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Stephen C Pratt - One of the best experts on this subject based on the ideXlab platform.
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route learning during tandem running in the rock ant Temnothorax albipennis
The Journal of Experimental Biology, 2020Co-Authors: Leo Danczak, Beth Thompson, Trisha Morshed, Takao Sasaki, Stephen C PrattAbstract:ABSTRACT Many animals use information from conspecifics to change their behavior in adaptive ways. When a rock ant, Temnothorax albipennis, finds food, she returns to her colony and uses a method called tandem running to lead nestmates, one at a time, from the nest to the food. In this way, naive ants can learn the location of a food source. Less clear is whether they also learn navigational cues that guide them from nest to food, although this is often assumed. We tested this idea by tracing the routes of individually marked ants as they followed tandem runs to a feeder, returned to the nest, and later traveled independently back to the food. Our results show, for the first time, that tandem run followers learn specific routes from their leaders. Independent journeys back to the food source were significantly more similar to the routes on which the ants had been led, compared with the routes taken by other tandem runs. In contrast, the homeward journey did not resemble the tandem run route. These results are consistent with followers memorizing visual cues during the tandem run that are useful for recapitulating the outward journey, but not as effective when facing in the opposite direction on the homeward journey. We further showed that foraging routes improved through individual experience over multiple trips but not through the social transfer of route information via tandem running. We discuss our findings in relation to social learning and integration of individual and social information in ants.
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rational time investment during collective decision making in Temnothorax ants
Biology Letters, 2019Co-Authors: Takao Sasaki, Benjamin Stott, Stephen C PrattAbstract:The study of rational choice in humans and other animals typically focuses on decision outcomes, but rationality also applies to decision latencies, especially when time is scarce and valuable. For...
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Correction: Visual Navigation during Colony Emigration by the Ant Temnothorax rugatulus
PloS one, 2015Co-Authors: Sean R. Bowens, Daniel P. Glatt, Stephen C PrattAbstract:In the title and Abstract of this article, the wrong species name is given. The correct species name is Temnothorax curvispinosus. The correct title is: Visual Navigation during Colony Emigration by the Ant Temnothorax curvispinosus. The second sentence of the Abstract should read: “We evaluated the roles of both modalities during colony emigration by Temnothorax curvispinosus. The correct citation is: Bowens SR, Glatt DP, Pratt SC (2013) Visual Navigation during Colony Emigration by the Ant Temnothorax curvispinosus. PLoS ONE 8(5): e64367. doi:10.1371/journal.pone.0064367
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Flexibility of collective decision making during house hunting in Temnothorax ants
Behavioral Ecology and Sociobiology, 2015Co-Authors: Takao Sasaki, Blake Colling, Anne Sonnenschein, May M Boggess, Stephen C PrattAbstract:Many social animals cooperatively process information during decision making, allowing them to concentrate on the best of several options. However, positive feedback created by information sharing can also lock the group into a suboptimal outcome if option quality changes over time. This creates a trade-off between consensus and flexibility, whose resolution depends on the information-sharing mechanisms groups employ. We investigated the influence of communication behavior on decision flexibility in nest site choice by colonies of the ant Temnothorax rugatulus . These ants divide their emigration into two distinct phases separated by a quorum rule. In the first phase, scouts recruit nestmates to promising sites using the slow method of tandem running. Once a site's population surpasses a quorum, they switch to the faster method of social transport. We gave colonies a choice between two sites of different quality, and then switched site quality at different points during the emigration. Before the quorum was met, colonies were able to switch their choice to the newly superior site, but once they began to transport, their flexibility dropped significantly. Close observation of single ants revealed that transporters were more likely than tandem leaders to continue recruiting to a site even after its quality was diminished. That is, tandem leaders continued to monitor the quality of the site, while transporters instead fully committed to the site without further assessment. We discuss how this change in commitment with quorum attainment may enhance the rapid achievement of consensus needed for nest site selection, but at a cost in flexibility once the quorum is met.
