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Sample records for interacting ant societies

  1. Chemically armed mercenary ants protect fungus-farming societies

    PubMed Central

    Adams, Rachelle M. M.; Liberti, Joanito; Illum, Anders A.; Jones, Tappey H.; Nash, David R.; Boomsma, Jacobus J.

    2013-01-01

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies. PMID:24019482

  2. Chemically armed mercenary ants protect fungus-farming societies.

    PubMed

    Adams, Rachelle M M; Liberti, Joanito; Illum, Anders A; Jones, Tappey H; Nash, David R; Boomsma, Jacobus J

    2013-09-24

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies.

  3. Ant aggression and evolutionary stability in plant-ant and plant-pollinator mutualistic interactions.

    PubMed

    Oña, L; Lachmann, M

    2011-03-01

    Mutualistic partners derive a benefit from their interaction, but this benefit can come at a cost. This is the case for plant-ant and plant-pollinator mutualistic associations. In exchange for protection from herbivores provided by the resident ants, plants supply various kinds of resources or nests to the ants. Most ant-myrmecophyte mutualisms are horizontally transmitted, and therefore, partners share an interest in growth but not in reproduction. This lack of alignment in fitness interests between plants and ants drives a conflict between them: ants can attack pollinators that cross-fertilize the host plants. Using a mathematical model, we define a threshold in ant aggressiveness determining pollinator survival or elimination on the host plant. In our model we observed that, all else being equal, facultative interactions result in pollinator extinction for lower levels of ant aggressiveness than obligatory interactions. We propose that the capacity to discriminate pollinators from herbivores should not often evolve in ants, and when it does it will be when the plants exhibit limited dispersal in an environment that is not seed saturated so that each seed produced can effectively generate a new offspring or if ants acquire an extra benefit from pollination (e.g. if ants eat fruit). We suggest specific mutualism examples where these hypotheses can be tested empirically. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  4. Ecological consequences of traffic organisation in ant societies

    NASA Astrophysics Data System (ADS)

    Burd, Martin

    2006-12-01

    Many species of ants engage in social foraging in which traffic develops over pathways defined by pheromones or physical roads cleared through debris. Worker ants from the same colony have a common underlying evolutionary interest in their collective performance. Thus, ant traffic makes an interesting comparison to other kinds of cellular or organismal traffic composed of elements with varying degrees of shared or disparate goals. Recent studies have revealed how small-scale interactions among ants amplify to create large-scale traffic structure, such as segregation of counterflows. However, much less is known about the ecological costs and benefits of different kinds of traffic organization. The common assumption that maximum traffic flux provides maximum ecological benefit needs closer scrutiny. Ant traffic provides a potentially useful model system for experimental study of crowd panics, and for assessing the role of transport networks in creating scaling relationships between the size and activity rates of the entities they serve.

  5. Fitness costs of worker specialization for ant societies.

    PubMed

    Jongepier, Evelien; Foitzik, Susanne

    2016-01-13

    Division of labour is of fundamental importance for the success of societies, yet little is known about how individual specialization affects the fitness of the group as a whole. While specialized workers may be more efficient in the tasks they perform than generalists, they may also lack the flexibility to respond to rapid shifts in task needs. Such rigidity could impose fitness costs when societies face dynamic and unpredictable events, such as an attack by socially parasitic slavemakers. Here, we experimentally assess the colony-level fitness consequences of behavioural specialization in Temnothorax longispinosus ants that are attacked by the slavemaker ant T. americanus. We manipulated the social organization of 102 T. longispinosus colonies, based on the behavioural responses of all 3842 workers. We find that strict specialization is disadvantageous for a colony's annual reproduction and growth during slave raids. These fitness costs may favour generalist strategies in dynamic environments, as we also demonstrate that societies exposed to slavemakers in the field show a lower degree of specialization than those originating from slavemaker-free populations. Our findings provide an explanation for the ubiquity of generalists and highlight their importance for the flexibility and functional robustness of entire societies.

  6. Fitness costs of worker specialization for ant societies

    PubMed Central

    Jongepier, Evelien; Foitzik, Susanne

    2016-01-01

    Division of labour is of fundamental importance for the success of societies, yet little is known about how individual specialization affects the fitness of the group as a whole. While specialized workers may be more efficient in the tasks they perform than generalists, they may also lack the flexibility to respond to rapid shifts in task needs. Such rigidity could impose fitness costs when societies face dynamic and unpredictable events, such as an attack by socially parasitic slavemakers. Here, we experimentally assess the colony-level fitness consequences of behavioural specialization in Temnothorax longispinosus ants that are attacked by the slavemaker ant T. americanus. We manipulated the social organization of 102 T. longispinosus colonies, based on the behavioural responses of all 3842 workers. We find that strict specialization is disadvantageous for a colony's annual reproduction and growth during slave raids. These fitness costs may favour generalist strategies in dynamic environments, as we also demonstrate that societies exposed to slavemakers in the field show a lower degree of specialization than those originating from slavemaker-free populations. Our findings provide an explanation for the ubiquity of generalists and highlight their importance for the flexibility and functional robustness of entire societies. PMID:26763706

  7. Long-Term Disease Dynamics for a Specialized Parasite of Ant Societies: A Field Study

    PubMed Central

    Loreto, Raquel G.; Elliot, Simon L.; Freitas, Mayara L. R.; Pereira, Thairine M.; Hughes, David P.

    2014-01-01

    Many studies have investigated how social insects behave when a parasite is introduced into their colonies. These studies have been conducted in the laboratory, and we still have a limited understanding of the dynamics of ant-parasite interactions under natural conditions. Here we consider a specialized parasite of ant societies (Ophiocordyceps camponoti-rufipedis infecting Camponotus rufipes) within a rainforest. We first established that the parasite is unable to develop to transmission stage when introduced within the host nest. Secondly, we surveyed all colonies in the studied area and recorded 100% prevalence at the colony level (all colonies were infected). Finally, we conducted a long-term detailed census of parasite pressure, by mapping the position of infected dead ants and foraging trails (future hosts) in the immediate vicinity of the colonies over 20 months. We report new dead infected ants for all the months we conducted the census – at an average of 14.5 cadavers/month/colony. Based on the low infection rate, the absence of colony collapse or complete recovery of the colonies, we suggest that this parasite represents a chronic infection in the ant societies. We also proposed a “terminal host model of transmission” that links the age-related polyethism to the persistence of a parasitic infection. PMID:25133749

  8. Opposing effects of allogrooming on disease transmission in ant societies.

    PubMed

    Theis, Fabian J; Ugelvig, Line V; Marr, Carsten; Cremer, Sylvia

    2015-05-26

    To prevent epidemics, insect societies have evolved collective disease defences that are highly effective at curing exposed individuals and limiting disease transmission to healthy group members. Grooming is an important sanitary behaviour--either performed towards oneself (self-grooming) or towards others (allogrooming)--to remove infectious agents from the body surface of exposed individuals, but at the risk of disease contraction by the groomer. We use garden ants (Lasius neglectus) and the fungal pathogen Metarhizium as a model system to study how pathogen presence affects self-grooming and allogrooming between exposed and healthy individuals. We develop an epidemiological SIS model to explore how experimentally observed grooming patterns affect disease spread within the colony, thereby providing a direct link between the expression and direction of sanitary behaviours, and their effects on colony-level epidemiology. We find that fungus-exposed ants increase self-grooming, while simultaneously decreasing allogrooming. This behavioural modulation seems universally adaptive and is predicted to contain disease spread in a great variety of host-pathogen systems. In contrast, allogrooming directed towards pathogen-exposed individuals might both increase and decrease disease risk. Our model reveals that the effect of allogrooming depends on the balance between pathogen infectiousness and efficiency of social host defences, which are likely to vary across host-pathogen systems. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  9. Acquisition of chemical recognition cues facilitates integration into ant societies

    PubMed Central

    2011-01-01

    Background Social insects maintain the integrity of their societies by discriminating between colony members and foreigners through cuticular hydrocarbon (CHC) signatures. Nevertheless, parasites frequently get access to social resources, for example through mimicry of host CHCs among other mechanisms. The origin of mimetic compounds, however, remains unknown in the majority of studies (biosynthesis vs. acquisition). Additionally, direct evidence is scarce that chemical mimicry is indeed beneficial to the parasites (e.g., by improving social acceptance). Results In the present study we demonstrated that the kleptoparasitic silverfish Malayatelura ponerophila most likely acquires CHCs directly from its host ant Leptogenys distinguenda by evaluating the transfer of a stable-isotope label from the cuticle of workers to the silverfish. In a second experiment, we prevented CHC pilfering by separating silverfish from their host for six or nine days. Chemical host resemblance as well as aggressive rejection behaviour by host ants was then quantified for unmanipulated and previously separated individuals. Separated individuals showed reduced chemical host resemblance and they received significantly more aggressive rejection behaviour than unmanipulated individuals. Conclusion Our study clarifies the mechanism of chemical mimicry in a social insect parasite in great detail. It shows empirically for the first time that social insect parasites are able to acquire CHCs from their host. Furthermore, it demonstrates that the accuracy of chemical mimicry can be crucial for social insect parasites by enhancing social acceptance and, thus, allowing successful exploitation. We discuss the results in the light of coevolutionary arms races between parasites and hosts. PMID:22133503

  10. Opposing effects of allogrooming on disease transmission in ant societies

    PubMed Central

    Theis, Fabian J.; Ugelvig, Line V.; Marr, Carsten; Cremer, Sylvia

    2015-01-01

    To prevent epidemics, insect societies have evolved collective disease defences that are highly effective at curing exposed individuals and limiting disease transmission to healthy group members. Grooming is an important sanitary behaviour—either performed towards oneself (self-grooming) or towards others (allogrooming)—to remove infectious agents from the body surface of exposed individuals, but at the risk of disease contraction by the groomer. We use garden ants (Lasius neglectus) and the fungal pathogen Metarhizium as a model system to study how pathogen presence affects self-grooming and allogrooming between exposed and healthy individuals. We develop an epidemiological SIS model to explore how experimentally observed grooming patterns affect disease spread within the colony, thereby providing a direct link between the expression and direction of sanitary behaviours, and their effects on colony-level epidemiology. We find that fungus-exposed ants increase self-grooming, while simultaneously decreasing allogrooming. This behavioural modulation seems universally adaptive and is predicted to contain disease spread in a great variety of host–pathogen systems. In contrast, allogrooming directed towards pathogen-exposed individuals might both increase and decrease disease risk. Our model reveals that the effect of allogrooming depends on the balance between pathogen infectiousness and efficiency of social host defences, which are likely to vary across host–pathogen systems. PMID:25870394

  11. Genetic royal cheats in leaf-cutting ant societies

    PubMed Central

    Hughes, William O. H.; Boomsma, Jacobus J.

    2008-01-01

    Social groups are vulnerable to cheating because the reproductive interests of group members are rarely identical. All cooperative systems are therefore predicted to involve a mix of cooperative and cheating genotypes, with the frequency of the latter being constrained by the suppressive abilities of the former. The most significant potential conflict in social insect colonies is over which individuals become reproductive queens rather than sterile workers. This reproductive division of labor is a defining characteristic of eusocial societies, but individual larvae will maximize their fitness by becoming queens whereas their nestmates will generally maximize fitness by forcing larvae to become workers. However, evolutionary constraints are thought to prevent cheating by removing genetic variation in caste propensity. Here, we show that one-fifth of leaf-cutting ant patrilines cheat their nestmates by biasing their larval development toward becoming queens rather than workers. Two distinct mechanisms appear to be involved, one most probably involving a general tendency to become a larger adult and the other relating specifically to the queen–worker developmental switch. Just as evolutionary theory predicts, these “royal” genotypes are rare both in the population and within individual colonies. The rarity of royal cheats is best explained as an evolutionary strategy to avoid suppression by cooperative genotypes, the efficiency of which is frequency-dependent. The results demonstrate that cheating can be widespread in even the most cooperative of societies and illustrate that identical principles govern social evolution in highly diverse systems. PMID:18339809

  12. Genetic royal cheats in leaf-cutting ant societies.

    PubMed

    Hughes, William O H; Boomsma, Jacobus J

    2008-04-01

    Social groups are vulnerable to cheating because the reproductive interests of group members are rarely identical. All cooperative systems are therefore predicted to involve a mix of cooperative and cheating genotypes, with the frequency of the latter being constrained by the suppressive abilities of the former. The most significant potential conflict in social insect colonies is over which individuals become reproductive queens rather than sterile workers. This reproductive division of labor is a defining characteristic of eusocial societies, but individual larvae will maximize their fitness by becoming queens whereas their nestmates will generally maximize fitness by forcing larvae to become workers. However, evolutionary constraints are thought to prevent cheating by removing genetic variation in caste propensity. Here, we show that one-fifth of leaf-cutting ant patrilines cheat their nestmates by biasing their larval development toward becoming queens rather than workers. Two distinct mechanisms appear to be involved, one most probably involving a general tendency to become a larger adult and the other relating specifically to the queen-worker developmental switch. Just as evolutionary theory predicts, these "royal" genotypes are rare both in the population and within individual colonies. The rarity of royal cheats is best explained as an evolutionary strategy to avoid suppression by cooperative genotypes, the efficiency of which is frequency-dependent. The results demonstrate that cheating can be widespread in even the most cooperative of societies and illustrate that identical principles govern social evolution in highly diverse systems.

  13. Diverse societies are more productive: a lesson from ants

    PubMed Central

    Modlmeier, Andreas P.; Liebmann, Julia E.; Foitzik, Susanne

    2012-01-01

    The fitness consequences of animal personalities (also known as behavioural syndromes) have recently been studied in several solitary species. However, the adaptive significance of collective personalities in social insects and especially of behavioural variation among group members remains largely unexplored. Although intracolonial behavioural variation is an important component of division of labour, and as such a key feature for the success of societies, empirical links between behavioural variation and fitness are scarce. We investigated aggression, exploration and brood care behaviour in Temnothorax longispinosus ant colonies. We focused on two distinct aspects: intercolonial variability and its consistency across time and contexts, and intracolonial variability and its influence on productivity. Aggressiveness was consistent over four to five months with a new generation of workers emerging in between trial series. Other behaviours were not consistent over time. Exploration of novel environments responded to the sequence of assays: colonies were faster in discovering when workers previously encountered opponents in aggression experiments. Suites of correlated behaviours (e.g. aggression–exploration syndrome) present in the first series did not persist over time. Finally, colonies with more intracolonial behavioural variation in brood care and exploration of novel objects were more productive under standardized conditions than colonies with less variation. PMID:22279166

  14. The interactions of ants with their biotic environment

    PubMed Central

    Renner, Susanne S.

    2017-01-01

    This special feature results from the symposium ‘Ants 2016: ant interactions with their biotic environments’ held in Munich in May 2016 and deals with the interactions between ants and other insects, plants, microbes and fungi, studied at micro- and macroevolutionary levels with a wide range of approaches, from field ecology to next-generation sequencing, chemical ecology and molecular genetics. In this paper, we review key aspects of these biotic interactions to provide background information for the papers of this special feature. After listing the major types of biotic interactions that ants engage in, we present a brief overview of ant/ant communication, ant/plant interactions, ant/fungus symbioses, and recent insights about ants and their endosymbionts. Using a large molecular clock-dated Formicidae phylogeny, we map the evolutionary origins of different ant clades' interactions with plants, fungi and hemiptera. Ants' biotic interactions provide ideal systems to address fundamental ecological and evolutionary questions about mutualism, coevolution, adaptation and animal communication. PMID:28298352

  15. Warring arthropod societies: Social spider colonies can delay annihilation by predatory ants via reduced apparency and increased group size.

    PubMed

    Keiser, Carl N; Wright, Colin M; Pruitt, Jonathan N

    2015-10-01

    Sociality provides individuals with benefits via collective foraging and anti-predator defense. One of the costs of living in large groups, however, is increased apparency to natural enemies. Here, we test how the individual-level and collective traits of spider societies can increase the risk of discovery and death by predatory ants. We transplanted colonies of the social spider Stegodyphus dumicola into a habitat dense with one of their top predators, the pugnacious ant Anoplolepis custodiens. With three different experiments, we test how colony-wide survivorship in a predator-dense habitat can be altered by colony apparency (i.e., the presence of a capture web), group size, and group composition (i.e., the proportion of bold and shy personality types present). We also test how spiders' social context (i.e., living solitarily vs. among conspecifics) modifies their behaviour toward ants in their capture web. Colonies with capture webs intact were discovered by predatory ants on average 25% faster than colonies with the capture web removed, and all discovered colonies eventually collapsed and succumbed to predation. However, the lag time from discovery by ants to colony collapse was greater for colonies containing more individuals. The composition of individual personality types in the group had no influence on survivorship. Spiders in a social group were more likely to approach ants caught in their web than were isolated spiders. Isolated spiders were more likely to attack a safe prey item (a moth) than they were to attack ants and were more likely to retreat from ants after contact than they were after contact with moths. Together, our data suggest that the physical structures produced by large animal societies can increase their apparency to natural enemies, though larger groups can facilitate a longer lag time between discovery and demise. Lastly, the interaction between spiders and predatory ants seems to depend on the social context in which spiders reside.

  16. Plant chemical defense indirectly mediates aphid performance via interactions with tending ants.

    PubMed

    Züst, Tobias; Agrawal, Anurag A

    2017-03-01

    The benefits of mutualistic interactions are often highly context dependent. We studied the interaction between the milkweed aphid Aphis asclepiadis and a tending ant, Formica podzolica. Although this interaction is generally considered beneficial, variation in plant genotype may alter it from mutualistic to antagonistic. Here we link the shift in strength and relative benefit of the ant-aphid interaction to plant genotypic variation in the production of cardenolides, a class of toxic defensive chemicals. In a field experiment with highly variable genotypes of the common milkweed (Asclepias syriaca), we show that plant cardenolides, especially polar forms, are ingested by aphids and excreted in honeydew proportionally to plant concentrations without directly affecting aphid performance. Ants consume honeydew, and aphids that excreted high amounts of cardenolides received fewer ant visits, which in turn reduced aphid survival. On at least some plant genotypes, aphid numbers per plant were reduced in the presence of ants to levels lower than in corresponding ant-exclusion treatments, suggesting antagonistic ant behavior. Although cardenolides appear ineffective as direct plant defenses against aphids, the multi-trophic context reveals an ant-mediated negative indirect effect on aphid performance and population dynamics. © 2016 by the Ecological Society of America.

  17. Cascading trait-mediated interactions induced by ant pheromones

    PubMed Central

    Hsieh, Hsun-Yi; Liere, Heidi; Soto, Estelí J; Perfecto, Ivette

    2012-01-01

    Trait-mediated indirect interactions (TMII) can be as important as density-mediated indirect interactions. Here, we provide evidence for a novel trait-mediated cascade (where one TMII affects another TMII) and demonstrate that the mechanism consists of a predator eavesdropping on chemical signaling. Ants protect scale insects from predation by adult coccinellid beetles – the first TMII. However, parasitic phorid flies reduce ant foraging activity by 50% – the second TMII, providing a window of opportunity for female beetles to oviposit in high-quality microsites. Beetle larvae are protected from ant predation and benefit from living in patches with high scale densities. We demonstrate that female beetles can detect pheromones released by the ant when attacked by phorids, and that only females, and especially gravid females, are attracted to the ant pheromone. As ants reduce their movement when under attack by phorids, we conclude that phorids facilitate beetle oviposition, thus producing the TMII cascade. PMID:23139877

  18. Cascading trait-mediated interactions induced by ant pheromones.

    PubMed

    Hsieh, Hsun-Yi; Liere, Heidi; Soto, Estelí J; Perfecto, Ivette

    2012-09-01

    Trait-mediated indirect interactions (TMII) can be as important as density-mediated indirect interactions. Here, we provide evidence for a novel trait-mediated cascade (where one TMII affects another TMII) and demonstrate that the mechanism consists of a predator eavesdropping on chemical signaling. Ants protect scale insects from predation by adult coccinellid beetles - the first TMII. However, parasitic phorid flies reduce ant foraging activity by 50% - the second TMII, providing a window of opportunity for female beetles to oviposit in high-quality microsites. Beetle larvae are protected from ant predation and benefit from living in patches with high scale densities. We demonstrate that female beetles can detect pheromones released by the ant when attacked by phorids, and that only females, and especially gravid females, are attracted to the ant pheromone. As ants reduce their movement when under attack by phorids, we conclude that phorids facilitate beetle oviposition, thus producing the TMII cascade.

  19. Ants at Plant Wounds: A Little-Known Trophic Interaction with Evolutionary Implications for Ant-Plant Interactions.

    PubMed

    Staab, Michael; Fornoff, Felix; Klein, Alexandra-Maria; Blüthgen, Nico

    2017-09-01

    Extrafloral nectaries (EFNs) allow plants to engage in mutualisms with ants, preventing herbivory in exchange for food. EFNs occur scattered throughout the plant phylogeny and likely evolved independent from herbivore-created wounds subsequently visited by ants collecting leaked sap. Records of wound-feeding ants are, however, anecdotal. By surveying 38,000 trees from 40 species, we conducted the first quantitative ecological study of this overlooked behavior. Ant-wound interactions were widespread (0.5% of tree individuals) and occurred on 23 tree species. Interaction networks were opportunistic, closely resembling ant-EFN networks. Fagaceae, a family lacking EFNs, was strongly overrepresented. For Fagaceae, ant occurrence at wounds correlated with species-level leaf damage, potentially indicating that wounds may attract mutualistic ants, which supports the hypothesis of ant-tended wounds as precursors of ant-EFN mutualisms. Given that herbivore wounds are common, wound sap as a steadily available food source might further help to explain the overwhelming abundance of ants in (sub)tropical forest canopies.

  20. Ant-caterpillar antagonism at the community level: interhabitat variation of tritrophic interactions in a neotropical savanna.

    PubMed

    Sendoya, Sebastián F; Oliveira, Paulo S

    2015-03-01

    host plant use by lepidopterans. The magnitude of ant-induced effects on caterpillar occurrence across the cerrado landscape may depend on how ants use plants locally and how they respond to liquid food on plants at different habitats. This study enhances the relevance of plant-ant and ant-herbivore interactions in cerrado and highlights the importance of a tritrophic perspective in this ant-rich environment. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

  1. Desert ants achieve reliable recruitment across noisy interactions.

    PubMed

    Razin, Nitzan; Eckmann, Jean-Pierre; Feinerman, Ofer

    2013-05-06

    We study how desert ants, Cataglyphis niger, a species that lacks pheromone-based recruitment mechanisms, inform each other about the presence of food. Our results are based on automated tracking that allows us to collect a large database of ant trajectories and interactions. We find that interactions affect an ant's speed within the nest. Fast ants tend to slow down, whereas slow ones increase their speed when encountering a faster ant. Faster ants tend to exit the nest more frequently than slower ones. So, if an ant gains enough speed through encounters with others, then she tends to leave the nest and look for food. On the other hand, we find that the probability for her to leave the nest depends only on her speed, but not on whether she had recently interacted with a recruiter that has found the food. This suggests a recruitment system in which ants communicate their state by very simple interactions. Based on this assumption, we estimate the information-theoretical channel capacity of the ants' pairwise interactions. We find that the response to the speed of an interacting nest-mate is very noisy. The question is then how random interactions with ants within the nest can be distinguished from those interactions with a recruiter who has found food. Our measurements and model suggest that this distinction does not depend on reliable communication but on behavioural differences between ants that have found the food and those that have not. Recruiters retain high speeds throughout the experiment, regardless of the ants they interact with; non-recruiters communicate with a limited number of nest-mates and adjust their speed following these interactions. These simple rules lead to the formation of a bistable switch on the level of the group that allows the distinction between recruitment and random noise in the nest. A consequence of the mechanism we propose is a negative effect of ant density on exit rates and recruitment success. This is, indeed, confirmed by our

  2. Interactions Increase Forager Availability and Activity in Harvester Ants

    PubMed Central

    Pinter-Wollman, Noa; Crow, Sam; Allen, Kelsey; Mathur, Maya B.; Gordon, Deborah M.

    2015-01-01

    Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated. PMID:26539724

  3. Interactions Increase Forager Availability and Activity in Harvester Ants.

    PubMed

    Pless, Evlyn; Queirolo, Jovel; Pinter-Wollman, Noa; Crow, Sam; Allen, Kelsey; Mathur, Maya B; Gordon, Deborah M

    2015-01-01

    Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.

  4. Desert ants achieve reliable recruitment across noisy interactions

    PubMed Central

    Razin, Nitzan; Eckmann, Jean-Pierre; Feinerman, Ofer

    2013-01-01

    We study how desert ants, Cataglyphis niger, a species that lacks pheromone-based recruitment mechanisms, inform each other about the presence of food. Our results are based on automated tracking that allows us to collect a large database of ant trajectories and interactions. We find that interactions affect an ant's speed within the nest. Fast ants tend to slow down, whereas slow ones increase their speed when encountering a faster ant. Faster ants tend to exit the nest more frequently than slower ones. So, if an ant gains enough speed through encounters with others, then she tends to leave the nest and look for food. On the other hand, we find that the probability for her to leave the nest depends only on her speed, but not on whether she had recently interacted with a recruiter that has found the food. This suggests a recruitment system in which ants communicate their state by very simple interactions. Based on this assumption, we estimate the information-theoretical channel capacity of the ants’ pairwise interactions. We find that the response to the speed of an interacting nest-mate is very noisy. The question is then how random interactions with ants within the nest can be distinguished from those interactions with a recruiter who has found food. Our measurements and model suggest that this distinction does not depend on reliable communication but on behavioural differences between ants that have found the food and those that have not. Recruiters retain high speeds throughout the experiment, regardless of the ants they interact with; non-recruiters communicate with a limited number of nest-mates and adjust their speed following these interactions. These simple rules lead to the formation of a bistable switch on the level of the group that allows the distinction between recruitment and random noise in the nest. A consequence of the mechanism we propose is a negative effect of ant density on exit rates and recruitment success. This is, indeed, confirmed by

  5. Ant plant herbivore interactions in the neotropical cerrado savanna

    NASA Astrophysics Data System (ADS)

    Oliveira, Paulo S.; Freitas, André V. L.

    2004-12-01

    The Brazilian cerrado savanna covers nearly 2 million km2 and has a high incidence on foliage of various liquid food sources such as extrafloral nectar and insect exudates. These liquid rewards generate intense ant activity on cerrado foliage, making ant plant herbivore interactions especially prevalent in this biome. We present data on the distribution and abundance of extrafloral nectaries in the woody flora of cerrado communities and in the flora of other habitats worldwide, and stress the relevance of liquid food sources (including hemipteran honeydew) for the ant fauna. Consumption by ants of plant and insect exudates significantly affects the activity of the associated herbivores of cerrado plant species, with varying impacts on the reproductive output of the plants. Experiments with an ant plant butterfly system unequivocally demonstrate that the behavior of both immature and adult lepidopterans is closely related to the use of a risky host plant, where intensive visitation by ants can have a severe impact on caterpillar survival. We discuss recent evidence suggesting that the occurrence of liquid rewards on leaves plays a key role in mediating the foraging ecology of foliage-dwelling ants, and that facultative ant plant mutualisms are important in structuring the community of canopy arthropods. Ant-mediated effects on cerrado herbivore communities can be revealed by experiments performed on wide spatial scales, including many environmental factors such as soil fertility and vegetation structure. We also present some research questions that could be rewarding to investigate in this major neotropical savanna.

  6. Arboreal Ant Colonies as ‘Hot-Points’ of Cryptic Diversity for Myrmecophiles: The Weaver Ant Camponotus sp. aff. textor and Its Interaction Network with Its Associates

    PubMed Central

    Pérez-Lachaud, Gabriela; Lachaud, Jean-Paul

    2014-01-01

    Introduction Systematic surveys of macrofaunal diversity within ant colonies are lacking, particularly for ants nesting in microhabitats that are difficult to sample. Species associated with ants are generally small and rarely collected organisms, which makes them more likely to be unnoticed. We assumed that this tendency is greater for arthropod communities in microhabitats with low accessibility, such as those found in the nests of arboreal ants that may constitute a source of cryptic biodiversity. Materials and Methods We investigated the invertebrate diversity associated with an undescribed, but already threatened, Neotropical Camponotus weaver ant. As most of the common sampling methods used in studies of ant diversity are not suited for evaluating myrmecophile diversity within ant nests, we evaluated the macrofauna within ant nests through exhaustive colony sampling of three nests and examination of more than 80,000 individuals. Results We identified invertebrates from three classes belonging to 18 taxa, some of which were new to science, and recorded the first instance of the co-occurrence of two brood parasitoid wasp families attacking the same ant host colony. This diversity of ant associates corresponded to a highly complex interaction network. Agonistic interactions prevailed, but the prevalence of myrmecophiles was remarkably low. Conclusions Our data support the hypothesis of the evolution of low virulence in a variety of symbionts associated with large insect societies. Because most myrmecophiles found in this work are rare, strictly specific, and exhibit highly specialized biology, the risk of extinction for these hitherto unknown invertebrates and their natural enemies is high. The cryptic, far unappreciated diversity within arboreal ant nests in areas at high risk of habitat loss qualifies these nests as ‘hot-points’ of biodiversity that urgently require special attention as a component of conservation and management programs. PMID:24941047

  7. Disease in the Society: Infectious Cadavers Result in Collapse of Ant Sub-Colonies

    PubMed Central

    Loreto, Raquel G.; Hughes, David P.

    2016-01-01

    Despite the growing number of experimental studies on mechanisms of social immunity in ant societies, little is known about how social behavior relates to disease progression within the nests of ants. In fact, when empirically studying disease in ant societies, it is common to remove dead ants from experiments to confirm infection by the studied parasite. This unfortunately does not allow disease to progress within the nest as it may be assumed would happen under natural conditions. Therefore, the approach taken so far has resulted in a limited knowledge of diseases dynamics within the nest environment. Here we introduced a single infectious cadaver killed by the fungus Beauveria bassiana into small nests of the ant Camponotus castaneus. We then observed the natural progression of the disease by not removing the corpses of the ants that died following the first entry of the disease. Because some behaviors such as social isolation of sick individuals or the removal of cadavers by nestmates are considered social immune functions and thus adaptations at the colony level that reduce disease spread, we also experimentally confined some sub-colonies to one or two chamber nests to prevent the expression of such behaviors. Based on 51 small nests and survival studies in 1,003 ants we found that a single introduced infectious cadaver was able to transmit within the nest, and social immunity did not prevent the collapse of the small sub-colonies here tested. This was true whether ants did or did not have the option to remove the infectious cadaver. Therefore, we found no evidence that the typically studied social immunity behaviors can reduce disease spread in the conditions here tested. PMID:27529548

  8. Disease in the Society: Infectious Cadavers Result in Collapse of Ant Sub-Colonies.

    PubMed

    Loreto, Raquel G; Hughes, David P

    2016-01-01

    Despite the growing number of experimental studies on mechanisms of social immunity in ant societies, little is known about how social behavior relates to disease progression within the nests of ants. In fact, when empirically studying disease in ant societies, it is common to remove dead ants from experiments to confirm infection by the studied parasite. This unfortunately does not allow disease to progress within the nest as it may be assumed would happen under natural conditions. Therefore, the approach taken so far has resulted in a limited knowledge of diseases dynamics within the nest environment. Here we introduced a single infectious cadaver killed by the fungus Beauveria bassiana into small nests of the ant Camponotus castaneus. We then observed the natural progression of the disease by not removing the corpses of the ants that died following the first entry of the disease. Because some behaviors such as social isolation of sick individuals or the removal of cadavers by nestmates are considered social immune functions and thus adaptations at the colony level that reduce disease spread, we also experimentally confined some sub-colonies to one or two chamber nests to prevent the expression of such behaviors. Based on 51 small nests and survival studies in 1,003 ants we found that a single introduced infectious cadaver was able to transmit within the nest, and social immunity did not prevent the collapse of the small sub-colonies here tested. This was true whether ants did or did not have the option to remove the infectious cadaver. Therefore, we found no evidence that the typically studied social immunity behaviors can reduce disease spread in the conditions here tested.

  9. Spatial organization and interactions of harvester ants during foraging activity.

    PubMed

    Davidson, Jacob D; Gordon, Deborah M

    2017-10-01

    Local interactions, when individuals meet, can regulate collective behaviour. In a system without any central control, the rate of interaction may depend simply on how the individuals move around. But interactions could in turn influence movement; individuals might seek out interactions, or their movement in response to interaction could influence further interaction rates. We develop a general framework to address these questions, using collision theory to establish a baseline expected rate of interaction based on proximity. We test the models using data from harvester ant colonies. A colony uses feedback from interactions inside the nest to regulate foraging activity. Potential foragers leave the nest in response to interactions with returning foragers with food. The time series of interactions and local density of ants show how density hotspots lead to interactions that are clustered in time. A correlated random walk null model describes the mixing of potential and returning foragers. A model from collision theory relates walking speed and spatial proximity with the probability of interaction. The results demonstrate that although ants do not mix homogeneously, trends in interaction patterns can be explained simply by the walking speed and local density of surrounding ants. © 2017 The Author(s).

