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Sean Odonnell - One of the best experts on this subject based on the ideXlab platform.
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multi year genetic sampling indicates maternal gene flow via colony emigrations in the Army Ant eciton burchellii parvispinum
Insectes Sociaux, 2020Co-Authors: Thomas W Soare, Anjali Kumar, Kerry A Naish, Sean OdonnellAbstract:Sex-biased dispersal occurs when one sex disperses more frequently or farther than the opposite sex. In Ants, dispersal is often male biased and males typically contribute more strongly to gene flow within and among Ant populations. However, Army Ants may offer an exceptional case of female-biased dispersal, because Army Ant colonies (particularly species in the Neotropical genus Eciton) routinely emigrate among nest sites. We hypothesized that maternal mobility via successive colony emigrations would reduce the relative male bias in dispersal, and that emigrations would contribute to gene flow within an Eciton population. We genotyped workers (highly variable DNA microsatellite loci) from Eciton burchellii parvispinum colonies collected over a 10 × 10 km area in Monteverde, Costa Rica. Samples were spaced approximately 3 years apart (in 2006 and 2009), the typical time between colony reproductive bouts. We used worker genotypes to reconstruct the genotypes of their mother queens and of a subset of the males that sired the workers. We then analyzed the population genetic structure of the queen and male genotypes by comparing individual-based relatedness estimates for each sex across geographic distance and over time. There was no significAnt difference in spatial genetic structure between the sexes, either within or between the 2006 and 2009 samples. There was some evidence against genetic philopatry: 2009 queens were significAntly unrelated to 2006 queens collected nearby (within 0.5 km). The patterns suggest maternal dispersal via emigrations contributes to gene flow, reducing or eliminating male biases in dispersal. From two populations, we estimated average queen dispersal distance to be 0.63–1.04 km, a greater distance than many winged Ant queens disperse. Because emigrations over the lifetime of Army Ant queens may contribute to gene flow across the landscape, habitat connectivity should be maintained to permit colony emigrations and support genetic diversity in populations of this keystone species.
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novel observation of a raptor collared forest falcon micrastur semitorquatus depredating a fleeing snake at an Army Ant eciton burchellii parvispinum raid front
The Wilson Journal of Ornithology, 2018Co-Authors: Robert J Driver, Sara Deleon, Sean OdonnellAbstract:ABSTRACT Eciton burchellii is a Neotropical Army Ant that influences the ecology of many associated animal species, including their prey and species that attend the Ant's foraging raids. At least 29 bird species are obligate specialists on foraging at Army Ant raid fronts, and additional species across diverse avian orders follow Army Ant raids in a facultative manner. These facultative Ant-following birds include species of raptors in Accipitriformes, Strigiformes, and Falconiformes. The most frequently documented raptors that follow raids are forest-falcons in the genus Micrastur. Micrastur falcons add a unique type of predation to raids, catching larger arthropod species that would otherwise likely escape the Ants, and also prey on small fleeing vertebrates, such as lizards and other Ant-following bird species. Here we present an observation of a Collared Forest-falcon (Micrastur semitorquatus) attending an E. b. parvispinum raid and flying toward a Ruddy Woodcreeper (Dendrocincla homochroa) at the rai...
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complex body size differences in thermal tolerance among Army Ant workers eciton burchellii parvispinum
Journal of Thermal Biology, 2018Co-Authors: Kaitlin M Baudier, Sean OdonnellAbstract:Abstract In social insects, group members can differ in thermal physiology, and these differences may affect colony function. Upper thermal tolerance limits (CTmax) generally increase with body size among and within Ant species, but size effects on lower thermal tolerances (CTmin) are poorly known. To test whether CTmin co-variation with body size matched patterns for CTmax, we measured CTmax and CTmin in workers of four size-based worker subcastes in the Army Ant Eciton burchellii parvispinum. CTmax increased with worker body size as expected. CTmin showed a more complex relationship with size: the two intermediate-size subcastes (media and porters) tolerated lower temperatures than the smallest (minims) and the largest (soldiers) worker subcastes. Body-size effects on CTmax were not predictive of body-size effects on CTmin. These patterns held for colonies collected across elevations that spanned approximately 8 °C in mean annual temperature, even though high-elevation colonies had significAntly lower CTmin overall. We predict Eciton Army Ant subcastes will be differentially affected by directional changes in high and low temperature extremes. Worker subcastes perform distinct but complementary roles in colony function, and differential temperature effects among subcastes could impair colony performance and negatively impact colony fitness.