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a context dependent alarm signal in the ant Temnothorax rugatulus
The Journal of Experimental Biology, 2014Co-Authors: Bert Hölldobler, Takao Sasaki, Jocelyn G. Millar, Stephen C PrattAbstract:Because collective cognition emerges from local signaling among group members, deciphering communication systems is crucial to understanding the underlying mechanisms. Alarm signals are widespread in the social insects and can elicit a variety of behavioral responses to danger, but the functional plasticity of these signals has not been well studied. Here we report an alarm pheromone in the ant Temnothorax rugatulus that elicits two different behaviors depending on context. When an ant was tethered inside an unfamiliar nest site and unable to move freely, she released a pheromone from her mandibular gland that signaled other ants to reject this nest as a potential new home, presumably to avoid potential danger. When the same pheromone was presented near the ants' home nest, they were instead attracted to it, presumably to respond to a threat to the colony. We used coupled gas chromatography/mass spectrometry to identify candidate compounds from the mandibular gland and tested each one in a nest choice bioassay. We found that 2,5-dimethylpyrazine was sufficient to induce rejection of a marked new nest and also to attract ants when released at the home nest. This is the first detailed investigation of chemical communication in the leptothoracine ants. We discuss the possibility that this pheromone's deterrent function can improve an emigrating colony's nest site selection performance.
Nigel R. Franks - One of the best experts on this subject based on the ideXlab platform.
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Asymmetric ommatidia count and behavioural lateralization in the ant Temnothorax albipennis
Scientific reports, 2018Co-Authors: Edmund R Hunt, Ana B. Sendova-franks, Ciara Dornan, Nigel R. FranksAbstract:Workers of the house-hunting ant Temnothorax albipennis rely on visual edge following and landmark recognition to navigate their rocky environment, and they also exhibit a leftward turning bias when exploring unknown nest sites. We used electron microscopy to count the number of ommatidia composing the compound eyes of workers, males and queens, to make an approximate assessment of their relative sampling resolution; and to establish whether there is an asymmetry in the number of ommatidia composing the workers’ eyes, which might provide an observable, mechanistic explanation for the turning bias. We hypothesise that even small asymmetries in relative visual acuity between left and right eyes could be magnified by developmental experience into a symmetry-breaking turning preference that results in the inferior eye pointing toward the wall. Fifty-six workers were examined: 45% had more ommatidia in the right eye, 36% more in the left, and 20% an equal number. A tentative connection between relative ommatidia count for each eye and turning behaviour was identified, with a stronger assessment of behavioural lateralization before imaging and a larger sample suggested for further work. There was a clear sexual dimorphism in ommatidia counts between queens and males.
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Ants determine their next move at rest: motor planning and causality in complex systems
Royal Society open science, 2016Co-Authors: Edmund R Hunt, Roland J. Baddeley, Alan Worley, Ana B. Sendova-franks, Nigel R. FranksAbstract:To find useful work to do for their colony, individual eusocial animals have to move, somehow staying attentive to relevant social information. Recent research on individual Temnothorax albipennis ...
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trail laying during tandem running recruitment in the ant Temnothorax albipennis
Naturwissenschaften, 2014Co-Authors: Norasmah Basari, Ana B Sendovafranks, Benita C Lairdhopkins, Nigel R. FranksAbstract:Tandem running is a recruitment strategy whereby one ant leads a single naive nest mate to a resource. While tandem running progresses towards the goal, the leader ant and the follower ant maintain contact mainly by tactile signals. In this paper, we investigated whether they also deposit chemical signals on the ground during tandem running. We filmed tandem-running ants and analysed the position of the gasters of leaders and followers. Our results show that leader ants are more likely to press their gasters down to the substrate compared to follower ants, single ants and transporter ants. Forward tandem-run leaders (those moving towards a new nest site) performed such trail-marking procedures three times more often than reverse tandem leaders (those moving towards an old nest site). That leader ants marked the trails more often during forward tandem runs may suggest that it is more important to maintain the bond with the follower ant on forward tandem runs than on reverse tandem runs. Marked trails on the ground may serve as a safety line that improves both the efficiency of tandem runs and their completion rates.
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How is activity distributed among and within tasks in Temnothorax ants?