  10. The effect of diet and opponent size on aggressive interactions involving caribbean crazy ants (Nylanderia fulva).

    PubMed

    Horn, Katherine C; Eubanks, Micky D; Siemann, Evan

    2013-01-01

    Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants.

  11. The Effect of Diet and Opponent Size on Aggressive Interactions Involving Caribbean Crazy Ants (Nylanderia fulva)

    PubMed Central

    Horn, Katherine C.; Eubanks, Micky D.; Siemann, Evan

    2013-01-01

    Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants. PMID:23776702

  12. Interaction between Mutualisms: Ant-tended butterflies exploit enemy-free space provided by ant-treehopper associations.

    PubMed

    Kaminski, Lucas A; Freitas, André V L; Oliveira, Paulo S

    2010-09-01

    Although mutualisms have been intensively investigated, demonstration of indirect effects between co-occurring mutualistic systems is rare. For instance, the ecological consequences of co-occurrence of ant-tended insects on a plant have never been examined for survival effects on either trophobiont species. Here, we assess the selective pressures mediating co-occurrence of a facultative ant-tended butterfly (Parrhasius polibetes) with ant-tended treehoppers (Guayaquila xiphias) on Schefflera vinosa shrubs. We evaluated host plant selection and caterpillar survival in P. polibetes in the presence and absence of ant-treehopper associations. Paired trials revealed that butterflies preferably oviposit on branches hosting ant-tended treehoppers when they had a choice between those and branches without this interaction. Presence of ant-tended treehoppers on a branch reduced the abundance of P. polibetes' natural enemies and improved caterpillar survival in both premyrmecophylic and ant-tended phases. Thus ant-tended treehoppers create an enemy-free space on foliage that butterflies exploit to protect larval offspring. These findings connect two widely documented ant-trophobiont mutualisms and highlight the importance of considering multiple interactions for a proper understanding of ant-plant-herbivore systems. Detection of other ant-based mutualisms on oviposition to improve offspring survival may have represented an important evolutionary step in the process of host plant selection in facultative myrmecophilous butterflies.

  13. Wet years have more caterpillars: interacting roles of plant litter and predation by ants.

    PubMed

    Karban, Richard; Grof-Tisza, Patrick; Holyoak, Marcel

    2017-09-01

    Climate is widely recognized as an important factor that affects temporal and spatial patterns of occurrence and abundance of herbivorous insects, although the ecological mechanisms responsible are poorly understood. We found that precipitation and standing water were positively correlated with locations and years of high abundance of caterpillars of the ranchman's tiger moth, Platyprepia virginalis. We analyzed 30 years of survey data and found that the number of large rainfall events was a better predictor of caterpillar abundance than total annual accumulation. We considered three ecological mechanisms that could drive this relationship and conducted observations and manipulative experiments to evaluate these mechanisms. (1) Rainfall facilitates more plant growth, although we found no evidence that increased food quality or quantity was causing the positive association between precipitation and caterpillar abundance. (2) Large rainfall events cause predatory ground-nesting ants to be less abundant and we found that the number of ants that recruited to local sites was negatively associated with survival and abundance of caterpillars. (3) We found that litter from wet sites provided a refuge from ant predation; litter from wet sites was not beneficial to caterpillars in the absence of ants. Both abiotic factors (precipitation) and biotic factors (predatory ants) affected the temporal and spatial abundance of caterpillars directly and interactively. Climate models predict that rainfall will become more variable, suggesting that populations of this caterpillar may also become more variable in the future. © 2017 by the Ecological Society of America.

  14. Density-mediated, context-dependent consumer-resource interactions between ants and extrafloral nectar plants.

    PubMed

    Chamberlain, Scott A; Holland, J Nathaniel

    2008-05-01

    Interspecific interactions are often mediated by the interplay between resource supply and consumer density. The supply of a resource and a consumer's density response to it may in turn yield context-dependent use of other resources. Such consumer-resource interactions occur not only for predator-prey and competitive interactions, but for mutualistic ones as well. For example, consumer-resource interactions between ants and extrafloral nectar (EFN) plants are often mutualistic, as EFN resources attract and reward ants which protect plants from herbivory. Yet, ants also commonly exploit floral resources, leading to antagonistic consumer-resource interactions by disrupting pollination and plant reproduction. EFN resources associated with mutualistic ant-plant interactions may also mediate antagonistic ant-flower interactions through the aggregative density response of ants on plants, which could either exacerbate ant-flower interactions or alternatively satiate and distract ants from floral resources. In this study, we examined how EFN resources mediate the density response of ants on senita cacti in the Sonoran Desert and their context-dependent use of floral resources. Removal of EFN resources reduced the aggregative density of ants on plants, both on hourly and daily time scales. Yet, the increased aggregative ant density on plants with EFN resources decreased rather than increased ant use of floral resources, including contacts with and time spent in flowers. Behavioral assays showed no confounding effect of floral deterrents on ant-flower interactions. Thus, ant use of floral resources depends on the supply of EFN resources, which mediates the potential for both mutualistic and antagonistic interactions by increasing the aggregative density of ants protecting plants, while concurrently distracting ants from floral resources. Nevertheless, only certain years and populations of study showed an increase in plant reproduction through herbivore protection or ant

  15. Characterizing the Collective Personality of Ant Societies: Aggressive Colonies Do Not Abandon Their Home

    PubMed Central

    Fries, Stephan; Tirard, Claire; Foitzik, Susanne

    2012-01-01

    Animal groups can show consistent behaviors or personalities just like solitary animals. We studied the collective behavior of Temnothorax nylanderi ant colonies, including consistency in behavior and correlations between different behavioral traits. We focused on four collective behaviors (aggression against intruders, nest relocation, removal of infected corpses and nest reconstruction) and also tested for links to the immune defense level of a colony and a fitness component (per-capita productivity). Behaviors leading to an increased exposure of ants to micro-parasites were expected to be positively associated with immune defense measures and indeed colonies that often relocated to other nest sites showed increased immune defense levels. Besides, colonies that responded with low aggression to intruders or failed to remove infected corpses, showed a higher likelihood to move to a new nest site. This resembles the trade-off between aggression and relocation often observed in solitary animals. Finally, one of the behaviors, nest reconstruction, was positively linked to per-capita productivity, whereas other colony-level behaviors, such as aggression against intruders, showed no association, albeit all behaviors were expected to be important for fitness under field conditions. In summary, our study shows that ant societies exhibit complex personalities that can be associated to the physiology and fitness of the colony. Some of these behaviors are linked in suites of correlated behaviors, similar to personalities of solitary animals. PMID:22457751

  16. Social prophylaxis: group interaction promotes collective immunity in ant colonies.

    PubMed

    Ugelvig, Line V; Cremer, Sylvia

    2007-11-20

    Life in a social group increases the risk of disease transmission. To counteract this threat, social insects have evolved manifold antiparasite defenses, ranging from social exclusion of infected group members to intensive care. It is generally assumed that individuals performing hygienic behaviors risk infecting themselves, suggesting a high direct cost of helping. Our work instead indicates the opposite for garden ants. Social contact with individual workers, which were experimentally exposed to a fungal parasite, provided a clear survival benefit to nontreated, naive group members upon later challenge with the same parasite. This first demonstration of contact immunity in Social Hymenoptera and complementary results from other animal groups and plants suggest its general importance in both antiparasite and antiherbivore defense. In addition to this physiological prophylaxis of adult ants, infection of the brood was prevented in our experiment by behavioral changes of treated and naive workers. Parasite-treated ants stayed away from the brood chamber, whereas their naive nestmates increased brood-care activities. Our findings reveal a direct benefit for individuals to perform hygienic behaviors toward others, and this might explain the widely observed maintenance of social cohesion under parasite attack in insect societies.

  17. Political Society and You: An Interactive Tutorial.

    ERIC Educational Resources Information Center

    Schick, James B. M.

    1991-01-01

    Describes the creation and use of an interactive tutorial for college students on the Declaration of Independence, called "Political Society and You." Activities that emphasize critical reading and historical interpretation are discussed, the computer software is explained, and the response form used for student feedback is described.…

  18. Plant genotype shapes ant-aphid interactions: implications for community structure and indirect plant defense.

    PubMed

    Mooney, Kailen A; Agrawal, Anurag A

    2008-06-01

    Little is known about the mechanisms by which plant genotype shapes arthropod community structure. In a field experiment, we measured the effects of milkweed (Asclepias syriaca) genotype and ants on milkweed arthropods. Populations of the ant-tended aphid Aphis asclepiadis and the untended aphid Myzocallis asclepiadis varied eight- to 18-fold among milkweed genotypes, depending on aphid species and whether ants were present. There was no milkweed effect on predatory arthropods. Ants increased Aphis abundance 59%, decreased Myzocallis abundance 52%, and decreased predator abundance 56%. Milkweed genotype indirectly influenced ants via direct effects on Aphis and Myzocallis abundance. Milkweed genotype also modified ant-aphid interactions, influencing the number of ants attracted per Aphis and Myzocallis. While ant effects on Myzocallis were consistently negative, effects on Aphis ranged from antagonistic to mutualistic among milkweed genotypes. As a consequence of milkweed effects on ant-aphid interactions, ant abundance varied 13-fold among milkweed genotypes, and monarch caterpillar survival was negatively correlated with genetic variation in ant abundance. We speculate that heritable variation in milkweed phloem sap drives these effects on aphids, ants, and caterpillars. In summary, milkweed exerts genetic control over the interactions between aphids and an ant that provides defense against foliage-feeding caterpillars.

  19. Conflict resolution in an ant-plant interaction: Acacia constricta traits reduce ant costs to reproduction.

    PubMed

    Nicklen, E Fleur; Wagner, Diane

    2006-05-01

    Many plant species attract ants onto their foliage with food rewards or nesting space. However, ants can interfere with plant reproduction when they visit flowers. This study tests whether Acacia constricta separates visiting ant species temporally or spatially from newly opened inflorescences and pollinators. The diurnal activity patterns of ants and A. constricta pollinators peaked at different times of day, and the activity of pollinators followed the daily dehiscence of A. constricta inflorescences. In addition to being largely temporally separated, ants rarely visited open inflorescences. A floral ant repellent contributes to the spatial separation of ants and inflorescences. In a field experiment, ants of four species were given equal access to inflorescences in different developmental stages. On average, the frequency with which ants made initial, antennal contact with the floral stages did not differ, but ants significantly avoided secondary contact with newly opened inflorescences relative to buds and old inflorescences, and old inflorescences relative to buds. Ants also avoided contact with pollen alone, indicating that pollen is at least one source of the repellent. The results suggest A. constricta has effectively resolved the potential conflict between visiting ants and plant reproduction.

  20. Interactions between astronomical ephemerides and society

    NASA Astrophysics Data System (ADS)

    Arlot, Jean-Eudes

    2011-06-01

    Ephemerides are regularly made by astronomers for their own uses. However, the general public is also interested, as well as official organisms, because of the interactions of ephemerides with society. Astronomers in charge of the making of calendars and keeping the time are of great importance every day. Their calculations are also required for the positioning of ships and airplanes. Some ephemerides are also requested by the general public.

  1. Trait-mediated indirect interactions of ant shape on the attack of caterpillars and fruits

    PubMed Central

    Aguirre, Armando; De la Torre, Pedro Luna; Kaminski, Lucas A.; García-Chávez, Juan; Rico-Gray, Víctor

    2016-01-01

    Mainly owing to their high diversity and abundance, ants are formidable as predators and defenders of foliage. Consequently, ants can exclude both invertebrate and vertebrate activity on plants via direct and indirect interactions as already shown in many previous studies. Here we present empirical evidence that objects resembling ant shape on dummy caterpillars were able to repel visually oriented predators. Moreover, we also show that rubber ants on dummy fruits can repel potential fruit dispersers. Our results have direct implications on the ecological and evolutionary dynamics of interactions in ant-based systems, as ant presence could affect the fitness of its partners. In short, our study highlights the importance of visual cues in interspecific interactions and opens a new way to study the effects of ant presence to test ecological and evolutionary hypotheses. PMID:27484648

  2. Trait-mediated indirect interactions of ant shape on the attack of caterpillars and fruits.

    PubMed

    Dáttilo, Wesley; Aguirre, Armando; De la Torre, Pedro Luna; Kaminski, Lucas A; García-Chávez, Juan; Rico-Gray, Víctor

    2016-08-01

    Mainly owing to their high diversity and abundance, ants are formidable as predators and defenders of foliage. Consequently, ants can exclude both invertebrate and vertebrate activity on plants via direct and indirect interactions as already shown in many previous studies. Here we present empirical evidence that objects resembling ant shape on dummy caterpillars were able to repel visually oriented predators. Moreover, we also show that rubber ants on dummy fruits can repel potential fruit dispersers. Our results have direct implications on the ecological and evolutionary dynamics of interactions in ant-based systems, as ant presence could affect the fitness of its partners. In short, our study highlights the importance of visual cues in interspecific interactions and opens a new way to study the effects of ant presence to test ecological and evolutionary hypotheses.

  3. Multitasking in a plant-ant interaction: how does Acacia myrtifolia manage both ants and pollinators?

    PubMed

    Martínez-Bauer, Angélica E; Martínez, Gerardo Cerón; Murphy, Daniel J; Burd, Martin

    2015-06-01

    Plant associations with protective ants are widespread among angiosperms, but carry the risk that ants will deter pollinators as well as herbivores. Such conflict, and adaptations to ameliorate or prevent the conflict, have been documented in African and neotropical acacias. Ant-acacia associations occur in Australia, but little is known of their ecology. Moreover, recent phylogenetic evidence indicates that Australian acacias are only distantly related to African and American acacias, providing an intercontinental natural experiment in the management of ant-pollinator conflict. We examined four populations of Acacia myrtifolia over a 400-km environmental gradient in southeastern Australia using ant and pollinator exclusion as well as direct observation of ants and pollinators to assess the potential for ant-pollinator conflict to affect seed set. Native bees were the only group of floral visitors whose visitation rates were a significant predictor of fruiting success, although beetles and wasps may play an important role as "insurance" pollinators. We found no increase in pollinator visitation or fruiting success following ant exclusion, even with large sample sizes and effective exclusion. Because ants are facultative visitors to A. myrtifolia plants, their presence may be insufficient to interfere greatly with floral visitors. It is also likely that the morphological location of extrafloral nectaries tends to draw ants away from reproductive parts, although we commonly observed ants on inflorescences, so the spatial separation is not strict. A. myrtifolia appears to maintain a generalized mutualism over a wide geographic range without the need for elaborate adaptations to resolve ant-pollinator conflict.

  4. Are ant-aphid associations a tritrophic interaction? Oleander aphids and Argentine ants.

    PubMed

    Bristow, C M

    1991-09-01

    Oleander aphids, (Aphis nerii), which are sporadically tended by ants, were used as a moded system to examine whether host plant factors associated with feeding site influenced the formation of ant-aphid associations. Seasonal patterns of host plant utilization and association with attendant ants were examined through bi-weekly censuses of the aphid population feeding on thirty ornamental oleander plands (Nerium oleander) in northern California in 1985 and 1986. Colonies occurred on both developing and senescing plant terminals, including leaf tips, floral structures, and pods. Aphids preferentially colonized leaf terminals early in the season, but showed no preference for feeding site during later periods. Argentine ants (Iridomyrmex humilis) occasionally tended aphid colonies. Colonies on floral tips were three to four times more likely to attract ants than colonies on leaf tips, even though the latter frequently contained more aphids. Ants showed a positive recruitment response to colonies on floral tips, with a significant correlation between colony size and number of ants. There was no recruitment response to colonies on leaf tips. These patterns were reproducible over two years despite large fluctuations in both aphid population density and ant activity. In a laboratory bioassay of aphid palatability, the generalist predator,Hippodamia convergens, took significantly more aphids reared on floral tips compared to those reared on leaf tips. The patterns reported here support the hypothesis that tritrophic factors may be important in modifying higher level arthropod mutualisms.

  5. Nestmate recognition in ants is possible without tactile interaction.

    PubMed

    Brandstaetter, Andreas Simon; Endler, Annett; Kleineidam, Christoph Johannes

    2008-07-01

    Ants of the genus Camponotus are able to discriminate recognition cues of colony members (nestmates) from recognition cues of workers of a different colony (non-nestmates) from a distance of 1 cm. Free moving, individual Camponotus floridanus workers encountered differently treated dummies on a T-bar and their behavior was recorded. Aggressive behavior was scored as mandibular threat towards dummies. Dummies were treated with hexane extracts of postpharyngeal glands (PPGs) from nestmates or non-nestmates which contain long-chain hydrocarbons in ratios comparable to what is found on the cuticle. The cuticular hydrocarbon profile bears cues which are essential for nestmate recognition. Although workers were prevented from antennating the dummies, they showed significantly less aggressive behavior towards dummies treated with nestmate PPG extracts than towards dummies treated with non-nestmate PPG extracts. In an additional experiment, we show that cis-9-tricosene, an alkene naturally not found in C. floridanus' cuticular profile, is behaviorally active and can interfere with nestmate recognition when presented together with a nestmate PPG extract. Our study demonstrates for the first time that the complex multi-component recognition cues can be perceived and discriminated by ants at close range. We conclude that contact chemosensilla are not crucial for nestmate recognition since tactile interaction is not necessary.

  6. The indirect consequences of a mutualism: comparing positive and negative components of the net interaction between honeydew-tending ants and host plants.

    PubMed

    Grinath, Joshua B; Inouye, Brian D; Underwood, Nora; Billick, Ian

    2012-03-01

    1. In ecological webs, net indirect interactions between species are composed of interactions that vary in sign and magnitude. Most studies have focused on negative component interactions (e.g. predation, herbivory) without considering the relative importance of positive interactions (e.g. mutualism, facilitation) for determining net indirect effects. 2. In plant/arthropod communities, ants have multiple top-down effects via mutualisms with honeydew-producing herbivores and harassment of and predation on other herbivores; these ant effects provide opportunities for testing the relative importance of positive and negative interspecific interactions. We manipulated the presence of ants, honeydew-producing membracids and leaf-chewing beetles on perennial host plants in field experiments in Colorado to quantify the relative strength of these different types of interactions and their impact on the ant's net indirect effect on plants. 3. In 2007, we demonstrated that ants simultaneously had a positive effect on membracids and a negative effect on beetles, resulting in less beetle damage on plants hosting the mutualism. 4. In 2008, we used structural equation modelling to describe interaction strengths through the entire insect herbivore community on plants with and without ants. The ant's mutualism with membracids was the sole strong interaction contributing to the net indirect effect of ants on plants. Predation, herbivory and facilitation were weak, and the net effect of ants reduced plant reproduction. This net indirect effect was also partially because of behavioural changes of herbivores in the presence of ants. An additional membracid manipulation showed that the membracid's effect on ant activity was largely responsible for the ant's net effect on plants; ant workers were nearly ten times as abundant on plants with mutualists, and effects on other herbivores were similar to those in the ant manipulation experiment. 5. These results demonstrate that mutualisms can

  7. Social interactions influence dopamine and octopamine homeostasis in the brain of the ant Formica japonica.

    PubMed

    Wada-Katsumata, Ayako; Yamaoka, Ryohei; Aonuma, Hitoshi

    2011-05-15

    In ants, including Formica japonica, trophallaxis and grooming are typical social behaviors shared among nestmates. After depriving ants of either food or nestmates and then providing them with either food or nestmates, a behavioral change in type and frequency of social interactions was observed. We hypothesized that starvation and isolation affected levels of brain biogenic amines including dopamine (DA) and octopamine (OA) - neuromediators modifying various insect behaviors - and tested the relationship between brain biogenic amines and social behaviors of stressed ants. Ants starved for 7 days contained lower brain DA levels and they did not perform trophallaxis toward nestmates. Feeding starved ants sucrose solution re-established trophallaxis but not brain DA levels. The performance of trophallaxis induced recovery of brain DA content to the level of untreated ants. Ants that were isolated for 2 days displayed markedly increased OA levels, which following nestmate interactions, returned to levels similar to those of control (non-isolated) ants and ants isolated for 1 h. We conclude that: (1) starvation reduced brain DA level but had no significant effect on brain OA (trophallaxis recovered the brain DA levels), and (2) isolation increased brain OA level but had no effect on brain DA (trophallaxis and grooming events recovered the brain OA levels). We suggest that social interactions with nestmates influenced brain biogenic amine homeostasis in stressed F. japonica.

  8. Interaction specificity between leaf-cutting ants and vertically transmitted Pseudonocardia bacteria.

    PubMed

    Andersen, Sandra B; Yek, Sze Huei; Nash, David R; Boomsma, Jacobus J

    2015-02-25

    The obligate mutualism between fungus-growing ants and microbial symbionts offers excellent opportunities to study the specificity and stability of multi-species interactions. In addition to cultivating fungus gardens, these ants have domesticated actinomycete bacteria to defend gardens against the fungal parasite Escovopsis and possibly other pathogens. Panamanian Acromyrmex echinatior leaf-cutting ants primarily associate with actinomycetes of the genus Pseudonocardia. Colonies are inoculated with one of two vertically transmitted phylotypes (Ps1 or Ps2), and maintain the same phylotype over their lifetime. We performed a cross-fostering experiment to test whether co-adaptations between ants and bacterial phylotypes have evolved, and how this affects bacterial growth and ant prophylactic behavior after infection with Escovopsis. We show that Pseudonocardia readily colonized ants irrespective of their colony of origin, but that the Ps2 phylotype, which was previously shown to be better able to maintain its monocultural integrity after workers became foragers than Ps1, reached a higher final cover when grown on its native host than on alternative hosts. The frequencies of major grooming and weeding behaviors co-varied with symbiont/host combinations, showing that ant behavior also was affected when cuticular actinomycete phylotypes were swapped. These results show that the interactions between leaf-cutting ants and Pseudonocardia bear signatures of mutual co-adaptation within a single ant population.

  9. Ecological consequences of interactions between ants and honeydew-producing insects

    PubMed Central

    Styrsky, John D; Eubanks, Micky D

    2006-01-01

    Interactions between ants and honeydew-producing hemipteran insects are abundant and widespread in arthropod food webs, yet their ecological consequences are very poorly known. Ant–hemipteran interactions have potentially broad ecological effects, because the presence of honeydew-producing hemipterans dramatically alters the abundance and predatory behaviour of ants on plants. We review several studies that investigate the consequences of ant–hemipteran interactions as ‘keystone interactions’ on arthropod communities and their host plants. Ant–hemipteran interactions have mostly negative effects on the local abundance and species richness of several guilds of herbivores and predators. In contrast, out of the 30 studies that document the effects of ant–hemipteran interactions on plants, the majority (73%) shows that plants actually benefit indirectly from these interactions. In these studies, increased predation or harassment of other, more damaging, herbivores by hemipteran-tending ants resulted in decreased plant damage and/or increased plant growth and reproduction. The ecological consequences of mutualistic interactions between honeydew-producing hemipterans and invasive ants relative to native ants have rarely been studied, but they may be of particular importance owing to the greater abundance, aggressiveness and extreme omnivory of invasive ants. We argue that ant–hemipteran interactions are largely overlooked and underappreciated interspecific interactions that have strong and pervasive effects on the communities in which they are embedded. PMID:17148245

  10. The interaction between Cistaceae and a highly specific seed-harvester ant in a Mediterranean scrubland.

    PubMed

    Bastida, F; Talavera, S; Ortiz, P L; Arista, M

    2009-01-01

    We studied the interaction between the ant Goniomma kugleri and Cistaceae in a Cistus ladanifer-dominated scrubland, in southwestern Spain. We monitored seed harvesting, and studied ant preferences among Cistaceae seeds and their capture efficiencies for preferred seeds. For the stand of C. ladanifer, we estimated seed losses due to the ants. Harvesting was restricted to two seasons: mid-autumn to late winter, and late spring. Ant diet relied on Cistaceae seeds: during autumn and winter 90% of seeds returned to nests were of C. ladanifer, and the remaining fraction also comprised Cistaceae seeds. At this time, the ants harvested seeds directly from the plants. In late spring, the ant diet consisted of Tuberaria guttata s.l. seeds. Goniomma kugleri selectively collected Cistaceae seeds. For preferred species, seed removal rates at the colony level and seed capture times invested by individual workers were correlated with seed size. Because of shorter capture time and higher success frequency, capture efficiency in terms of number of seeds captured per unit time was higher for small-seeded species. Although each ant colony collected large numbers (up to 10(5)) of C. ladanifer seeds over the autumn-winter season, the impact of ant removal on the annual seed output was moderate, at around 20%. It is likely that, in C. ladanifer, the staggered seed release period, and the pulsed exposure of seed clumps in capsules through progressive locule dehiscence, effectively minimise seed losses to the ants.

  11. Interaction complexity matters: disentangling services and disservices of ant communities driving yield in tropical agroecosystems

    PubMed Central

    Wielgoss, Arno; Tscharntke, Teja; Rumede, Alfianus; Fiala, Brigitte; Seidel, Hannes; Shahabuddin, Saleh; Clough, Yann

    2014-01-01

    Owing to complex direct and indirect effects, impacts of higher trophic levels on plants is poorly understood. In tropical agroecosystems, ants interact with crop mutualists and antagonists, but little is known about how this integrates into the final ecosystem service, crop yield. We combined ant exclusion and introduction of invasive and native-dominant species in cacao agroecosystems to test whether (i) ant exclusion reduces yield, (ii) dominant species maximize certain intermediate ecosystem services (e.g. control of specific pests) rather than yield, which depends on several, cascading intermediate services and (iii) even, species-rich ant communities result in highest yields. Ants provided services, including reduced leaf herbivory and fruit pest damage and indirect pollination facilitation, but also disservices, such as increased mealybug density, phytopathogen dissemination and indirect pest damage enhancement. Yields were highest with unmanipulated, species-rich, even communities, whereas ant exclusion decreased yield by 27%. Introduction of an invasive-dominant ant decreased species density and evenness and resulted in 34% lower yields, whereas introduction of a non-invasive-dominant species resulted in similar species density and yields as in the unmanipulated control. Species traits and ant community structure affect services and disservices for agriculture in surprisingly complex ways, with species-rich and even communities promoting highest yield. PMID:24307667

  12. Interaction complexity matters: disentangling services and disservices of ant communities driving yield in tropical agroecosystems.

    PubMed

    Wielgoss, Arno; Tscharntke, Teja; Rumede, Alfianus; Fiala, Brigitte; Seidel, Hannes; Shahabuddin, Saleh; Clough, Yann

    2014-01-22

    Owing to complex direct and indirect effects, impacts of higher trophic levels on plants is poorly understood. In tropical agroecosystems, ants interact with crop mutualists and antagonists, but little is known about how this integrates into the final ecosystem service, crop yield. We combined ant exclusion and introduction of invasive and native-dominant species in cacao agroecosystems to test whether (i) ant exclusion reduces yield, (ii) dominant species maximize certain intermediate ecosystem services (e.g. control of specific pests) rather than yield, which depends on several, cascading intermediate services and (iii) even, species-rich ant communities result in highest yields. Ants provided services, including reduced leaf herbivory and fruit pest damage and indirect pollination facilitation, but also disservices, such as increased mealybug density, phytopathogen dissemination and indirect pest damage enhancement. Yields were highest with unmanipulated, species-rich, even communities, whereas ant exclusion decreased yield by 27%. Introduction of an invasive-dominant ant decreased species density and evenness and resulted in 34% lower yields, whereas introduction of a non-invasive-dominant species resulted in similar species density and yields as in the unmanipulated control. Species traits and ant community structure affect services and disservices for agriculture in surprisingly complex ways, with species-rich and even communities promoting highest yield.

  13. Variable interaction specificity and symbiont performance in Panamanian Trachymyrmex and Sericomyrmex fungus-growing ants.

    PubMed

    De Fine Licht, Henrik H; Boomsma, Jacobus J

    2014-12-04

    Cooperative benefits of mutualistic interactions are affected by genetic variation among the interacting partners, which may have consequences for interaction-specificities across guilds of sympatric species with similar mutualistic life histories. The gardens of fungus-growing (attine) ants produce carbohydrate active enzymes that degrade plant material collected by the ants and offer them food in exchange. The spectrum of these enzyme activities is an important symbiont service to the host but may vary among cultivar genotypes. The sympatric occurrence of several Trachymyrmex and Sericomyrmex higher attine ants in Gamboa, Panama provided the opportunity to do a quantitative study of species-level interaction-specificity. We genotyped the ants for Cytochrome Oxidase and their Leucoagaricus fungal cultivars for ITS rDNA. Combined with activity measurements for 12 carbohydrate active enzymes, these data allowed us to test whether garden enzyme activity was affected by fungal strain, farming ants or combinations of the two. We detected two cryptic ant species, raising ant species number from four to six, and we show that the 38 sampled colonies reared a total of seven fungal haplotypes that were different enough to represent separate Leucoagaricus species. The Sericomyrmex species and one of the Trachymyrmex species reared the same fungal cultivar in all sampled colonies, but the remaining four Trachymyrmex species largely shared the other cultivars. Fungal enzyme activity spectra were significantly affected by both cultivar species and farming ant species, and more so for certain ant-cultivar combinations than others. However, relative changes in activity of single enzymes only depended on cultivar genotype and not on the ant species farming a cultivar. Ant cultivar symbiont-specificity varied from almost full symbiont sharing to one-to-one specialization, suggesting that trade-offs between enzyme activity spectra and life-history traits such as desiccation

  14. Composition of extrafloral nectar influences interactions between the myrmecophyte Humboldtia brunonis and its ant associates.

    PubMed

    Shenoy, Megha; Radhika, Venkatesan; Satish, Suma; Borges, Renee M

    2012-01-01

    Ant-plant interactions often are mediated by extrafloral nectar (EFN) composition that may influence plant visitation by ants. Over a 300 km range in the Indian Western Ghats, we investigated the correlation between the EFN composition of the myrmecophytic ant-plant Humboldtia brunonis (Fabaceae) and the number and species of ants visiting EFN. EFN composition varied among H. brunonis populations and between plant organs (floral bud vs. young leaf EFN). In general, EFN was rich in sugars with small quantities of amino acids, especially essential amino acids, and had moderate invertase activity. In experiments at the study sites with sugar and amino acid solutions and with leaf or floral bud EFN mimics, dominant EFN-feeding ants differentiated between solutions as well as between mimics. The castration parasite Crematogaster dohrni (northern study site) was the least selective and did not exhibit any clear feeding preferences, while the largely trophobiont-tending non-protective Myrmicaria brunnea (middle study site) preferred higher sucrose concentrations and certain essential/non-essential amino acid mixtures. The mutualistic Technomyrmex albipes (southern study site) preferred sucrose over glucose or fructose solutions and consumed the leaf EFN mimic to a greater extent than the floral bud EFN mimic. This young leaf EFN mimic had low sugar concentrations, the lowest viscosity and sugar:amino acid ratio, was rich in essential amino acids, and appeared ideally suited to the digestive physiology of T. albipes. This preference for young leaf EFN may explain the greater protection afforded to young leaves than to floral buds by T. albipes, and may also help to resolve ant-pollinator conflicts. The differential response of dominant ants to sugar, amino acids, or solution viscosity suggests that plants can fine-tune their interactions with local ants via EFN composition. Thus, EFN can mediate local partner-choice mechanisms in ant-plant interactions.

  15. Intraguild interactions between spiders and ants and top-down control in a grassland food web.

    PubMed

    Sanders, Dirk; Platner, Christian

    2007-01-01

    In most terrestrial ecosystems ants (Formicidae) as eusocial insects and spiders (Araneida) as solitary trappers and hunters are key predators. To study the role of predation by these generalist predators in a dry grassland, we manipulated densities of ants and spiders (natural and low density) in a two-factorial field experiment using fenced plots. The experiment revealed strong intraguild interactions between ants and spiders. Higher densities of ants negatively affected the abundance and biomass of web-building spiders. The density of Linyphiidae was threefold higher in plots without ant colonies. The abundance of Formica cunicularia workers was significantly higher in spider-removal plots. Also, population size of springtails (Collembola) was negatively affected by the presence of wandering spiders. Ants reduced the density of Lepidoptera larvae. In contrast, the abundance of coccids (Ortheziidae) was positively correlated with densities of ants. To gain a better understanding of the position of spiders, ants and other dominant invertebrate groups in the studied food web and important trophic links, we used a stable isotope analysis ((15)N and (13)C). Adult wandering spiders were more enriched in (15)N relative to (14)N than juveniles, indicating a shift to predatory prey groups. Juvenile wandering and web-building spiders showed delta(15)N ratios just one trophic level above those of Collembola, and they had similar delta(13)C values, indicating that Collembola are an important prey group for ground living spiders. The effects of spiders demonstrated in the field experiment support this result. We conclude that the food resource of spiders in our study system is largely based on the detrital food web and that their effects on herbivores are weak. The effects of ants are not clear-cut and include predation as well as mutualism with herbivores. Within this diverse predator guild, intraguild interactions are important structuring forces.

