1
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Antenna movements as a function of odorants' biological value in honeybees (Apis mellifera L.). Sci Rep 2022; 12:11674. [PMID: 35804161 PMCID: PMC9270438 DOI: 10.1038/s41598-022-14354-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 06/06/2022] [Indexed: 11/21/2022] Open
Abstract
In honeybees, the antennae are highly mobile sensory organs that express scanning movements in various behavioral contexts and toward many stimuli, especially odorants. The rules underlying these movements are still unclear. Using a motion-capture system, we analyzed bees’ antennal responses to a panel of pheromonal and other biologically relevant odorants. We observed clear differences in bees’ antennal responses, with opposite movements to stimuli related to opposite contexts: slow backward movements were expressed in response to alarm pheromones, while fast forward movements were elicited by food related cues as well as brood and queen related pheromones. These responses are reproducible, as a similar pattern of odor-specific responses was observed in bees from different colonies, on different years. We then tested whether odorants’ attractiveness for bees, measured using an original olfactory orientation setup, may predict antenna movements. This simple measure of odorants’ valence did however not correlate with either antennal position or velocity measures, showing that more complex rules than simple hedonics underlie bees’ antennal responses to odorants. Lastly, we show that newly-emerged bees express only limited antennal responses compared to older bees, suggesting that a significant part of the observed responses are acquired during bees’ behavioral development.
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2
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Abbot P. Defense in Social Insects: Diversity, Division of Labor, and Evolution. ANNUAL REVIEW OF ENTOMOLOGY 2022; 67:407-436. [PMID: 34995089 DOI: 10.1146/annurev-ento-082521-072638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
All social insects defend their colony from predators, parasites, and pathogens. In Oster and Wilson's classic work, they posed one of the key paradoxes about defense in social insects: Given the universal necessity of defense, why then is there so much diversity in mechanisms? Ecological factors undoubtedly are important: Predation and usurpation have imposed strong selection on eusocial insects, and active defense by colonies is a ubiquitous feature of all social insects. The description of diverse insect groups with castes of sterile workers whose main duty is defense has broadened the purview of social evolution in insects, in particular with respect to caste and behavior. Defense is one of the central axes along which we can begin to organize and understand sociality in insects. With the establishment of social insect models such as the honey bee, new discoveries are emerging regarding the endocrine, neural, and gene regulatory mechanisms underlying defense in social insects. The mechanisms underlying morphological and behavioral defense traits may be shared across diverse groups, providing opportunities for identifying both conserved and novel mechanisms at work. Emerging themes highlight the context dependency of and interaction between factors that regulate defense in social insects.
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Affiliation(s)
- Patrick Abbot
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA;
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3
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Baracchi D, Giurfa M, d'Ettorre P. Formic acid modulates latency and accuracy of nestmate recognition in carpenter ants. J Exp Biol 2021; 224:272354. [PMID: 34605911 DOI: 10.1242/jeb.242784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 09/26/2021] [Indexed: 11/20/2022]
Abstract
Decision-making processes face the dilemma of being accurate or faster, a phenomenon that has been described as speed-accuracy trade-off in numerous studies on animal behaviour. In social insects, discriminating between colony members and aliens is subject to this trade-off as rapid and accurate rejection of enemies is of primary importance for the maintenance and ecological success of insect societies. Recognition cues distinguishing aliens from nestmates are embedded in the cuticular hydrocarbon (CHC) layer and vary among colonies. In walking carpenter ants, exposure to formic acid (FA), an alarm pheromone, improves the accuracy of nestmate recognition by decreasing both alien acceptance and nestmate rejection. Here, we studied the effect of FA exposure on the spontaneous aggressive mandible opening response (MOR) of harnessed Camponotus aethiops ants presented with either nestmate or alien CHCs. FA modulated both MOR accuracy and the latency to respond to odours of conspecifics. In particular, FA decreased the MOR towards nestmates but increased it towards aliens. Furthermore, FA decreased MOR latency towards aliens but not towards nestmates. As response latency can be used as a proxy of response speed, we conclude that contrary to the prediction of the speed-accuracy trade-off theory, ants did not trade off speed against accuracy in the process of nestmate recognition.