Behavioral Ecology and Sociobiology, 2012Co-Authors: Noa Pinter-wollman, Nigel R. Franks, Julia Hubler, Jo-anne Holley, Anna DornhausAbstract:How social insect colonies behave results from the actions of their workers. Individual variation among workers in their response to various tasks is necessary for the division of labor within colonies. A worker may be active in only a subset of tasks (specialist), perform all tasks (elite), or exhibit no particular pattern of task activity (idiosyncratic). Here we examine how worker activity is distributed among and within tasks in ants of the genus Temnothorax . We found that workers exhibited elitism within a situation, i.e., in particular sets of tasks, such as those associated with emigrations, nest building, or foraging. However, there was weak specialization for working in a particular situation. A few workers exhibited elitism across all situations, i.e., high performance in all tasks in all situations. Within any particular task, the distribution of activity among workers was skewed, with few ants performing most of the work and most ants performing very little of the work. We further found that workers persisted in their task preference over days, with the same individuals performing most of the work day after day. Interestingly, colonies were robust to the removal of these highly active workers; they were replaced by other individuals that were previously less active. This replacement was not short-lived; when the removed individuals were returned to the colony, not all of them resumed their prior high activity levels, and not all the workers that replaced them reduced their activity. Thus, even though some workers specialize in tasks within a particular situation and are persistent in performing them, task allocation in a colony is plastic and colonies can withstand removal of highly active individuals.
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group dynamics and record signals in the ant Temnothorax albipennis
Journal of the Royal Society Interface, 2011Co-Authors: Nigel R. Franks, Thomas O Richardson, Kim Christensen, H Jensen, Ana B SendovafranksAbstract:Many purely physical complex systems, in which there are both stochasticity and local interactions between the components, exhibit record dynamics. The temporal statistics of record dynamics is a Poisson process operating on a logarithmic rather than a linear time scale (i.e. a log-Poisson process). Record dynamics often drive substantial changes in complex systems when new high water marks in partially stochastic processes trigger new events. Social insect colonies are exemplary complex biological systems in which many of the local interactions of the components have been moulded by natural selection for the common good. Here, we combine experimental manipulation of ant colony demography with modelling to test the hypothesis that social interactions are the mechanism underlying the record dynamics. We found that compared with the control, log-Poisson statistics were disrupted in colonies in which the pattern of interactions was modified by the removal of the brood, and disappeared completely in ‘callow’ colonies composed entirely of very young workers from the same age cohort. We conclude that a subtle interplay between the demography of the society and the pattern of the interactions between the ants is crucial for the emergence of record dynamics. This could help identify what makes an ant colony a cohesive society.
Jürgen Heinze - One of the best experts on this subject based on the ideXlab platform.
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Comparative analyses of caste, sex, and developmental stage-specific transcriptomes in two Temnothorax ants.
Ecology and evolution, 2020Co-Authors: Claudia Gstöttl, Jürgen Heinze, Barbara Feldmeyer, Evelien Jongepier, Marah Stoldt, Erich Bornberg-bauer, Susanne FoitzikAbstract:Social insects dominate arthropod communities worldwide due to cooperation and division of labor in their societies. This, however, makes them vulnerable to exploitation by social parasites, such as slave-making ants. Slave-making ant workers pillage brood from neighboring nests of related host ant species. After emergence, host workers take over all nonreproductive colony tasks, whereas slavemakers have lost the ability to care for themselves and their offspring. Here, we compared transcriptomes of different developmental stages (larvae, pupae, and adults), castes (queens and workers), and sexes of two related ant species, the slavemaker Temnothorax americanus and its host Temnothorax longispinosus. Our aim was to investigate commonalities and differences in group-specific transcriptomes, whereupon across-species differences possibly can be explained by their divergent lifestyles. Larvae and pupae showed the highest similarity between the two species and upregulated genes with enriched functions of translation and chitin metabolism, respectively. Workers commonly upregulated oxidation-reduction genes, possibly indicative of their active lifestyle. Host workers, but not workers of the slavemaker, upregulated a "social behavior" gene. In slavemaker queens and workers, genes associated with the regulation of transposable elements were upregulated. Queens of both species showed transcriptomic signals of anti-aging mechanisms, with hosts upregulating various DNA repair pathways and slavemaker queens investing in trehalose metabolism. The transcriptomes of males showed enriched functions for quite general terms realized in different genes and pathways in each species. In summary, the strong interspecific commonalities in larvae, pupae, and workers were reflected in the same enriched Gene Ontology (GO) terms. Less commonalities occurred in the transcriptomes of queens and males, which apparently utilize different pathways to achieve a long life and sperm production, respectively. We found that all analyzed groups in this study show characteristic GO terms, with similar patterns in both species.