  16. Identifying robustness in the regulation of collective foraging of ant colonies using an interaction-based model with backward bifurcation.

    PubMed

    Udiani, Oyita; Pinter-Wollman, Noa; Kang, Yun

    2015-02-21

    Collective behaviors in social insect societies often emerge from simple local rules. However, little is known about how these behaviors are dynamically regulated in response to environmental changes. Here, we use a compartmental modeling approach to identify factors that allow harvester ant colonies to regulate collective foraging activity in response to their environment. We propose a set of differential equations describing the dynamics of: (1) available foragers inside the nest, (2) active foragers outside the nest, and (3) successful returning foragers, to understand how colony-specific parameters, such as baseline number of foragers, interactions among foragers, food discovery rates, successful forager return rates, and foraging duration might influence collective foraging dynamics, while maintaining functional robustness to perturbations. Our analysis indicates that the model can undergo a forward (transcritical) bifurcation or a backward bifurcation depending on colony-specific parameters. In the former case, foraging activity persists when the average number of recruits per successful returning forager is larger than one. In the latter case, the backward bifurcation creates a region of bistability in which the size and fate of foraging activity depends on the distribution of the foraging workforce among the model's compartments. We validate the model with experimental data from harvester ants (Pogonomyrmex barbatus) and perform sensitivity analysis. Our model provides insights on how simple, local interactions can achieve an emergent and robust regulatory system of collective foraging activity in ant colonies.

  17. A novel type of nutritional ant-plant interaction: ant partners of carnivorous pitcher plants prevent nutrient export by dipteran pitcher infauna.

    PubMed

    Scharmann, Mathias; Thornham, Daniel G; Grafe, T Ulmar; Federle, Walter

    2013-01-01

    Many plants combat herbivore and pathogen attack indirectly by attracting predators of their herbivores. Here we describe a novel type of insect-plant interaction where a carnivorous plant uses such an indirect defence to prevent nutrient loss to kleptoparasites. The ant Camponotus schmitzi is an obligate inhabitant of the carnivorous pitcher plant Nepenthes bicalcarata in Borneo. It has recently been suggested that this ant-plant interaction is a nutritional mutualism, but the detailed mechanisms and the origin of the ant-derived nutrient supply have remained unexplained. We confirm that N. bicalcarata host plant leaves naturally have an elevated (15)N/(14)N stable isotope abundance ratio (δ(15)N) when colonised by C. schmitzi. This indicates that a higher proportion of the plants' nitrogen is insect-derived when C. schmitzi ants are present (ca. 100%, vs. 77% in uncolonised plants) and that more nitrogen is available to them. We demonstrated direct flux of nutrients from the ants to the host plant in a (15)N pulse-chase experiment. As C. schmitzi ants only feed on nectar and pitcher contents of their host, the elevated foliar δ(15)N cannot be explained by classic ant-feeding (myrmecotrophy) but must originate from a higher efficiency of the pitcher traps. We discovered that C. schmitzi ants not only increase the pitchers' capture efficiency by keeping the pitchers' trapping surfaces clean, but they also reduce nutrient loss from the pitchers by predating dipteran pitcher inhabitants (infauna). Consequently, nutrients the pitchers would have otherwise lost via emerging flies become available as ant colony waste. The plants' prey is therefore conserved by the ants. The interaction between C. schmitzi, N. bicalcarata and dipteran pitcher infauna represents a new type of mutualism where animals mitigate the damage by nutrient thieves to a plant.

  18. Ant-diaspore interactions during secondary succession in the Atlantic forest of Brazil.

    PubMed

    Zwiener, Victor P; Bihn, Jochen H; Marques, Márcia C M

    2012-06-01

    Animal-plant interactions are important for the recovery of diversity and processes in secondary forests, which increasingly dominate the tropical landscape. We used a combination of observational and experimental approaches to study the interactions of ants with diaspores across a successional gradient of forests in Southern Brazil, from August 2007 to April 2008. In addition to diaspore removal rates, we assessed the species richness, diversity and behaviour of ants interacting with diaspores, in three replicated sites of four successional stages of forests. We recorded 22 ant species interacting with diaspores (an estimated 15% of the total species pool in the region). Species richness and diversity did not differ among successional stages but the behaviour of ants towards diaspores changed with the age of secondary forests. In old successional stages the removal of entire diaspores was more common than in young successional stages of forests. Concordantly, diaspore removal rates were lowest in the youngest successional stage of secondary forests and increased with the age of forests. These results indicate that ant-diaspore interactions in secondary forests are disturbed and lower removal rates in secondary forests are likely to constrain the recruitment of plant populations during secondary succession.

  19. Multiple interaction types determine the impact of ant predation of caterpillars in a forest community.

    PubMed

    Clark, Robert E; Farkas, Timothy E; Lichter-Marck, Isaac; Johnson, Emily R; Singer, Michael S

    2016-12-01

    Direct and indirect effects of predators are highly variable in complex communities, and understanding the sources of this variation is a research priority in community ecology. Recent evidence indicates that herbivore community structure is a primary determinant of predation strength and its cascading impacts on plants. In this study, we use variation in herbivore community structure among plant species to experimentally test two hypotheses in a temperate forest food web. First, variation in the strength of predator effects, such as ant predation of caterpillars, is predicted to be density dependent, exhibiting stronger effects when prey abundance is high (density-dependent predation hypothesis). Second, mutualistic interactions between ants and sap-feeding herbivores are expected to increase the abundance of predatory ants, strengthening predation effects on herbivores with cascading effects on host plants (keystone mutualism hypothesis). Using a large-scale predator exclusion experiment across eight dominant tree species, we tracked changes in insect density on 862 plants across two years, recording 2,322 ants, 1,062 sap-feeders, 5,322 caterpillars, and quantifying herbivory on 199, 338 leaves. In this experiment, density-dependent predation did not explain variation in the direct or indirect effects of ants on caterpillars and herbivory. In partial support of the keystone mutualism hypothesis, sap-feeders strengthened top-down effects of ants on caterpillars under some conditions. However, stronger ant predation of caterpillars did not lead to measurable trophic cascades on trees occupied by sap-feeders. Instead, the presence of sap-feeders was associated with increased per capita feeding damage by caterpillars, and this bottom-up effect attenuated the indirect effects of ants on host plants. These findings demonstrate that examining the multi-trophic impacts of mutualisms and predation in the context of the broader community can reveal patterns otherwise

  20. The Effect of Temperature Increases on an Ant-Hemiptera-Plant Interaction

    PubMed Central

    Gibb, Heloise

    2016-01-01

    Global temperature increases are significantly altering species distributions and the structure of ecological communities. However, the impact of temperature increases on multi- species interactions is poorly understood. We used an ant-Hemiptera-plant interaction to examine the potential outcomes of predicted temperature increases for each partner and for the availability of honeydew, a keystone resource in many forest ecosystems. We re-created this interaction in growth cabinets using predicted mean summer temperatures for Melbourne, Australia, for the years 2011 (23°C), 2050 (25°C) and 2100 (29°C), respectively, under an unmitigated greenhouse gas emission scenario. Plant growth and ant foraging activities increased, while scale insect growth, abundance and size, honeydew standing crop per tree and harvesting by ants decreased at 29°C, relative to lower temperatures (23 and 25°C). This led to decreased scale insect infestations of plants and reduced honeydew standing crop per tree at the highest temperature. At all temperatures, honeydew standing crop was lower when ants harvested the honeydew from scale insects, but the impact of ant harvesting was particularly significant at 29°C, where combined effects of temperature and ants reduced honeydew standing crop to below detectable levels. Although temperature increases in the next 35 years will have limited effects on this system, by the end of this century, warmer temperatures may cause the availability of honeydew to decline. Decline of honeydew may have far-reaching trophic effects on honeydew and ant-mediated interactions. However, field-based studies that consider the full complexity of ecosystems may be required to elucidate these impacts. PMID:27434232

  1. The Effect of Temperature Increases on an Ant-Hemiptera-Plant Interaction.

    PubMed

    Sagata, Katayo; Gibb, Heloise

    2016-01-01

    Global temperature increases are significantly altering species distributions and the structure of ecological communities. However, the impact of temperature increases on multi- species interactions is poorly understood. We used an ant-Hemiptera-plant interaction to examine the potential outcomes of predicted temperature increases for each partner and for the availability of honeydew, a keystone resource in many forest ecosystems. We re-created this interaction in growth cabinets using predicted mean summer temperatures for Melbourne, Australia, for the years 2011 (23°C), 2050 (25°C) and 2100 (29°C), respectively, under an unmitigated greenhouse gas emission scenario. Plant growth and ant foraging activities increased, while scale insect growth, abundance and size, honeydew standing crop per tree and harvesting by ants decreased at 29°C, relative to lower temperatures (23 and 25°C). This led to decreased scale insect infestations of plants and reduced honeydew standing crop per tree at the highest temperature. At all temperatures, honeydew standing crop was lower when ants harvested the honeydew from scale insects, but the impact of ant harvesting was particularly significant at 29°C, where combined effects of temperature and ants reduced honeydew standing crop to below detectable levels. Although temperature increases in the next 35 years will have limited effects on this system, by the end of this century, warmer temperatures may cause the availability of honeydew to decline. Decline of honeydew may have far-reaching trophic effects on honeydew and ant-mediated interactions. However, field-based studies that consider the full complexity of ecosystems may be required to elucidate these impacts.

  2. Interactions between extrafloral nectaries, ants (Hymenoptera: Formicidae), and other natural enemies affect biological control of Grapholita molesta (Lepidoptera: Tortricidae) on peach (Rosales: Rosaceae).

    PubMed

    Mathews, Clarissa R; Bottrell, Dale G; Brown, Mark W

    2011-02-01

    Extrafloral nectaries (EFNs) are reported to benefit some plants when ants (Hymenoptera: Formicidae) use their secretions and fend off herbivores, but in some cases resulting competitive interactions may reduce biological control of specific herbivores. This research examined the interactions between ants and other natural enemies associated with the EFNs of peach [Prunus persica (L.) Batcsh] and the implications for biological control of a key pest, the oriental fruit moth [Grapholita molesta (Busck)]. Studies using sentinel G. molesta placed on peach trees ('Lovell' cultivar) with EFNs present and absent revealed that several natural enemy groups associated with the EFNs contribute to reductions in G. molesta eggs, larvae, and pupae in peach orchards. Ants on trees with EFNs antagonized the G. molesta egg parasitoid Trichogramma minutum (Riley), but the ants were crucial in reducing G. molesta in both the larval and pupal stages. Overall, individual trees with EFNs experienced higher ant and other (nonant) natural enemy densities and subsequent pest reductions, as compared with trees without EFNs. However, the implications of EFN-natural enemy-pest interactions to orchard-level biological control will likely depend on local G. molesta population dynamics. © 2011 Entomological Society of America

  3. Ant trophallactic networks: simultaneous measurement of interaction patterns and food dissemination

    NASA Astrophysics Data System (ADS)

    Greenwald, Efrat; Segre, Enrico; Feinerman, Ofer

    2015-07-01

    Eusocial societies and ants, in particular, maintain tight nutritional regulation at both individual and collective levels. The mechanisms that underlie this control are far from trivial since, in these distributed systems, information about the global supply and demand is not available to any single individual. Here we present a novel technique for non-intervening frequent measurement of the food load of all individuals in an ant colony, including during trophallactic events in which food is transferred by mouth-to-mouth feeding. Ants are imaged using a dual camera setup that produces both barcode-based identification and fluorescence measurement of labeled food. This system provides detailed measurements that enable one to quantitatively study the adaptive food distribution network. To demonstrate the capabilities of our method, we present sample observations that were unattainable using previous techniques, and could provide insight into the mechanisms underlying food exchange.

  4. Ant trophallactic networks: simultaneous measurement of interaction patterns and food dissemination

    PubMed Central

    Greenwald, Efrat; Segre, Enrico; Feinerman, Ofer

    2015-01-01

    Eusocial societies and ants, in particular, maintain tight nutritional regulation at both individual and collective levels. The mechanisms that underlie this control are far from trivial since, in these distributed systems, information about the global supply and demand is not available to any single individual. Here we present a novel technique for non-intervening frequent measurement of the food load of all individuals in an ant colony, including during trophallactic events in which food is transferred by mouth-to-mouth feeding. Ants are imaged using a dual camera setup that produces both barcode-based identification and fluorescence measurement of labeled food. This system provides detailed measurements that enable one to quantitatively study the adaptive food distribution network. To demonstrate the capabilities of our method, we present sample observations that were unattainable using previous techniques, and could provide insight into the mechanisms underlying food exchange. PMID:26224025

  5. Plant-ants use symbiotic fungi as a food source: new insight into the nutritional ecology of ant-plant interactions.

    PubMed

    Blatrix, Rumsaïs; Djiéto-Lordon, Champlain; Mondolot, Laurence; La Fisca, Philippe; Voglmayr, Hermann; McKey, Doyle

    2012-10-07

    Usually studied as pairwise interactions, mutualisms often involve networks of interacting species. Numerous tropical arboreal ants are specialist inhabitants of myrmecophytes (plants bearing domatia, i.e. hollow structures specialized to host ants) and are thought to rely almost exclusively on resources derived from the host plant. Recent studies, following up on century-old reports, have shown that fungi of the ascomycete order Chaetothyriales live in symbiosis with plant-ants within domatia. We tested the hypothesis that ants use domatia-inhabiting fungi as food in three ant-plant symbioses: Petalomyrmex phylax/Leonardoxa africana, Tetraponera aethiops/Barteria fistulosa and Pseudomyrmex penetrator/Tachigali sp. Labelling domatia fungal patches in the field with either a fluorescent dye or (15)N showed that larvae ingested domatia fungi. Furthermore, when the natural fungal patch was replaced with a piece of a (15)N-labelled pure culture of either of two Chaetothyriales strains isolated from T. aethiops colonies, these fungi were also consumed. These two fungi often co-occur in the same ant colony. Interestingly, T. aethiops workers and larvae ingested preferentially one of the two strains. Our results add a new piece in the puzzle of the nutritional ecology of plant-ants.

  6. Visualization of Metabolic Interaction Networks in Microbial Communities Using VisANT 5.0.

    PubMed

    Granger, Brian R; Chang, Yi-Chien; Wang, Yan; DeLisi, Charles; Segrè, Daniel; Hu, Zhenjun

    2016-04-01

    The complexity of metabolic networks in microbial communities poses an unresolved visualization and interpretation challenge. We address this challenge in the newly expanded version of a software tool for the analysis of biological networks, VisANT 5.0. We focus in particular on facilitating the visual exploration of metabolic interaction between microbes in a community, e.g. as predicted by COMETS (Computation of Microbial Ecosystems in Time and Space), a dynamic stoichiometric modeling framework. Using VisANT's unique metagraph implementation, we show how one can use VisANT 5.0 to explore different time-dependent ecosystem-level metabolic networks. In particular, we analyze the metabolic interaction network between two bacteria previously shown to display an obligate cross-feeding interdependency. In addition, we illustrate how a putative minimal gut microbiome community could be represented in our framework, making it possible to highlight interactions across multiple coexisting species. We envisage that the "symbiotic layout" of VisANT can be employed as a general tool for the analysis of metabolism in complex microbial communities as well as heterogeneous human tissues. VisANT is freely available at: http://visant.bu.edu and COMETS at http://comets.bu.edu.

  7. Nutrition and interference competition have interactive effects on the behavior and performance of Argentine ants.

    PubMed

    Kay, Adam D; Zumbusch, Taylor; Heinen, Justa L; Marsh, Tom C; Holway, David A

    2010-01-01

    Food availability often influences competitive outcomes through effects on consumer growth. Although it has received less attention, food availability may also affect competition through nutritional effects on behavior. One hypothesis linking nutrition and competition in ants posits that increased access to carbohydrates favors greater investment in worker traits that underlie behavioral dominance. We tested this hypothesis by varying dietary protein:carbohydrate (P:C) ratios and levels of interspecific interference for Argentine ants (Linepithema humile), a widespread invasive species. As predicted, colonies facing interference increased patrolling more when reared on low P:C diets; this result is the first demonstration of an interactive effect of nutrition and interference on ant colonies. Several results suggest that this dietary effect on patrolling was due primarily to changes in colony size rather than worker behavior. Colonies on lower P:C diets had lower worker mortality and larger final colony sizes. Diet had little effect on per capita patrolling, and worker behavior in performance assays depended more on previous exposure to interference than on diet. Our findings indicate that dietary P:C ratios can influence Argentine ant performance in a competitive environment and suggest a mechanism by which monopolization of carbohydrate-rich resources can help invasive ants displace native ant competitors.

  8. Mathematical modeling on obligate mutualism: Interactions between leaf-cutter ants and their fungus garden.

    PubMed

    Kang, Yun; Clark, Rebecca; Makiyama, Michael; Fewell, Jennifer

    2011-11-21

    We propose a simple mathematical model by applying Michaelis-Menton equations of enzyme kinetics to study the mutualistic interaction between the leaf cutter ant and its fungus garden at the early stage of colony expansion. We derive sufficient conditions on the extinction and coexistence of these two species. In addition, we give a region of initial condition that leads to the extinction of two species when the model has an interior attractor. Our global analysis indicates that the division of labor by worker ants and initial conditions are two important factors that determine whether leaf cutter ants' colonies and their fungus garden can survive and grow or not. We validate the model by comparing model simulations and data on fungal and ant colony growth rates under laboratory conditions. We perform sensitive analysis of the model based on the experimental data to gain more biological insights on ecological interactions between leaf-cutter ants and their fungus garden. Finally, we give conclusions and discuss potential future work.

  9. "Holding High the Standard": The Influence of the American Education Society in Ante-Bellum Education.

    ERIC Educational Resources Information Center

    Naylor, Natalie A.

    1984-01-01

    The primary concerns of the American Education Society (AES), formed in Boston in 1815 as part of a Protestant crusade to save the nation, were the education of ministers and the revitalization of religion. The educational influence of the AES in antebellum higher education is discussed. (RM)

  10. A neurotoxic pesticide changes the outcome of aggressive interactions between native and invasive ants

    PubMed Central

    Barbieri, Rafael F.; Lester, Philip J.; Miller, Alexander S.; Ryan, Ken G.

    2013-01-01

    Neurotoxic pesticides, such as neonicotinoids, negatively affect the cognitive capacity and fitness of non-target species, and could also modify interspecific interactions. We tested whether sublethal contamination with neonicotinoid could affect foraging, colony fitness and the outcome of behavioural interactions between a native (Monomorium antarcticum) and an invasive ant species (Linepithema humile). The foraging behaviour of both ants was not affected by neonicotinoid exposure. Colonies of the invasive species exposed to the neonicotinoid produced significantly fewer brood. In interspecific confrontations, individuals of the native species exposed to the neonicotinoid lowered their aggression towards the invasive species, although their survival probability was not affected. Exposed individuals of the invasive species interacting with non-exposed native ants displayed increased aggression and had their survival probability reduced. Non-exposed individuals of the invasive species were less aggressive but more likely to survive when interacting with exposed native ants. These results suggest that non-target exposure of invaders to neonicotinoids could either increase or decrease the probability of survival according to the exposure status of the native species. Given that, in any community, different species have different food preferences, and thus different exposure to pesticides, non-target exposure could potentially change the dynamics of communities and influence invasion success. PMID:24266038

  11. Positive interactions between desert granivores: localized facilitation of harvester ants by kangaroo rats.

    PubMed

    Edelman, Andrew J

    2012-01-01

    Facilitation, when one species enhances the environment or performance of another species, can be highly localized in space. While facilitation in plant communities has been intensely studied, the role of facilitation in shaping animal communities is less well understood. In the Chihuahuan Desert, both kangaroo rats and harvester ants depend on the abundant seeds of annual plants. Kangaroo rats, however, are hypothesized to facilitate harvester ants through soil disturbance and selective seed predation rather than competing with them. I used a spatially explicit approach to examine whether a positive or negative interaction exists between banner-tailed kangaroo rat (Dipodomys spectabilis) mounds and rough harvester ant (Pogonomyrmex rugosus) colonies. The presence of a scale-dependent interaction between mounds and colonies was tested by comparing fitted spatial point process models with and without interspecific effects. Also, the effect of proximity to a mound on colony mortality and spatial patterns of surviving colonies was examined. The spatial pattern of kangaroo rat mounds and harvester ant colonies was consistent with a positive interspecific interaction at small scales (<10 m). Mortality risk of vulnerable, recently founded harvester ant colonies was lower when located close to a kangaroo rat mound and proximity to a mound partly predicted the spatial pattern of surviving colonies. My findings support localized facilitation of harvester ants by kangaroo rats, likely mediated through ecosystem engineering and foraging effects on plant cover and composition. The scale-dependent effect of kangaroo rats on abiotic and biotic factors appears to result in greater founding and survivorship of young colonies near mounds. These results suggest that soil disturbance and foraging by rodents can have subtle impacts on the distribution and demography of other species.

  12. VisANT: an online visualization and analysis tool for biological interaction data

    PubMed Central

    Hu, Zhenjun; Mellor, Joseph; Wu, Jie; DeLisi, Charles

    2004-01-01

    Background New techniques for determining relationships between biomolecules of all types – genes, proteins, noncoding DNA, metabolites and small molecules – are now making a substantial contribution to the widely discussed explosion of facts about the cell. The data generated by these techniques promote a picture of the cell as an interconnected information network, with molecular components linked with one another in topologies that can encode and represent many features of cellular function. This networked view of biology brings the potential for systematic understanding of living molecular systems. Results We present VisANT, an application for integrating biomolecular interaction data into a cohesive, graphical interface. This software features a multi-tiered architecture for data flexibility, separating back-end modules for data retrieval from a front-end visualization and analysis package. VisANT is a freely available, open-source tool for researchers, and offers an online interface for a large range of published data sets on biomolecular interactions, including those entered by users. This system is integrated with standard databases for organized annotation, including GenBank, KEGG and SwissProt. VisANT is a Java-based, platform-independent tool suitable for a wide range of biological applications, including studies of pathways, gene regulation and systems biology. Conclusion VisANT has been developed to provide interactive visual mining of biological interaction data sets. The new software provides a general tool for mining and visualizing such data in the context of sequence, pathway, structure, and associated annotations. Interaction and predicted association data can be combined, overlaid, manipulated and analyzed using a variety of built-in functions. VisANT is available at . PMID:15028117

  13. ACC-FMD: ant colony clustering for functional module detection in protein-protein interaction networks.

    PubMed

    Ji, Junzhong; Liu, Hongxin; Zhang, Aidong; Liu, Zhijun; Liu, Chunnian

    2015-01-01

    Mining functional modules in Protein-Protein Interaction (PPI) networks is a very important research for revealing the structure-functionality relationships in biological processes. More recently, some swarm intelligence algorithms have been successfully applied in the field. This paper presents a new nature-inspired approach, ACC-FMD, which is based on ant colony clustering to detect functional modules. First, some proteins with the higher clustering coefficients are, respectively, selected as ant seed nodes. And then, the picking and dropping operations based on ant probabilistic models are developed and employed to assign proteins into the corresponding clusters represented by seeds. Finally, the best clustering result in each generation is used to perform the information transmission by updating the similarly function. Experimental results on some benchmarked datasets show that ACC-FMD outperforms the CFinder and MCODE algorithms and has comparative performance with the MINE, COACH, DPClus and Core algorithms in terms of the general evaluation metrics.

  14. Ants use odour cues to exploit fig-fig wasp interactions

    NASA Astrophysics Data System (ADS)

    Schatz, Bertrand; Hossaert-McKey, Martine

    2010-01-01

    Fig wasps may constitute a relatively abundant food source for ants associated with the fig-fig wasp nursery pollination mutualism. We found previously that a Mediterranean ant species detects fig wasps by chemical signals. In this paper we want to test the generality of this finding by studying two tropical ants, Oecophylla smaragdina and Crematogaster sp., preying on fig wasps on the dioecious Ficus fistulosa in Brunei (Borneo). Behavioural tests in a Y-tube olfactometer showed that these two ants were attracted both to odours emitted by receptive figs and to those emitted by fig wasps (male and female of the pollinator, and a non-pollinating fig wasp) used here as a kairomone. Naïve workers were not attracted to fig wasps, suggesting that olfactory learning may play a role in prey detection. We also found that O. smaragdina was much more likely to be present on figs of male trees (where fig wasps are more abundant), and that the abundance of this ant species varied strongly with developmental phase of figs on individual trees. Moreover, its aggressiveness was also strongly influenced by the nature of the object presented in our behavioural tests, the site of the test and the developmental phase of the fig tested. Investigation on the chemical and behavioural ecology of the different interacting species provides important insights into the intricate relationships supported by the fig-fig wasp mutualism.

  15. Visualization of metabolic interaction networks in microbial communities using VisANT 5.0

    SciTech Connect

    Granger, Brian R.; Chang, Yi -Chien; Wang, Yan; DeLisi, Charles; Segre, Daniel; Hu, Zhenjun

    2016-04-15

    Here, the complexity of metabolic networks in microbial communities poses an unresolved visualization and interpretation challenge. We address this challenge in the newly expanded version of a software tool for the analysis of biological networks, VisANT 5.0. We focus in particular on facilitating the visual exploration of metabolic interaction between microbes in a community, e.g. as predicted by COMETS (Computation of Microbial Ecosystems in Time and Space), a dynamic stoichiometric modeling framework. Using VisANT's unique meta-graph implementation, we show how one can use VisANT 5.0 to explore different time-dependent ecosystem-level metabolic networks. In particular, we analyze the metabolic interaction network between two bacteria previously shown to display an obligate cross-feeding interdependency. In addition, we illustrate how a putative minimal gut microbiome community could be represented in our framework, making it possible to highlight interactions across multiple coexisting species. We envisage that the "symbiotic layout" of VisANT can be employed as a general tool for the analysis of metabolism in complex microbial communities as well as heterogeneous human tissues.

  16. Changes in the speed of ants as a result of aggressive interactions.

    PubMed

    Ślipiński, Piotr; Żmihorski, Michał

    2017-10-01

    Subordinate ant species utilize different tactics to reduce competition with the stronger, larger and more aggressive individuals of a dominant species. In our experimental study, we assessed the behavioral response of individual workers of 4 subordinate ant species during their co-occurrence with workers of a single dominant species. Contrary to most classical experiments focused on aggressive interactions, we assessed workers' speed as a crucial factor in the outcome of co-occurrence. Generally, there was a large intraspecific variation in the speed of the studied species-each had slow and fast individuals. Workers of all studied species moved faster just after interaction, suggesting that contact between 2 hostile workers is a stressful stimulus, generating a behavioral reaction of increasing speed. Also, the number of aggressive contacts experienced by a given individual positively affected its speed. Moreover, workers which were fast when exploring territory were also fast after interspecific interactions. The duration of aggression was significantly reduced by the speed and body size of a subordinate species worker-the more quickly a worker reacted and bigger it was, the shorter was the time of cumulative aggression. To our knowledge, this is the first study of this type to be conducted on ants and we conclude that speed is an overlooked and important characteristic of species and also individuals, therefore it should be considered as a driver of patterns of co-occurrence in ant assemblages. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  17. Visualization of metabolic interaction networks in microbial communities using VisANT 5.0

    DOE PAGES

    Granger, Brian R.; Chang, Yi -Chien; Wang, Yan; ...

    2016-04-15

    Here, the complexity of metabolic networks in microbial communities poses an unresolved visualization and interpretation challenge. We address this challenge in the newly expanded version of a software tool for the analysis of biological networks, VisANT 5.0. We focus in particular on facilitating the visual exploration of metabolic interaction between microbes in a community, e.g. as predicted by COMETS (Computation of Microbial Ecosystems in Time and Space), a dynamic stoichiometric modeling framework. Using VisANT's unique meta-graph implementation, we show how one can use VisANT 5.0 to explore different time-dependent ecosystem-level metabolic networks. In particular, we analyze the metabolic interaction networkmore » between two bacteria previously shown to display an obligate cross-feeding interdependency. In addition, we illustrate how a putative minimal gut microbiome community could be represented in our framework, making it possible to highlight interactions across multiple coexisting species. We envisage that the "symbiotic layout" of VisANT can be employed as a general tool for the analysis of metabolism in complex microbial communities as well as heterogeneous human tissues.« less

  18. Assessing the impact of deforestation of the Atlantic rainforest on ant-fruit interactions: a field experiment using synthetic fruits.

    PubMed

    Bieber, Ana Gabriela D; Silva, Paulo S D; Sendoya, Sebastián F; Oliveira, Paulo S

    2014-01-01

    Ants frequently interact with fleshy fruits on the ground of tropical forests. This interaction is regarded as mutualistic because seeds benefit from enhanced germination and dispersal to nutrient-rich microsites, whereas ants benefit from consuming the nutritious pulp/aril. Considering that the process of deforestation affects many attributes of the ecosystem such as species abundance and composition, and interspecific interactions, we asked whether the interaction between ants and fallen fleshy fruits in the Brazilian Atlantic forest differs between human-created fragments and undisturbed forests. We controlled diaspore type and quantity by using synthetic fruits (a plastic 'seed' covered by a lipid-rich 'pulp'), which were comparable to lipid-rich fruits. Eight independent areas (four undisturbed forests, and four disturbed forest fragments) were used in the field experiment, in which we recorded the attracted ant species, ant behaviour, and fruit removal distance. Fruits in undisturbed forest sites attracted a higher number of species than those in disturbed forests. Moreover, the occurrence of large, fruit-carrying ponerine ants (Pachycondyla, Odontomachus; 1.1 to 1.4 cm) was higher in undisturbed forests. Large species (≥3 mm) of Pheidole (Myrmicinae), also able to remove fruits, did not differ between forest types. Following these changes in species occurrence, fruit displacement was more frequent in undisturbed than in disturbed forests. Moreover, displacement distances were also greater in the undisturbed forests. Our data suggest that fallen fleshy fruits interacting with ants face different fates depending on the conservation status of the forest. Together with the severe loss of their primary dispersers in human-disturbed tropical forest sites, vertebrate-dispersed fruits may also be deprived of potential ant-derived benefits in these habitats due to shifts in the composition of interacting ant species. Our data illustrate the use of synthetic fruits

  19. Assessing the Impact of Deforestation of the Atlantic Rainforest on Ant-Fruit Interactions: A Field Experiment Using Synthetic Fruits

    PubMed Central

    Bieber, Ana Gabriela D.; Silva, Paulo S. D.; Sendoya, Sebastián F.; Oliveira, Paulo S.

    2014-01-01

    Ants frequently interact with fleshy fruits on the ground of tropical forests. This interaction is regarded as mutualistic because seeds benefit from enhanced germination and dispersal to nutrient-rich microsites, whereas ants benefit from consuming the nutritious pulp/aril. Considering that the process of deforestation affects many attributes of the ecosystem such as species abundance and composition, and interspecific interactions, we asked whether the interaction between ants and fallen fleshy fruits in the Brazilian Atlantic forest differs between human-created fragments and undisturbed forests. We controlled diaspore type and quantity by using synthetic fruits (a plastic ‘seed’ covered by a lipid-rich ‘pulp’), which were comparable to lipid-rich fruits. Eight independent areas (four undisturbed forests, and four disturbed forest fragments) were used in the field experiment, in which we recorded the attracted ant species, ant behaviour, and fruit removal distance. Fruits in undisturbed forest sites attracted a higher number of species than those in disturbed forests. Moreover, the occurrence of large, fruit-carrying ponerine ants (Pachycondyla, Odontomachus; 1.1 to 1.4 cm) was higher in undisturbed forests. Large species (≥3 mm) of Pheidole (Myrmicinae), also able to remove fruits, did not differ between forest types. Following these changes in species occurrence, fruit displacement was more frequent in undisturbed than in disturbed forests. Moreover, displacement distances were also greater in the undisturbed forests. Our data suggest that fallen fleshy fruits interacting with ants face different fates depending on the conservation status of the forest. Together with the severe loss of their primary dispersers in human-disturbed tropical forest sites, vertebrate-dispersed fruits may also be deprived of potential ant-derived benefits in these habitats due to shifts in the composition of interacting ant species. Our data illustrate the use of synthetic

  20. Biodiversity on Broadway--enigmatic diversity of the societies of ants (Formicidae) on the streets of New York City.

    PubMed

    Pećarević, Marko; Danoff-Burg, James; Dunn, Robert R

    2010-10-05

    Each year, a larger proportion of the Earth's surface is urbanized, and a larger proportion of the people on Earth lives in those urban areas. The everyday nature, however, that humans encounter in cities remains poorly understood. Here, we consider perhaps the most urban green habitat, street medians. We sampled ants from forty-four medians along three boulevards in New York City and examined how median properties affect the abundance and species richness of native and introduced ants found on them. Ant species richness varied among streets and increased with area but was independent of the other median attributes measured. Ant assemblages were highly nested, with three numerically dominant species present at all medians and additional species present at a subset of medians. The most common ant species were the introduced Pavement ant (Tetramorium caespitum) and the native Thief ant (Solenopsis molesta) and Cornfield ant (Lasius neoniger). The common introduced species on the medians responded differently to natural and disturbed elements of medians. Tetramorium caespitum was most abundant in small medians, with the greatest edge/area ratio, particularly if those medians had few trees, whereas Nylanderia flavipes was most abundant in the largest medians, particularly if they had more trees. Many of the species encountered in Manhattan were similar to those found in other large North American cities, such that a relatively small subset of ant species probably represent most of the encounters humans have with ants in North America.