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Affiliation(s)
- David Baracchi
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, F-31062 Toulouse, France.,Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, F-31062 Toulouse, France.,Institut Universitaire de France (IUF), 75231 Paris, France
| | - Patrizia d'Ettorre
- Institut Universitaire de France (IUF), 75231 Paris, France.,Laboratory of Experimental and Comparative Ethology, University Sorbonne Paris Nord, 93430 Villetaneuse, France
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4
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Varnon CA, Vallely N, Beheler C, Coffin C. The disturbance leg-lift response (DLR): an undescribed behavior in bumble bees. PeerJ 2021; 9:e10997. [PMID: 33828912 PMCID: PMC8005288 DOI: 10.7717/peerj.10997] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 02/02/2021] [Indexed: 01/25/2023] Open
Abstract
Background Bumble bees, primarily Bombus impatiens and B. terrestris, are becoming increasingly popular organisms in behavioral ecology and comparative psychology research. Despite growing use in foraging and appetitive conditioning experiments, little attention has been given to innate antipredator responses and their ability to be altered by experience. In this paper, we discuss a primarily undescribed behavior, the disturbance leg-lift response (DLR). When exposed to a presumably threatening stimulus, bumble bees often react by lifting one or multiple legs. We investigated DLR across two experiments. Methods In our first experiment, we investigated the function of DLR as a prerequisite to later conditioning research. We recorded the occurrence and sequence of DLR, biting and stinging in response to an approaching object that was either presented inside a small, clear apparatus containing a bee, or presented directly outside of the subject’s apparatus. In our second experiment, we investigated if DLR could be altered by learning and experience in a similar manner to many other well-known bee behaviors. We specifically investigated habituation learning by repeatedly presenting a mild visual stimulus to samples of captive and wild bees. Results The results of our first experiment show that DLR and other defensive behaviors occur as a looming object approaches, and that the response is greater when proximity to the object is lower. More importantly, we found that DLR usually occurs first, rarely precedes biting, and often precedes stinging. This suggests that DLR may function as a warning signal that a sting will occur. In our second experiment, we found that DLR can be altered as a function of habituation learning in both captive and wild bees, though the captive sample initially responded more. This suggests that DLR may be a suitable response for many other conditioning experiments.
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Affiliation(s)
- Christopher A Varnon
- Department of Psychology, Converse College, Spartanburg, SC, United States of America
| | - Noelle Vallely
- Department of Psychology, Converse College, Spartanburg, SC, United States of America
| | - Charlie Beheler
- Department of Psychology, Converse College, Spartanburg, SC, United States of America
| | - Claudia Coffin
- Department of Psychology, Converse College, Spartanburg, SC, United States of America
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5
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Murmu MS, Hanoune J, Choi A, Bureau V, Renou M, Dacher M, Deisig N. Modulatory effects of pheromone on olfactory learning and memory in moths. JOURNAL OF INSECT PHYSIOLOGY 2020; 127:104159. [PMID: 33127358 DOI: 10.1016/j.jinsphys.2020.104159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 09/28/2020] [Accepted: 10/23/2020] [Indexed: 06/11/2023]
Abstract
Pheromones are chemical communication signals known to elicit stereotyped behaviours and/or physiological processes in individuals of the same species, generally in relation to a specific function (e.g. mate finding in moths). However, recent research suggests that pheromones can modulate behaviours, which are not directly related to their usual function and thus potentially affect behavioural plasticity. To test this hypothesis, we studied the possible modulatory effects of pheromones on olfactory learning and memory in Agrotis ipsilon moths, which are well-established models to study sex-pheromones. To achieve this, sexually mature male moths were trained to associate an odour with either a reward (appetitive learning) or punishment (aversive learning) and olfactory memory was tested at medium- and long-term (1 h or 1.5 h, and 24 h). Our results show that male moths can learn to associate an odour with a sucrose reward, as well as a mild electric shock, and that olfactory memory persists over medium- and long-term range. Pheromones facilitated both appetitive and aversive olfactory learning: exposure to the conspecific sex-pheromone before conditioning enhanced appetitive but not aversive learning, while exposure to a sex-pheromone component of a heterospecific species (repellent) facilitated aversive but not appetitive learning. However, this effect was short-term, as medium- and long-term memory were not improved. Thus, in moths, pheromones can modulate olfactory learning and memory, indicating that they contribute to behavioural plasticity allowing optimization of the animal's behaviour under natural conditions. This might occur through an alteration of sensitization.