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the structured diversity of specialized gut symbionts of the new world Army Ants
Molecular Ecology, 2017Co-Authors: Piotr łukasik, Daniel J C Kronauer, C Moreau, Sean Odonnell, Justin A Newton, Jon G Sanders, Yi Hu, Ryuichi Koga, Jacob A RussellAbstract:Symbiotic bacteria play importAnt roles in the biology of their arthropod hosts. Yet the microbiota of many diverse and influential groups remain understudied, resulting in a paucity of information on the fidelities and histories of these associations. Motivated by prior findings from a smaller scale, 16S rRNA-based study, we conducted a broad phylogenetic and geographic survey of microbial communities in the ecologically dominAnt New World Army Ants (Formicidae: Dorylinae). Amplicon sequencing of the 16S rRNA gene across 28 species spanning the five New World genera showed that the microbial communities of Army Ants consist of very few common and abundAnt bacterial species. The two most abundAnt microbes, referred to as Unclassified Firmicutes and Unclassified Entomoplasmatales, appear to be specialized Army Ant associates that dominate microbial communities in the gut lumen of three host genera, Eciton, Labidus and Nomamyrmex. Both are present in other Army Ant genera, including those from the Old World, suggesting that Army Ant symbioses date back to the Cretaceous. Extensive sequencing of bacterial protein-coding genes revealed multiple strains of these symbionts coexisting within colonies, but seldom within the same individual Ant. Bacterial strains formed multiple host species-specific lineages on phylogenies, which often grouped strains from distAnt geographic locations. These patterns deviate from those seen in other social insects and raise intriguing questions about the influence of Army Ant colony swarm-founding and within-colony genetic diversity on strain coexistence, and the effects of hosting a diverse suite of symbiont strains on colony ecology.
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microhabitat and body size effects on heat tolerance implications for responses to climate change Army Ants formicidae ecitoninae
Journal of Animal Ecology, 2015Co-Authors: Kaitlin M Baudier, Abigail E. Mudd, Shayna C. Erickson, Sean OdonnellAbstract:1. Models that predict organismal and population responses to climate change may be improved by considering ecological factors that affect species thermal tolerance. Species differences in microhabitat use can expose animals to diverse thermal selective environments at a given site and may cause sympatric species to evolve different thermal tolerances. 2. We tested the hypothesis that species differences in body size and microhabitat use (above- vs. below-ground activity) would correspond to differences in thermal tolerance (maximum critical temperatures: CTmax ). Thermal buffering effects of soil can reduce exposure to extreme high temperatures for below-ground active species. We predicted larger-bodied individuals and species would have higher CTmax and that species mean CTmax would covary positively with degree of above-ground activity. We used Neotropical Army Ants (Formicidae: Ecitoninae) as models. Army Ants vary in microhabitat use from largely subterranean to largely above-ground active species and are highly size polymorphic. 3. We collected data on above- and below-ground temperatures in habitats used by Army Ants to test for microhabitat temperature differences, and we conducted CTmax assays for Army Ant species with varying degrees of surface activity and with different body sizes within and between species. We then tested whether microhabitat use was associated with species differences in CTmax and whether microhabitat was a better predictor of CTmax than body size for species that overlapped in size. 4. Microhabitat use was a highly significAnt predictor of species' upper thermal tolerance limits, both for raw data and after accounting for the effects of phylogeny. Below-ground species were more thermally sensitive, with lower maximum critical temperatures (CTmax ). The smallest workers within each species were the least heat tolerAnt, but the magnitude of CTmax change with body size was greater in below-ground species. Species-typical microhabitat was a stronger predictor of CTmax than body size for species that overlapped in size. Compared to the soil surface, 10-cm subsoil was a significAntly moderated thermal environment for below-ground Army Ants, while maximum surface raid temperatures sometimes exceeded CTmax for the most thermally sensitive Army Ant castes. 5. We conclude sympatric species differences in thermal physiology correspond to microhabitat use. These patterns should be accounted for in models of species and community responses to thermal variation and climate change.