  1. Biodiversity on Broadway - Enigmatic Diversity of the Societies of Ants (Formicidae) on the Streets of New York City

    PubMed Central

    Pećarević, Marko; Danoff-Burg, James; Dunn, Robert R.

    2010-01-01

    Each year, a larger proportion of the Earth's surface is urbanized, and a larger proportion of the people on Earth lives in those urban areas. The everyday nature, however, that humans encounter in cities remains poorly understood. Here, we consider perhaps the most urban green habitat, street medians. We sampled ants from forty-four medians along three boulevards in New York City and examined how median properties affect the abundance and species richness of native and introduced ants found on them. Ant species richness varied among streets and increased with area but was independent of the other median attributes measured. Ant assemblages were highly nested, with three numerically dominant species present at all medians and additional species present at a subset of medians. The most common ant species were the introduced Pavement ant (Tetramorium caespitum) and the native Thief ant (Solenopsis molesta) and Cornfield ant (Lasius neoniger). The common introduced species on the medians responded differently to natural and disturbed elements of medians. Tetramorium caespitum was most abundant in small medians, with the greatest edge/area ratio, particularly if those medians had few trees, whereas Nylanderia flavipes was most abundant in the largest medians, particularly if they had more trees. Many of the species encountered in Manhattan were similar to those found in other large North American cities, such that a relatively small subset of ant species probably represent most of the encounters humans have with ants in North America. PMID:20957156

  2. Disease Dynamics in Ants: A Critical Review of the Ecological Relevance of Using Generalist Fungi to Study Infections in Insect Societies.

    PubMed

    Loreto, R G; Hughes, D P

    2016-01-01

    It is assumed that social life can lead to the rapid spread of infectious diseases and outbreaks. In ants, disease outbreaks are rare and the expression of collective behaviors is invoked to explain the absence of epidemics in natural populations. Here, we address the ecological approach employed by many studies that have notably focused (89% of the studies) on two genera of generalist fungal parasites (Beauveria and Metarhizium). We ask whether these are the most representative models to study the evolutionary ecology of ant-fungal parasite interactions. To assess this, we critically examine the literature on ants and their interactions with fungal parasites from the past 114years (1900-2014). We discuss how current evolutionary ecology approaches emerged from studies focused on the biological control of pest ants. We also analyzed the ecological relevance of the laboratory protocols used in evolutionary ecology studies employing generalist parasites, as well as the rare natural occurrence of these parasites on ants. After a detailed consideration of all the publications, we suggest that using generalist pathogens such as Beauveria and Metarhizium is not an optimal approach if the goal is to study the evolutionary ecology of disease in ants. We conclude by advocating for approaches that incorporate greater realism. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Nature of the interactions between hypocrealean fungi and the mutualistic fungus of leaf-cutter ants.

    PubMed

    Varanda-Haifig, Sadala Schmidt; Albarici, Tatiane Regina; Nunes, Pablo Henrique; Haifig, Ives; Vieira, Paulo Cezar; Rodrigues, Andre

    2017-04-01

    Leaf-cutter ants cultivate and feed on the mutualistic fungus, Leucoagaricus gongylophorus, which is threatened by parasitic fungi of the genus Escovopsis. The mechanism of Escovopsis parasitism is poorly understood. Here, we assessed the nature of the antagonism of different Escovopsis species against its host. We also evaluated the potential antagonism of Escovopsioides, a recently described fungal genus from the attine ant environment whose role in the colonies of these insects is unknown. We performed dual-culture assays to assess the interactions between L. gongylophorus and both fungi. We also evaluated the antifungal activity of compounds secreted by the latter on L. gongylophorus growth using crude extracts of Escovopsis spp. and Escovopsioides nivea obtained either in (1) absence or (2) presence of the mutualistic fungus. The physical interaction between these fungi and the mutualistic fungus was examined under scanning electron microscopy (SEM). Escovopsis spp. and E. nivea negatively affected the growth of L. gongylophorus, which was also significantly inhibited by both types of crude extract. These results indicate that Escovopsis spp. and E. nivea produce antifungal metabolites against the mutualistic fungus. SEM showed that Escovopsis spp. and E. nivea maintained physical contact with the mutualistic fungus, though no specialised structures related to mycoparasitism were observed. These results showed that Escovopsis is a destructive mycoparasite that needs physical contact for the death of the mutualistic fungus to occur. Also, our findings suggest that E. nivea is an antagonist of the ant fungal cultivar.

  4. Indirect interactions between ant-tended hemipterans, a dominant ant Azteca instabilis (Hymenoptera: Formicidae), and shade trees in a tropical agroecosystem.

    PubMed

    Livingston, George F; White, Adam M; Kratz, Carley J

    2008-06-01

    The occurrence, intensity, and composition of mutualisms are dependent not only on the co-occurrence of mutualists, but also the broader biotic context in which they are embedded. Here, the influence of the specific nest tree identity of the ant Azteca instabilis (F. Smith) on the density of the green coffee scale (Coccus viridis Green) was studied in a coffee agroecosystem in southern Mexico. The hypothesis that an indirect competitive interaction for ant attendance occurs between a scale species (Octolecanium sp. Kondo) in the canopy of the shade tree Inga micheliana Harms and C. viridis, which inhabits coffee bushes (Coffea arabica) beneath the shade trees was tested. Coffee bushes beneath a different shade tree species (Alchornea latifolia Swartz) were used as an indication of C. viridis density in a noncompetitive environment. Results indicate that C. viridis occurs in significantly lower density adjacent to nests in Inga, supporting the hypothesis of indirect competition. Additional experimentation suggests that there is a mutualism between Azteca and Octolecanium and that this interaction may be mediated by a hierarchy in ant attendance of scale insects. Our results show the importance of considering the biotic context of ant-hemipteran mutualisms. In coffee agroecosystems, consideration of shade tree diversity and species composition may be directly applicable to the biological control of insect pests.

  5. Geographic and taxonomic distribution of a positive interaction: ant-tended homopterans indirectly benefit figs across southern Africa.

    PubMed

    Cushman, J Hall; Compton, Stephen G; Zachariades, Costas; Ware, Anthony B; Nefdt, Rory J C; Rashbrook, Vanessa K

    1998-09-01

    Although species pairs and assemblages often occur across geographic regions, ecologists know very little about the outcome of their interactions on such large spatial scales. Here, we assess the geographic distribution and taxonomic diversity of a positive interaction involving ant-tended homopterans and fig trees in the genus Ficus. Previous experimental studies at a few locations in South Africa indicated that Ficus sur indirectly benefited from the presence of a homopteran (Hilda patruelis) because it attracted ants (primarily Pheidole megacephala) that reduced the effects of both pre-dispersal ovule gallers and parasitoids of pollinating wasps. Based on this work, we evaluated three conditions that must be met in order to support the hypothesis that this indirect interaction involves many fig species and occurs throughout much of southern Africa and Madagascar. Data on 429 trees distributed among five countries indicated that 20 of 38 Ficus species, and 46% of all trees sampled, had ants on their figs. Members of the Sycomorus subgenus were significantly more likely to attract ants than those in the Urostigma subgenus, and ant-colonization levels on these species were significantly greater than for Urostigma species. On average, each ant-occupied F.sur tree had 37% of its fig crop colonized by ants, whereas the value was 24% for other Ficus species. H. patruelis was the most common source for attracting ants, although figs were also attacked by a range of other ant-tended homopterans. P. megacephala was significantly more common on figs than other ant species, being present on 58% of sampled trees. Ant densities commonly exceeded 4.5 per fig, which a field experiment indicated was sufficient to provide protection from ovule gallers and parasitoids of pollinators. Forty-nine percent of all colonized F. sur trees sampled had ant densities equal to or greater than 4.5 per fig, whereas this value was 23% for other Ficus species. We conclude that there is

  6. Antagonistic Bacterial Interactions Help Shape Host-Symbiont Dynamics within the Fungus-Growing Ant-Microbe Mutualism

    PubMed Central

    Poulsen, Michael; Erhardt, Daniel P.; Molinaro, Daniel J.; Lin, Ting-Li; Currie, Cameron R.

    2007-01-01

    Conflict within mutually beneficial associations is predicted to destabilize relationships, and theoretical and empirical work exploring this has provided significant insight into the dynamics of cooperative interactions. Within mutualistic associations, the expression and regulation of conflict is likely more complex than in intraspecific cooperative relationship, because of the potential presence of: i) multiple genotypes of microbial species associated with individual hosts, ii) multiple species of symbiotic lineages forming cooperative partner pairings, and iii) additional symbiont lineages. Here we explore complexity of conflict expression within the ancient and coevolved mutualistic association between attine ants, their fungal cultivar, and actinomycetous bacteria (Pseudonocardia). Specifically, we examine conflict between the ants and their Pseudonocardia symbionts maintained to derive antibiotics against parasitic microfungi (Escovopsis) infecting the ants' fungus garden. Symbiont assays pairing isolates of Pseudonocardia spp. associated with fungus-growing ants spanning the phylogenetic diversity of the mutualism revealed that antagonism between strains is common. In contrast, antagonism was substantially less common between more closely related bacteria associated with Acromyrmex leaf-cutting ants. In both experiments, the observed variation in antagonism across pairings was primarily due to the inhibitory capabilities and susceptibility of individual strains, but also the phylogenetic relationships between the ant host of the symbionts, as well as the pair-wise genetic distances between strains. The presence of antagonism throughout the phylogenetic diversity of Pseudonocardia symbionts indicates that these reactions likely have shaped the symbiosis from its origin. Antagonism is expected to prevent novel strains from invading colonies, enforcing single-strain rearing within individual ant colonies. While this may align ant-actinomycete interests in the

  7. Antagonistic bacterial interactions help shape host-symbiont dynamics within the fungus-growing ant-microbe mutualism.

    PubMed

    Poulsen, Michael; Erhardt, Daniel P; Molinaro, Daniel J; Lin, Ting-Li; Currie, Cameron R

    2007-09-26

    Conflict within mutually beneficial associations is predicted to destabilize relationships, and theoretical and empirical work exploring this has provided significant insight into the dynamics of cooperative interactions. Within mutualistic associations, the expression and regulation of conflict is likely more complex than in intraspecific cooperative relationship, because of the potential presence of: i) multiple genotypes of microbial species associated with individual hosts, ii) multiple species of symbiotic lineages forming cooperative partner pairings, and iii) additional symbiont lineages. Here we explore complexity of conflict expression within the ancient and coevolved mutualistic association between attine ants, their fungal cultivar, and actinomycetous bacteria (Pseudonocardia). Specifically, we examine conflict between the ants and their Pseudonocardia symbionts maintained to derive antibiotics against parasitic microfungi (Escovopsis) infecting the ants' fungus garden. Symbiont assays pairing isolates of Pseudonocardia spp. associated with fungus-growing ants spanning the phylogenetic diversity of the mutualism revealed that antagonism between strains is common. In contrast, antagonism was substantially less common between more closely related bacteria associated with Acromyrmex leaf-cutting ants. In both experiments, the observed variation in antagonism across pairings was primarily due to the inhibitory capabilities and susceptibility of individual strains, but also the phylogenetic relationships between the ant host of the symbionts, as well as the pair-wise genetic distances between strains. The presence of antagonism throughout the phylogenetic diversity of Pseudonocardia symbionts indicates that these reactions likely have shaped the symbiosis from its origin. Antagonism is expected to prevent novel strains from invading colonies, enforcing single-strain rearing within individual ant colonies. While this may align ant-actinomycete interests in the

  8. Interaction between ants and fruits of Guapira opposita (Nyctaginaceae) in a Brazilian sandy plain rainforest: ant effects on seeds and seedlings.

    PubMed

    Passos, Luciana; Oliveira, Paulo S

    2004-05-01

    This study examines the dispersal system of Guapira opposita in a tropical sandy rainforest in southeast Brazil. Guapira trees produce small fruits with a high protein content (28.4%) and low lipid content (0.3%), and the plant is primarily dispersed by birds. Mature fruits of G. opposita can fall spontaneously with the pulp intact, or be dropped by birds with bits of pulp attached. In either case, ground-dwelling ants rapidly remove the fruits to their nest (93% after 12 h). The ponerine ants Odontomachus chelifer and Pachycondyla striata are the main seed vectors among the ants, and together account for 56% (20 of 36) of the ant-fruit interactions recorded on the forest floor. Individual workers of O. chelifer and P. striata transport single fruits to their nests. Bits of pulp are fed to larvae and worker nestmates, and intact seeds are discarded outside the nest. Germination success in Guapira is higher for cleaned seeds (pulp removed) than for seeds coated by pulp. Guapira seedlings and juveniles are more frequent close to Odontomachus nests than at sites without such nests. Soil samples from Odontomachus nests had greater penetrability, and higher concentrations of P, K, and Ca than random soil samples. Field experiments suggest that the association between G. opposita seedlings and O. chelifer nests can potentially render the plant some protection against herbivores. Results indicate that fruit displacement by ponerine ants play an important role in the biology of G. opposita seeds and seedlings in the sandy forest, and illustrate the complex nature of the dispersal ecology of tropical tree species.

  9. Fire in the Amazon: impact of experimental fuel addition on responses of ants and their interactions with myrmecochorous seeds.

    PubMed

    Paolucci, Lucas N; Maia, Maria L B; Solar, Ricardo R C; Campos, Ricardo I; Schoereder, José H; Andersen, Alan N

    2016-10-01

    The widespread clearing of tropical forests causes lower tree cover, drier microclimate, and higher and drier fuel loads of forest edges, increasing the risk of fire occurrence and its intensity. We used a manipulative field experiment to investigate the influence of fire and fuel loads on ant communities and their interactions with myrmecochorous seeds in the southern Amazon, a region currently undergoing extreme land-use intensification. Experimental fires and fuel addition were applied to 40 × 40-m plots in six replicated blocks, and ants were sampled between 15 and 30 days after fires in four strata: subterranean, litter, epigaeic, and arboreal. Fire had extensive negative effects on ant communities. Highly specialized cryptobiotic and predator species of the litter layer and epigaeic specialist predators were among the most sensitive, but we did not find evidence of overall biotic homogenization following fire. Fire reduced rates of location and transport of myrmecochorous seeds, and therefore the effectiveness of a key ecosystem service provided by ants, which we attribute to lower ant abundance and increased thermal stress. Experimental fuel addition had only minor effects on attributes of fire severity, and limited effects on ant responses to fire. Our findings indicate that enhanced fuel loads will not decrease ant diversity and ecosystem services through increased fire severity, at least in wetter years. However, higher fuel loads can still have a significant effect on ants from Amazonian rainforests because they increase the risk of fire occurrence, which has a detrimental impact on ant communities and a key ecosystem service they provide.

  10. At Lunch with a Killer: The Effect of Weaver Ants on Host-Parasitoid Interactions on Mango

    PubMed Central

    Migani, Valentina; Ekesi, Sunday; Merkel, Katharina; Hoffmeister, Thomas

    2017-01-01

    Predator-prey interactions can affect the behaviour of the species involved, with consequences for population distribution and competitive interactions. Under predation pressure, potential prey may adopt evasive strategies. These responses can be costly and could impact population growth. As some prey species may be more affected than others, predation pressure could also alter the dynamics among species within communities. In field cages and small observation cages, we studied the interactions between a generalist predator, the African weaver ant, Oecophylla longinoda, two species of fruit flies that are primary pests of mango fruits, Ceratitis cosyra and Bactrocera dorsalis, and their two exotic parasitoids, Fopius arisanus and Diachasmimorpha longicaudata. In all experiments, either a single individual (observation cage experiments) or groups of individuals (field cage experiments) of a single species were exposed to foraging in the presence or absence of weaver ants. Weaver ant presence reduced the number of eggs laid by 75 and 50 percent in B. dorsalis and C. cosyra respectively. Similarly, parasitoid reproductive success was negatively affected by ant presence, with success of parasitism reduced by around 50 percent for both F. arisanus and D. longicaudata. The negative effect of weaver ants on both flies and parasitoids was mainly due to indirect predation effects. Encounters with weaver ant workers increased the leaving tendency in flies and parasitoids, thus reduced the time spent foraging on mango fruits. Parasitoids were impacted more strongly than fruit flies. We discuss how weaver ant predation pressure may affect the population dynamics of the fruit flies, and, in turn, how the alteration of host dynamics could impact parasitoid foraging behaviour and success. PMID:28146561

  11. Effect of post-fire resprouting on leaf fluctuating asymmetry, extrafloral nectar quality, and ant-plant-herbivore interactions

    NASA Astrophysics Data System (ADS)

    Alves-Silva, Estevão; Del-Claro, Kleber

    2013-06-01

    Fires in the Cerrado savanna are a severe form of disturbance, but some species are capable of resprouting afterwards. It is unknown, however, how and whether post-fire resprouting represents a stressful condition to plants and how their rapid re-growth influences both the production of biochemical compounds, and interactions with mutualistic ants. In this study, we examined the influence of post-fire resprouting on biotic interactions (ant-plant-herbivore relationships) and on plant stress. The study was performed on two groups of the extrafloral nectaried shrub Banisteriopsis campestris (Malpighiaceae); one group was recovering from fire while the other acted as control. With respect to biotic interactions, we examined whether resprouting influenced extrafloral nectar concentration (milligrams per microliter), the abundance of the ant Camponotus crassus and leaf herbivory rates. Plant stress was assessed via fluctuating asymmetry (FA) analysis, which refers to deviations from perfect symmetry in bilaterally symmetrical traits (e.g., leaves) and indicates whether species are under stress. Results revealed that FA, sugar concentration, and ant abundance were 51.7 %, 35.7 % and 21.7 % higher in resprouting plants. Furthermore, C. crassus was significantly associated with low herbivory rates, but only in resprouting plants. This study showed that post-fire resprouting induced high levels of plant stress and influenced extrafloral nectar quality and ant-herbivore relationships in B. campestris. Therefore, despite being a stressful condition to the plant, post-fire resprouting individuals had concentrated extrafloral nectar and sustained more ants, thus strengthening the outcomes of ant-plant mutualism.

  12. The diversity of ant-associated black yeasts: insights into a newly discovered world of symbiotic interactions.

    PubMed

    Voglmayr, Hermann; Mayer, Veronika; Maschwitz, Ulrich; Moog, Joachim; Djieto-Lordon, Champlain; Blatrix, Rumsaïs

    2011-10-01

    thin-walled hyphae, and are commonly sporulating. In both carton and domatia, the fungal species seem to be specific to each ant-plant symbiosis. Representative examples of carton and domatia ant-fungus symbioses are illustrated. We discuss hypotheses on the ecological significance of the Chaetothyriales associated with ants. Copyright © 2010 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  13. Genetic interaction between AINTEGUMENTA (ANT) and the ovule identity genes SEEDSTICK (STK), SHATTERPROOF1 (SHP1) and SHATTERPROOF2 (SHP2).

    PubMed

    Losa, Alessia; Colombo, Monica; Brambilla, Vittoria; Colombo, Lucia

    2010-06-01

    AINTEGUMENTA (ANT) promotes initiation and growth of ovule integuments which cell fate is specified by ovule identity factors, such as SEEDSTICK (STK), SHATTERPROOF1 (SHP1) and SHATTERPROOF2 (SHP2). To study the genetic interaction between ANT and the ovule identity genes, we have obtained a stk shp1 shp2 ant quadruple mutant. The molecular and morphological characterization of the quadruple mutant and its comparison with the stk shp1 shp2 triple mutant, the shp1 shp2 ant triple mutant and the stk ant double mutant are here presented.

  14. Feeding behavior and social interactions of the Argentine ant Linepithema humile change with sucrose concentration.

    PubMed

    Sola, F J; Josens, R

    2016-08-01

    Liquid sugar baits are well accepted by the Argentine ant Linepithema humile and are suitable for the chemical control of this invasive species. We evaluated how sugar concentrations affect the foraging behavior of L. humile individuals. We quantified feeding variables for individual foragers (ingested load, feeding time and solution intake rate) when feeding on sucrose solutions of different concentrations, as well as post-feeding interactions with nestmates. Solutions of intermediate sucrose concentrations (10-30%) were the most consumed and had the highest intake rates, whereas solutions of high sucrose concentrations (60 and 70%) resulted in extended feeding times, low intake rates and ants having smaller crop loads. In terms of post-feeding interactions, individuals fed solutions of intermediate sucrose concentrations (20%) had the highest probability of conducting trophallaxis and the smallest latency to drop exposure (i.e. lowest time delay). Trophallaxis duration increased with increasing sucrose concentrations. Behavioral motor displays, including contacts with head jerking and walking with a gaster waggle, were lowest for individuals that ingested the more dilute sucrose solution (5%). These behaviors have been previously suggested to act as a communication channel for the activation and/or recruitment of nestmates. We show here that sucrose concentration affects feeding dynamics and modulates decision making related to individual behavior and social interactions of foragers. Our results indicate that intermediate sucrose concentrations (ca. 20%), appear to be most appropriate for toxic baits because they promote rapid foraging cycles, a high crop load per individual, and a high degree of stimulation for recruitment.

  15. Isolated and Community Contexts Produce Distinct Responses by Host Plants to the Presence of Ant-Aphid Interaction: Plant Productivity and Seed Viability

    PubMed Central

    Santiago, Graziele Silva; Zurlo, Luana Fonseca; Ribas, Carla Rodrigues; Carvalho, Rafaela Pereira; Alves, Guilherme Pereira; Carvalho, Mariana Comanucci Silva; Souza, Brígida

    2017-01-01

    Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this purpose we tested the hypothesis that in both isolated and community contexts, the presence of an ant-aphid interaction will have a positive effect on fruit and seed production, seed biomass and rate of seed germination, and a negative effect on abnormal seedling rates, in comparison to plants without ants. We performed a field mesocosm experiment containing five treatments: Ant-aphid, Aphid, Community, Ant-free community and Control. We counted fruits and seeds produced by each treatment, and conducted experiments for seed biomass and germinability. We found that in the community context the presence of an ant-aphid interaction negatively affected fruit and seed production. We think this may be because aphid attendance by tending-ants promotes aphid damage to the host plant, but without an affect on seed weight and viability. On the other hand, when isolated, the presence of an ant-aphid interaction positively affected fruit and seed production. These positive effects are related to the cleaning services offered to aphids by tending-ants, which prevent the development of saprophytic fungi on the surface of leaves, which would cause a decrease in photosynthetic rates. Our study is important because we evaluated some parameters of plant fitness that have not been addressed very well by other studies involving the effects of ant-aphid interactions mainly on plants with short life cycles. Lastly, our context dependent approach sheds new light on how ecological interactions can vary among different methods of crop management. PMID:28141849

  16. Isolated and Community Contexts Produce Distinct Responses by Host Plants to the Presence of Ant-Aphid Interaction: Plant Productivity and Seed Viability.

    PubMed

    Canedo-Júnior, Ernesto Oliveira; Santiago, Graziele Silva; Zurlo, Luana Fonseca; Ribas, Carla Rodrigues; Carvalho, Rafaela Pereira; Alves, Guilherme Pereira; Carvalho, Mariana Comanucci Silva; Souza, Brígida

    2017-01-01

    Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this purpose we tested the hypothesis that in both isolated and community contexts, the presence of an ant-aphid interaction will have a positive effect on fruit and seed production, seed biomass and rate of seed germination, and a negative effect on abnormal seedling rates, in comparison to plants without ants. We performed a field mesocosm experiment containing five treatments: Ant-aphid, Aphid, Community, Ant-free community and Control. We counted fruits and seeds produced by each treatment, and conducted experiments for seed biomass and germinability. We found that in the community context the presence of an ant-aphid interaction negatively affected fruit and seed production. We think this may be because aphid attendance by tending-ants promotes aphid damage to the host plant, but without an affect on seed weight and viability. On the other hand, when isolated, the presence of an ant-aphid interaction positively affected fruit and seed production. These positive effects are related to the cleaning services offered to aphids by tending-ants, which prevent the development of saprophytic fungi on the surface of leaves, which would cause a decrease in photosynthetic rates. Our study is important because we evaluated some parameters of plant fitness that have not been addressed very well by other studies involving the effects of ant-aphid interactions mainly on plants with short life cycles. Lastly, our context dependent approach sheds new light on how ecological interactions can vary among different methods of crop management.

  17. Interaction between Workers during a Short Time Window Is Required for Bacterial Symbiont Transmission in Acromyrmex Leaf-Cutting Ants

    PubMed Central

    Marsh, Sarah E.; Poulsen, Michael; Pinto-Tomás, Adrián; Currie, Cameron R.

    2014-01-01

    Stable associations between partners over time are critical for the evolution of mutualism. Hosts employ a variety of mechanisms to maintain specificity with bacterial associates. Acromyrmex leaf-cutting ants farm a fungal cultivar as their primary nutrient source. These ants also carry a Pseudonocardia Actinobacteria exosymbiont on their bodies that produces antifungal compounds that help inhibit specialized parasites of the ants' fungal garden. Major workers emerge from their pupal cases (eclose) symbiont-free, but exhibit visible Actinobacterial coverage within 14 days post-eclosion. Using subcolony experiments, we investigate exosymbiont transmission within Acromyrmex colonies. We found successful transmission to newly eclosed major workers fostered by major workers with visible Actinobacteria in all cases (100% acquiring, n = 19). In contrast, newly eclosed major workers reared without exosymbiont-carrying major workers did not acquire visible Actinobacteria (0% acquiring, n = 73). We further show that the majority of ants exposed to major workers with exosymbionts within 2 hours of eclosion acquired bacteria (60.7% acquiring, n = 28), while normal acquisition did not occur when exposure occurred later than 2 hours post-eclosion (0% acquiring, n = 18). Our findings show that transmission of exosymbionts to newly eclosed major workers occurs through interactions with exosymbiont-covered workers within a narrow time window after eclosion. This mode of transmission likely helps ensure the defensive function within colonies, as well as specificity and partner fidelity in the ant-bacterium association. PMID:25058579

  18. Interaction between workers during a short time window is required for bacterial symbiont transmission in Acromyrmex leaf-cutting ants.

    PubMed

    Marsh, Sarah E; Poulsen, Michael; Pinto-Tomás, Adrián; Currie, Cameron R

    2014-01-01

    Stable associations between partners over time are critical for the evolution of mutualism. Hosts employ a variety of mechanisms to maintain specificity with bacterial associates. Acromyrmex leaf-cutting ants farm a fungal cultivar as their primary nutrient source. These ants also carry a Pseudonocardia Actinobacteria exosymbiont on their bodies that produces antifungal compounds that help inhibit specialized parasites of the ants' fungal garden. Major workers emerge from their pupal cases (eclose) symbiont-free, but exhibit visible Actinobacterial coverage within 14 days post-eclosion. Using subcolony experiments, we investigate exosymbiont transmission within Acromyrmex colonies. We found successful transmission to newly eclosed major workers fostered by major workers with visible Actinobacteria in all cases (100% acquiring, n = 19). In contrast, newly eclosed major workers reared without exosymbiont-carrying major workers did not acquire visible Actinobacteria (0% acquiring, n = 73). We further show that the majority of ants exposed to major workers with exosymbionts within 2 hours of eclosion acquired bacteria (60.7% acquiring, n = 28), while normal acquisition did not occur when exposure occurred later than 2 hours post-eclosion (0% acquiring, n = 18). Our findings show that transmission of exosymbionts to newly eclosed major workers occurs through interactions with exosymbiont-covered workers within a narrow time window after eclosion. This mode of transmission likely helps ensure the defensive function within colonies, as well as specificity and partner fidelity in the ant-bacterium association.

  19. Mutualism exploitation: predatory drosophilid larvae sugar-trap ants and jeopardize facultative ant-plant mutualism.

    PubMed

    Vidal, Mayra C; Sendoya, Sebastian F; Oliveira, Paulo S

    2016-07-01

    An open question in the evolutionary ecology of ant-plant facultative mutualism is how other members of the associated community can affect the interaction to a point where reciprocal benefits are disrupted. While visiting Qualea grandiflora shrubs to collect sugary rewards at extrafloral nectaries, tropical savanna ants deter herbivores and reduce leaf damage. Here we show that larvae of the fly Rhinoleucophenga myrmecophaga, which develop on extrafloral nectaries, lure potentially mutualistic, nectar-feeding ants and prey on them. Foraging ants spend less time on fly-infested foliage. Field experiments showed that predation (or the threat of predation) on ants by fly larvae produces cascading effects through three trophic levels, resulting in fewer protective ants on leaves, increased numbers of chewing herbivores, and greater leaf damage. These results reveal an undocumented mode of mutualism exploitation by an opportunistic predator at a plant-provided food source, jeopardizing ant-derived protection services to the plant. Our study documents a rather unusual case of predation of adult ants by a dipteran species and demonstrates a top-down trophic cascade within a generalized ant-plant mutualism. © 2016 by the Ecological Society of America.

  20. Behavioural effects of juvenile hormone and their influence on division of labour in leaf-cutting ant societies.

    PubMed

    Norman, Victoria C; Hughes, William O H

    2016-01-01

    Division of labour in social insects represents a major evolutionary transition, but the physiological mechanisms that regulate this are still little understood. Experimental work with honey bees, and correlational analyses in other social insects, have implicated juvenile hormone (JH) as a regulatory factor, but direct experimental evidence of behavioural effects of JH in social insects is generally lacking. Here, we used experimental manipulation of JH to show that raised JH levels in leaf-cutting ants results in workers becoming more active, phototactic and threat responsive, and engaging in more extranidal activity - behavioural changes that we show are all characteristic of the transition from intranidal work to foraging. These behavioural effects on division of labour suggest that the JH mediation of behaviour occurs across multiple independent evolutions of eusociality, and may be a key endocrine regulator of the division of labour which has produced the remarkable ecological and evolutionary success of social insects.

  1. Performance of the species-typical alarm response in young workers of the ant Myrmica sabuleti (Hymenoptera: Formicidae) is induced by interactions with mature workers.

    PubMed

    Cammaerts, Marie-Claire

    2014-01-01

    Young workers of the ant Myrmica sabuleti (Hymenoptera: Formicidae) Meinert 1861 perceived nestmate alarm pheromone but did not display normal alarm behavior (orientation toward the source of emission, increased running speed). They changed their initial behavior when in the presence of older nestmates exhibiting normal alarm behavior. Four days later, the young ants exhibited an imperfect version of normal alarm behavior. This change of behavior did not occur in young ants, which were not exposed to older ants reacting to alarm pheromone. Queen ants perceived the alarm pheromone and, after a few seconds, moved toward its source. Thus, the ants' ability to sense the alarm pheromone and to identify it as an alarm signal is native, while the adult alarm reaction is acquired over time (= age based polyethism) by young ants. It is possible that the change in behavior observed in young ants could be initiated and/or enhanced (via experience-induced developmental plasticity, learning, and/or other mechanisms) by older ants exhibiting alarm behavior. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  2. Test of local adaptation to biotic interactions and soil abiotic conditions in the ant-tended Chamaecrista fasciculata (Fabaceae).