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Affiliation(s)
- Meena Sriti Murmu
- Sorbonne Université, Université Paris Est Créteil, INRAE, CNRS, IRD - Institute for Ecology and Environmental Sciences of Paris, iEES Paris, 75252 Paris, France; Commissariat à l'Energie Atomique et aux énergies Alternatives (CEA), Institut des Sciences du Vivant Frédéric Joliot, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), CEA de Saclay, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
| | - Jeremy Hanoune
- Sorbonne Université, Université Paris Est Créteil, INRAE, CNRS, IRD - Institute for Ecology and Environmental Sciences of Paris, iEES Paris, 75252 Paris, France
| | - Abraham Choi
- Sorbonne Université, Université Paris Est Créteil, INRAE, CNRS, IRD - Institute for Ecology and Environmental Sciences of Paris, iEES Paris, 75252 Paris, France
| | - Valentin Bureau
- Sorbonne Université, Université Paris Est Créteil, INRAE, CNRS, IRD - Institute for Ecology and Environmental Sciences of Paris, iEES Paris, 75252 Paris, France
| | - Michel Renou
- Sorbonne Université, Université Paris Est Créteil, INRAE, CNRS, IRD - Institute for Ecology and Environmental Sciences of Paris, iEES Paris, 75252 Paris, France
| | - Matthieu Dacher
- Sorbonne Université, Université Paris Est Créteil, INRAE, CNRS, IRD - Institute for Ecology and Environmental Sciences of Paris, iEES Paris, 75252 Paris, France.
| | - Nina Deisig
- Sorbonne Université, Université Paris Est Créteil, INRAE, CNRS, IRD - Institute for Ecology and Environmental Sciences of Paris, iEES Paris, 75252 Paris, France; Computational Systems Neuroscience, Institute of Zoology, University of Cologne, Cologne, Germany.
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6
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Oberhauser FB, Wendt S, Czaczkes TJ. Trail Pheromone Does Not Modulate Subjective Reward Evaluation in Lasius niger Ants. Front Psychol 2020; 11:555576. [PMID: 33071878 PMCID: PMC7540218 DOI: 10.3389/fpsyg.2020.555576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 09/01/2020] [Indexed: 11/29/2022] Open
Abstract
Comparing the value of options is at the heart of economic decision-making. While an option may have an absolute quality (e.g. a food source has a fixed energy content), the perceived value of the option may be malleable. The factors affecting the perceived value of an option may thus strongly influence which option is ultimately chosen. Expectations have been shown to be a strong driver of perceived value in both humans and social insects, causing an undervaluation of a given option if a better option was expected, and an overvaluation if a poorer one was expected. In humans, perceived value can be strongly affected by social information. Value perception in some insects has also been shown to be affected by social information, showing conformism as in humans and other animals. Here, over a series of experiments, we tested whether pheromone trail presence, a social information source, influenced the perceived value of a food source in the ant Lasius niger. We found that the presence of pheromone trails leading to a sucrose solution does not influence food acceptance, pheromone deposition when returning from a food source, drinking time, or frequency of U-turns on return from the food. Two further assays for measuring changes in food acceptance, designed to increase sensitivity by avoiding ceiling effects, also showed no effect of pheromone presence on food acceptance. In a separate study, L. niger have also been found to show no preference for, or avoidance of, odors associated with foods found in the presence of pheromone. We are thus confident that trail pheromone presence does not affect the perceived value of a food source in these ants.
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Affiliation(s)
- Felix B Oberhauser
- Animal Comparative Economics Laboratory, University of Regensburg, Regensburg, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - Stephanie Wendt
- Animal Comparative Economics Laboratory, University of Regensburg, Regensburg, Germany
| | - Tomer J Czaczkes
- Animal Comparative Economics Laboratory, University of Regensburg, Regensburg, Germany
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7
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Rossi N, Pereyra M, Moauro MA, Giurfa M, d'Ettorre P, Josens R. Trail pheromone modulates subjective reward evaluation in Argentine ants. J Exp Biol 2020; 223:jeb230532. [PMID: 32680904 DOI: 10.1242/jeb.230532] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/15/2020] [Indexed: 12/13/2022]
Abstract
The Argentine ant, Linepithema humile, is native to South America but has become one of the most invasive species in the world. These ants heavily rely on trail pheromones for foraging, and previous studies have focused on such signals to develop a strategy for chemical control. Here, we studied the effects of pre-exposure to the trail pheromone on sugar acceptance and olfactory learning in Argentine ants. We used the synthetic trail pheromone component (Z)-9-hexadecenal, which triggers the same attraction and trail-following behavior as the natural trail pheromone. We found that pre-exposure to (Z)-9-hexadecenal increases the acceptance of sucrose solutions of different concentrations, thus changing the ants' subjective evaluation of a food reward. However, although ants learned to associate an odor with a sucrose reward, pheromone pre-exposure affected neither the learning nor the mid-term memory of the odor-reward association. Taking into account the importance of the Argentine ant as a pest and invasive organism, our results highlight the importance of pheromonal cues in resource evaluation, a fact that could be useful in control strategies implemented for this species.