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Additional file 2: of Queens stay, workers leave: caste-specific responses to fatal infections in an ant
2018Co-Authors: Julia Giehr, Jürgen HeinzeAbstract:Table S1. Pairwise survival comparison of young Temnothorax crassispinus workers in queenless (QL) and queenright (QR) colonies, treated with a control solution (QLCo, QRCo, QRQInf) or infected with Metarhizium brunneu, (QLInf, QRWInf). Significant p-values (corrected for a false discovery rate “fdr”) are marked in bold. Table S2. Pairwise survival comparison of young Temnothorax crassispinus workers of queenless colonies infected with Metarhizum brunneum. Significant p-values (corrected for a false discovery rate “fdr”) are marked in bold. Figure S1. Proportion of old (left) and young (right) Temnothorax crassispinus workers leaving the nest in colonies with young workers either infected with Metarhizium brunneum (infected colonies) or treated with a control solution (control colonies) independent of queen presence. Both young and old workers leave the nest more often when they themselves or nestmates are infected. Boxplots show median, 25 and 75 quartile and 95% percentile (*0.05 < p > 0.01; corrected for a false discovery rate: “fdr”). Figure S2. Reproductive rate of queenless Temnothorax crassispinus colonies during the first 25 days after the treatment. Eggs in infected colonies (top) vanish frequently and the colonies produce less eggs than control colonies (bottom). Figure S3. Number of eggs produced in queenright T. crassispinus control colonies (QRCo, left) or colonies with a control queen and M. brunneum infected workers (QRWInf, right). Whereas control queens increase their egg laying rate with time, the small number of eggs produced in colonies with infected workers vanish repeatedly. Figure S4. Ovaries of Temnothorax crassispinus queens infected with Metarhizium brunneum. Developmental status of the ovaries cannot be analyzed in five out of six queens as the gaster show excessive spore growth. (DOCX 2791 kb
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Multiple Convergent Origins of Workerlessness and Inbreeding in the Socially Parasitic Ant Genus Myrmoxenus
PloS one, 2015Co-Authors: Jürgen Heinze, Alfred Buschinger, Theo Poettinger, Masaki SuefujiAbstract:The socially parasitic ant genus Myrmoxenus varies strongly in fundamental life history traits, such as queen-worker ratio, the timing of sexual production, and mating behavior. Myrmoxenus queens generally take over nests of Temnothorax ants, kill the resident queen by throttling, and force the workers to take care of the social parasite’s brood. Young queens of M. ravouxi and other species produce large numbers of workers, which during “slave-raids” pillage host pupae from neighboring Temnothorax colonies to increase the workforce in their own nests. Other species, such as M. corsicus, have lost caste polyphenism and rear only male and female sexual offspring. Using sequences of the genes CO I / CO II and wingless we reconstruct the phylogeny of Myrmoxenus and document that the worker caste was lost convergently at least three times. Furthermore, mating in the nest and inbreeding obviously also evolved in parallel from ancestors whose sexuals presumably mated during nuptial flights. Myrmoxenus might thus provide a suitable model to investigate caste differentiation and the plasticity of mating behavior in Hymenoptera.
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Cryptic diversity in the Mediterranean Temnothorax lichtensteini species complex (Hymenoptera:Formicidae)
Organisms Diversity & Evolution, 2013Co-Authors: Sándor Csősz, Bernhard Seifert, Andreas Schulz, Benedikt Müller, Andreas Trindl, Jürgen HeinzeAbstract:In this paper we provide insight into the cryptic diversity and biogeographic patterns of a widely distributed Mediterranean ant species, Temnothorax lichtensteini (Bondroit Annales de la Societe Entomologique de France 87:1–174, 1918), based on evidence from multiple data sources. An exploratory analysis of morphometric data, combined with sequencing of a 652 bp fragment of the mitochondrial gene for the cytochrome c oxidase subunit I (CO I), indicates the existence of three distinct lineages. Divergence of two recognised genetic lineages, Western and Eastern Mediterranean clusters, is not reliably supported by confirmatory analysis of morphological data. We hypothesise that this reflects incomplete speciation in separate glacial refugia and therefore discuss only biogeographic aspects of these two parapatric populations. However, the third, Peloponnese, lineage is divergent in both morphology and CO I sequences and its separation from the other two lineages is convincingly confirmed. For this lineage we assume a completed speciation and describe the taxon formally as Temnothorax laconicus sp.n., the sister species of T. lichtensteini.