    PubMed

    Abdala-Roberts, Luis; Marquis, Robert J

    2007-11-01

    Few previous studies have assessed the role of herbivores and the third trophic level in the evolution of local adaptation in plants. The overall objectives of this study were to determine (1) whether local adaptation is present in the ant-defended plant, Chamaecrista fasciculata, and (2) the contribution of ant-plant-herbivore interactions and soil source to such adaptation. We used three C. fasciculata populations and performed both a field and a greenhouse experiment. The first involved reciprocally transplanting C. fasciculata seedlings from each population-source to each site, and subsequently applying one of three treatments to one-third of the seedlings of each population-source at each site: control, reduced ant density and reduced folivory. The greenhouse experiment involved reciprocal transplants of population-sources with soil sources to test for a soil-source effect on flower production and local adaptation to soil conditions. Field results showed that ant and herbivore treatments reduced ant density (increasing folivory) and herbivore damage relative to controls, respectively; however, these manipulations did not impact C. fasciculata reproduction or the likelihood of survival. In contrast, greenhouse results showed that soil source significantly affected flower production. Overall, plants in both experiments, regardless of population-source, always had higher reproductive output at one specific site. Native populations did not outperform nonnative ones, causing us to reject the hypothesis of local adaptation. The absence of treatment effects on plant reproduction and the likelihood of survival suggest a limited effect of ants and folivores on C. fasciculata fitness and local adaptation during the study year. Temporally inconsistent effects of biotic forces across years, coupled with the young age of populations, relative proximity of populations and possible counter effects of seed predators may reduce the likelihood of local adaptation in the

  3. Unusual animal-plant interaction: Feeding of Schomburgkia tibicinis (Orchidaceae) by ants

    SciTech Connect

    Rico-Gray, V. ); Barber, J.T.; Thien, L.B.; Ellgaard, E.G.; Toney, J.J. )

    1989-04-01

    The hollow pseudobulbs of Schomburgkia tibicinis (Orchidaceae; Central America) serve as domatia for many species of ants. The ants pack many of the pseudobulbs with debris including dead insects, plant material, and sand. Ants were fed {sup 14}C-labelled D-glucose in honey, killed, and placed in the pseudobulbs for up to eight weeks. Samples of plant tissue were harvested and tested for radioactivity after 1, 2, 3, 4, 6, and 8 weeks. The labelled material had moved into various parts of the plant and demonstrated direct nutrient uptake.

  4. Rotating panoramic view: interaction between visual and olfactory cues in ants

    PubMed Central

    Minoura, Mai; Sonoda, Kohei; Sakiyama, Tomoko; Gunji, Yukio-Pegio

    2016-01-01

    Insects use a navigational toolkit consisting of multiple strategies such as path integration, view-dependent recognition methods and olfactory cues. The question arises as to how directional cues afforded by a visual panorama combine with olfactory cues from a pheromone trail to guide ants towards their nest. We positioned a garden ant Lasius niger on a rotating table, whereon a segment of a pheromone trail relative to the stationary panorama was rotated while the ant walked along the trail towards its nest. The rotational speed of the table (3 r.p.m.) was set so that the table would rotate through about 90° by the time that an ant had walked from the start to the centre of the table. The ant completed a U-turn at about this point and so travelled in a nest-ward direction without leaving the trail. These results suggest that the ants persist on the pheromone trail and use visual input to determine their direction of travel along the trail. PMID:26909169

  5. Population responses to environmental change in a tropical ant: the interaction of spatial and temporal dynamics.

    PubMed

    Jackson, Doug; Vandermeer, John; Perfecto, Ivette; Philpott, Stacy M

    2014-01-01

    Spatial structure can have a profound, but often underappreciated, effect on the temporal dynamics of ecosystems. Here we report on a counterintuitive increase in the population of a tree-nesting ant, Azteca sericeasur, in response to a drastic reduction in the number of potential nesting sites. This surprising result is comprehensible when viewed in the context of the self-organized spatial dynamics of the ants and their effect on the ants' dispersal-limited natural enemies. Approximately 30% of the trees in the study site, a coffee agroecosystem in southern Mexico, were pruned or felled over a two-year period, and yet the abundance of the ant nests more than doubled over the seven-year study. Throughout the transition, the spatial distribution of the ants maintained a power-law distribution - a signal of spatial self organization - but the local clustering of the nests was reduced post-pruning. A cellular automata model incorporating the changed spatial structure of the ants and the resulting partial escape from antagonists reproduced the observed increase in abundance, highlighting how self-organized spatial dynamics can profoundly influence the responses of ecosystems to perturbations.

  6. Antagonistic Interactions between the African Weaver Ant Oecophylla longinoda and the Parasitoid Anagyrus pseudococci Potentially Limits Suppression of the Invasive Mealybug Rastrococcus iceryoides.

    PubMed

    Tanga, Chrysantus M; Ekesi, Sunday; Govender, Prem; Nderitu, Peterson W; Mohamed, Samira A

    2015-12-23

    The ant Oecophylla longinoda Latreille forms a trophobiotic relationship with the invasive mealybug Rastrococus iceryoides Green and promotes the latter's infestations to unacceptable levels in the presence of their natural enemies. In this regard, the antagonistic interactions between the ant and the parasitoid Anagyrus pseudococci Girault were assessed under laboratory conditions. The percentage of parasitism of R. iceryoides by A. pseudococci was significantly higher on "ant-excluded" treatments (86.6% ± 1.27%) compared to "ant-tended" treatments (51.4% ± 4.13%). The low female-biased sex-ratio observed in the "ant-tended" treatment can be attributed to ants' interference during the oviposition phase, which disrupted parasitoids' ability to fertilize eggs. The mean foraging time, host handling time and number of successful oviposition in "ant-excluded" treatment were significantly higher compared to "ant-tended" treatments. When ant workers were allowed access to sterilized sand grains, mummified and unmummified R. iceryoides, they selectively removed the mummified mealybugs, indicating that they recognized the mummies as potential foods (1.2 ± 0.46 to 7.8 ± 1.17 mummies at 10 min intervals for 2 h). Percentage emergence from mummified R. iceryoides removed by the ants was significantly lower compared to emergence from mummies not exposed to ants. Although, host seeking parasitoids frequently evaded attacks, some were killed by the foraging ant workers (2.0 ± 0.38 to 6.0 ± 0.88 at 10 min intervals for 2 h). These results suggest for the first time that the presence of O. longinoda has a detrimental effect on the abundance, reproductive success and possibly oviposition strategy of female parasitoids, which might be a delimiting factor in field conditions if both natural enemies are to be recommended for use within the same agro-ecosystem.

  7. Common-garden experiments reveal geographical variation in the interaction among Crotalaria pallida (Leguminosae: Papilionideae), Utetheisa ornatrix L. (Lepidoptera: Arctiidae), and extrafloral nectary visiting ants.

    PubMed

    Franco, M S; Cogni, R

    2013-06-01

    The study of geographical variation is a key approach to understand evolution of ecological interactions. We investigated geographical variation in the interaction among Crotalaria pallida (Leguminosae: Papilionideae), its specialized herbivore, Utetheisa ornatrix L. (Lepidoptera: Arctiidae), and ants attracted to extrafloral nectaries (EFNs). First, we used common-garden experiments with plants collected in different sites at different geographical scales to test for differences among populations in C. pallida attractiveness to ants. When we compared three populations from Southeast Brazil (150 km apart), the number of visiting ants per plant, and the percent of termite baits attacked by ants, were significantly different among plant populations. In a comparison of populations from SE Brazil and Florida (USA), there was no significant difference between the populations in the number of ants per plant or the frequency of baits attacked. Second, we tested in a common garden if U. ornatrix larvae present any behavior to avoid ant predation, and if there were genetic differences among populations. We observed that most larvae moved away from the vicinity of the EFNs (flowers and fruits) to the plant leaves. Of the larvae that moved to leaves, only 10% were attacked by ants while 89% of larvae that stayed near the fruit/flower were attacked. There was a significant difference among populations in the frequency of larvae that moved to the leaves and the frequency of larvae attacked by ants. We discuss the possible causes of the geographical differences observed and propose future research directions in this system.

  8. Fire disturbance disrupts an acacia ant-plant mutualism in favor of a subordinate ant species.

    PubMed

    Sensenig, Ryan L; Kimuyu, Duncan K; Ruiz Guajardo, Juan C; Veblen, Kari E; Riginos, Corinna; Young, Truman P

    2017-05-01

    Although disturbance theory has been recognized as a useful framework in examining the stability of ant-plant mutualisms, very few studies have examined the effects of fire disturbance on these mutualisms. In myrmecophyte-dominated savannas, fire and herbivory are key drivers that could influence ant-plant mutualisms by causing complete colony mortality and/or decreasing colony size, which potentially could alter dominance hierarchies if subordinate species are more fire resilient. We used a large-scale, replicated fire experiment to examine long-term effects of fire on acacia-ant community composition. To determine if fire shifted ant occupancy from a competitive dominant to a subordinate ant species, we surveyed the acacia-ant community in 6-7 yr old burn sites and examined how the spatial scale of these burns influenced ant community responses. We then used two short-term fire experiments to explore possible mechanisms for the shifts in community patterns observed. Because survival of ant colonies is largely dependent on their ability to detect and escape an approaching fire, we first tested the evacuation response of all four ant species when exposed to smoke (fire signal). Then to better understand how fire and its interaction with large mammal herbivory affect the density of ants per tree, we quantified ant worker density in small prescribed burns within herbivore exclusion plots. We found clear evidence suggesting that fire disturbance favored the subordinate ant Crematogaster nigriceps more than the dominant and strong mutualist ant C. mimosae, whereby C. nigriceps (1) was the only species to occupy a greater proportion of trees in 6-7 yr old burn sites compared to unburned sites, (2) had higher burn/unburn tree ratios with increasing burn size, and (3) evacuated significantly faster than C. mimosae in the presence of smoke. Fire and herbivory had opposite effects on ant density per meter of branch for both C. nigriceps and C. mimosae, with fire

  9. Indirect effects of alternative food resources in an ant-plant interaction.

    PubMed

    Boulay, R; Fedriani, J M; Manzaneda, A J; Cerdá, X

    2005-06-01

    The seeds of many plant species present a food body that is consumed by animal dispersers. In theory, if the animals are polyphagous, the availability of alternative food resource other than the diaspore itself may influence its dispersal and survival. We used the myrmecochore Helleborus foetidus L. (Ranunculaceae), the seeds of which are attached to a lipid-rich elaiosome that is attractive to ants, as a model system to investigate (1) whether alternative foods that are present along with the plant affect ant foraging behavior and diaspore removal and (2) whether food availability in an ant nest affects seed predation and germination. In a field experiment, artificial diaspore depots were offered together with either sugar, insect corpses, seed, or no food (control). Contrary to the prediction that ants would rather concentrate their foraging effort on the highly rewarding alternative foods only, many workers, attracted by the sugar, switched to the hellebore diaspores, which significantly enhanced removal rate. Results obtained in the laboratory further indicated that the larvae of Aphaenogaster iberica (a major seed disperser) predated more on the H. foetidus embryos when no alternative food was available. This, in turn, slightly reduced seed germination. Overall, these results shed light, for the first time, on the potential indirect effects of alternative resources on the fate of diaspores adapted for ant dispersal.

  10. Lack of interactions between fire ant control products and white grubs (Coleoptera: Scarabaeidae) in turfgrass.

    PubMed

    Barden, S Addison; Held, David W; Graham, L C Fudd

    2011-12-01

    Insecticides are widely used to manage turfgrass pest such as white grubs (Coleoptera: Scarabaeidae). Red imported fire ants, Solenopsis invicta (Buren) are important predators and pests in managed turfgrass. We tested the susceptibility of white grub life stages (adults, egg, and larvae) to predation by S. invicta and determined if insecticides applied for control of S. invicta would result in locally greater white grub populations. Field trials over 2 yr evaluated bifenthrin, fipronil, and hydramethylnon applied to large and small scale turfgrass plots for impacts on fire ant foraging and white grub populations. Coincident with these trials, adults, larvae, and eggs of common scarab species were evaluated for susceptibility to predation by S. invicta under field conditions. Field trials with insecticides failed to show a significant increase in white grub populations resulting from treatment of turfgrass for fire ants. This, in part, may be because of a lack of predation of S. invicta on adult and larval scarabs. Egg predation was greatest at 70% but < 20% of adults and larvae were attacked in a 24 h test. Contrary to other studies, results presented here suggest that fire ants and fire ant control products applied to turfgrass have a minimal impact on white grub populations.

  11. Population Responses to Environmental Change in a Tropical Ant: The Interaction of Spatial and Temporal Dynamics

    PubMed Central

    Jackson, Doug; Vandermeer, John; Perfecto, Ivette; Philpott, Stacy M.

    2014-01-01

    Spatial structure can have a profound, but often underappreciated, effect on the temporal dynamics of ecosystems. Here we report on a counterintuitive increase in the population of a tree-nesting ant, Azteca sericeasur, in response to a drastic reduction in the number of potential nesting sites. This surprising result is comprehensible when viewed in the context of the self-organized spatial dynamics of the ants and their effect on the ants’ dispersal-limited natural enemies. Approximately 30% of the trees in the study site, a coffee agroecosystem in southern Mexico, were pruned or felled over a two-year period, and yet the abundance of the ant nests more than doubled over the seven-year study. Throughout the transition, the spatial distribution of the ants maintained a power-law distribution – a signal of spatial self organization – but the local clustering of the nests was reduced post-pruning. A cellular automata model incorporating the changed spatial structure of the ants and the resulting partial escape from antagonists reproduced the observed increase in abundance, highlighting how self-organized spatial dynamics can profoundly influence the responses of ecosystems to perturbations. PMID:24842117

  12. Climate, fishery and society interactions: Observations from the North Atlantic

    NASA Astrophysics Data System (ADS)

    Hamilton, Lawrence C.

    2007-11-01

    Interdisciplinary studies comparing fisheries-dependent regions across the North Atlantic find a number of broad patterns. Large ecological shifts, disastrous to historical fisheries, have resulted when unfavorable climatic events occur atop overfishing. The "teleconnections" linking fisheries crises across long distances include human technology and markets, as well as climate or migratory fish species. Overfishing and climate-driven changes have led to a shift downwards in trophic levels of fisheries takes in some ecosystems, from dominance by bony fish to crustaceans. Fishing societies adapt to new ecological conditions through social reorganization that have benefited some people and places, while leaving others behind. Characteristic patterns of demographic change are among the symptoms of such reorganization. These general observations emerge from a review of recent case studies of individual fishing communities, such as those conducted for the North Atlantic Arc research project.

  13. Antagonistic Interactions between the African Weaver Ant Oecophylla longinoda and the Parasitoid Anagyrus pseudococci Potentially Limits Suppression of the Invasive Mealybug Rastrococcus iceryoides

    PubMed Central

    Tanga, Chrysantus M.; Ekesi, Sunday; Govender, Prem; Nderitu, Peterson W.; Mohamed, Samira A.

    2015-01-01

    The ant Oecophylla longinoda Latreille forms a trophobiotic relationship with the invasive mealybug Rastrococus iceryoides Green and promotes the latter’s infestations to unacceptable levels in the presence of their natural enemies. In this regard, the antagonistic interactions between the ant and the parasitoid Anagyrus pseudococci Girault were assessed under laboratory conditions. The percentage of parasitism of R. iceryoides by A. pseudococci was significantly higher on “ant-excluded” treatments (86.6% ± 1.27%) compared to “ant-tended” treatments (51.4% ± 4.13%). The low female-biased sex-ratio observed in the “ant-tended” treatment can be attributed to ants’ interference during the oviposition phase, which disrupted parasitoids’ ability to fertilize eggs. The mean foraging time, host handling time and number of successful oviposition in “ant-excluded” treatment were significantly higher compared to “ant-tended” treatments. When ant workers were allowed access to sterilized sand grains, mummified and unmummified R. iceryoides, they selectively removed the mummified mealybugs, indicating that they recognized the mummies as potential foods (1.2 ± 0.46 to 7.8 ± 1.17 mummies at 10 min intervals for 2 h). Percentage emergence from mummified R. iceryoides removed by the ants was significantly lower compared to emergence from mummies not exposed to ants. Although, host seeking parasitoids frequently evaded attacks, some were killed by the foraging ant workers (2.0 ± 0.38 to 6.0 ± 0.88 at 10 min intervals for 2 h). These results suggest for the first time that the presence of O. longinoda has a detrimental effect on the abundance, reproductive success and possibly oviposition strategy of female parasitoids, which might be a delimiting factor in field conditions if both natural enemies are to be recommended for use within the same agro-ecosystem. PMID:26703741

  14. Role of social and individual experience in interaction of the meadow ant Formica pratensis (Hymenoptera: Formicidae) with ladybird imagines and hoverfly larvae.

    PubMed

    Novgorodova, Tatiana A

    2015-03-01

    The ability to recognize aphidophages is one of the key points in the protection ants provide aphids against their natural enemies. Behavior of honeydew collectors from nature ("field," control) and laboratory reared "naive" ants of Formica pratensis Retzius, which had never met either "mature" workers or aphids and aphidophages, was observed during their pairwise interactions with ladybird imagines and hoverfly larvae. The majority of the "naive" ants perceived ladybirds as an enemy at their first encounter attacking them immediately without any prior antennation. Ants seem to have a certain innate "enemy image" that lets them react very quickly to protect aphids. Hoverfly larvae were rarely attacked by both "field" and "naive" ants (>15%). During tests with ladybirds ants from nature attacked them and also demonstrated the most aggressive reactions (series of bites and "death grip") less frequently than the "naive" ants. The percentage of ants avoiding aphidophages after a contact with their chemical defense (reflex bleeding and glue-like saliva) was significantly higher in the control group. Whereas the "naive" ants did not learn to avoid danger, foragers from nature usually tried to avoid negative experience and used tactics of "short bites." Overall, experience has been proved to be unimportant for displaying key behavioral reactions underlying ant-ladybird interaction. However, accumulation of experience has been assumed to play an important role in the formation of behavioral strategy that allows honeydew collectors to drive aphidophages away with lower energy costs and avoid or minimize negative consequences of aphidophages' chemical defense. © 2014 Institute of Zoology, Chinese Academy of Sciences.

  15. Honey Ants.

    ERIC Educational Resources Information Center

    Conway, John R.

    1984-01-01

    Provides background information on honey ants. These ants are found in dry or desert regions of North America, Africa, and Australia. Also provides a list of activities using local species of ants. (JN)

  16. Honey Ants.

    ERIC Educational Resources Information Center

    Conway, John R.

    1984-01-01

    Provides background information on honey ants. These ants are found in dry or desert regions of North America, Africa, and Australia. Also provides a list of activities using local species of ants. (JN)

  17. Modeling the Interactions between Hydrological Extremes, Water Management and Society.

    NASA Astrophysics Data System (ADS)

    Martinez, Fabian; Di Baldassarre, Giuliano; Kalantari, Zahra

    2016-04-01

    Over the past years, several studies have focused on exploring human impacts on the hydrological regime. Even though the dominant hydrological processes are mostly well understood, there are still several challenges related to modeling the coevolution of human impacts on (and responses to) hydrological extremes, such as floods and droughts. Some initial modeling attempts have proved to capture the essential dynamics emerging from two-way feedbacks between hydrological and social processes. However, they have predominantly focused on flooding. This research aims to develop a new conceptual model unraveling the interplay between hydrological extremes (floods and droughts) and human societies in a changing climate. In particular, this socio-hydrological model aims at understanding, and predicting the dynamics of coupled human-water systems to explain and capture how the occurrence of hydrological extremes changes water management approach, and how such a change (in turn) mitigates the impacts of hydrological extremes. The conceptual model is then applied to a case study to test its ability in simulating the dynamics emerging from the interplay between hydrological and social processes.

  18. Farm animal welfare research in interaction with society.

    PubMed

    Blokhuis, H J; Ekkel, E D; Korte, S M; Hopster, H; van Reenen, C G

    2000-10-01

    Over the last 30 years concern about farm animal welfare has increased and has become a public issue in the Netherlands. Public discussion has stimulated research in this field, financed by both government and industry. Dutch society in general and consumers of animal products in particular, want to see high standards of welfare for production animals. Good animal welfare has gradually gained more impact in the total quality concept of the product. This will encourage scientists to continue to analyse the welfare status of animals and to come up with innovative solutions for the remaining problems. At ID-Lelystad much effort is put into farm animal welfare research. This research includes for example, the development of behavioural tests for quantifying and interpreting fear in cattle, investigations into the effects of dietary iron supply and a lack of roughage on behaviour, immunology, stress physiology, and pathology in veal calves, studies of the ontogeny of tail biting in finishing pigs and feather pecking in laying hens as well as evaluation of the welfare effects of automatic milking in dairy cows. The results of these projects contribute to concrete improvements in animal husbandry and expertise and support policy making and legislation. The animal industry as well as retailers should aim at the further implementation of this knowledge and to specify welfare standards to guarantee consumer acceptance of animal production.

  19. Interactions of the polarization and the sun compass in path integration of desert ants.

    PubMed

    Lebhardt, Fleur; Ronacher, Bernhard

    2014-08-01

    Desert ants, Cataglyphis fortis, perform large-scale foraging trips in their featureless habitat using path integration as their main navigation tool. To determine their walking direction they use primarily celestial cues, the sky's polarization pattern and the sun position. To examine the relative importance of these two celestial cues, we performed cue conflict experiments. We manipulated the polarization pattern experienced by the ants during their outbound foraging excursions, reducing it to a single electric field (e-)vector direction with a linear polarization filter. The simultaneous view of the sun created situations in which the directional information of the sun and the polarization compass disagreed. The heading directions of the homebound runs recorded on a test field with full view of the natural sky demonstrate that none of both compasses completely dominated over the other. Rather the ants seemed to compute an intermediate homing direction to which both compass systems contributed roughly equally. Direct sunlight and polarized light are detected in different regions of the ant's compound eye, suggesting two separate pathways for obtaining directional information. In the experimental paradigm applied here, these two pathways seem to feed into the path integrator with similar weights.

  20. A Novel Type of Nutritional Ant–Plant Interaction: Ant Partners of Carnivorous Pitcher Plants Prevent Nutrient Export by Dipteran Pitcher Infauna

    PubMed Central

    Scharmann, Mathias; Thornham, Daniel G.; Grafe, T. Ulmar; Federle, Walter

    2013-01-01

    Many plants combat herbivore and pathogen attack indirectly by attracting predators of their herbivores. Here we describe a novel type of insect–plant interaction where a carnivorous plant uses such an indirect defence to prevent nutrient loss to kleptoparasites. The ant Camponotus schmitzi is an obligate inhabitant of the carnivorous pitcher plant Nepenthes bicalcarata in Borneo. It has recently been suggested that this ant–plant interaction is a nutritional mutualism, but the detailed mechanisms and the origin of the ant-derived nutrient supply have remained unexplained. We confirm that N. bicalcarata host plant leaves naturally have an elevated 15N/14N stable isotope abundance ratio (δ15N) when colonised by C. schmitzi. This indicates that a higher proportion of the plants’ nitrogen is insect-derived when C. schmitzi ants are present (ca. 100%, vs. 77% in uncolonised plants) and that more nitrogen is available to them. We demonstrated direct flux of nutrients from the ants to the host plant in a 15N pulse-chase experiment. As C. schmitzi ants only feed on nectar and pitcher contents of their host, the elevated foliar δ15N cannot be explained by classic ant-feeding (myrmecotrophy) but must originate from a higher efficiency of the pitcher traps. We discovered that C. schmitzi ants not only increase the pitchers' capture efficiency by keeping the pitchers’ trapping surfaces clean, but they also reduce nutrient loss from the pitchers by predating dipteran pitcher inhabitants (infauna). Consequently, nutrients the pitchers would have otherwise lost via emerging flies become available as ant colony waste. The plants’ prey is therefore conserved by the ants. The interaction between C. schmitzi, N. bicalcarata and dipteran pitcher infauna represents a new type of mutualism where animals mitigate the damage by nutrient thieves to a plant. PMID:23717446

  1. Bottom-up effects of host-plant species diversity and top-down effects of ants interactively increase plant performance.

    PubMed

    Moreira, Xoaquín; Mooney, Kailen A; Zas, Rafael; Sampedro, Luis

    2012-11-07

    While plant diversity is well known to increase primary productivity, whether these bottom-up effects are enhanced by reciprocal top-down effects from the third trophic level is unknown. We studied whether pine tree species diversity, aphid-tending ants and their interaction determined plant performance and arthropod community structure. Plant diversity had a positive effect on aphids, but only in the presence of mutualistic ants, leading to a threefold greater number of both groups in the tri-specific cultures than in monocultures. Plant diversity increased ant abundance not only by increasing aphid number, but also by increasing ant recruitment per aphid. The positive effect of diversity on ants in turn cascaded down to increase plant performance; diversity increased plant growth (but not biomass), and this effect was stronger in the presence of ants. Consequently, bottom-up effects of diversity within the same genus and guild of plants, and top-down effects from the third trophic level (predatory ants), interactively increased plant performance.

  2. Unwritten rules: virtual bargaining underpins social interaction, culture, and society.

    PubMed

    Misyak, Jennifer B; Melkonyan, Tigran; Zeitoun, Hossam; Chater, Nick

    2014-10-01

    Many social interactions require humans to coordinate their behavior across a range of scales. However, aspects of intentional coordination remain puzzling from within several approaches in cognitive science. Sketching a new perspective, we propose that the complex behavioral patterns - or 'unwritten rules' - governing such coordination emerge from an ongoing process of 'virtual bargaining'. Social participants behave on the basis of what they would agree to do if they were explicitly to bargain, provided the agreement that would arise from such discussion is commonly known. Although intuitively simple, this interpretation has implications for understanding a broad spectrum of social, economic, and cultural phenomena (including joint action, team reasoning, communication, and language) that, we argue, depend fundamentally on the virtual bargains themselves.

  3. Ants: the supreme soil manipulators

    USDA-ARS?s Scientific Manuscript database

    This review focuses on the semiochemical interactions between ants and their soil environment. Ants occupy virtually every ecological niche and have evolved mechanisms to not just cope with, but also manipulate soil organisms. The metapleural gland, specific to ants was thought to be the major sourc...

  4. Let your enemy do the work: within-host interactions between two fungal parasites of leaf-cutting ants.

    PubMed

    Hughes, W O H; Boomsma, J J

    2004-02-07

    Within-host competition is an important factor in host-parasite relationships, yet most studies consider interactions involving only single parasite species. We investigated the interaction between a virulent obligate entomopathogenic fungus, Metarhizium anisopliae var. anisopliae, and a normally avirulent, opportunistic fungal pathogen, Aspergillus flavus, in their leaf-cutting ant host, Acromyrmex echinatior. Surprisingly, the latter normally out-competed the former in mixed infections and had enhanced fitness relative to when infecting in isolation. The result is most probably due to Metarhizium inhibiting the host's immune defences, which would otherwise normally prevent infections by Aspergillus. With the host defences negated by the virulent parasite, the avirulent parasite was then able to out-compete its competitor. This result is strikingly similar to that seen in immunocompromised vertebrate hosts and indicates that avirulent parasites may play a more important role in host life histories than is generally realized.

  5. Ant-Plant Interaction in a Tropical Savanna: May the Network Structure Vary over Time and Influence on the Outcomes of Associations?

    PubMed Central

    Lange, Denise; Del-Claro, Kleber

    2014-01-01

    Plant-animal interactions occur in a community context of dynamic and complex ecological interactive networks. The understanding of who interacts with whom is a basic information, but the outcomes of interactions among associates are fundamental to draw valid conclusions about the functional structure of the network. Ecological networks studies in general gave little importance to know the true outcomes of interactions and how they may change over time. We evaluate the dynamic of an interaction network between ants and plants with extrafloral nectaries, by verifying the temporal variation in structure and outcomes of mutualism for the plant community (leaf herbivory). To reach this goal, we used two tools: bipartite network analysis and experimental manipulation. The networks exhibited the same general pattern as other mutualistic networks: nestedness, asymmetry and low specialization and this pattern was maintained over time, but with internal changes (species degree, connectance and ant abundance). These changes influenced the protection effectiveness of plants by ants, which varied over time. Our study shows that interaction networks between ants and plants are dynamic over time, and that these alterations affect the outcomes of mutualisms. In addition, our study proposes that the set of single systems that shape ecological networks can be manipulated for a greater understanding of the entire system. PMID:25141007

  6. Ant-plant interaction in a tropical savanna: may the network structure vary over time and influence on the outcomes of associations?

    PubMed

    Lange, Denise; Del-Claro, Kleber

    2014-01-01

    Plant-animal interactions occur in a community context of dynamic and complex ecological interactive networks. The understanding of who interacts with whom is a basic information, but the outcomes of interactions among associates are fundamental to draw valid conclusions about the functional structure of the network. Ecological networks studies in general gave little importance to know the true outcomes of interactions and how they may change over time. We evaluate the dynamic of an interaction network between ants and plants with extrafloral nectaries, by verifying the temporal variation in structure and outcomes of mutualism for the plant community (leaf herbivory). To reach this goal, we used two tools: bipartite network analysis and experimental manipulation. The networks exhibited the same general pattern as other mutualistic networks: nestedness, asymmetry and low specialization and this pattern was maintained over time, but with internal changes (species degree, connectance and ant abundance). These changes influenced the protection effectiveness of plants by ants, which varied over time. Our study shows that interaction networks between ants and plants are dynamic over time, and that these alterations affect the outcomes of mutualisms. In addition, our study proposes that the set of single systems that shape ecological networks can be manipulated for a greater understanding of the entire system.

  7. Ant colonies and foraging line dynamics: Modeling, experiments and computations

    NASA Astrophysics Data System (ADS)

    Rossi, Louis

    2005-11-01

    Ants are one of several types of insects that form robust and complex societies, and as such, provide rich theoretical ground for the exploration and understanding of collective dynamics and the behaviorial parameters that drive the dynamics. Many species of ants are nearly or completely blind, so they interact locally through behaviorial cues with nearby ants, and through pheromone trails left by other ants. Consistent with biological observation, two populations of ants are modeled, those seeking food and those returning to the nest with food. A simple constitutive model relating ant densities to pheromone concentrations yields a system of equations describing two interacting fluids and predicts left- and right-moving traveling waves. All the model parameters can be reduced to two Froude numbers describing the ratio between a chemical potential and the kinetic energy of the traveling ants. Laboratory experiments on Tetramorium caespitum (L) clearly indicate left and right-moving traveling density waves in agreement with the mathematical model. We focus on understanding the evolutionary utility of the traveling waves, and the optimality of the Froude numbers and other parameters.

  8. Exploitation and interference competition between the invasive Argentine ant, Linepithema humile, and native ant species.

    PubMed

    Human, Kathleen G; Gordon, Deborah M

    1996-02-01

    Interactions between the invasive Argentine ant, Linepithema humile, and native ant species were studied in a 450-ha biological reserve in northern California. Along the edges of the invasion, the presence of Argentine ants significantly reduced the foraging success of native ant species, and vice versa. Argentine ants were consistently better than native ants at exploiting food sources: Argentine ants found and recruited to bait more consistently and in higher numbers than native ant species, and they foraged for longer periods throughout the day. Native ants and Argentine ants frequently fought when they recruited to the same bait, and native ant species were displaced from bait during 60% of these encounters. In introduction experiments, Argentine ants interfered with the foraging of native ant species, and prevented the establishment of new colonies of native ant species by preying upon winged native ant queens. The Argentine ants' range within the preserve expanded by 12 ha between May 1993 and May 1994, and 13 between September 1993 and September 1994, with a corresponding reduction of the range of native ant species. Although some native ants persist locally at the edges of the invasion of Argentine ants, most eventually disappear from invaded areas. Both interference and exploitation competition appear to be important in the displacement of native ant species from areas invaded by Argentine ants.

  9. Multilingual Interaction and Minority Languages: Proficiency and Language Practices in Education and Society

    ERIC Educational Resources Information Center

    Gorter, Durk

    2015-01-01

    In this plenary speech I examine multilingual interaction in a number of European regions in which minority languages are being revitalized. Education is a crucial variable, but the wider society is equally significant. The context of revitalization is no longer bilingual but increasingly multilingual. I draw on the results of a long-running…

  10. Dynamic changes in host-virus interactions associated with colony founding and social environment in fire ant queens (Solenopsis invicta).

    PubMed

    Manfredini, Fabio; Shoemaker, DeWayne; Grozinger, Christina M

    2016-01-01

    The dynamics of host-parasite interactions can change dramatically over the course of a chronic infection as the internal (physiological) and external (environmental) conditions of the host change. When queens of social insects found a colony, they experience changes in both their physiological state (they develop their ovaries and begin laying eggs) and the social environment (they suddenly stop interacting with the other members of the mother colony), making this an excellent model system for examining how these factors interact with chronic infections. We investigated the dynamics of host-viral interactions in queens of Solenopsis invicta (fire ant) as they transition from mating to colony founding/brood rearing to the emergence of the first workers. We examined these dynamics in naturally infected queens in two different social environments, where queens either founded colonies as individuals or as pairs. We hypothesized that stress associated with colony founding plays an important role in the dynamics of host-parasite interactions. We also hypothesized that different viruses have different modalities of interaction with the host that can be quantified by physiological measures and genomic analysis of gene expression in the host. We found that the two most prevalent viruses, SINV-1 and SINV-2, are associated with different fitness costs that are mirrored by different patterns of gene expression in the host. In fact SINV-2, the virus that imposes the significant reduction of a queen's reproductive output is also associated with larger changes of global gene expression in the host. These results show the complexity of interactions between S. invicta and two viral parasites. Our findings also show that chronic infections by viral parasites in insects are dynamic processes that may pose different challenges in the host, laying the groundwork for interesting ecological and evolutionary considerations.