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Affiliation(s)
- Natacha Rossi
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria Pab. II. (C1428 EHA), Buenos Aires, Argentina
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, F-31062 Toulouse Cedex 09, France
| | - Muriel Pereyra
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria Pab. II. (C1428 EHA), Buenos Aires, Argentina
| | - Mariel A Moauro
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria Pab. II. (C1428 EHA), Buenos Aires, Argentina
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, F-31062 Toulouse Cedex 09, France
- Institut Universitaire de France (IUF), Paris, France
| | - Patrizia d'Ettorre
- Laboratory of Experimental and Comparative Ethology, UR4443, University Sorbonne Paris Nord, Villetaneuse, France
- Institut Universitaire de France (IUF), Paris, France
| | - Roxana Josens
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria Pab. II. (C1428 EHA), Buenos Aires, Argentina
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8
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Baracchi D, Cabirol A, Devaud JM, Haase A, d'Ettorre P, Giurfa M. Pheromone components affect motivation and induce persistent modulation of associative learning and memory in honey bees. Commun Biol 2020; 3:447. [PMID: 32807870 PMCID: PMC7431541 DOI: 10.1038/s42003-020-01183-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 06/30/2020] [Indexed: 01/11/2023] Open
Abstract
Since their discovery in insects, pheromones are considered as ubiquitous and stereotyped chemical messengers acting in intraspecific animal communication. Here we studied the effect of pheromones in a different context as we investigated their capacity to induce persistent modulations of associative learning and memory. We used honey bees, Apis mellifera, and combined olfactory conditioning and pheromone preexposure with disruption of neural activity and two-photon imaging of olfactory brain circuits, to characterize the effect of pheromones on olfactory learning and memory. Geraniol, an attractive pheromone component, and 2-heptanone, an aversive pheromone, improved and impaired, respectively, olfactory learning and memory via a durable modulation of appetitive motivation, which left odor processing unaffected. Consistently, interfering with aminergic circuits mediating appetitive motivation rescued or diminished the cognitive effects induced by pheromone components. We thus show that these chemical messengers act as important modulators of motivational processes and influence thereby animal cognition.
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Affiliation(s)
- David Baracchi
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse, Cedex 09, France.
- Department of Biology, University of Florence, Via Madonna del Piano, 6, 50019, Sesto Fiorentino, Italy.
| | - Amélie Cabirol
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Piazza Manifattura 1, I-38068, Rovereto, Italy
| | - Jean-Marc Devaud
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse, Cedex 09, France
| | - Albrecht Haase
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Piazza Manifattura 1, I-38068, Rovereto, Italy
- Department of Physics, University of Trento, Via Sommarive 14, I-38123, Povo, Italy
| | - Patrizia d'Ettorre
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse, Cedex 09, France
- Laboratory of Experimental and Comparative Ethology, University of Paris 13, F-93430, Sorbonne Paris Cité, France
- Institut Universitaire de France (IUF), Paris, France
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse, Cedex 09, France.
- Institut Universitaire de France (IUF), Toulouse, France.
