression increased significantly and aggressive workers were significantly more likely to become egg layers, consistent with workers monitoring queen fecundity to assess the net benefit of future reproduction. Overall, by upholding key assumptions and predictions of the model, our results provide novel empirical support for kin-selected conflict over resource inheritance.
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Queen Control or Queen Signal in Ants: What Remains of the Controversy 25 Years After Keller and Nonacs' Seminal Paper? J Chem Ecol 2018; 44:805-817. [PMID: 29858748 DOI: 10.1007/s10886-018-0974-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/05/2018] [Accepted: 05/25/2018] [Indexed: 10/14/2022]
Abstract
Ant queen pheromones (QPs) have long been known to affect colony functioning. In many species, QPs affect important reproductive functions such as diploid larvae sexualization and egg-laying by workers, unmated queens (gynes), or other queens. Until the 1990s, these effects were generally viewed to be the result of queen manipulation through the use of coercive or dishonest signals. However, in their seminal 1993 paper, Keller and Nonacs challenged this idea, suggesting that QPs had evolved as honest signals that informed workers and other colony members of the queen's presence and reproductive state. This paper has greatly influenced the study of ant QPs and inspired numerous attempts to identify fertility-related compounds and test their physiological and behavioral effects. In the present article, we review the literature on ant QPs in various contexts and pay special attention to the role of cuticular hydrocarbons (CHCs). Although the controversy generated by Keller and Nonacs' (Anim Behav 45:787-794, 1993) paper is currently less intensively debated, there is still no clear evidence which allows the rejection of the queen control hypothesis in favor of the queen signal hypothesis. We argue that important questions remain regarding the mode of action of QPs, and their targets which may help understanding their evolution.
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10
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Affiliation(s)
- Luke Holman
- School of BioSciences, University of Melbourne, Royal Parade, Melbourne, VIC 3010, Australia
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11
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Ghaninia M, Haight K, Berger SL, Reinberg D, Zwiebel LJ, Ray A, Liebig J. Chemosensory sensitivity reflects reproductive status in the ant Harpegnathos saltator. Sci Rep 2017; 7:3732. [PMID: 28623371 PMCID: PMC5473913 DOI: 10.1038/s41598-017-03964-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 04/04/2017] [Indexed: 11/08/2022] Open
Abstract
Insects communicate with pheromones using sensitive antennal sensilla. Although trace amounts of pheromones can be detected by many insects, context-dependent increased costs of high sensitivity might lead to plasticity in sensillum responsiveness. We have functionally characterized basiconic sensilla of the ant Harpegnathos saltator for responses to general odors in comparison to cuticular hydrocarbons which can act as fertility signals emitted by the principal reproductive(s) of a colony to inhibit reproduction by worker colony members. When released from inhibition workers may become reproductive gamergates. We observed plasticity in olfactory sensitivity after transition to reproductive status with significant reductions in electrophysiological responses to several long-chained cuticular hydrocarbons. Although gamergates lived on average five times longer than non-reproductive workers, the shift to reproductive status rather than age differences matched the pattern of changes in olfactory sensitivity. Decreasing sensillum responsiveness to cuticular hydrocarbons could potentially reduce mutually inhibitory or self-inhibitory effects on gamergate reproduction.
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Affiliation(s)
- Majid Ghaninia
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
- Division of Entomology, Department of Plant Protection, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | - Kevin Haight
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Shelley L Berger
- Departments of Cell and Developmental Biology, Genetics and Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Danny Reinberg
- Howard Hughes Medical Institute and Department of Molecular Pharmacology and Biochemistry, New York University School of Medicine, New York, NY, 10016, USA
| | - Laurence J Zwiebel
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37235, USA
| | - Anandasankar Ray
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Jürgen Liebig
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA.
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12
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Holman L, Lanfear R, d'Ettorre P. The evolution of queen pheromones in the ant genus Lasius. J Evol Biol 2013; 26:1549-58. [PMID: 23662630 DOI: 10.1111/jeb.12162] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 02/21/2013] [Accepted: 03/14/2013] [Indexed: 11/28/2022]
Abstract
Queen pheromones are among the most important chemical messages regulating insect societies yet they remain largely undiscovered, hindering research into interesting proximate and ultimate questions. Identifying queen pheromones in multiple species would give new insight into the selective pressures and evolutionary constraints acting on these ubiquitous signals. Here, we present experimental and comparative evidence that 3-methylalkanes, hydrocarbons present on the queen's cuticle, are a queen pheromone throughout the ant genus Lasius. Interspecific variation in the chemical profile is consistent with 3-methylalkanes evolving more slowly than other types of hydrocarbons, perhaps due to differential selection or evolutionary constraints. We argue that the sensory ecology of the worker response imposes strong stabilizing selection on queen pheromones relative to other hydrocarbons. 3-Methylalkanes are also strongly physiologically and genetically coupled with fecundity in at least one Lasius species, which may translate into evolutionary constraints. Our results highlight how honest signalling could minimize evolutionary conflict over reproduction, promoting the evolution and maintenance of eusociality.
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Affiliation(s)
- L Holman
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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