Daniel J C Kronauer - One of the best experts on this subject based on the ideXlab platform.
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Chemical and behavioral integration of Army Ant-associated rove beetles – a comparison between specialists and generalists
Frontiers in Zoology, 2018Co-Authors: Christoph Von Beeren, Munetoshi Maruyama, Adrian Brückner, Griffin Burke, Jana Wieschollek, Daniel J C KronauerAbstract:Host-symbiont interactions are embedded in ecological communities and range from unspecific to highly specific relationships. Army Ants and their arthropod guests represent a fascinating example of species-rich host-symbiont associations where host specificity ranges across the entire generalist - specialist continuum. In the present study, we compared the behavioral and chemical integration mechanisms of two extremes of the generalist - specialist continuum: generalist Ant-predators in the genus Tetradonia (Staphylinidae: Aleocharinae: Athetini), and specialist Ant-mimics in the genera Ecitomorpha and Ecitophya (Staphylinidae: Aleocharinae: Ecitocharini). Similar to a previous study of Tetradonia beetles, we combined DNA barcoding with morphological studies to define species boundaries in Ant-mimicking beetles. This approach found four Ant-mimicking species at our study site at La Selva Biological Station in Costa Rica. Community sampling of Eciton Army Ant parasites revealed that Ant-mimicking beetles were perfect host specialists, each beetle species being associated with a single Eciton species. These specialists were seamlessly integrated into the host colony, while generalists avoided physical contact to host Ants in behavioral assays. Analysis of the Ants’ nestmate recognition cues, i.e. cuticular hydrocarbons (CHCs), showed close similarity in CHC composition and CHC concentration between specialists and Eciton burchellii foreli host Ants. On the contrary, the chemical profiles of generalists matched host profiles less well, indicating that high accuracy in chemical host resemblance is only accomplished by socially integrated species. Considering the interplay between behavior, morphology, and cuticular chemistry, specialists but not generalists have cracked the Ants’ social code with respect to various sensory modalities. Our results support the long-standing idea that the evolution of host-specialization in parasites is a trade-off between the range of potential host species and the level of specialization on any particular host.
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the structured diversity of specialized gut symbionts of the new world Army Ants
Molecular Ecology, 2017Co-Authors: Piotr łukasik, Daniel J C Kronauer, C Moreau, Sean Odonnell, Justin A Newton, Jon G Sanders, Yi Hu, Ryuichi Koga, Jacob A RussellAbstract:Symbiotic bacteria play importAnt roles in the biology of their arthropod hosts. Yet the microbiota of many diverse and influential groups remain understudied, resulting in a paucity of information on the fidelities and histories of these associations. Motivated by prior findings from a smaller scale, 16S rRNA-based study, we conducted a broad phylogenetic and geographic survey of microbial communities in the ecologically dominAnt New World Army Ants (Formicidae: Dorylinae). Amplicon sequencing of the 16S rRNA gene across 28 species spanning the five New World genera showed that the microbial communities of Army Ants consist of very few common and abundAnt bacterial species. The two most abundAnt microbes, referred to as Unclassified Firmicutes and Unclassified Entomoplasmatales, appear to be specialized Army Ant associates that dominate microbial communities in the gut lumen of three host genera, Eciton, Labidus and Nomamyrmex. Both are present in other Army Ant genera, including those from the Old World, suggesting that Army Ant symbioses date back to the Cretaceous. Extensive sequencing of bacterial protein-coding genes revealed multiple strains of these symbionts coexisting within colonies, but seldom within the same individual Ant. Bacterial strains formed multiple host species-specific lineages on phylogenies, which often grouped strains from distAnt geographic locations. These patterns deviate from those seen in other social insects and raise intriguing questions about the influence of Army Ant colony swarm-founding and within-colony genetic diversity on strain coexistence, and the effects of hosting a diverse suite of symbiont strains on colony ecology.