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Cuticular hydrocarbons in two parapatric species of ants and their hybrid.
Integrative zoology, 2011Co-Authors: Mohamed El-shehaby, Mohamed S. Salama, Elisabeth Brunner, Jürgen HeinzeAbstract:Discrimination between nestmates and non-nestmates in social insects is thought to rely on the pattern of cuticular hydrocarbons. We investigated the cuticular hydrocarbon profiles of 2 parapatric sibling ant species, Temnothorax nylanderi (Forster, 1850) and Temnothorax crassispinus (Karavaiev, 1926), and their hybrid. We found that although the profiles show considerable similarities, a discriminant analysis based on the relative peak areas of cuticular hydrocarbons separates the 3 taxa. The profiles of hybrids were not consistently intermediate between those of the paternal species, suggesting either non-additive interactions among the parental biosynthetic pathways or systematic differences in environment-derived odor cues.
Takao Sasaki - One of the best experts on this subject based on the ideXlab platform.
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route learning during tandem running in the rock ant Temnothorax albipennis
The Journal of Experimental Biology, 2020Co-Authors: Leo Danczak, Beth Thompson, Trisha Morshed, Takao Sasaki, Stephen C PrattAbstract:ABSTRACT Many animals use information from conspecifics to change their behavior in adaptive ways. When a rock ant, Temnothorax albipennis, finds food, she returns to her colony and uses a method called tandem running to lead nestmates, one at a time, from the nest to the food. In this way, naive ants can learn the location of a food source. Less clear is whether they also learn navigational cues that guide them from nest to food, although this is often assumed. We tested this idea by tracing the routes of individually marked ants as they followed tandem runs to a feeder, returned to the nest, and later traveled independently back to the food. Our results show, for the first time, that tandem run followers learn specific routes from their leaders. Independent journeys back to the food source were significantly more similar to the routes on which the ants had been led, compared with the routes taken by other tandem runs. In contrast, the homeward journey did not resemble the tandem run route. These results are consistent with followers memorizing visual cues during the tandem run that are useful for recapitulating the outward journey, but not as effective when facing in the opposite direction on the homeward journey. We further showed that foraging routes improved through individual experience over multiple trips but not through the social transfer of route information via tandem running. We discuss our findings in relation to social learning and integration of individual and social information in ants.
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rational time investment during collective decision making in Temnothorax ants
Biology Letters, 2019Co-Authors: Takao Sasaki, Benjamin Stott, Stephen C PrattAbstract:The study of rational choice in humans and other animals typically focuses on decision outcomes, but rationality also applies to decision latencies, especially when time is scarce and valuable. For...
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Flexibility of collective decision making during house hunting in Temnothorax ants
Behavioral Ecology and Sociobiology, 2015Co-Authors: Takao Sasaki, Blake Colling, Anne Sonnenschein, May M Boggess, Stephen C PrattAbstract:Many social animals cooperatively process information during decision making, allowing them to concentrate on the best of several options. However, positive feedback created by information sharing can also lock the group into a suboptimal outcome if option quality changes over time. This creates a trade-off between consensus and flexibility, whose resolution depends on the information-sharing mechanisms groups employ. We investigated the influence of communication behavior on decision flexibility in nest site choice by colonies of the ant Temnothorax rugatulus . These ants divide their emigration into two distinct phases separated by a quorum rule. In the first phase, scouts recruit nestmates to promising sites using the slow method of tandem running. Once a site's population surpasses a quorum, they switch to the faster method of social transport. We gave colonies a choice between two sites of different quality, and then switched site quality at different points during the emigration. Before the quorum was met, colonies were able to switch their choice to the newly superior site, but once they began to transport, their flexibility dropped significantly. Close observation of single ants revealed that transporters were more likely than tandem leaders to continue recruiting to a site even after its quality was diminished. That is, tandem leaders continued to monitor the quality of the site, while transporters instead fully committed to the site without further assessment. We discuss how this change in commitment with quorum attainment may enhance the rapid achievement of consensus needed for nest site selection, but at a cost in flexibility once the quorum is met.