- College of Animal Science (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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9
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Varnon CA, Dinges CW, Vest AJ, Abramson CI. Conspecific and interspecific stimuli reduce initial performance in an aversive learning task in honey bees (Apis mellifera). PLoS One 2020; 15:e0228161. [PMID: 32097420 PMCID: PMC7041878 DOI: 10.1371/journal.pone.0228161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/08/2020] [Indexed: 11/26/2022] Open
Abstract
The purpose of this experiment was to investigate whether honey bees (Apis mellifera) are able to use social discriminative stimuli in a spatial aversive conditioning paradigm. We tested bees' ability to avoid shock in a shuttle box apparatus across multiple groups when either shock, or the absence of shock, was associated with a live hive mate, a dead hive mate, a live Polistes exclamans wasp or a dead wasp. Additionally, we used several control groups common to bee shuttle box research where shock was only associated with spatial cues, or where shock was associated with a blue or yellow color. While bees were able to learn the aversive task in a simple spatial discrimination, the presence of any other stimuli (color, another bee, or a wasp) reduced initial performance. While the color biases we discovered are in line with other experiments, the finding that the presence of another animal reduces performance is novel. Generally, it appears that the use of bees or wasps as stimuli initially causes an increase in overall activity that interferes with early performance in the spatial task. During the course of the experiment, the bees habituate to the insect stimuli (bee or wasp), and begin learning the aversive task. Additionally, we found that experimental subject bees did not discriminate between bees or wasps used as stimulus animals, nor did they discriminate between live or dead stimulus animals. This may occur, in part, due to the specialized nature of the worker honey bee. Results are discussed with implications for continual research on honey bees as models of aversive learning, as well as research on insect social learning in general.
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Affiliation(s)
- Christopher A. Varnon
- Laboratory of Comparative Psychology and Behavioral Ecology, Department of Psychology, Converse College, Spartanburg, South Carolina, United States of America
| | - Christopher W. Dinges
- Laboratory of Comparative Psychology and Behavioral Biology, Department of Psychology, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Adam J. Vest
- Laboratory of Comparative Psychology and Behavioral Biology, Department of Psychology, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Charles I. Abramson
- Laboratory of Comparative Psychology and Behavioral Biology, Department of Psychology, Oklahoma State University, Stillwater, Oklahoma, United States of America
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10
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Hostachy C, Couzi P, Portemer G, Hanafi-Portier M, Murmu M, Deisig N, Dacher M. Exposure to Conspecific and Heterospecific Sex-Pheromones Modulates Gustatory Habituation in the Moth Agrotis ipsilon. Front Physiol 2019; 10:1518. [PMID: 31920719 PMCID: PMC6933015 DOI: 10.3389/fphys.2019.01518] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 12/03/2019] [Indexed: 12/18/2022] Open
Abstract
In several insects, sex-pheromones are essential for reproduction and reproductive isolation. Pheromones generally elicit stereotyped behaviors. In moths, these are attraction to conspecific sex-pheromone sources and deterrence for heterospecific sex-pheromone. Contrasting with these innate behaviors, some results in social insects point toward effects of non-sex-pheromones on perception and learning. We report the effects of sex-pheromone pre-exposure on gustatory perception and habituation (a non-associative learning) in male Agrotis ipsilon moths, a non-social insect. We also studied the effect of Z5-decenyl acetate (Z5), a compound of the sex-pheromone of the related species Agrotis segetum. We hypothesized that conspecific sex-pheromone and Z5 would have opposite effects. Pre-exposure to either the conspecific sex-pheromone or Z5 lasted 15 min and was done either immediately or 24 h before the experiments, using their solvent alone (hexane) as control. In a sucrose responsiveness assay, pre-exposure to the conspecific sex-pheromone had no effect on the dose-response curve at either delays. By contrast, Z5 slightly improved sucrose responsiveness 15 min but not 24 h after pre-exposure. Interestingly, the conspecific sex-pheromone and Z5 had time-dependent effects on gustatory habituation: pre-exposing the moths with Z5 hindered learning after immediate but not 24-h pre-exposure, whereas pre-exposure to the conspecific sex-pheromone hindered learning at 24-h but not immediate pre-exposure. They did not have opposite effects. This is the first time a sex-pheromone is reported to affect learning in a non-social insect. The difference in modulation between conspecific sex-pheromone and Z5 suggests that con- and hetero-specific sex-pheromones act on plasticity through different cerebral pathways.