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community sampling and integrative taxonomy reveal new species and host specificity in the Army Ant associated beetle genus tetradonia coleoptera staphylinidae aleocharinae
PLOS ONE, 2016Co-Authors: Munetoshi Maruyama, Christoph Von Beeren, Daniel J C KronauerAbstract:Army Ant colonies host a diverse community of arthropod symbionts. Among the best-studied symbiont communities are those of Neotropical Army Ants of the genus Eciton. It is clear, however, that even in these comparatively well studied systems, a large proportion of symbiont biodiversity remains unknown. Even more striking is our lack of knowledge regarding the nature and specificity of these host-symbiont interactions. Here we surveyed the diversity and host specificity of rove beetles of the genus Tetradonia Wasmann, 1894 (Staphylinidae: Aleocharinae). Systematic community sampling of 58 colonies of the six local Eciton species at La Selva Biological Station, Costa Rica, combined with an integrative taxonomic approach, allowed us to uncover species diversity, host specificity, and co-occurrence patterns of symbionts in unprecedented detail. We used an integrative taxonomic approach combining morphological and genetic analyses, to delineate species boundaries. Mitochondrial DNA barcodes were analyzed for 362 Tetradonia specimens, and additional nuclear markers for a subset of 88 specimens. All analyses supported the presence of five Tetradonia species, including two species new to science. Host specificity is highly variable across species, ranging from generalists such as T. laticeps, which parasitizes all six local Eciton species, to specialists such as T. lizonae, which primarily parasitizes a single species, E. hamatum. Here we provide a dichotomous key along with diagnostic molecular characters for identification of Tetradonia species at La Selva Biological Station. By reliably assessing biodiversity and providing tools for species identification, we hope to set the baseline for future studies of the ecological and evolutionary dynamics in these species-rich host-symbiont networks.
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Kronauer et al Raw Data
2016Co-Authors: Daniel J C Kronauer, Jacobus J Boomsma, Sean O'donnell, Naomi E. PierceAbstract:This file contains the raw microsatellite data (coded as allele sizes in base pairs) for the following article published in Molecular Ecology: Strict monandry in the ponerine Army Ant genus Simopelta suggests that colony size and complexity drive mating system evolution in social insects. Authors: Daniel J. C. Kronauer, Sean O'Donnell, Jacobus J. Boomsma, Naomi E. Pierc
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strict monandry in the ponerine Army Ant genus simopelta suggests that colony size and complexity drive mating system evolution in social insects
Molecular Ecology, 2011Co-Authors: Daniel J C Kronauer, Jacobus J Boomsma, Sean Odonnell, Naomi E. PierceAbstract:Altruism in social insects has evolved between closely related full-siblings. It is therefore of considerable interest why some groups have secondarily evolved low within-colony relatedness, which in turn affects the relatedness incentives of within-colony cooperation and conflict. The highest queen mating frequencies, and therefore among the lowest degrees of colony relatedness, occur in Apis honeybees and Army Ants of the subfamilies Aenictinae, Ecitoninae, and Dorylinae, suggesting that common life history features such as reproduction by colony fission and male biased numerical sex-ratios have convergently shaped these mating systems. Here we show that ponerine Army Ants of the genus Simopelta, which are distAntly related but similar in general biology to other Army Ants, have strictly monandrous queens. Preliminary data suggest that workers reproduce in queenright colonies, which is in sharp contrast to other Army Ants. We hypothesize that differences in mature colony size and social complexity may explain these striking
Nigel R Franks - One of the best experts on this subject based on the ideXlab platform.