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a context dependent alarm signal in the ant Temnothorax rugatulus
The Journal of Experimental Biology, 2014Co-Authors: Bert Hölldobler, Takao Sasaki, Jocelyn G. Millar, Stephen C PrattAbstract:Because collective cognition emerges from local signaling among group members, deciphering communication systems is crucial to understanding the underlying mechanisms. Alarm signals are widespread in the social insects and can elicit a variety of behavioral responses to danger, but the functional plasticity of these signals has not been well studied. Here we report an alarm pheromone in the ant Temnothorax rugatulus that elicits two different behaviors depending on context. When an ant was tethered inside an unfamiliar nest site and unable to move freely, she released a pheromone from her mandibular gland that signaled other ants to reject this nest as a potential new home, presumably to avoid potential danger. When the same pheromone was presented near the ants' home nest, they were instead attracted to it, presumably to respond to a threat to the colony. We used coupled gas chromatography/mass spectrometry to identify candidate compounds from the mandibular gland and tested each one in a nest choice bioassay. We found that 2,5-dimethylpyrazine was sufficient to induce rejection of a marked new nest and also to attract ants when released at the home nest. This is the first detailed investigation of chemical communication in the leptothoracine ants. We discuss the possibility that this pheromone's deterrent function can improve an emigrating colony's nest site selection performance.
Susanne Foitzik - One of the best experts on this subject based on the ideXlab platform.
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Comparative analyses of caste, sex, and developmental stage-specific transcriptomes in two Temnothorax ants.
Ecology and evolution, 2020Co-Authors: Claudia Gstöttl, Jürgen Heinze, Barbara Feldmeyer, Evelien Jongepier, Marah Stoldt, Erich Bornberg-bauer, Susanne FoitzikAbstract:Social insects dominate arthropod communities worldwide due to cooperation and division of labor in their societies. This, however, makes them vulnerable to exploitation by social parasites, such as slave-making ants. Slave-making ant workers pillage brood from neighboring nests of related host ant species. After emergence, host workers take over all nonreproductive colony tasks, whereas slavemakers have lost the ability to care for themselves and their offspring. Here, we compared transcriptomes of different developmental stages (larvae, pupae, and adults), castes (queens and workers), and sexes of two related ant species, the slavemaker Temnothorax americanus and its host Temnothorax longispinosus. Our aim was to investigate commonalities and differences in group-specific transcriptomes, whereupon across-species differences possibly can be explained by their divergent lifestyles. Larvae and pupae showed the highest similarity between the two species and upregulated genes with enriched functions of translation and chitin metabolism, respectively. Workers commonly upregulated oxidation-reduction genes, possibly indicative of their active lifestyle. Host workers, but not workers of the slavemaker, upregulated a "social behavior" gene. In slavemaker queens and workers, genes associated with the regulation of transposable elements were upregulated. Queens of both species showed transcriptomic signals of anti-aging mechanisms, with hosts upregulating various DNA repair pathways and slavemaker queens investing in trehalose metabolism. The transcriptomes of males showed enriched functions for quite general terms realized in different genes and pathways in each species. In summary, the strong interspecific commonalities in larvae, pupae, and workers were reflected in the same enriched Gene Ontology (GO) terms. Less commonalities occurred in the transcriptomes of queens and males, which apparently utilize different pathways to achieve a long life and sperm production, respectively. We found that all analyzed groups in this study show characteristic GO terms, with similar patterns in both species.
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Supplmementary information II from Ant behaviour and brain gene expression of defending hosts depend on the ecological success of the intruding social parasite
2019Co-Authors: Rajbir Kaur, Barbara Feldmeyer, Evelien Jongepier, Marah Stoldt, Florian Menzel, Erich Bornberg-bauer, Susanne FoitzikAbstract:Genome of Temnothorax longispinosus: methods, assembly and annotatio
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Comparative analyses of co-evolving host-parasite associations reveal unique gene expression patterns underlying slavemaker raiding and host defensive phenotypes.