  11. BEHAVIORAL INTERACTIONS OF THE BLACK IMPORTED FIRE ANT (SOLENOPSIS RICHTERI FOREL) AND ITS PARASITOID FLY (PSEUDACTEON CURVATUS BORGMEIER) AS REVEALED BY HIGH-SPEED VIDEO.

    USDA-ARS?s Scientific Manuscript database

    High-speed video recordings were used to study the interactions between the phorid fly (Pseudacteon curvatus), and the black imported fire ant (Solenopsis richteri) in the field. Phorid flies are extremely fast agile fliers that can hover and fly in all directions. Wingbeat frequency recorded with...

  12. What are the consequences of ant-seed interactions on the abundance of two dry-fruited shrubs in a Mediterranean scrub?

    PubMed

    Arnan, Xavier; Rodrigo, A; Retana, J

    2011-12-01

    Strong interactions between dry-fruited shrubs and seed-harvesting ants are expected in early successional scrubs, where both groups have a major presence. We have analysed the implications of the seed characteristics of two dry-fruited shrub species (Coronilla minima and Dorycnium pentaphyllum) on seed predation and dispersal mediated by harvester ants and the consequences of these processes on spatio-temporal patterns of plant abundance in a heterogeneous environment. We found that large C. minima seeds were collected much more (39%) than small D. pentaphyllum seeds (2%). However, not all of the removed seeds of these plant species were consumed, and 12.8% of the seeds were lost along the trails, which increased dispersal distances compared with abiotic dispersal alone. Seed dropping occurred among all microhabitats of the two plant species, but especially in open microhabitats, which are the most suitable ones for plant establishment. The two plant species increased their presence in the study area during the study period: C. minima in open microhabitats and D. pentaphyllum in high vegetation. The large size of C. minima seeds probably limited the primary seed dispersal of this species, but may have allowed strong interaction with ants. Thus, seed dispersal by ants resulted in C. minima seeds reaching more suitable microhabitats by means of increasing dispersal distance and redistribution among microhabitats. In contrast, the smaller size of D. pentaphyllum seeds arguably allows abiotic seed dispersal over longer distances and colonization of all types of microhabitats, although it probably also limits their interaction with ants and, consequently, their redistribution in suitable microhabitats. We suggest that dyszoochory could contribute to the success of plant species with different seed characteristics in scrub habitats where seeds are abundantly collected by seed-harvesting ants.

  13. The Pied Piper: A Parasitic Beetle’s Melodies Modulate Ant Behaviours

    PubMed Central

    Di Giulio, Andrea; Maurizi, Emanuela; Barbero, Francesca; Sala, Marco; Fattorini, Simone; Balletto, Emilio; Bonelli, Simona

    2015-01-01

    Ants use various communication channels to regulate their social organisation. The main channel that drives almost all the ants’ activities and behaviours is the chemical one, but it is long acknowledged that the acoustic channel also plays an important role. However, very little is known regarding exploitation of the acoustical channel by myrmecophile parasites to infiltrate the ant society. Among social parasites, the ant nest beetles (Paussus) are obligate myrmecophiles able to move throughout the colony at will and prey on the ants, surprisingly never eliciting aggression from the colonies. It has been recently postulated that stridulatory organs in Paussus might be evolved as an acoustic mechanism to interact with ants. Here, we survey the role of acoustic signals employed in the Paussus beetle-Pheidole ant system. Ants parasitised by Paussus beetles produce caste-specific stridulations. We found that Paussus can “speak” three different “languages”, each similar to sounds produced by different ant castes (workers, soldiers, queen). Playback experiments were used to test how host ants respond to the sounds emitted by Paussus. Our data suggest that, by mimicking the stridulations of the queen, Paussus is able to dupe the workers of its host and to be treated as royalty. This is the first report of acoustic mimicry in a beetle parasite of ants. PMID:26154266

  14. Report on "Methodologies for Investigating Microbial-Mineral Interactions: A Clay Minerals Society Short Course"

    SciTech Connect

    Maurice, Patricia A.

    2010-02-08

    A workshop entitled, “Methods of Investigating Microbial-Mineral Interactions,” was held at the Clay Minerals Society meeting at the Pacific Northwest National Laboratory in Richland, WA on June 19, 2004. The workshop was organized by Patricia A. Maurice (University of Notre Dame) and Lesley A. Warren (McMaster University, CA). Speakers included: Dr. P. Bennett, Dr. J. Fredrickson (PNNL), Dr. S. Lower (Ohio State University), Dr. P. Maurice, Dr. S. Myneni (Princeton University), Dr. E. Shock (Arizona State), Dr. M. Tien (Penn State), Dr. L. Warren, and Dr. J. Zachara (PNNL). There were approximately 75 attendees at the workshop, including more than 20 students. A workshop volume was published by the Clay Minerals Society [Methods for Study of Microbe-Mineral Interactions (2006), CMS Workshop Lectures, vol 14(Patricia A. Maurice and Leslie A. Warren, eds.) ISBN 978-1-881208-15-0, 166 pp.

  15. The Interacting Effects of Ungulate Hoofprints and Predatory Native Ants on Metamorph Cane Toads in Tropical Australia

    PubMed Central

    Cabrera-Guzmán, Elisa; Crossland, Michael R.; González-Bernal, Edna; Shine, Richard

    2013-01-01

    Many invasive species exploit the disturbed habitats created by human activities. Understanding the effects of habitat disturbance on invasion success, and how disturbance interacts with other factors (such as biotic resistance to the invaders from the native fauna) may suggest new ways to reduce invader viability. In tropical Australia, commercial livestock production can facilitate invasion by the cane toad (Rhinella marina), because hoofprints left by cattle and horses around waterbody margins provide distinctive (cool, moist) microhabitats; nevertheless the same microhabitat can inhibit the success of cane toads by increasing the risks of predation or drowning. Metamorph cane toads actively select hoofprints as retreat-sites to escape dangerous thermal and hydric conditions in the surrounding landscape. However, hoofprint geometry is important: in hoofprints with steep sides the young toads are more likely to be attacked by predatory ants (Iridomyrmex reburrus) and are more likely to drown following heavy rain. Thus, anthropogenic changes to the landscape interact with predation by native taxa to affect the ability of cane toads in this vulnerable life-history stage to thrive in the harsh abiotic conditions of tropical Australia. PMID:24255703

  16. Ant Tower

    NASA Astrophysics Data System (ADS)

    Mlot, Nathan; Shinotsuka, Sho; Hu, David

    2010-11-01

    Ants walk via adhesive drops of fluid extruded by their feet. They also use these drops as mortar to build structures such as rafts, bridges and towers, each composed of thousands of ants linked together. We investigate experimentally the construction of triangular ant towers braced by hydrophobic walls. Particular attention is paid to the relationship between tower height and contact angle hysteresis of the wall. We rationalize tower height according to ant adhesion, and tower shape according to the constraints on a column of constant strength.

  17. Interaction and cooperative effort among scientific societies. Twelve years of COSCE.

    PubMed

    Martín, Nazario; Andradas, Carlos

    2015-12-01

    The evolution of knowledge and technology in recent decades has brought profound changes in science policy, not only in the countries but also in the supranational organizations. It has been necessary, therefore, to adapt the scientific institutions to new models in order to achieve a greater and better communication between them and the political counterparts responsible for defining the general framework of relations between science and society. The Federationon of Scientific Societies of Spain (COSCE, Confederación de Sociedades Científicas de España) was founded in October 2003 to respond to the urgent need to interact with the political institutions and foster a better orientation in the process of making decisions about the science policy. Currently COSCE consists of over 70 Spanish scientific societies and more than 40,000 scientists. During its twelve years of active life, COSCE has developed an intense work of awareness of the real situation of science in Spain by launching several initiatives (some of which have joined other organizations) or by joining initiatives proposed from other groups related to science both at the Spanish level and at the European and non-European scenarios. [Int Microbiol 18(4): 245-251 (2015)]. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  18. Interaction between the Hawaiian dark-rumped petrel and the Argentine ant in Haleakala National Park, Maui, Hawaii

    USGS Publications Warehouse

    Krushelnycky, Paul D.; Hodges, Cathleen S.N.; Medeiros, Arthur C.; Loope, Lloyd L.

    2001-01-01

    The endemic biota of the Hawaiian islands is believed to have evolved in the absence of ant predation. However, it was suspected that this endemic biota is highly vulnerable to the effect of immigrant ants especially with regard to an aggressive predator known as the Argentine ant (Linepithema humile). First recorded in the Haleakala National Park on the island of Maui in 1967, this ant was believed to have reduced populations of native arthropods in high-elevation subalpine shrublands. In addition, concerns were raised that this immigrant ant may have also reduced the breeding success of the endangered Hawaiian Dark-rumped Petrel (Pterodroma phaeopygia sandwichensis), a native seabird. If so, then it was believe that this ant could become another major threat to the survival of this endangered seabird in addition to the threat that was caused by the introduction of introduced mammals, the advent of hunting by the Polynesians, and a loss of breeding habitat. As a result, the purpose of this study was to determine if the Argentine ant affects the nesting success of this native Hawaiian seabird.

  19. Temporal patterns of diversity: Assessing the biotic and abiotic controls on ant assemblages

    USGS Publications Warehouse

    Dunn, R.R.; Parker, C.R.; Sanders, N.J.

    2007-01-01

    In this study, we use 12 months of data from 11 ant assemblages to test whether seasonal variation in ant diversity is governed by either the structuring influences of interspecific competition or environmental conditions. Because the importance of competition might vary along environmental gradients, we also test whether the signature of competition depends on elevation. We find little evidence that competition structures the seasonal patterns of activity in the ant assemblages considered, but find support for the effects of temperature on seasonal patterns of diversity, especially at low-elevation sites. Although, in general, both competition and the environment interact to structure ant assemblages, our results suggest that environmental conditions are the primary force structuring the seasonal activity of the ant assemblages studied here. ?? 2007 The Linnean Society of London.

  20. The MeCP2/YY1 interaction regulates ANT1 expression at 4q35: novel hints for Rett syndrome pathogenesis.

    PubMed

    Forlani, Greta; Giarda, Elisa; Ala, Ugo; Di Cunto, Ferdinando; Salani, Monica; Tupler, Rossella; Kilstrup-Nielsen, Charlotte; Landsberger, Nicoletta

    2010-08-15

    Rett syndrome is a severe neurodevelopmental disorder mainly caused by mutations in the transcriptional regulator MeCP2. Although there is no effective therapy for Rett syndrome, the recently discovered disease reversibility in mice suggests that there are therapeutic possibilities. Identification of MeCP2 targets or modifiers of the phenotype can facilitate the design of curative strategies. To identify possible novel MeCP2 interactors, we exploited a bioinformatic approach and selected Ying Yang 1 (YY1) as an interesting candidate. We demonstrate that MeCP2 interacts in vitro and in vivo with YY1, a ubiquitous zinc-finger epigenetic factor regulating the expression of several genes. We show that MeCP2 cooperates with YY1 in repressing the ANT1 gene encoding a mitochondrial adenine nucleotide translocase. Importantly, ANT1 mRNA levels are increased in human and mouse cell lines devoid of MeCP2, in Rett patient fibroblasts and in the brain of Mecp2-null mice. We further demonstrate that ANT1 protein levels are upregulated in Mecp2-null mice. Finally, the identified MeCP2-YY1 interaction, together with the well-known involvement of YY1 in the regulation of D4Z4-associated genes at 4q35, led us to discover the anomalous depression of FRG2, a subtelomeric gene of unknown function, in Rett fibroblasts. Collectively, our data indicate that mutations in MeCP2 might cause the aberrant overexpression of genes located at a specific locus, thus providing new candidates for the pathogenesis of Rett syndrome. As both ANT1 mutations and overexpression have been associated with human diseases, we consider it highly relevant to address the consequences of ANT1 deregulation in Rett syndrome.

  1. Imaging mass spectrometry and MS/MS molecular networking reveals chemical interactions among cuticular bacteria and pathogenic fungi associated with fungus-growing ants.

    PubMed

    Boya P, Cristopher A; Fernández-Marín, Hermógenes; Mejía, Luis C; Spadafora, Carmenza; Dorrestein, Pieter C; Gutiérrez, Marcelino

    2017-07-17

    The fungus-growing ant-microbe symbiosis is an ideal system to study chemistry-based microbial interactions due to the wealth of microbial interactions described, and the lack of information on the molecules involved therein. In this study, we employed a combination of MALDI imaging mass spectrometry (MALDI-IMS) and MS/MS molecular networking to study chemistry-based microbial interactions in this system. MALDI IMS was used to visualize the distribution of antimicrobials at the inhibition zone between bacteria associated to the ant Acromyrmex echinatior and the fungal pathogen Escovopsis sp. MS/MS molecular networking was used for the dereplication of compounds found at the inhibition zones. We identified the antibiotics actinomycins D, X2 and X0β, produced by the bacterium Streptomyces CBR38; and the macrolides elaiophylin, efomycin A and efomycin G, produced by the bacterium Streptomyces CBR53.These metabolites were found at the inhibition zones using MALDI IMS and were identified using MS/MS molecular networking. Additionally, three shearinines D, F, and J produced by the fungal pathogen Escovopsis TZ49 were detected. This is the first report of elaiophylins, actinomycin X0β and shearinines in the fungus-growing ant symbiotic system. These results suggest a secondary prophylactic use of these antibiotics by A. echinatior because of their permanent production by the bacteria.

  2. Local and Landscape Drivers of Ant Parasitism in a Coffee Landscape.

    PubMed

    De la Mora, Aldo; Pérez-Lachaud, Gabriela; Lachaud, Jean-Paul; Philpott, Stacy M

    2015-08-01

    Parasitism of ants that nest in rotting wood by eucharitid wasps was studied in order to examine whether habitat and season influence ant parasitism, vegetation complexity and agrochemical use correlate with ant parasitism, and whether specific local and landscape features of agricultural landscapes correlate with changes in ant parasitism. In a coffee landscape, 30 coffee and 10 forest sites were selected in which local management (e.g., vegetation, agrochemical use) and landscape features (e.g., distance to forest, percent of rustic coffee nearby) were characterized. Rotten logs were sampled and ant cocoons were collected from logs and cocoons were monitored for parasitoid emergence. Sixteen ant morphospecies in three ant subfamilies (Ectatomminae, Ponerinae, and Formicinae) were found. Seven ant species parasitized by two genera of Eucharitidae parasitoids (Kapala and Obeza) were reported and some ant-eucharitid associations were new. According to evaluated metrics, parasitism did not differ with habitat (forest, high-shade coffee, low-shade coffee), but did increase in the dry season for Gnamptogenys ants. Parasitism increased with vegetation complexity for Gnamptogenys and Pachycondyla and was high in sites with both high and low agrochemical use. Two landscape variables and two local factors positively correlated with parasitism for some ant genera and species. Thus, differences in vegetation complexity at the local and landscape scale and agrochemical use in coffee landscapes alter ecological interactions between parasitoids and their ant hosts. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Biotic and abiotic controls of argentine ant invasion success at local and landscape scales

    USGS Publications Warehouse

    Menke, S.B.; Fisher, R.N.; Jetz, W.; Holway, D.A.

    2007-01-01

    Although the ecological success of introduced species hinges on biotic interactions and physical conditions, few experimental studies - especially on animals - have simultaneously investigated the relative importance of both types of factors. The lack of such research may stem from the common assumption that native and introduced species exhibit similar environmental tolerances. Here we combine experimental and spatial modeling approaches (1) to determine the relative importance of biotic and abiotic controls of Argentine ant (Linepithema humile) invasion success, (2) to examine how the importance of these factors changes with spatial scale in southern California (USA), and (3) to assess how Argentine ants differ from native ants in their environmental tolerances. A factorial field experiment that combined native ant removal with irrigation revealed that Argentine ants failed to invade any dry plots (even those lacking native ants) but readily invaded all moist plots. Native ants slowed the spread of Argentine ants into irrigated plots but did not prevent invasion. In areas without Argentine ants, native ant species showed variable responses to irrigation. At the landscape scale, Argentine ant occurrence was positively correlated with minimum winter temperature (but not precipitation), whereas native ant diversity increased with precipitation and was negatively correlated with minimum winter temperature. These results are of interest for several reasons. First, they demonstrate that fine-scale differences in the physical environment can eclipse biotic resistance from native competitors in determining community susceptibility to invasion. Second, our results illustrate surprising complexities with respect to how the abiotic factors limiting invasion can change with spatial scale, and third, how native and invasive species can differ in their responses to the physical environment. Idiosyncratic and scale-dependent processes complicate attempts to forecast where

  4. 'Bio-nano interactions: new tools, insights and impacts': summary of the Royal Society discussion meeting.

    PubMed

    Lynch, Iseult; Feitshans, Ilise L; Kendall, Michaela

    2015-02-05

    Bio-nano interactions can be defined as the study of interactions between nanoscale entities and biological systems such as, but not limited to, peptides, proteins, lipids, DNA and other biomolecules, cells and cellular receptors and organisms including humans. Studying bio-nano interactions is particularly useful for understanding engineered materials that have at least one dimension in the nanoscale. Such materials may consist of discrete particles or nanostructured surfaces. Much of biology functions at the nanoscale; therefore, our ability to manipulate materials such that they are taken up at the nanoscale, and engage biological machinery in a designed and purposeful manner, opens new vistas for more efficient diagnostics, therapeutics (treatments) and tissue regeneration, so-called nanomedicine. Additionally, this ability of nanomaterials to interact with and be taken up by cells allows nanomaterials to be used as probes and tools to advance our understanding of cellular functioning. Yet, as a new technology, assessment of the safety of nanomaterials, and the applicability of existing regulatory frameworks for nanomaterials must be investigated in parallel with development of novel applications. The Royal Society meeting 'Bio-nano interactions: new tools, insights and impacts' provided an important platform for open dialogue on the current state of knowledge on these issues, bringing together scientists, industry, regulatory and legal experts to concretize existing discourse in science law and policy. This paper summarizes these discussions and the insights that emerged.

  5. Stinging ants.

    PubMed

    Rhoades, R

    2001-08-01

    Ants belong to the order Hymenoptera, along with bees, wasps, yellow jackets, etc., they are the most successful animal genera in this world. It is their selfless social structure which accounts for their huge impact. Their effect on man ranges from the parasol ant, which makes plant cultivation untenable in certain parts of South America, to Solenopsis Invicta in the southeastern United States of America, which kill ground dwelling birds and small animals, harass livestock, and renders farmland unusable. With the exception of the Bulldog Ant of Australia (which is the size of a medium cockroach) direct toxic effects are not a lethal threat to man. Human fatalities and morbidity are related to secondary infections of excoriated stings or allergic anaphylaxis. This article reviews history and recent developments regarding stinging ants around the world.

  6. Do aphids actively search for ant partners?

    PubMed

    Fischer, Christophe Y; Vanderplanck, Maryse; Lognay, Georges C; Detrain, Claire; Verheggen, François J

    2015-04-01

    The aphid-ant mutualistic relationships are not necessarily obligate for neither partners but evidence is that such interactions provide them strong advantages in terms of global fitness. While it is largely assumed that ants actively search for their mutualistic partners namely using volatile cues; whether winged aphids (i.e., aphids' most mobile form) are able to select ant-frequented areas had not been investigated so far. Ant-frequented sites would indeed offer several advantages for these aphids including a lower predation pressure through ant presence and enhanced chances of establishing mutuaslistic interactions with neighbor ant colonies. In the field, aphid colonies are often observed in higher densities around ant nests, which is probably linked to a better survival ensured by ants' services. Nevertheless, this could also result from a preferential establishment of winged aphids in ant-frequented areas. We tested this last hypothesis through different ethological assays and show that the facultative myrmecophilous black bean aphid, Aphis fabae L., does not orientate its search for a host plant preferentially toward ant-frequented plants. However, our results suggest that ants reduce the number of winged aphids leaving the newly colonized plant. Thus, ants involved in facultative myrmecophilous interactions with aphids appear to contribute to structure aphid populations in the field by ensuring a better establishment and survival of newly established colonies rather than by inducing a deliberate plant selection by aphid partners based on the proximity of ant colonies.

  7. Seed Selection by the Harvester Ant Pogonomyrmex rugosus (Hymenoptera: Formicidae) in Coastal Sage Scrub: Interactions With Invasive Plant Species.

    PubMed

    Briggs, C M; Redak, R A

    2016-08-01

    Harvester ants can be the dominant seed predators on plants by collecting and eating seeds and are known to influence plant communities. Harvester ants are abundant in coastal sage scrub (CSS), and CSS is frequently invaded by several exotic plant species. This study used observations of foraging and cafeteria-style experiments to test for seed species selection by the harvester ant Pogonomyrmex rugosus Emery (Hymenoptera: Formicidae) in CSS. Analysis of foraging behavior showed that P. rugosus carried seeds of exotic Erodium cicutarium (L.) and exotic Brassica tournefortii (Gouan) on 85 and 15% of return trips to the nest (respectively), and only a very few ants carried the native seeds found within the study areas. When compared with the availability of seeds in the field, P. rugosus selected exotic E. cicutarium and avoided both native Encelia farinosa (Torrey & A. Gray) and exotic B. tournefortii. Foraging by P. rugosus had no major effect on the seed bank in the field. Cafeteria-style experiments confirmed that P. rugosus selected E. cicutarium over other available seeds. Native Eriogonum fasciculatum (Bentham) seeds were even less selected than E. farinosa and B. tournefortii.

  8. Solenopsis invicta virus (sinv-1) infection and insecticide interactions in the red imported fire ant (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Controlling invasive species is a growing concern; however, pesticides can be detrimental for non-target organisms. The red imported fire ant (Solenopsis invicta Buren; Hymenoptera: Formicidae) has aggressively invaded approximately 138 million ha in the USA and causes over $6 billion in damage and ...

  9. Combinatorial expression of a ftz-zen fusion promoter suggests the occurrence of cis interactions between genes of the ANT-C.

    PubMed Central

    Rushlow, C; Levine, M

    1988-01-01

    The nine homeobox genes contained within the Antennapedia gene complex (ANT-C) are precisely regulated during embryonic development. It is not known to what extent the physical linkage of these genes contributes to their normal patterns of expression. Here we show that cis regulatory elements associated with one homeobox gene can act over a long distance (approximately 20 kb) to influence the expression of another homeobox gene. Specifically, fushi tarazu (ftz) promoter elements can direct the periodic expression of the z2 gene, which normally shows a simple 'dorsal on/ventral off' pattern of expression. An 80 kb deletion within the ANT-C [Df(3R)LIN] juxtaposes the z2 and ftz promoters, resulting in a hybrid expression pattern whereby z2 transcripts are distributed within periodic stripes that are confined to dorsal and lateral tissues and not observed in the ventral mesoderm. This observation suggests that separate promoter elements of different genes can function in a combinatorial manner, and that the patterns of ANT-C gene expression might depend on cis regulatory interactions. Images PMID:2905262

  10. Competition between honeydew producers in an ant-hemipteran interaction may enhance biological control of an invasive pest.

    PubMed

    Tena, A; Hoddle, C D; Hoddle, M S

    2013-12-01

    Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an invasive citrus pest in southern California, which secretes honeydew and has the potential to spread a lethal bacterial disease, huanglongbing, of citrus. In urban citrus, Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), also an invasive pest, tends honeydew-producing hemipterans. We used field data to determine whether the mutualistic relationship between L. humile and six established species of honeydew producers may hinder or favor the establishment of D. citri and its biological control with Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) in citrus via competition or mutualism for ants, respectively. In the field, L. humile and D. citri are engaged in a mutualistic relationship. Ants harvest solid honeydew secreted by psyllid nymphs and tended more than 55% of observed D. citri colonies. Linepithema humile displayed a preference hierarchy when tending honeydew producers infesting citrus. It responded equally or less intensively to D. citri than to other honeydew-producing species. Consequently, the mutualism between L. humile and D. citri was affected by the presence of other honeydew-producing species, and the percentage of D. citri colonies tended by L. humile. The number of ants per D. citri colony also decreased as the number of other honeydew producers increased. Diaphorina citri density was also affected by the presence of other honeydew producers. Both colony size and the number of D. citri nymphs counted per tree decreased as the number of other honeydew producers increased. Our results indicate that competition between honeydew producers for the mutualist ant L. humile may hinder the establishment of D. citri by possibly facilitating increased biological control.

  11. Context-dependent expression of the foraging gene in field colonies of ants: the interacting roles of age, environment and task

    PubMed Central

    Gordon, Deborah M.; Greene, Michael; Kahler, John; Peteru, Swetha

    2016-01-01

    Task allocation among social insect workers is an ideal framework for studying the molecular mechanisms underlying behavioural plasticity because workers of similar genotype adopt different behavioural phenotypes. Elegant laboratory studies have pioneered this effort, but field studies involving the genetic regulation of task allocation are rare. Here, we investigate the expression of the foraging gene in harvester ant workers from five age- and task-related groups in a natural population, and we experimentally test how exposure to light affects foraging expression in brood workers and foragers. Results from our field study show that the regulation of the foraging gene in harvester ants occurs at two time scales: levels of foraging mRNA are associated with ontogenetic changes over weeks in worker age, location and task, and there are significant daily oscillations in foraging expression in foragers. The temporal dissection of foraging expression reveals that gene expression changes in foragers occur across a scale of hours and the level of expression is predicted by activity rhythms: foragers have high levels of foraging mRNA during daylight hours when they are most active outside the nests. In the experimental study, we find complex interactions in foraging expression between task behaviour and light exposure. Oscillations occur in foragers following experimental exposure to 13 L : 11 D (LD) conditions, but not in brood workers under similar conditions. No significant differences were seen in foraging expression over time in either task in 24 h dark (DD) conditions. Interestingly, the expression of foraging in both undisturbed field and experimentally treated foragers is also significantly correlated with the expression of the circadian clock gene, cycle. Our results provide evidence that the regulation of this gene is context-dependent and associated with both ontogenetic and daily behavioural plasticity in field colonies of harvester ants. Our results underscore

  12. Context-dependent expression of the foraging gene in field colonies of ants: the interacting roles of age, environment and task.

    PubMed

    Ingram, Krista K; Gordon, Deborah M; Friedman, Daniel A; Greene, Michael; Kahler, John; Peteru, Swetha

    2016-08-31

    Task allocation among social insect workers is an ideal framework for studying the molecular mechanisms underlying behavioural plasticity because workers of similar genotype adopt different behavioural phenotypes. Elegant laboratory studies have pioneered this effort, but field studies involving the genetic regulation of task allocation are rare. Here, we investigate the expression of the foraging gene in harvester ant workers from five age- and task-related groups in a natural population, and we experimentally test how exposure to light affects foraging expression in brood workers and foragers. Results from our field study show that the regulation of the foraging gene in harvester ants occurs at two time scales: levels of foraging mRNA are associated with ontogenetic changes over weeks in worker age, location and task, and there are significant daily oscillations in foraging expression in foragers. The temporal dissection of foraging expression reveals that gene expression changes in foragers occur across a scale of hours and the level of expression is predicted by activity rhythms: foragers have high levels of foraging mRNA during daylight hours when they are most active outside the nests. In the experimental study, we find complex interactions in foraging expression between task behaviour and light exposure. Oscillations occur in foragers following experimental exposure to 13 L : 11 D (LD) conditions, but not in brood workers under similar conditions. No significant differences were seen in foraging expression over time in either task in 24 h dark (DD) conditions. Interestingly, the expression of foraging in both undisturbed field and experimentally treated foragers is also significantly correlated with the expression of the circadian clock gene, cycle Our results provide evidence that the regulation of this gene is context-dependent and associated with both ontogenetic and daily behavioural plasticity in field colonies of harvester ants. Our results underscore

  13. Persistence of pollination mutualisms in the presence of ants.

    PubMed

    Wang, Yuanshi; Wang, Shikun

    2015-01-01

    This paper considers plant-pollinator-ant systems in which the plant-pollinator interaction is mutualistic but ants have both positive and negative effects on plants. The ants also interfere with pollinators by preventing them from accessing plants. While a Beddington-DeAngelis (BD) formula can describe the plant-pollinator interaction, the formula is extended in this paper to characterize the pollination mutualism under the ant interference. Then, a plant-pollinator-ant system with the extended BD functional response is discussed, and global dynamics of the model demonstrate the mechanisms by which pollination mutualism can persist in the presence of ants. When the ant interference is strong, it can result in extinction of pollinators. Moreover, if the ants depend on pollination mutualism for survival, the strong interference could drive pollinators into extinction, which consequently lead to extinction of the ants themselves. When the ant interference is weak, a cooperation between plant-ant and plant-pollinator mutualisms could occur, which promotes survival of both ants and pollinators, especially in the case that ants (respectively, pollinators) cannot survive in the absence of pollinators (respectively, ants). Even when the level of ant interference remains invariant, varying ants' negative effect on plants can result in survival/extinction of both ants and pollinators. Therefore, our results provide an explanation for the persistence of pollination mutualism when there exist ants.

  14. Is host plant choice by a clytrine leaf beetle mediated through interactions with the ant Crematogaster lineolata?

    PubMed

    Stiefel, Vernon L; Margolies, David C

    1998-07-01

    In the grasslands of northeastern Kansas, adult populations of Anomoea flavokansiensis, an oligophagous leaf beetle (subfamily Clytrinae), specialize on Illinois bundleflower (Desmanthus illinoensis) even though other reported host species commonly occur and are simultaneously available. We performed choice feeding tests to examine whether A. flavokansiensis adults have a fixed feeding preference for bundleflower. In choice tests, beetles ate similar amounts of bundleflower and honey locust (Gleditsia triacanthos). In addition, we measured fecundity and longevity of adults in no-choice tests to determine if adults were adapted solely to bundleflower. In no-choice tests, fecundity and longevity were no different for adults feeding on bundleflower and honey locust. We next examined the influence of host plant on the attractiveness of beetle eggs to ants. In northeastern Kansas, Crematogaster lineolata ants are attracted to A. flavokansiensis eggs and carry them into their nests where the larvae hatch and apparently reside as inquilines. C. lineolata exhibited a strong preference for eggs from female A. flavokansiensis that fed exclusively on bundleflower compared to eggs from females that fed exclusively on honey locust. Local populations of A. flavokansiensis in northeastern Kansas may specialize on bundleflower to increase the chances of their eggs being transported by C. lineolata ants into their nests. C. lineolata nests may serve as a predator-free and sheltered environment in which A. flavokansiensis eggs undergo embryogenesis.

  15. Introduced fire ants can exclude native ants from critical mutualist-provided resources.

    PubMed

    Wilder, Shawn M; Barnum, Thomas R; Holway, David A; Suarez, Andrew V; Eubanks, Micky D

    2013-05-01

    Animals frequently experience resource imbalances in nature. For ants, one resource that may be particularly valuable for both introduced and native species is high-carbohydrate honeydew from hemipteran mutualists. We conducted field and laboratory experiments: (1) to test if red imported fire ants (Solenopsis invicta) competed with native ants for access to mutualisms with aphids, and (2) to quantify the effects of aphid honeydew presence or absence on colony growth of native ants. We focused on native dolichoderine ants (Formicidae, Dolichoderinae) because they are abundant ants that have omnivorous diets that frequently include mutualist-provided carbohydrates. At two sites in the southeastern US, native dolichoderine ants were far less frequent, and fire ants more frequent, at carbohydrate baits than would be expected based on their frequency in pitfall traps. A field experiment confirmed that a native ant species, Dorymyrmex bureni, was only found tending aphids when populations of S. invicta were suppressed. In the laboratory, colonies of native dolichoderine ants with access to both honeydew and insect prey had twice as many workers and over twice as much brood compared to colonies fed only ad libitum insect prey. Our results provide the first experimental evidence that introduced ants compete for access to mutualist-provided carbohydrates with native ants and that these carbohydrates represent critical resources for both introduced and native ants. These results challenge traditional paradigms of arthropod and ant nutrition and contribute to growing evidence of the importance of nutrition in mediating ecological interactions.

  16. Intellectual property as an instrument of interaction between government, business, science and society

    NASA Astrophysics Data System (ADS)

    Nikitenko, S. M.; Mesyats, M. A.; Rozhkova, O. V.