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dispersal and population structure of a new world predator the Army Ant eciton burchellii
Journal of Evolutionary Biology, 2008Co-Authors: Stefanie M Berghoff, Keith J Edwards, Daniel J C Kronauer, Nigel R FranksAbstract:The Army Ant Eciton burchellii is probably the most importAnt arthropod predator in the Neotropics, and many animal species depend upon it. Sexbiased dispersal with winged males and permanently wingless queens may render this species especially sensitive to habitat fragmentation and natural barriers, which might have severe impacts on population structure and lead to population decline. Using nuclear microsatellite markers and mitochondrial sequences, we investigated genetic differentiation in a fragmented population in the Panama Canal area. While nuclear markers showed little differentiation between subpopulations (FST = 0.017), mitochondrial differentiation was maximal in some cases (FST = 1). This suggests that, while females are not capable of crossing barriers such as large rivers, flying males are able to promote nuclear gene flow between the studied forest patches. Consistent with this interpretation, we did not find any evidence for inbreeding or genetic deterioration on Barro Colorado Island over the last 90 years since its formation.
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how a few help all living pothole plugs speed prey delivery in the Army Ant eciton burchellii
Animal Behaviour, 2007Co-Authors: Scott Powell, Nigel R FranksAbstract:We investigated an extreme behavioural specialization in the Army Ant Eciton burchellii. The spectacular group raids of these Ants, which can contain up to 200 000 workers, always remain connected to the nest by a ‘principal trail’ of forager traffic. Remarkably, some workers use their bodies to plug potholes in the natural surfaces that the principal trail travels over, to provide a partly living surface for their nestmates to use. We found that this highly specialized behaviour results in a clear net benefit to the colony. Our experiments show that foragers do not discriminate against surfaces that force all individuals to run as slowly as the smallest workers, but that this prompts some Ants to plug neighbouring low-quality surfaces. Individuals size-match to the hole they plug and cooperate to plug larger holes. The resulting modified surface allows prey-laden foragers to attain maximum speed. Overall, this results in a strong positive relationship between Ant size and speed and an increase in the mean speed of prey-laden traffic. Moreover, calculations suggest that under a range of realistic scenarios, plugging behaviour results in a clear increase in daily prey intake. Broadly, our study provides rare quAntitative evidence that extreme specialization by a minority can significAntly improve the performance of a majority, and benefit the group as a whole. It also suggests, however, that these benefits are a consequence of the unusual and derived foraging strategy of E. burchellii. This highlights the importance of considering ecology and evolutionary history in the study of social organization in animal societies.
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ecology and the evolution of worker morphological diversity a comparative analysis with eciton Army Ants
Functional Ecology, 2006Co-Authors: Scott Powell, Nigel R FranksAbstract:Summary 1Certain Ants have considerable morphological diversity within the workforce, with individuals physically specialized for particular jobs. The ecological conditions that select for this phenomenon are still poorly understood. 2We use a comparative analysis to address the hypothesis that prey type has selected for greater morphological diversity in the small, monophyletic Army Ant genus Eciton. These Ants are nomadic group-predators and transport loads in the limited space below the body, so bulkier prey types should select for more diverse worker morphology. 3We show that five Eciton species differ in the presence or absence of a distinct ‘submajor caste’, the morphological exaggeration of submajors when present, and the allometric scaling of standard workers over a broad size range. Crucially, the presence and morphological exaggeration of submajors is associated with the variety of awkwardly shaped prey types that the species takes, and this caste specializes in prey transport. 4Our findings support the importance of dietary composition in the evolution of worker morphological diversity in Eciton and demonstrate the utility of our general approach. Future critical tests of this hypothesis are discussed, as well as how our approach can contribute to a broader understanding of the relationship between ecology and the evolution of worker morphological diversity.
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a reassessment of the mating system characteristics of the Army Ant eciton burchellii
Naturwissenschaften, 2006Co-Authors: Daniel J C Kronauer, Nigel R Franks, Scott Powell, Jay A Denny, Keith J Edwards, Stefanie M Berghoff, Jacobus J BoomsmaAbstract:In a recent study, Denny et al. (2004a) showed that queens of the Army Ant, Eciton burchellii, mate with multiple males and presented estimates suggesting that they mate with more males than queens of any other Ant species so far investigated. They also inferred that data were consistent with queens being inseminated repeatedly throughout their life, which would be exceptional among the social Hymenoptera and contradictory to predictions from kin selection theory. In the present study, we reanalyze these data using new software and supplement them with similar microsatellite data from other colonies of the same species. Mating frequencies in E. burchellii are indeed very high (mean observed and effective queen-mating frequencies of 12.9 each) but considerably lower than the previous estimates. We show that the number of patrilines represented in the first worker offspring of a young queen is lower than in older queens but suggest that this may be due to initial sperm clumping in the queen’s sperm storage organ, rather than to repeated inseminations. Moreover, we found no evidence for repeated mating by genotyping sequential worker generations produced by a single old queen, showing that she did not obtain new inseminations despite ample opportunities for mating.