Scientific reports, 2018Co-Authors: Austin R. Alleman, Barbara Feldmeyer, Susanne FoitzikAbstract:The transition to parasitism is a drastic shift in lifestyle, involving rapid changes in gene structure, function, and expression. After the establishment of antagonistic relationships, parasites and hosts co-evolve through reciprocal adaptations, often resulting in evolutionary arms-races. Repeated evolution of social parasitism and slavery among Temnothorax ants allows us to examine those gene expression patterns that characterize slavemaker raiding and reciprocal host defensive phenotypes. Previous behavioural studies have established that raiding strategies between Temnothorax slavemakers diverge, while host defense portfolios shift similarly under parasite pressure. We are the first to confirm this at the molecular level, revealing that slavemaking species exhibit a wider variety of genes with species-specific patterns of expression within their raiding phenotypes, whereas expression similarity is commonly found during the non-raiding phenotype. Host species response to slavemaker aggression, however, is indicated by strong changes in the expression of a relatively few number genes. Additionally, the expression of individual genes such as Acyl-CoA-Delta(11) desaturase and Trypsin-7 is strongly associated with the raiding phenotype of all three slavemaking species. Here, we provide novel insight into the gene expression patterns associated with raiding and nest defense behavior in Temnothorax ants, suggesting lineage-specific evolutionary patterns among both slavemakers and hosts.
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The influence of space and time on the evolution of altruistic defence: the case of ant slave rebellion
Journal of evolutionary biology, 2016Co-Authors: Dirk Metzler, Tobias Pamminger, F. Jordan, Susanne FoitzikAbstract:How can antiparasite defence traits evolve even if they do not directly benefit their carriers? An example of such an indirect defence is rebellion of enslaved Temnothorax longispinosus ant workers against their social parasite Temnothorax americanus, a slavemaking ant. Ant slaves have been observed to kill their oppressors' offspring, a behaviour from which the sterile slaves cannot profit directly. Parasite brood killing could, however, reduce raiding pressure on related host colonies nearby. We analyse with extensive computer simulations for the Temnothorax slavemaker system under what conditions a hypothetical rebel allele could invade a host population, and in particular, how host-parasite dynamics and population structure influence the rebel allele's success. Exploring a wide range of model parameters, we only found a small number of parameter combinations for which kin selection or multilevel selection could allow a slave rebellion allele to spread in the host population. Furthermore, we did not detect any cases in which the reduction of raiding pressure in the close vicinity of the slavemaker nest would substantially contribute to the inclusive fitness of rebels. This suggests that slave rebellion is not costly and perhaps a side-effect of some other beneficial trait. In some of our simulations, however, even a costly rebellion allele could spread in the population. This was possible when host-parasite interactions led to a metapopulation dynamic with frequent local extinctions and recolonizations of demes by the offspring of few immigrants.
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The ecological success of a social parasite increases with manipulation of collective host behaviour
Journal of evolutionary biology, 2015Co-Authors: Evelien Jongepier, Isabelle Kleeberg, Susanne FoitzikAbstract:Many parasites alter the behaviour of their host to their own advantage, yet hosts often vary in their susceptibility to manipulation. The ecological and evolutionary implications of such variation can be profound, as resistant host populations may suffer lower parasite pressures than those susceptible to manipulation. To test this prediction, we assessed parasite-induced aggressive behaviours across 16 populations of two Temnothorax ant species, many of which harbour the slavemaker ant Protomognathus americanus. This social parasite uses its Dufour's gland secretions to manipulate its hosts into attacking nestmates, which may deter defenders away from itself during invasion. We indeed find that colonies that were manipulated into attacking their Dufour-treated nestmates were less aggressive towards the slavemaker than those that did not show slavemaker-induced nestmate attack. Slavemakers benefited from altering their hosts' aggression, as both the likelihood that slavemakers survived host encounters and slavemaker prevalence in ant communities increased with slavemaker-induced nestmate attack. Finally, we show that Temnothorax longispinosus colonies were more susceptible to manipulation than Temnothorax curvispinosus colonies. This explains why T. curvispinosus colonies responded with more aggression towards invading slavemakers, why they were less likely to let slavemakers escape and why they were less frequently parasitized by the slavemaker than T. longispinosus. Our findings highlight that large-scale geographic variation in resistance to manipulation can have important implications for the prevalence and host preference of parasites.