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Affiliation(s)
- Camille Hostachy
- CNRS, INRA, IRD, Institute for Ecology and Environmental Sciences of Paris, Sorbonne Universite, Universite Paris Est Creteil, Paris, France
| | - Philippe Couzi
- CNRS, INRA, IRD, Institute for Ecology and Environmental Sciences of Paris, Sorbonne Universite, Universite Paris Est Creteil, Paris, France
| | - Guillaume Portemer
- CNRS, INRA, IRD, Institute for Ecology and Environmental Sciences of Paris, Sorbonne Universite, Universite Paris Est Creteil, Paris, France
| | - Melissa Hanafi-Portier
- CNRS, INRA, IRD, Institute for Ecology and Environmental Sciences of Paris, Sorbonne Universite, Universite Paris Est Creteil, Paris, France
| | - Meena Murmu
- CNRS, INRA, IRD, Institute for Ecology and Environmental Sciences of Paris, Sorbonne Universite, Universite Paris Est Creteil, Paris, France
| | - Nina Deisig
- CNRS, INRA, IRD, Institute for Ecology and Environmental Sciences of Paris, Sorbonne Universite, Universite Paris Est Creteil, Paris, France
| | - Matthieu Dacher
- CNRS, INRA, IRD, Institute for Ecology and Environmental Sciences of Paris, Sorbonne Universite, Universite Paris Est Creteil, Paris, France
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11
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Finkelstein AB, Brent CS, Giurfa M, Amdam GV. Foraging Experiences Durably Modulate Honey Bees' Sucrose Responsiveness and Antennal Lobe Biogenic Amine Levels. Sci Rep 2019; 9:5393. [PMID: 30931967 PMCID: PMC6443788 DOI: 10.1038/s41598-019-41624-0] [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: 08/15/2018] [Accepted: 03/13/2019] [Indexed: 11/10/2022] Open
Abstract
Foraging exposes organisms to rewarding and aversive events, providing a selective advantage for maximizing the former while minimizing the latter. Honey bees (Apis mellifera) associate environmental stimuli with appetitive or aversive experiences, forming preferences for scents, locations, and visual cues. Preference formation is influenced by inter-individual variation in sensitivity to rewarding and aversive stimuli, which can be modulated by pharmacological manipulation of biogenic amines. We propose that foraging experiences act on biogenic amine pathways to induce enduring changes to stimulus responsiveness. To simulate varied foraging conditions, freely-moving bees were housed in cages where feeders offered combinations of sucrose solution, floral scents, and aversive electric shock. Transient effects were excluded by providing bees with neutral conditions for three days prior to all subsequent assays. Sucrose responsiveness was reduced in bees that had foraged for scented rather than unscented sucrose under benign conditions. This was not the case under aversive foraging conditions, suggesting an adaptive tuning process which maximizes preference for high quality, non-aversive floral sites. Foraging conditions also influenced antennal lobe octopamine and serotonin, neuromodulators involved in stimulus responsiveness and foraging site evaluation. Our results suggest that individuals’ foraging experiences durably modify neurochemistry and shape future foraging behaviour.
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Affiliation(s)
| | - Colin S Brent
- United States Department of Agriculture, Arid Land Agricultural Research Center, Maricopa, USA
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse, Cedex 09, France
| | - Gro V Amdam
- School of Life Sciences, Arizona State University, Tempe, USA.,Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway
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Rossi N, Baracchi D, Giurfa M, d'Ettorre P. Pheromone-Induced Accuracy of Nestmate Recognition in Carpenter Ants: Simultaneous Decrease in Type I and Type II Errors. Am Nat 2018; 193:267-278. [PMID: 30720368 DOI: 10.1086/701123] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The ecological and evolutionary success of social insects relies on their ability to efficiently discriminate between group members and aliens. Nestmate recognition occurs by phenotype matching, the comparison of the referent (colony) phenotype to the one of an encountered individual. Based on the level of dissimilarity between the two, the discriminator accepts or rejects the target. The tolerated degree of mismatch is predicted by the acceptance threshold model, which assumes adaptive threshold shifts depending on the costs of discrimination errors. Inherent in the model is that rejection (type I) and acceptance (type II) errors are reciprocally related: if one type decreases, the other increases. We studied whether alarm pheromones modulate the acceptance threshold. We exposed Camponotus aethiops ants to formic acid and subsequently measured aggression toward nestmates and nonnestmates. Formic acid induced both more nonnestmate rejection and more nestmate acceptance than a control treatment, thus uncovering an unexpected effect of an alarm pheromone on responses to nestmates. Nestmate discrimination accuracy was improved via a decrease in both types of errors, a result that cannot be explained by a shift in the acceptance threshold. We propose that formic acid increases the amount of information available to the ants, thus decreasing the perceived phenotypic overlap between nestmate and nonnestmate recognition cues. This mechanism for improved discrimination reveals a novel function of alarm pheromones in recognition processes and may have far-reaching implications in our understanding of the modus operandi of recognition systems in general.
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Knight K. Pheromones fiddle with bee perception. J Exp Biol 2018. [DOI: 10.1242/jeb.178426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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