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eight highly polymorphic microsatellite markers for the Army Ant eciton burchellii
Molecular Ecology Notes, 2004Co-Authors: Jay A Denny, Nigel R Franks, Keith J EdwardsAbstract:The Army Ant Eciton burchellii is a nomadic predator in the rain forests of Central and South America. Detailed work has documented many aspects of this species’ ecology, behaviour and life history. However, a detailed investigation into within colony relatedness structure requires the development of genetic tools. Here we present eight microsatellite markers with between nine and 25 alleles. For each loci there is close agreement between observed and expected heterozygosity.
Jacobus J Boomsma - One of the best experts on this subject based on the ideXlab platform.
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Kronauer et al Raw Data
2016Co-Authors: Daniel J C Kronauer, Jacobus J Boomsma, Sean O'donnell, Naomi E. PierceAbstract:This file contains the raw microsatellite data (coded as allele sizes in base pairs) for the following article published in Molecular Ecology: Strict monandry in the ponerine Army Ant genus Simopelta suggests that colony size and complexity drive mating system evolution in social insects. Authors: Daniel J. C. Kronauer, Sean O'Donnell, Jacobus J. Boomsma, Naomi E. Pierc
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strict monandry in the ponerine Army Ant genus simopelta suggests that colony size and complexity drive mating system evolution in social insects
Molecular Ecology, 2011Co-Authors: Daniel J C Kronauer, Jacobus J Boomsma, Sean Odonnell, Naomi E. PierceAbstract:Altruism in social insects has evolved between closely related full-siblings. It is therefore of considerable interest why some groups have secondarily evolved low within-colony relatedness, which in turn affects the relatedness incentives of within-colony cooperation and conflict. The highest queen mating frequencies, and therefore among the lowest degrees of colony relatedness, occur in Apis honeybees and Army Ants of the subfamilies Aenictinae, Ecitoninae, and Dorylinae, suggesting that common life history features such as reproduction by colony fission and male biased numerical sex-ratios have convergently shaped these mating systems. Here we show that ponerine Army Ants of the genus Simopelta, which are distAntly related but similar in general biology to other Army Ants, have strictly monandrous queens. Preliminary data suggest that workers reproduce in queenright colonies, which is in sharp contrast to other Army Ants. We hypothesize that differences in mature colony size and social complexity may explain these striking
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colony fusion and worker reproduction after queen loss in Army Ants
Proceedings of The Royal Society B: Biological Sciences, 2010Co-Authors: Daniel J C Kronauer, Caspar Schoning, Patrizia Dettorre, Jacobus J BoomsmaAbstract:Theory predicts that altruism is only evolutionarily stable if it is preferentially directed towards relatives, so that any such behaviour towards seemingly unrelated individuals requires scrutiny. Queenless Army Ant colonies, which have anecdotally been reported to fuse with queenright foreign colonies, are such an enigmatic case. Here we combine experimental queen removal with population genetics and cuticular chemistry analyses to show that colonies of the African Army Ant Dorylus molestus frequently merge with neighbouring colonies after queen loss. Merging colonies often have no direct co-ancestry, but are on average probably distAntly related because of overall population viscosity. The alternative of male production by orphaned workers appears to be so inefficient that residual inclusive fitness of orphaned workers might be maximized by indiscriminately merging with neighbouring colonies to increase their reproductive success. We show that worker chemical recognition profiles remain similar after queen loss, but rapidly change into a mixed colony Gestalt odour after fusion, consistent with indiscriminate acceptance of alien workers that are no longer aggressive. We hypothesize that colony fusion after queen loss might be more widespread, especially in spatially structured populations of social insects where worker reproduction is not profitable.