    2017-09-01

    This article is devoted to research the characteristics associated with pledge of intellectual property in foreign and domestic practice. Holding intellectual property objects’ pledge transactions accelerates the pace of creating innovative systems in the economy. In present paper the modern scheme for bank loan, financing secured with patented intellectual property is researched. The authors give the brief description of features of pledge security registration for loans in some Europe countries. The Europe Union experience shows that as collateral for monetary loans can be used trademarks, patents on the intellectual property, as well as their registration requests. Russian experience of the pledge operations of the intellectual property is too small. This way of bank lending is at an early stage of development. The main constraint is the difficulty of assessing the value of the pledged intellectual property as intangible assets. However, taking into account world and domestic practice this direction for Russian market is estimated by the authors as promising one. Pledge transactions take place within the framework of the Quadruple-Helix Model concept that involves four participants: “science”, “business”, “government” and “society”. Intellectual property are estimates by the authors as an instrument of interaction between government, business, science and society.

  17. The Mutually Beneficial Interaction of Science and Religion in Contemporary Society

    NASA Astrophysics Data System (ADS)

    Stoeger, William

    2007-10-01

    The natural and human sciences are in creative tension with religion, but it is a mistake to consider them to be in essential conflict. In fact, their interaction within society and culture can be, and often is, mutually beneficial, as long as the limitations and strengths of each are acknowledged and respected. This is strongly supported by the history of their relationship, and by the issues and interests connecting the two today. Three examples of this are: 1. the way in which each can reveal the competencies and deficiencies of the other; 2. the deep complementarity between the understanding of the universe we have from Big Bang and quantum cosmology and that resulting from elaborating the best classical philosophical Jewish-Christian-Islamic understandings of creation;and 3. the validation of rational inquiry by physics and cosmology, which provides a platform for exploring beyond where the natural sciences can go -- to philosophical and even theological questions. Though the Vatican Observatory is primarily dedicated to scientific research, its history is testimony to this deep and dynamic complementarity.

  18. Raised Bed Rivers in Japan -historical scenery of the interaction between environmental changes and society-

    NASA Astrophysics Data System (ADS)

    Toshitaka, Kamai

    2010-05-01

    Raised bed river should be a typical artificial landforms caused by the environmental changes in the upstream region of rivers. Typical raised bed rivers have developed in the western part of Japan, especially Kyoto, Osaka, Nara, Shiga region, induced by artificial fixing of alluvial river channels and increasing of bed load in floods. Inter-disciplinal approach of archaeological and geological investigations in southern Kyoto region, Kizu River, revealed that the raising of river bed started from 14th century and accelerated the raising rate from 17th century. The development of upstream mountainous area, deforestation and keeping grass field in long term period, led to increasing landslides and topsoil erosion in the mountainous slope, so that the bare mountains were common scenery around the advanced developed region in Japan during the ages of raised bed rivers from 14th to 19th century. The backgrounds of the beginning of these exhaustive developments in mountainous slope surrounding of urban region should be reflected in the social changes going on 14th century. Social confusion continues to demise of ancient order forced to take the regional social and economic integration and generated the new integrated villages that they interested to increasing food production by cultivation needed to large quantity of grass supplied from surrounding grass (bare) mountains. The classic landscape of raised bed rivers in Japan initiated from the mediaeval ages shows the history of interaction between environmental changes and ancient society.

  19. Effects of dam-induced landscape fragmentation on amazonian ant-plant mutualistic networks.

    PubMed

    Emer, Carine; Venticinque, Eduardo Martins; Fonseca, Carlos Roberto

    2013-08-01

    Mutualistic networks are critical to biological diversity maintenance; however, their structures and functionality may be threatened by a swiftly changing world. In the Amazon, the increasing number of dams poses a large threat to biological diversity because they greatly alter and fragment the surrounding landscape. Tight coevolutionary interactions typical of tropical forests, such as the ant-myrmecophyte mutualism, where the myrmecophyte plants provide domatia nesting space to their symbiotic ants, may be jeopardized by the landscape changes caused by dams. We analyzed 31 ant-myrmecophyte mutualistic networks in undisturbed and disturbed sites surrounding Balbina, the largest Central Amazonian dam. We tested how ant-myrmecophyte networks differ among dam-induced islands, lake edges, and undisturbed forests in terms of species richness, composition, structure, and robustness (number of species remaining in the network after partner extinctions). We also tested how landscape configuration in terms of area, isolation, shape, and neighborhood alters the structure of the ant-myrmecophyte networks on islands. Ant-myrmecophytic networks were highly compartmentalized in undisturbed forests, and the compartments had few strongly connected mutualistic partners. In contrast, networks at lake edges and on islands were not compartmentalized and were negatively affected by island area and isolation in terms of species richness, density, and composition. Habitat loss and fragmentation led to coextinction cascades that contributed to the elimination of entire ant-plant compartments. Furthermore, many myrmecophytic plants in disturbed sites lost their mutualistic ant partners or were colonized by opportunistic, nonspecialized ants. Robustness of ant-myrmecophyte networks on islands was lower than robustness near lake edges and in undisturbed forest and was particularly susceptible to the extinction of plants. Beyond the immediate habitat loss caused by the building of large dams

  20. The Ants Have It!

    ERIC Educational Resources Information Center

    Daugherty, Belinda

    2001-01-01

    Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)

  1. The Ants Have It!

    ERIC Educational Resources Information Center

    Daugherty, Belinda

    2001-01-01

    Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)

  2. Ant nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A new Hubble Space Telescope image of a celestial object called the Ant Nebula may shed new light on the future demise of our Sun. The image is available at http://www.jpl.nasa.gov/pictures/wfpc .

    The nebula, imaged on July 20, 1997, and June 30, 1998, by Hubble's Wide Field and Planetary Camera 2, was observed by Drs. Raghvendra Sahai and John Trauger of NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Bruce Balick of the University of Washington in Seattle; and Vincent Icke of Leiden University in the Netherlands. JPL designed and built the camera.

    The Ant Nebula, whose technical name is Mz3, resembles the head and thorax of an ant when observed with ground-based telescopes. The new Hubble image, with 10 times the resolution revealing 100 times more detail, shows the 'ant's' body as a pair of fiery lobes protruding from a dying, Sun- like star. The Ant Nebula is located between 3,000 and 6,000 light years from Earth in the southern constellation Norma.

    The image challenges old ideas about what happens to dying stars. This observation, along with other pictures of various remnants of dying stars called planetary nebulae, shows that our Sun's fate will probably be much more interesting, complex and dramatic than astronomers previously believed.

    Although the ejection of gas from the dying star in the Ant Nebula is violent, it does not show the chaos one might expect from an ordinary explosion, but instead shows symmetrical patterns. One possibility is that the central star has a closely orbiting companion whose gravitational tidal forces shape the outflowing gas. A second possibility is that as the dying star spins, its strong magnetic fields are wound up into complex shapes like spaghetti in an eggbeater. Electrically charged winds, much like those in our Sun's solar wind but millions of times denser and moving at speeds up to 1,000 kilometers per second (more than 600 miles per second) from the star, follow the twisted field lines on their way

  3. Ant nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A new Hubble Space Telescope image of a celestial object called the Ant Nebula may shed new light on the future demise of our Sun. The image is available at http://www.jpl.nasa.gov/pictures/wfpc .

    The nebula, imaged on July 20, 1997, and June 30, 1998, by Hubble's Wide Field and Planetary Camera 2, was observed by Drs. Raghvendra Sahai and John Trauger of NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Bruce Balick of the University of Washington in Seattle; and Vincent Icke of Leiden University in the Netherlands. JPL designed and built the camera.

    The Ant Nebula, whose technical name is Mz3, resembles the head and thorax of an ant when observed with ground-based telescopes. The new Hubble image, with 10 times the resolution revealing 100 times more detail, shows the 'ant's' body as a pair of fiery lobes protruding from a dying, Sun- like star. The Ant Nebula is located between 3,000 and 6,000 light years from Earth in the southern constellation Norma.

    The image challenges old ideas about what happens to dying stars. This observation, along with other pictures of various remnants of dying stars called planetary nebulae, shows that our Sun's fate will probably be much more interesting, complex and dramatic than astronomers previously believed.

    Although the ejection of gas from the dying star in the Ant Nebula is violent, it does not show the chaos one might expect from an ordinary explosion, but instead shows symmetrical patterns. One possibility is that the central star has a closely orbiting companion whose gravitational tidal forces shape the outflowing gas. A second possibility is that as the dying star spins, its strong magnetic fields are wound up into complex shapes like spaghetti in an eggbeater. Electrically charged winds, much like those in our Sun's solar wind but millions of times denser and moving at speeds up to 1,000 kilometers per second (more than 600 miles per second) from the star, follow the twisted field lines on their way

  4. [Interactions using the Internet among parents and pediatric societies in Spain and the Latin American Pediatric Association].

    PubMed

    Díaz Vázquez, C A; Mola Caballero de Rodas, P

    2004-07-01

    The Internet has revolutionized access to biomedical information among health professionals and the general public. There is demand for pediatric societies to develop quality contents directed at both pediatricians and parents. To evaluate interaction through the Internet among parents and the pediatric societies in Spain and member organizations of the Latin American Pediatric Association. All the official Spanish pediatric societies (n = 45) and the national organizations belonging to the Latin American Pediatric Association (25) were examined. Societies with their own websites (26 in Spain and 13 in Latin America) were identified. For each website, the following data were collected: size, access to contents, adherence to an ethical code, terms of use, division of contents for pediatricians and those for parents, and means of contact for parents. All the websites provided free access to biomedical information. Only 35 % of websites from Spain and 15.4 % of those from the Latin American Pediatric Association subscribed to an ethical code while 54 % and 84.6 % respectively had no terms of use section. Overall, 46 % had a specific area for parents. The most common means of contact between parents and websites was through electronic mail and 5 % of the sites explicitly accepted online consultations. Only six out of 39 websites fulfilled all the criteria evaluated. The presence of pediatric societies on the Internet is acceptable, without noteworthy differences between Spanish organizations and member organizations of the Latin American Pediatric Association. In general, interaction with parents is of poor quality.

  5. Microorganisms transported by ants induce changes in floral nectar composition of an ant-pollinated plant.

    PubMed

    de Vega, Clara; Herrera, Carlos M

    2013-04-01

    Interactions between plants and ants abound in nature and have significant consequences for ecosystem functioning. Recently, it has been suggested that nectar-foraging ants transport microorganisms to flowers; more specifically, they transport yeasts, which can potentially consume sugars and alter nectar composition. Therefore, ants could indirectly change nectar sugar profile, an important floral feature involved in the plant-pollinator mutualism. But this novel role for ants has never been tested. We here investigate the effects of nectarivorous ants and their associated yeasts on the floral nectar sugar composition of an ant-pollinated plant. Differences in the nectar sugar composition of ant-excluded and ant-visited flowers were examined in 278 samples by using high-performance liquid-chromatography. The importance of the genetic identity and density of ant-transported basidiomycetous and ascomycetous yeasts on the variation of nectar traits was also evaluated. Ant visitation had significant effects on nectar sugar composition. The nectar of ant-visited flowers contained significantly more fructose, more glucose, and less sucrose than the nectar of ant-excluded flowers, but these effects were context dependent. Nectar changes were correlated with the density of yeast cells in nectar. The magnitude of the effects of ant-transported ascomycetes was much higher than that of basiodiomycetes. Ants and their associated yeasts induce changes in nectar sugar traits, reducing the chemical control of the plant over this important floral trait. The potential relevance of this new role for ants as indirect nectar modifiers is a rich topic for future research into the ecology of ant-flower interactions.

  6. A multidisciplinary approach to understand interactions of red wood ants (Formica rufa-group) and geotectonic processes

    NASA Astrophysics Data System (ADS)

    Berberich, G. M.; Berberich, M. B.; Grumpe, A.; Becker, A.; Tejeda, A.; Simpson, H.; Obamwonyi, S.; Schumann, M.; Hartmann, J.; Wöhler, C.; Ellison, A. M.

    2016-12-01

    Red wood ants (RWA; Formica rufa-group) are biological indicators of seismically active, gas-permeable faults and nest most successfully atop of them. Exploratory testing of gases in and around RWA nests revealed that geochemical anomalies were absent from nearby, tectonically inactive, areas. Changes in activity patterns of RWA were correlated with regularly changing gas concentrations and tectonic events. Field work was done from March to September 2016 in the seismically active East Eifel Volcanic Field (western Germany) to investigate relationships at time scales of two weeks and, during one month, eight hours, respectively, between activity patterns of F. polyctena recorded and analyzed with an image-based monitoring system (AntCam); gas concentrations (CO2, He, Rn, H2S, CH4) in nests, soil, and nearby mineral springs; CH4 concentrations in nest gas to determine the origin (biogenic, geogenic) of d13CCH4; geophysical processes (seismic events, earth-tides); influences from space weather on Earth's magnetic field (e.g., Kp-index, hourly mean values of the magnetic variations); local weather and climatic conditions. We analyzed geochemical, geophysical, and biological data with spatiotemporal Bayesian statistics and principal component analysis to identify possible causes of associations among RWA activity, degassing, and earthquakes. We observed significantly increased He and Rn concentrations in mineral gas and moderate increases in nest gas after two low-magnitude earthquakes. We expect more unknown geo-bio-correlations following additional analysis on the acquired data. The combination of seismically active fault zones and biological activity in RWA nests may contribute significantly to greenhouse gas emissions and ongoing climatic change. Funded by VW Foundation-Initiative "Experiment!" (Az 91 140).

  7. Diversity and evolution of a trait mediating ant-plant interactions: insights from extrafloral nectaries in Senna (Leguminosae).

    PubMed

    Marazzi, Brigitte; Conti, Elena; Sanderson, Michael J; McMahon, Michelle M; Bronstein, Judith L

    2013-06-01

    Plants display a wide range of traits that allow them to use animals for vital tasks. To attract and reward aggressive ants that protect developing leaves and flowers from consumers, many plants bear extrafloral nectaries (EFNs). EFNs are exceptionally diverse in morphology and locations on a plant. In this study the evolution of EFN diversity is explored by focusing on the legume genus Senna, in which EFNs underwent remarkable morphological diversification and occur in over 80 % of the approx. 350 species. EFN diversity in location, morphology and plant ontogeny was characterized in wild and cultivated plants, using scanning electron microscopy and microtome sectioning. From these data EFN evolution was reconstructed in a phylogenetic framework comprising 83 Senna species. Two distinct kinds of EFNs exist in two unrelated clades within Senna. 'Individualized' EFNs (iEFNs), located on the compound leaves and sometimes at the base of pedicels, display a conspicuous, gland-like nectary structure, are highly diverse in shape and characterize the species-rich EFN clade. Previously overlooked 'non-individualized' EFNs (non-iEFNs) embedded within stipules, bracts, and sepals are cryptic and may represent a new synapomorphy for clade II. Leaves bear EFNs consistently throughout plant ontogeny. In one species, however, early seedlings develop iEFNs between the first pair of leaflets, but later leaves produce them at the leaf base. This ontogenetic shift reflects our inferred diversification history of iEFN location: ancestral leaves bore EFNs between the first pair of leaflets, while leaves derived from them bore EFNs either between multiple pairs of leaflets or at the leaf base. EFNs are more diverse than previously thought. EFN-bearing plant parts provide different opportunities for EFN presentation (i.e. location) and individualization (i.e. morphology), with implications for EFN morphological evolution, EFN-ant protective mutualisms and the evolutionary role of EFNs in

  8. Dynamics of an ant-ant Obligate Mutualism: Colony Growth, Density Dependence and Frequency Dependence

    USDA-ARS?s Scientific Manuscript database

    In insect societies, worker versus queen development (reproductive caste) is typically governed by environmental factors, but many Pogonomyrmex seed-harvester ants exhibit strict genetic caste determination, resulting in an obligate mutualism between two reproductively isolated lineages. Same-linea...

  9. Long-term dynamics emerging in floodplains and deltas from the interactions between hydrology and society in a changing climate

    NASA Astrophysics Data System (ADS)

    Di Baldassarre, Giuliano; Viglione, Alberto; Yan, Kun; Brandimarte, Luigia; Blöschl, Günter

    2014-05-01

    Economic losses and fatalities associated to flood events have increased dramatically over the past decades. This situation might worsen in the near future because of rapid urbanization of many floodplains and deltas, along with enhancement of flood water levels as a result of human interventions, climate variability or sea level rise. To explore future dynamics, we developed a novel approach, which takes into account the dynamic nature of flood risk by an explicit treatment of the interactions and feedbacks between the hydrological and social components of flood risk (i.e. probability of flooding, and potential adverse consequences). In particular, we developed a socio-hydrological model that allows considering how the frequency and magnitude of flooding shapes the evolution of societies, while, at the same time, dynamic societies shape the frequency and magnitude of flooding. We then use this model to simulate long-term dynamics of different types of societies under hydrological change, e.g. increasing flood frequency. Based on the study of long-term dynamics of different floodplains and deltas around the world (e.g. Netherlands, Bangladesh), we identify two main typologies of flood-shaped societies: i) techno-societies, which "fight floods", and typically deal with risk by building and strengthening flood protection structures, such as levees or dikes; and ii) green-societies, which "lives with floods", and mainly cope with risk via adaptation measures, such as resettling out of flood prone areas. The outcomes of this study are relevant for the management of deltas and floodplains as they allow a comparison of long-term dynamics between diverse types of societies in terms of robustness to hydrological change.

  10. Effect of Leader's Strategy on Opinion Formation in Networked Societies with Local Interactions

    NASA Astrophysics Data System (ADS)

    Sobkowicz, Pawel

    The work investigates the influence of leader on opinion formation in artificial networked societies. The strength of the social influence is assumed to be dictated by distance from one agent to another, as well as individual strengths of the agents. The leader is assumed to have much greater resources, which allows him to tune the way he influences the other agents. We study various strategies of using these resources to optimize the conditions needed to "convince" the whole society to leader's opinion. The flexibility of the model allows it to be used in studies of political, social and marketing activities and opinion formation.

  11. Extrafloral nectar fuels ant life in deserts.

    PubMed

    Aranda-Rickert, Adriana; Diez, Patricia; Marazzi, Brigitte

    2014-11-07

    Interactions mediated by extrafloral nectary (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal desert of northwestern Argentina, we surveyed the richness and phenology of EFN plants and their associated ants and examined the patterns in ant-plant interaction networks. We found that 25 ant species and 11 EFN-bearing plant species were linked together through 96 pairs of associations. Plants bearing EFNs were abundant, representing ca. 19 % of the species encountered in transects and 24 % of the plant cover. Most ant species sampled (ca. 77 %) fed on EF nectar. Interactions showed a marked seasonal pattern: EFN secretion was directly related to plant phenology and correlated with the time of highest ant ground activity. Our results reveal that EFN-mediated interactions are ecologically relevant components of deserts, and that EFN-bearing plants are crucial for the survival of desert ant communities. Published by Oxford University Press on behalf of the Annals of Botany Company.

  12. Reporting whole-body vibration intervention studies: recommendations of the International Society of Musculoskeletal and Neuronal Interactions.

    PubMed

    Rauch, F; Sievanen, H; Boonen, S; Cardinale, M; Degens, H; Felsenberg, D; Roth, J; Schoenau, E; Verschueren, S; Rittweger, J

    2010-09-01

    Whole-body vibration (WBV) is receiving increasing interest as a therapeutic modality to improve neuromuscular performance or to increase bone mass or density. In order to help improve the quality of reports about WBV treatment studies, the International Society of Musculoskeletal and Neuronal Interactions (ISMNI) invited experts in the field to provide suggestions on how the intervention should be described in such reports. The recommendations are presented here.

  13. A World of Ants.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1992-01-01

    Presents a discussion of interesting aspects of ants that was launched by the author's reading of "The Ants" by Holldobler and Wilson (1990). Describes how the study of the early history of ant taxonomy could be viewed as "entertaining." Their huge numbers and segregation into colonial social systems makes ants good research organisms. (PR)

  14. Performance of the Species-Typical Alarm Response in Young Workers of the Ant Myrmica sabuleti (Hymenoptera: Formicidae) Is Induced by Interactions with Mature Workers

    PubMed Central

    Cammaerts, Marie-Claire

    2014-01-01

    Young workers of the ant Myrmica sabuleti (Hymenoptera: Formicidae) Meinert 1861 perceived nestmate alarm pheromone but did not display normal alarm behavior (orientation toward the source of emission, increased running speed). They changed their initial behavior when in the presence of older nestmates exhibiting normal alarm behavior. Four days later, the young ants exhibited an imperfect version of normal alarm behavior. This change of behavior did not occur in young ants, which were not exposed to older ants reacting to alarm pheromone. Queen ants perceived the alarm pheromone and, after a few seconds, moved toward its source. Thus, the ants’ ability to sense the alarm pheromone and to identify it as an alarm signal is native, while the adult alarm reaction is acquired over time (= age based polyethism) by young ants. It is possible that the change in behavior observed in young ants could be initiated and/or enhanced (via experience-induced developmental plasticity, learning, and/or other mechanisms) by older ants exhibiting alarm behavior. PMID:25525102

  15. How to be an ant on figs

    NASA Astrophysics Data System (ADS)

    Bain, Anthony; Harrison, Rhett D.; Schatz, Bertrand

    2014-05-01

    Mutualistic interactions are open to exploitation by one or other of the partners and a diversity of other organisms, and hence are best understood as being embedded in a complex network of biotic interactions. Figs participate in an obligate mutualism in that figs are dependent on agaonid fig wasps for pollination and the wasps are dependent on fig ovules for brood sites. Ants are common insect predators and abundant in tropical forests. Ants have been recorded on approximately 11% of fig species, including all six subgenera, and often affect the fig-fig pollinator interaction through their predation of either pollinating and parasitic wasps. On monoecious figs, ants are often associated with hemipterans, whereas in dioecious figs ants predominantly prey on fig wasps. A few fig species are true myrmecophytes, with domatia or food rewards for ants, and in at least one species this is linked to predation of parasitic fig wasps. Ants also play a role in dispersal of fig seeds and may be particularly important for hemi-epiphytic species, which require high quality establishment microsites in the canopy. The intersection between the fig-fig pollinator and ant-plant systems promises to provide fertile ground for understanding mutualistic interactions within the context of complex interaction networks.

  16. Extrafloral nectar fuels ant life in deserts

    PubMed Central

    Aranda-Rickert, Adriana; Diez, Patricia; Marazzi, Brigitte

    2014-01-01

    Interactions mediated by extrafloral nectary (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal desert of northwestern Argentina, we surveyed the richness and phenology of EFN plants and their associated ants and examined the patterns in ant–plant interaction networks. We found that 25 ant species and 11 EFN-bearing plant species were linked together through 96 pairs of associations. Plants bearing EFNs were abundant, representing ca. 19 % of the species encountered in transects and 24 % of the plant cover. Most ant species sampled (ca. 77 %) fed on EF nectar. Interactions showed a marked seasonal pattern: EFN secretion was directly related to plant phenology and correlated with the time of highest ant ground activity. Our results reveal that EFN-mediated interactions are ecologically relevant components of deserts, and that EFN-bearing plants are crucial for the survival of desert ant communities. PMID:25381258

  17. How Ants Drop Out: Ant Abundance on Tropical Mountains

    PubMed Central

    Longino, John T.; Branstetter, Michael G.; Colwell, Robert K.

    2014-01-01

    In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica) and examined the impact of elevation (as a proxy for temperature) and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops. PMID:25098722

  18. Transdisciplinary science: a path to understanding the interactions among ocean acidification, ecosystems, and society

    USGS Publications Warehouse

    Yates, Kimberly K.; Turley, Carol; Hopkinson, Brian M.; Todgham, Anne E.; Cross, Jessica N.; Greening, Holly; Williamson, Phillip; Van Hooidonk, Ruben; Deheyn, Dimitri D.; Johnson, Zachary

    2015-01-01

    The global nature of ocean acidification (OA) transcends habitats, ecosystems, regions, and science disciplines. The scientific community recognizes that the biggest challenge in improving understanding of how changing OA conditions affect ecosystems, and associated consequences for human society, requires integration of experimental, observational, and modeling approaches from many disciplines over a wide range of temporal and spatial scales. Such transdisciplinary science is the next step in providing relevant, meaningful results and optimal guidance to policymakers and coastal managers. We discuss the challenges associated with integrating ocean acidification science across funding agencies, institutions, disciplines, topical areas, and regions, and the value of unifying science objectives and activities to deliver insights into local, regional, and global scale impacts. We identify guiding principles and strategies for developing transdisciplinary research in the ocean acidification science community.

  19. Differential Recruitment of Camponotus femoratus (Fabricius) Ants in Response to Ant Garden Herbivory.

    PubMed

    Vicente, R E; Dáttilo, W; Izzo, T J

    2014-12-01

    Although several studies have shown that ants can recognize chemical cues from their host plants in ant-plant systems, it is poorly demonstrated in ant gardens (AGs). In this interaction, ant species constantly interact with various epiphyte species. Therefore, it is possible to expect a convergence of chemical signals released by plants that could be acting to ensure that ants are able to recognize and defend epiphyte species frequently associated with AGs. In this study, it was hypothesized that ants recognize and differentiate among chemical stimuli released by AG epiphytes and non-AG epiphytes. We experimentally simulated leaf herbivore damage on three epiphyte species restricted to AGs and a locally abundant understory herb, Piper hispidum, in order to quantify the number of recruited Camponotus femoratus (Fabricius) defenders. When exposed to the AG epiphytes Peperomia macrostachya and Codonanthe uleana leaves, it was observed that the recruitment of C. femoratus workers was, on average, respectively 556% and 246% higher than control. However, the number of ants recruited by the AG epiphyte Markea longiflora or by the non-AG plant did not differ from paper pieces. This indicated that ants could discern between chemicals released by different plants, suggesting that ants can select better plants. These results can be explained by evolutionary process acting on both ants' capability in discerning plants' chemical compounds (innate attraction) or by ants' learning based on the epiphyte frequency in AGs (individual experience). To disentangle an innate behavior, a product of classical coevolutionary process, from an ant's learned behavior, is a complicated but important subject to understand in the evolution of ant-plant mutualisms.

  20. Dynamics of an ant-plant-pollinator model

    NASA Astrophysics Data System (ADS)

    Wang, Yuanshi; DeAngelis, Donald L.; Nathaniel Holland, J.

    2015-03-01

    In this paper, we consider plant-pollinator-ant systems in which plant-pollinator interaction and plant-ant interaction are both mutualistic, but there also exists interference of pollinators by ants. The plant-pollinator interaction can be described by a Beddington-DeAngelis formula, so we extend the formula to characterize plant-pollinator mutualisms, including the interference by ants, and form a plant-pollinator-ant model. Using dynamical systems theory, we show uniform persistence of the model. Moreover, we demonstrate conditions under which boundary equilibria are globally asymptotically stable. The dynamics exhibit mechanisms by which the three species could coexist when ants interfere with pollinators. We define a threshold in ant interference. When ant interference is strong, it can drive plant-pollinator mutualisms to extinction. Furthermore, if the ants depend on pollination mutualism for their persistence, then sufficiently strong ant interference could lead to their own extinction as well. Yet, when ant interference is weak, plant-ant and plant-pollinator mutualisms can promote the persistence of one another.

  1. ‘Bio-nano interactions: new tools, insights and impacts’: summary of the Royal Society discussion meeting

    PubMed Central

    Lynch, Iseult; Feitshans, Ilise L.; Kendall, Michaela

    2015-01-01

    Bio-nano interactions can be defined as the study of interactions between nanoscale entities and biological systems such as, but not limited to, peptides, proteins, lipids, DNA and other biomolecules, cells and cellular receptors and organisms including humans. Studying bio-nano interactions is particularly useful for understanding engineered materials that have at least one dimension in the nanoscale. Such materials may consist of discrete particles or nanostructured surfaces. Much of biology functions at the nanoscale; therefore, our ability to manipulate materials such that they are taken up at the nanoscale, and engage biological machinery in a designed and purposeful manner, opens new vistas for more efficient diagnostics, therapeutics (treatments) and tissue regeneration, so-called nanomedicine. Additionally, this ability of nanomaterials to interact with and be taken up by cells allows nanomaterials to be used as probes and tools to advance our understanding of cellular functioning. Yet, as a new technology, assessment of the safety of nanomaterials, and the applicability of existing regulatory frameworks for nanomaterials must be investigated in parallel with development of novel applications. The Royal Society meeting ‘Bio-nano interactions: new tools, insights and impacts' provided an important platform for open dialogue on the current state of knowledge on these issues, bringing together scientists, industry, regulatory and legal experts to concretize existing discourse in science law and policy. This paper summarizes these discussions and the insights that emerged. PMID:25533104

  2. Fire Ant Allergy

    MedlinePlus

    ... Serious Reaction For people with fire ant allergy, stings may cause a life-threatening reaction called anaphylaxis ( ... Fire ants bite with their jaws while they sting. This allows them to pull the stinger out, ...

  3. Variation in Extrafloral Nectary Productivity Influences the Ant Foraging

    PubMed Central

    2017-01-01

    Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system. PMID:28046069

  4. Variation in Extrafloral Nectary Productivity Influences the Ant Foraging.

    PubMed

    Lange, Denise; Calixto, Eduardo Soares; Del-Claro, Kleber

    2017-01-01

    Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system.

  5. Self-organized criticality in ant brood tending.

    PubMed

    O'Toole, D V; Robinson, P A; Myerscough, M R

    2003-03-07

    A new stochastic lattice gas model of ant brood tending is formulated to examine the role played by repulsive ant-ant interactions in the even distribution of care among brood members. The deterministic limit of the model is known to be self-organized critical. Numerical simulations of the model show that the ant-ant repulsion facilitates an even distribution of brood care in the middle of the brood. This provides a possible explanation for the fact that ants sort their brood so that the youngest brood (which are most in need of care) are placed in the middle. Simulations show that the uniformity of brood care distribution is optimal when ants operate in a regime intermediate between completely random and completely deterministic. A certain degree of randomness helps ants to avoid becoming trapped in suboptimal configurations but does not destroy the long-range correlations that are inherent to self-organized critical systems.

  6. Ant-plants and fungi: a new threeway symbiosis.

    PubMed

    Defossez, Emmanuel; Selosse, Marc-André; Dubois, Marie-Pierre; Mondolot, Laurence; Faccio, Antonella; Djieto-Lordon, Champlain; McKey, Doyle; Blatrix, Rumsaïs

    2009-06-01

    Symbioses between plants and fungi, fungi and ants, and ants and plants all play important roles in ecosystems. Symbioses involving all three partners appear to be rare. Here, we describe a novel tripartite symbiosis in which ants and a fungus inhabit domatia of an ant-plant, and present evidence that such interactions are widespread. We investigated 139 individuals of the African ant-plant Leonardoxa africana for occurrence of fungus. Behaviour of mutualist ants toward the fungus within domatia was observed using a video camera fitted with an endoscope. Fungi were identified by sequencing a fragment of their ribosomal DNA. Fungi were always present in domatia occupied by mutualist ants but never in domatia occupied by opportunistic or parasitic ants. Ants appear to favour the propagation, removal and maintenance of the fungus. Similar fungi were associated with other ant-plants in Cameroon. All belong to the ascomycete order Chaetothyriales; those from L. africana formed a monophyletic clade. These new plant-ant-fungus associations seem to be specific, as demonstrated within Leonardoxa and as suggested by fungal phyletic identities. Such tripartite associations are widespread in African ant-plants but have long been overlooked. Taking fungal partners into account will greatly enhance our understanding of symbiotic ant-plant mutualisms.

  7. Predatory birds and ants partition caterpillar prey by body size and diet breadth.

    PubMed

    Singer, Michael S; Clark, Robert E; Lichter-Marck, Issac H; Johnson, Emily R; Mooney, Kailen A

    2017-07-07

    The effects of predator assemblages on herbivores are predicted to depend critically on predator-predator interactions and the extent to which predators partition prey resources. The role of prey heterogeneity in generating such multiple predator effects has received limited attention. Vertebrate and arthropod insectivores constitute two co-dominant predatory taxa in many ecosystems, and the emergent properties of their joint effects on insect herbivores inform theory on multiple predator effects as well as biological control of insect herbivores. Here we use a large-scale factorial manipulation to assess the extent to which birds and ants engage in antagonistic predator-predator interactions and the consequences of heterogeneity in herbivore body size and diet breadth (i.e. the diversity of host plants used) for prey partitioning. We excluded birds and reduced ant density (by 60%) in the canopies of eight northeastern USA deciduous tree species during two consecutive years and measured the community composition and traits of lepidopteran larvae (caterpillars). Birds did not affect ant density, implying limited intraguild predation between these taxa in this system. Birds preyed selectively upon large-bodied caterpillars (reducing mean caterpillar length by 12%) and ants preyed selectively upon small-bodied caterpillars (increasing mean caterpillar length by 6%). Birds and ants also partitioned caterpillar prey by diet breadth. Birds reduced the frequency dietary generalist caterpillars by 24%, while ants had no effect. In contrast, ants reduced the frequency of dietary specialists by 20%, while birds had no effect, but these effects were non-additive; under bird exclusion, ants had no detectable effect, while in the presence of birds, they reduced the frequency of specialists by 40%. As a likely result of prey partitioning by body size and diet breadth, the combined effects of birds and ants on total caterpillar density were additive, with birds and ants reducing

  8. Uncovering the complexity of ant foraging trails.

    PubMed

    Czaczkes, Tomer J; Grüter, Christoph; Jones, Sam M; Ratnieks, Francis L W

    2012-01-01

    The common garden ant Lasius niger use both trail pheromones and memory of past visits to navigate to and from food sources. In a recent paper we demonstrated a synergistic effect between route memory and trail pheromones: the presence of trail pheromones results in experienced ants walking straighter and faster. We also found that experienced ants leaving a pheromone trail deposit less pheromone. Here we focus on another finding of the experiment: the presence of cuticular hydrocarbons (CHCs), which are used as home range markers by ants, also affects pheromone deposition behavior. When walking on a trail on which CHCs are present but trail pheromones are not, experienced foragers deposit less pheromone on the outward journey than on the return journey. The regulatory mechanisms ants use during foraging and recruitment behavior is subtle and complex, affected by multiple interacting factors such as route memory, travel direction and the presence trail pheromone and home-range markings.