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worker caste determination in the Army Ant eciton burchellii
Biology Letters, 2007Co-Authors: Rodolfo Jaffe, Daniel J C Kronauer, Bernhard F Kraus, Jacobus J Boomsma, Robin F A MoritzAbstract:Elaborate division of labour has contributed significAntly to the ecological success of social insects. Division of labour is achieved either by behavioural task specialization or by morphological specialization of colony members. In physical caste systems, the diet and rearing environment of developing larvae is known to determine the phenotype of adult individuals, but recent studies have shown that genetic components also contribute to the determination of worker caste. One of the most extreme cases of worker caste differentiation occurs in the Army Ant genus Eciton, where queens mate with many males and colonies are therefore composed of numerous full-sister subfamilies. This high intracolonial genetic diversity, in combination with the extreme caste polymorphism, provides an excellent test system for studying the extent to which caste determination is genetically controlled. Here we show that genetic effects contribute significAntly to worker caste fate in Eciton burchellii. We conclude that the combination of polyandry and genetic variation for caste determination may have facilitated the evolution of worker caste diversity in some lineages of social insects.
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a reassessment of the mating system characteristics of the Army Ant eciton burchellii
Naturwissenschaften, 2006Co-Authors: Daniel J C Kronauer, Nigel R Franks, Scott Powell, Jay A Denny, Keith J Edwards, Stefanie M Berghoff, Jacobus J BoomsmaAbstract:In a recent study, Denny et al. (2004a) showed that queens of the Army Ant, Eciton burchellii, mate with multiple males and presented estimates suggesting that they mate with more males than queens of any other Ant species so far investigated. They also inferred that data were consistent with queens being inseminated repeatedly throughout their life, which would be exceptional among the social Hymenoptera and contradictory to predictions from kin selection theory. In the present study, we reanalyze these data using new software and supplement them with similar microsatellite data from other colonies of the same species. Mating frequencies in E. burchellii are indeed very high (mean observed and effective queen-mating frequencies of 12.9 each) but considerably lower than the previous estimates. We show that the number of patrilines represented in the first worker offspring of a young queen is lower than in older queens but suggest that this may be due to initial sperm clumping in the queen’s sperm storage organ, rather than to repeated inseminations. Moreover, we found no evidence for repeated mating by genotyping sequential worker generations produced by a single old queen, showing that she did not obtain new inseminations despite ample opportunities for mating.
Christoph Von Beeren - One of the best experts on this subject based on the ideXlab platform.
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Prey overview images
2019Co-Authors: Philipp Hoenle, Adrian Brückner, Nico Blüthgen, Daniel Kronauer, Brigitte Fiala, David Donoso, Alex Smith, Bryan Ospina Jara, Christoph Von BeerenAbstract:Overview photos of prey items collected from Army Ant raids/emigrations/prey caches collected at La Selva Biological Station, Costa Rica. Folder names give collection event IDs (see main article for more information)
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Chemical and behavioral integration of Army Ant-associated rove beetles – a comparison between specialists and generalists
Frontiers in Zoology, 2018Co-Authors: Christoph Von Beeren, Munetoshi Maruyama, Adrian Brückner, Griffin Burke, Jana Wieschollek, Daniel J C KronauerAbstract:Host-symbiont interactions are embedded in ecological communities and range from unspecific to highly specific relationships. Army Ants and their arthropod guests represent a fascinating example of species-rich host-symbiont associations where host specificity ranges across the entire generalist - specialist continuum. In the present study, we compared the behavioral and chemical integration mechanisms of two extremes of the generalist - specialist continuum: generalist Ant-predators in the genus Tetradonia (Staphylinidae: Aleocharinae: Athetini), and specialist Ant-mimics in the genera Ecitomorpha and Ecitophya (Staphylinidae: Aleocharinae: Ecitocharini). Similar to a previous study of Tetradonia beetles, we combined DNA barcoding with morphological studies to define species boundaries in Ant-mimicking beetles. This approach found four Ant-mimicking species at our study site at La Selva Biological Station in Costa Rica. Community sampling of Eciton Army Ant parasites revealed that Ant-mimicking beetles were perfect host specialists, each beetle species being associated with a single Eciton species. These specialists were seamlessly integrated into the host colony, while generalists avoided physical contact to host Ants in behavioral assays. Analysis of the Ants’ nestmate recognition cues, i.e. cuticular hydrocarbons (CHCs), showed close similarity in CHC composition and CHC concentration between specialists and Eciton burchellii foreli host Ants. On the contrary, the chemical profiles of generalists matched host profiles less well, indicating that high accuracy in chemical host resemblance is only accomplished by socially integrated species. Considering the interplay between behavior, morphology, and cuticular chemistry, specialists but not generalists have cracked the Ants’ social code with respect to various sensory modalities. Our results support the long-standing idea that the evolution of host-specialization in parasites is a trade-off between the range of potential host species and the level of specialization on any particular host.
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Additional file 1: of Brain investment under colony-level selection: soldier specialization in Eciton Army Ants (Formicidae: Dorylinae)
2018Co-Authors: Sean Oâdonnell, Susan Bulova, Meghan Barrett, Christoph Von BeerenAbstract:Table S1. Brain region volume and head capsule size data for all subjects used in the analysis of caste differences in Army Ant brain investment. Species and caste for each subject are indicated. (XLSX 40 kb
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Infection of Army Ant pupae by two new parasitoid mites (Mesostigmata: Uropodina).
PeerJ, 2017Co-Authors: Adrian Brückner, Hans Klompen, Andrew I. Bruce, Rosli Hashim, Christoph Von BeerenAbstract:A great variety of parasites and parasitoids exploit Ant societies. Among them are the Mesostigmata mites, a particularly common and diverse group of Ant-associated arthropods. While parasitism is ubiquitous in Mesostigmata, parasitoidism has only been described in the genus Macrodinychus. Yet information about the basic biology of most Macrodinychus species is lacking. Out of 24 formally described species, information about basic life-history traits is only available for three species. Here we formally describe two new Macrodinychus species, i.e. Macrodinychus hilpertae and Macrodinychus derbyensis. In both species, immature stages developed as ecto-parasitoids on Ant pupae of the South-East Asian Army Ant Leptogenys distinguenda. By piercing the developing Ant with their chelicera, the mites apparently suck Ant hemolymph, ultimately killing host individuals. We compare infection rates among all studied Macrodinychus species and discuss possible host countermeasures against parasitoidism. The cryptic lifestyle of living inside Ant nests has certainly hampered the scientific discovery of Macrodinychus mites and we expect that many more macrodinychid species await scientific discovery and description.
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nymphister kronaueri von beeren tishechkin sp nov an Army Ant associated beetle species coleoptera histeridae haeteriinae with an exceptional mechanism of phoresy
BMC Zoology, 2017Co-Authors: Christoph Von Beeren, Alexey K TishechkinAbstract:For more than a century we have known that a high diversity of arthropod species lives in close relationship with Army Ant colonies. For instance, several hundred guest species have been described to be associated with the Neotropical Army Ant Eciton burchellii Westwood, 1842. Despite ongoing efforts to survey Army Ant guest diversity, it is evident that many more species await scientific discovery. We conducted a large-scale community survey of Eciton-associated symbionts, combined with extensive DNA barcoding, which led to the discovery of numerous new species, among them a highly specialized histerid beetle, which is formally described here. Analyses of genitalic morphology with support of molecular characters revealed that the new species is a member of the genus Nymphister. We provide a literature review of host records and host-following mechanisms of Eciton-associated Haeteriinae demonstrating that the new species uses an unusual way of phoretic transport to track the nomadic habit of host Ants. Using its long mandibles as gripping pliers, the beetle attaches between the Ants’ petiole and postpetiole. The beetles specifically attach to medium-sized Ant workers, thus participating as hitchhikers in the regular colony emigrations of the single host species Eciton mexicanum Roger, 1863. By providing tools for reliable species identification via morphology and DNA barcodes for hitherto unknown Army Ant guest species, we set the baseline for studies targeting the ecological and evolutionary dynamics in these species-rich host-symbiont communities.