  9. The genome of the fire ant Solenopsis invicta

    USDA-ARS?s Scientific Manuscript database

    Ants have evolved very complex societies and are key ecosystem members. Some of them are also major pests, as exemplified by the fire ant Solenopsis invicta. We present here the draft genome of S. invicta, assembled from 454 and Illumina reads obtained from a focal haploid male and his brothers. In ...

  10. Ant species confer different partner benefits on two neotropical myrmecophytes.

    PubMed

    Frederickson, Megan E

    2005-04-01

    The dynamics of mutualistic interactions involving more than a single pair of species depend on the relative costs and benefits of interaction among alternative partners. The neotropical myrmecophytes Cordia nodosa and Duroia hirsuta associate with several species of obligately symbiotic ants. I compared the ant partners of Cordia and Duroia with respect to two benefits known to be important in ant-myrmecophyte interactions: protection against herbivores provided by ants, and protection against encroaching vegetation provided by ants. Azteca spp., Myrmelachista schumanni, and Allomerus octoarticulatus demerarae ants all provide the leaves of Cordia and Duroia some protection against herbivores. However, Azteca and Allomerus provide more protection than does Myrmelachista to the leaves of their host plants. Although Allomerus protects the leaves of its hosts, plants occupied by Allomerus suffer more attacks by herbivores to their stems than do plants occupied by other ants. Relative to Azteca or Allomerus, Myrmelachista ants provide better protection against encroaching vegetation, increasing canopy openness over their host plants. These differences in benefits among the ant partners of Cordia and Duroia are reflected in the effect of each ant species on host plant size, growth rate, and reproduction. The results of this study show how mutualistic ant partners can differ with respect to both the magnitude and type of benefits they provide to the same species of myrmecophytic host.

  11. Moral foundations in an interacting neural networks society: A statistical mechanics analysis

    NASA Astrophysics Data System (ADS)

    Vicente, R.; Susemihl, A.; Jericó, J. P.; Caticha, N.

    2014-04-01

    The moral foundations theory supports that people, across cultures, tend to consider a small number of dimensions when classifying issues on a moral basis. The data also show that the statistics of weights attributed to each moral dimension is related to self-declared political affiliation, which in turn has been connected to cognitive learning styles by the recent literature in neuroscience and psychology. Inspired by these data, we propose a simple statistical mechanics model with interacting neural networks classifying vectors and learning from members of their social neighbourhood about their average opinion on a large set of issues. The purpose of learning is to reduce dissension among agents when disagreeing. We consider a family of learning algorithms parametrized by δ, that represents the importance given to corroborating (same sign) opinions. We define an order parameter that quantifies the diversity of opinions in a group with homogeneous learning style. Using Monte Carlo simulations and a mean field approximation we find the relation between the order parameter and the learning parameter δ at a temperature we associate with the importance of social influence in a given group. In concordance with data, groups that rely more strongly on corroborating evidence sustain less opinion diversity. We discuss predictions of the model and propose possible experimental tests.

  12. Mistrust of physicians in China: society, institution, and interaction as root causes.

    PubMed

    Chan, Cheris Shun-Ching

    2017-09-08

    Based on two years' ethnographic research on doctor-patient relations in urban China, this paper examines the causes of patients' mistrust of physicians. I identify the major factors at the societal, institutional, and interpersonal levels that lead to patients' mistrust of physicians. First, I set the context by describing the extent of mistrust at the societal level. Then, I investigate the institutional sources of mistrust. I argue that the financing mechanism of public hospitals and physicians' income structures are the most crucial factors in inducing patients' mistrust. Hospitals' heavy reliance on self-finance has basically caused public hospitals to run like private hospitals, resulting in blatant conflicts of interest between hospitals and patients. Related to this is physicians' reliance on bonuses and commissions as part of their regular incomes, which has inevitably resulted in overtreatment and, hence, mistrust from the patients. At the interpersonal level, I describe how individual physicians' attitudes toward and interaction with patients may also affect patients' sense of trust or mistrust in physicians. In conclusion, I discuss the ethical implications of the mistrust problem, and suggest changes at the institutional and interpersonal levels to mitigate the problem. © 2017 John Wiley & Sons Ltd.

  13. Mechanism of leaf-cutting ant colony suppression by fipronil used in attractive toxic baits.

    PubMed

    Gandra, Lailla C; Amaral, Karina D; Couceiro, Joel C; Della Lucia, Terezinha Mc; Guedes, Raul Nc

    2016-08-01

    Attractive toxic baits are the prevailing method for managing leaf-cutting ants in the eucalypt forests planted for the production of pulp, paper, timber and charcoal. For successful use in these baits, the insecticidal compounds need to circumvent the typical defences of the eusocial leaf-cutting ants. The challenge is to have an insecticide in the bait that will not directly harm and/or compromise foraging workers, but that will eventually suppress the colony. These underlying mechanisms are poorly known, and here the potential mechanism of fipronil activity in toxic baits for leaf-cutting ants was assessed using colonies of the representative Neotropical Acromyrmex subterraneus subterraneus (Forel, 1893). Although forager activity was not directly impaired by fipronil, the insecticide affected forager nestmate interactions (auto- and allogrooming) and waste removal and, more importantly, greatly affected the minor workers, impairing their activities of fungus garden cultivation and progeny handling. The fast decay of the fungus garden compromised the sustainability of the colonies, ultimately leading to their demise within 8 days. The behavioural effects of sublethal insecticide exposure towards minor workers are the main determinants of insecticide activity as ant baits and should be targeted in developing such compounds. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Biogenic amine levels, reproduction and social dominance in the queenless ant Streblognathus peetersi

    NASA Astrophysics Data System (ADS)

    Cuvillier-Hot, Virginie; Lenoir, Alain

    2006-03-01

    Social harmony often relies on ritualised dominance interactions between society members, particularly in queenless ant societies, where colony members do not have developmentally predetermined castes but have to fight for their status in the reproductive and work hierarchy. In this behavioural plasticity, their social organisation resembles more that of vertebrates than that of the “classic” social insects. The present study investigates the neurochemistry of the queenless ant species, Streblognathus peetersi, to better understand the neural basis of the high behavioural plasticity observed in queenless ants. We report measurements of brain biogenic amines [octopamine, dopamine, serotonin] of S. peetersi ants; they reveal a new set of biogenic amine influences on social organisation with no common features with other “primitively organised societies” (bumble bees) and some common features with “highly eusocial” species (honey bees). This similarity to honey bees may either confirm the heritage of queenless species from their probably highly eusocial ancestors or highlight independent patterns of biogenic amine influences on the social organisation of these highly derived species.

  15. Rationality in collective decision-making by ant colonies.

    PubMed

    Edwards, Susan C; Pratt, Stephen C

    2009-10-22

    Economic models of animal behaviour assume that decision-makers are rational, meaning that they assess options according to intrinsic fitness value and not by comparison with available alternatives. This expectation is frequently violated, but the significance of irrational behaviour remains controversial. One possibility is that irrationality arises from cognitive constraints that necessitate short cuts like comparative evaluation. If so, the study of whether and when irrationality occurs can illuminate cognitive mechanisms. We applied this logic in a novel setting: the collective decisions of insect societies. We tested for irrationality in colonies of Temnothorax ants choosing between two nest sites that varied in multiple attributes, such that neither site was clearly superior. In similar situations, individual animals show irrational changes in preference when a third relatively unattractive option is introduced. In contrast, we found no such effect in colonies. We suggest that immunity to irrationality in this case may result from the ants' decentralized decision mechanism. A colony's choice does not depend on site comparison by individuals, but instead self-organizes from the interactions of multiple ants, most of which are aware of only a single site. This strategy may filter out comparative effects, preventing systematic errors that would otherwise arise from the cognitive limitations of individuals.

  16. How citizen seismology is transforming rapid public earthquake information and interactions between seismologists and society

    NASA Astrophysics Data System (ADS)

    Bossu, Rémy; Steed, Robert; Mazet-Roux, Gilles; Roussel, Fréderic; Caroline, Etivant

    2015-04-01

    Historical earthquakes are only known to us through written recollections and so seismologists have a long experience of interpreting the reports of eyewitnesses, explaining probably why seismology has been a pioneer in crowdsourcing and citizen science. Today, Internet has been transforming this situation; It can be considered as the digital nervous system comprising of digital veins and intertwined sensors that capture the pulse of our planet in near real-time. How can both seismology and public could benefit from this new monitoring system? This paper will present the strategy implemented at Euro-Mediterranean Seismological Centre (EMSC) to leverage this new nervous system to detect and diagnose the impact of earthquakes within minutes rather than hours and how it transformed information systems and interactions with the public. We will show how social network monitoring and flashcrowds (massive website traffic increases on EMSC website) are used to automatically detect felt earthquakes before seismic detections, how damaged areas can me mapped through concomitant loss of Internet sessions (visitors being disconnected) and the benefit of collecting felt reports and geolocated pictures to further constrain rapid impact assessment of global earthquakes. We will also describe how public expectations within tens of seconds of ground shaking are at the basis of improved diversified information tools which integrate this user generated contents. A special attention will be given to LastQuake, the most complex and sophisticated Twitter QuakeBot, smartphone application and browser add-on, which deals with the only earthquakes that matter for the public: the felt and damaging earthquakes. In conclusion we will demonstrate that eyewitnesses are today real time earthquake sensors and active actors of rapid earthquake information.

  17. Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem.

    PubMed

    Stuble, Katharine L; Kirkman, L Katherine; Carroll, C Ronald; Sanders, Nathan J

    2011-06-01

    The degree to which changes in community composition mediate the probability of colonization and spread of non-native species is not well understood, especially in animal communities. High species richness may hinder the establishment of non-native species. Distinguishing between this scenario and cases in which non-native species become established in intact (lacking extensive anthropogenic soil disturbance) communities and subsequently diminish the abundance and richness of native species is challenging on the basis of observation alone. The red imported fire ant (Solenopsis invicta), an invasive species that occurs throughout much of the southeastern United States, is such an example. Rather than competitively displacing native species, fire ants may become established only in disturbed areas in which native species richness and abundance are already reduced. We used insecticide to reduce the abundance of native ants and fire ants in four experimental plots. We then observed the reassembly and reestablishment of the ants in these plots for 1 year after treatment. The abundance of fire ants in treated plots did not differ from abundance in control plots 1 year after treatment. Likewise, the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants and fire ants to disturbance can be comparable. ©2011 Society for Conservation Biology.

  18. Acoustic communication by ants

    NASA Astrophysics Data System (ADS)

    Hickling, Robert

    2002-05-01

    Many ant species communicate acoustically by stridulating, i.e., running a scraper over a washboard-like set of ridges. Ants appear to be insensitive to airborne sound. Consequently, myrmecologists have concluded that the stridulatory signals are transmitted through the substrate. This has tended to diminish the importance of acoustic communication, and it is currently believed that ant communication is based almost exclusively on pheromones, with acoustic communication assigned an almost nonexistent role. However, it can be shown that acoustic communication between ants is effective only if the medium is air and not the substrate. How, then, is it possible for ants to appear deaf to airborne sound and yet communicate through the air? An explanation is provided in a paper [R. Hickling and R. L. Brown, ``Analysis of acoustic communication by ants,'' J. Acoust. Soc. Am. 108, 1920-1929 (2000)]. Ants are small relative to the wavelengths they generate. Hence, they create a near field, which is characterized by a major increase in sound velocity (particle velocity of sound) in the vicinity of the source. Hair sensilla on the ants' antennae respond to sound velocity. Thus, ants are able to detect near-field sound from other ants and to exclude extraneous airborne sound.

  19. Honey Bees Avoiding Ant Harassment at Flowers Using Scent Cues.

    PubMed

    Sidhu, Sheena C; Wilson Rankin, Erin E

    2016-02-01

    Pollinators require resources throughout the year to maintain healthy populations. Along the urban-natural interface, floral resource availability may be limited especially when the system experiences extreme drought and fire threats. In such areas, succulents, such as Aloe spp., are commonly planted to serve as functional drought-tolerant, fire-protective landscaping, which can also support pollinator populations. However, access to this resource may be restricted by competition from other floral foragers, including invasive pests. We measured free-foraging honey bee (Apis mellifera L.) visitation rate and visitation duration to aloe flowers with and without Argentine ants (Linepithema humile (Mayr)) in a drought-stressed environment and found that bees actively avoided foraging on the ant-occupied flowers. To determine the mechanisms of avoidance, our subsequent experiments assessed visitation in the absence of ants and compared aloe flowers treated with ant pheromone to unmanipulated flowers lacking ant pheromone. Bees approached all flowers equally, but accepted flowers without ants at a higher rate than flowers with ants. Visitation duration also increased twofold on ant-excluded flowers, which suggests that Argentine ants may limit resource acquisition by bees. Honey bees similarly avoided flowers with Argentine ant pheromone and preferentially visited unmanipulated flowers at threefold higher rate. This study demonstrates that honey bees avoid foraging on floral resources with invasive Argentine ants and that bees use ant odors to avoid ant-occupied flowers. Resource limitation by this invasive pest ant may have serious implication for sustaining healthy pollinator populations at the urban-natural interface. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Exploring with PAM: Prospecting ANTS Missions for Solar System Surveys

    NASA Technical Reports Server (NTRS)

    Clark, P. E.; Rilee, M. L.; Curtis, S. A.

    2003-01-01

    ANTS (Autonomous Nano-Technology Swarm), a large (1000 member) swarm of nano to picoclass (10 to 1 kg) totally autonomous spacecraft, are being developed as a NASA advanced mission concept. ANTS, based on a hierarchical insect social order, use an evolvable, self-similar, hierarchical neural system in which individual spacecraft represent the highest level nodes. ANTS uses swarm intelligence attained through collective, cooperative interactions of the nodes at all levels of the system. At the highest levels this can take the form of cooperative, collective behavior among the individual spacecraft in a very large constellation. The ANTS neural architecture is designed for totally autonomous operation of complex systems including spacecraft constellations. The ANTS (Autonomous Nano Technology Swarm) concept has a number of possible applications. A version of ANTS designed for surveying and determining the resource potential of the asteroid belt, called PAM (Prospecting ANTS Mission), is examined here.

  1. Exploring with PAM: Prospecting ANTS Missions for Solar System Surveys

    NASA Technical Reports Server (NTRS)

    Clark, P. E.; Rilee, M. L.; Curtis, S. A.

    2003-01-01

    ANTS (Autonomous Nano-Technology Swarm), a large (1000 member) swarm of nano to picoclass (10 to 1 kg) totally autonomous spacecraft, are being developed as a NASA advanced mission concept. ANTS, based on a hierarchical insect social order, use an evolvable, self-similar, hierarchical neural system in which individual spacecraft represent the highest level nodes. ANTS uses swarm intelligence attained through collective, cooperative interactions of the nodes at all levels of the system. At the highest levels this can take the form of cooperative, collective behavior among the individual spacecraft in a very large constellation. The ANTS neural architecture is designed for totally autonomous operation of complex systems including spacecraft constellations. The ANTS (Autonomous Nano Technology Swarm) concept has a number of possible applications. A version of ANTS designed for surveying and determining the resource potential of the asteroid belt, called PAM (Prospecting ANTS Mission), is examined here.

  2. Effects of Solenopsis invicta (Hymenoptera: Formicidae) and Its Interaction With Aphids on the Seed Productions of Mungbean and Rapeseed Plants.

    PubMed

    Wu, Duan; Zeng, Ling; Lu, Yongyue; Xu, Yijuan

    2014-10-01

    Although many reports suggested the economic importance of the red imported fire ant, Solenopsis invicta Buren, few attempts to test the hypothesis that the red imported fire ant-aphid mutualism enhances the occurrence of red imported fire ant on crops, thereby interfering with their flowering and fruiting and affecting their output. To address this problem, we compare the effects of red imported fire ant on the flowering and fruiting of self-pollinating and cross-pollinating crops by field investigations and indoor experiments. In the field, our results revealed that regardless of the aphid interaction, red imported fire ant preferred flowering mungbean plants, and their activities decreased the yields of single plants, total pod number, kernel number, and kernel weight. The interaction of red imported fire ant and aphids generated unfavorable effects on rapeseed yields per plant, total pod number, grain number, grain weight, and thousand-kernel weight and stimulated an elevated proportion of malformed seeds. However, the differences were not significant if only red imported fire ant was present. In the laboratory, although red imported fire ant display no apparent preference toward the seedlings of mungbean or rapeseed, the ants clearly favor the flowering plants of mungbeans. Therefore, this study indicated that one of the main mechanisms whereby red imported fire ants affect the crop yield is by compromising the reproduction processes. © 2014 Entomological Society of America.

  3. Ants in Space

    NASA Image and Video Library

    2014-01-12

    ISS038-E-029065 (12 Jan. 2014) --- In the International Space Station's Destiny laboratory, NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, uses a video camera to photograph the Ant Forage Habitat Facility which will study ant behavior and colonization in microgravity.

  4. Ants in Space

    NASA Image and Video Library

    2014-01-13

    ISS038-E-029133 (12 Jan. 2014) --- The Ant Forage Habitat Facility is featured in this image photographed by an Expedition 38 crew member on the International Space Station. The study examines the behavior of ants by comparing groups living on Earth to those in space.

  5. Ants in Space

    NASA Image and Video Library

    2014-01-12

    ISS038-E-029059 (12 Jan. 2014) --- In the International Space Station's Destiny laboratory, NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, uses a video camera to photograph the Ant Forage Habitat Facility which will study ant behavior and colonization in microgravity.

  6. Ants in Space

    NASA Image and Video Library

    2014-01-12

    ISS038-E-029077 (12 Jan. 2014) --- In the International Space Station's Harmony node, NASA astronaut Mike Hopkins, Expedition 38 flight engineer, uses a video camera to photograph the Ant Forage Habitat Facility which will study ant behavior and colonization in microgravity.

  7. Ants in Space

    NASA Image and Video Library

    2014-01-13

    ISS038-E-029106 (12 Jan. 2014) --- The Ant Forage Habitat Facility is featured in this image photographed by an Expedition 38 crew member on the International Space Station. The study examines the behavior of ants by comparing groups living on Earth to those in space.

  8. Ants in Space

    NASA Image and Video Library

    2014-01-12

    ISS038-E-029062 (12 Jan. 2014) --- In the International Space Station's Destiny laboratory, NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, uses a video camera to photograph the Ant Forage Habitat Facility which will study ant behavior and colonization in microgravity.

  9. Ants in Space

    NASA Image and Video Library

    2014-01-14

    ISS038-E-029161 (12 Jan. 2014) --- The Ant Forage Habitat Facility is featured in this image photographed by an Expedition 38 crew member on the International Space Station. The study examines the behavior of ants by comparing groups living on Earth to those in space.

  10. Dead ant walking: a myrmecophilous beetle predator uses parasitoid host location cues to selectively prey on parasitized ants

    PubMed Central

    2016-01-01

    Myrmecophiles (i.e. organisms that associate with ants) use a variety of ecological niches and employ different strategies to survive encounters with ants. Because ants are typically excellent defenders, myrmecophiles may choose moments of weakness to take advantage of their ant associates. This hypothesis was studied in the rove beetle, Myrmedonota xipe, which associates with Azteca sericeasur ants in the presence of parasitoid flies. A combination of laboratory and field experiments show that M. xipe beetles selectively locate and prey upon parasitized ants. These parasitized ants are less aggressive towards beetles than healthy ants, allowing beetles to eat the parasitized ants alive without interruption. Moreover, behavioural assays and chemical analysis reveal that M. xipe are attracted to the ant's alarm pheromone, the same secretion used by the phorid fly parasitoids in host location. This strategy allows beetles access to an abundant but otherwise inaccessible resource, as A. sericeasur ants are typically highly aggressive. These results are the first, to our knowledge, to demonstrate a predator sharing cues with a parasitoid to gain access to an otherwise unavailable prey item. Furthermore, this work highlights the importance of studying ant–myrmecophile interactions beyond just their pairwise context. PMID:27512148

  11. Friend or foe? A behavioral and stable isotopic investigation of an ant-plant symbiosis.

    PubMed

    Tillberg, Chadwick V

    2004-08-01

    In ant-plant symbioses, the behavior of ant inhabitants affects the nature of the interaction, ranging from mutualism to parasitism. Mutualistic species confer a benefit to the plant, while parasites reap the benefits of the interaction without reciprocating, potentially resulting in a negative impact on the host plant. Using the ant-plant symbiosis between Cordia alliodora and its ant inhabitants as a model system, I examine the costs and benefits of habitation by the four most common ant inhabitants at La Selva Biological Station, Costa Rica. Costs are measured by counting coccoids associated with each ant species. Benefits include patrolling behavior, effectiveness at locating resources, and recruitment response. I also compare the diets of the four ant species using stable isotope analysis of nitrogen (N) and carbon (C). Ants varied in their rates of association with coccoids, performance of beneficial behaviors, and diet. These differences in cost, benefit, and diet among the ant species suggest differences in the nature of the symbiotic relationship between C. alliodora and its ants. Two of the ant species behave in a mutualistic manner, while the other two ant species appear to be parasites of the mutualism. I determined that the mutualistic ants feed at a higher trophic level than the parasitic ants. Behavioral and dietary evidence indicate the protective role of the mutualists, and suggest that the parasitic ants do not protect the plant by consuming herbivores.

  12. Bioturbation by Fire Ants in the Coastal Prairie of Texas

    NASA Astrophysics Data System (ADS)

    Cameron, G.; Williams, L.

    2001-12-01

    Fire ants (Solenopsis invicta) were introduced to the US in the early part of the last century. They have spread throughout the southeastern US in the absence of native competitors and predators with a range limited by abiotic factors. Each fire ant mound contains thousands of individuals, can be large, and can be numerous enough to comprise a dominant feature of the landscape. Studies of this species have focused upon its spread, formation of single- and multiple-queen colonies, genetic structure, and impact on native fauna and human health. Some studies have analyzed native fire ant-soil interactions, but few studies have examined the process of bioturbation by introduced fire ants in native ecosystems. Fire ants on the coastal prairie of Texas primarily are of the multiple-queen type that exhibit a much higher density of mounds than the single-queen type. Consequently, mound-building activities by fire ants can have a marked effect upon soil structure and nutrient content and may affect soil organisms and plants. Fire ant activity, mound density, mound dispersion, soil texture, soil permeability, soil moisture content, and soil nutrients were measured. Fire ants mounds are visible aboveground from April-November. Density of mounds was 117-738/ha, and average mound lifespan was 3.6 months with only 9% of the mounds remaining active throughout the entire season. Mounds were dispersed randomly. Foraging activity by fire ants was from June through October with a peak in July. Annual soil turnover was estimated by collecting and weighing mounds. There was no effect of ant mounds on soil texture, but water infiltration was higher in areas with ant mounds. Early-season samples showed no nutrient differences, but late-season samples showed that ant mounds contained higher amounts of micronutrients than random samples of soil. These data are compared to similar data on effects of mounds from native ants and from native and introduced ants in different habitats.

  13. Size matters: nest colonization patterns for twig-nesting ants

    PubMed Central

    Jiménez-Soto, Estelí; Philpott, Stacy M

    2015-01-01

    Understanding the drivers of ant diversity and co-occurrence in agroecosystems is fundamental because ants participate in interactions that influence agroecosystem processes. Multiple local and regional factors influence ant community assembly. We examined local factors that influence the structure of a twig-nesting ant community in a coffee system in Mexico using an experimental approach. We investigated whether twig characteristics (nest entrance size and diversity of nest entrance sizes) and nest strata (canopy shade tree or coffee shrub) affected occupation, species richness, and community composition of twig-nesting ants and whether frequency of occupation of ant species varied with particular nest entrance sizes or strata. We conducted our study in a shaded coffee farm in Chiapas, Mexico, between March and June 2012. We studied ant nest colonization by placing artificial nests (bamboo twigs) on coffee shrubs and shade trees either in diverse or uniform treatments. We also examined whether differences in vegetation (no. of trees, canopy cover and coffee density) influenced nest colonization. We found 33 ant species occupying 73% of nests placed. Nest colonization did not differ with nest strata or size. Mean species richness of colonizing ants was significantly higher in the diverse nest size entrance treatment, but did not differ with nest strata. Community composition differed between strata and also between the diverse and uniform size treatments on coffee shrubs, but not on shade trees. Some individual ant species were more frequently found in certain nest strata and in nests with certain entrance sizes. Our results indicate that twig-nesting ants are nest-site limited, quickly occupy artificial nests of many sizes, and that trees or shrubs with twigs of a diversity of entrance sizes likely support higher ant species richness. Further, individual ant species more frequently occupy nests with different sized entrances promoting ant richness on individual

  14. Density-dependent benefits in ant-hemipteran mutualism? The case of the ghost ant Tapinoma melanocephalum (Hymenoptera: Formicidae) and the invasive mealybug Phenacoccus solenopsis (Hemiptera: Pseudococcidae).

    PubMed

    Zhou, Aiming; Kuang, Beiqing; Gao, Yingrui; Liang, Guangwen

    2015-01-01

    Although density-dependent benefits to hemipterans from ant tending have been measured many times, few studies have focused on integrated effects such as interactions between ant tending, natural enemy density, and hemipteran density. In this study, we tested whether the invasive mealybug Phenacoccus solenopsis is affected by tending by ghost ants (Tapinoma melanocephalum), the presence of parasitoids, mealybug density, parasitoid density and interactions among these factors. Our results showed that mealybug colony growth rate and percentage parasitism were significantly affected by ant tending, parasitoid presence, and initial mealybug density separately. However, there were no interactions among the independent factors. There were also no significant interactions between ant tending and parasitoid density on either mealybug colony growth rate or percentage parasitism. Mealybug colony growth rate showed a negative linear relationship with initial mealybug density but a positive linear relationship with the level of ant tending. These results suggest that benefits to mealybugs are density-independent and are affected by ant tending level.

  15. Transgenerational effects and the cost of ant tending in aphids.

    PubMed

    Tegelaar, Karolina; Glinwood, Robert; Pettersson, Jan; Leimar, Olof

    2013-11-01

    In mutualistic interactions, partners obtain a net benefit, but there may also be costs associated with the provision of benefits for a partner. The question of whether aphids suffer such costs when attended by ants has been raised in previous work. Transgenerational effects, where offspring phenotypes are adjusted based on maternal influences, could be important in the mutualistic interaction between aphids and ants, in particular because aphids have telescoping generations where two offspring generations can be present in a mature aphid. We investigated the immediate and transgenerational influence of ant tending on aphid life history and reproduction by observing the interaction between the facultative myrmecophile Aphis fabae and the ant Lasius niger over 13 aphid generations in the laboratory. We found that the effect of ant tending changes dynamically over successive aphid generations after the start of tending. Initially, total aphid colony weight, aphid adult weight and aphid embryo size decreased compared with untended aphids, consistent with a cost of ant association, but these differences disappeared within four generations of interaction. We conclude that transgenerational effects are important in the aphid-ant interactions and that the costs for aphids of being tended by ants can vary over generations.

  16. Ecology of a fig ant-plant

    NASA Astrophysics Data System (ADS)

    Harrison, Rhett D.

    2014-05-01

    Mutualistic interactions are embedded in networks of interactions that affect the benefits accruing to the mutualistic partners. Figs and their pollinating wasps are engaged in an obligate mutualism in which the fig is dependent on the fig pollinator for pollination services and the pollinator is dependent on fig ovules for brood sites. This mutualism is exploited by non-pollinating fig wasps that utilise the same ovules, but do not provide a pollination service. Most non-pollinating wasps oviposit from outside the inflorescence (syconium), where they are vulnerable to ant predation. Ficus schwarzii is exposed to high densities of non-pollinating wasps, but Philidris sp. ants patrolling the syconia prevent them from ovipositing. Philidris rarely catch wasps, but the fig encourages the patrolling by providing a reward through extra-floral nectaries on the surface of syconia. Moreover, the reward is apparently only produced during the phase when parasitoids are ovipositing. An ant-exclusion experiment demonstrated that, in the absence of ants, syconia were heavily attacked and many aborted as a consequence. Philidris was normally rare on the figs during the receptive phase or at the time of day when wasp offspring are emerging, so predation on pollinators was limited. However, Myrmicaria sp. ants, which only occurred on three trees, preyed substantially on pollinating as well as non-pollinating wasps. F. schwarzii occurs in small clusters of trees and has an exceptionally rapid crop turnover. These factors appear to promote high densities of non-pollinating wasps and, as a consequence, may have led to both a high incidence of ants on trees and increased selective pressure on fig traits that increase the payoffs of the fig-ant interaction for the fig. The fig receives no direct benefit from the reward it provides, but protects pollinating wasps that will disperse its pollen.

  17. Lycaenid Caterpillar Secretions Manipulate Attendant Ant Behavior.

    PubMed

    Hojo, Masaru K; Pierce, Naomi E; Tsuji, Kazuki

    2015-08-31

    Mutualistic interactions typically involve the exchange of different commodities between species. Nutritious secretions are produced by a number of insects and plants in exchange for services such as defense. These rewards are valuable metabolically and can be used to reinforce the behavior of symbiotic partners that can learn and remember them effectively. We show here novel effects of insect exocrine secretions produced by caterpillars in modulating the behavior of attendant ants in the food-for-defense interaction between lycaenid butterflies and ants. Reward secretions from the dorsal nectary organ (DNO) of Narathura japonica caterpillars function to reduce the locomotory activities of their attendant ants, Pristomyrmex punctatus workers. Moreover, workers that feed from caterpillar secretions are significantly more likely to show aggressive responses to eversion of the tentacle organs of the caterpillars. Analysis of the neurogenic amines in the brains of workers that consumed caterpillar secretions showed a significant decrease in levels of dopamine compared with controls. Experimental treatments in which reserpine, a known inhibitor of dopamine in Drosophila, was fed to workers similarly reduced their locomotory activity. We conclude that DNO secretions of lycaenid caterpillars can manipulate attendant ant behavior by altering dopaminergic regulation and increasing partner fidelity. Unless manipulated ants also receive a net nutritional benefit from DNO secretions, this suggests that similar reward-for-defense interactions that have been traditionally considered to be mutualisms may in fact be parasitic in nature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Congestion and communication in confined ant traffic

    NASA Astrophysics Data System (ADS)

    Gravish, Nick; Gold, Gregory; Zangwill, Andrew; Goodisman, Michael A. D.; Goldman, Daniel I.

    2014-03-01

    Many social animals move and communicate within confined spaces. In subterranean fire ants Solenopsis invicta, mobility within crowded nest tunnels is important for resource and information transport. Within confined tunnels, communication and traffic flow are at odds: trafficking ants communicate through tactile interactions while stopped, yet ants that stop to communicate impose physical obstacles on the traffic. We monitor the bi-directional flow of fire ant workers in laboratory tunnels of varied diameter D. The persistence time of communicating ant aggregations, τ, increases approximately linearly with the number of participating ants, n. The sensitivity of traffic flow increases as D decreases and diverges at a minimum diameter, Dc. A cellular automata model incorporating minimal traffic features--excluded volume and communication duration--reproduces features of the experiment. From the model we identify a competition between information transfer and the need to maintain jam-free traffic flow. We show that by balancing information transfer and traffic flow demands, an optimum group strategy exists which maximizes information throughput. We acknowledge funding from NSF PoLS #0957659 and #PHY-1205878.

  19. Entangled active matter: From cells to ants

    NASA Astrophysics Data System (ADS)

    Hu, D. L.; Phonekeo, S.; Altshuler, E.; Brochard-Wyart, F.

    2016-07-01

    Both cells and ants belong to the broad field of active matter, a novel class of non-equilibrium materials composed of many interacting units that individually consume energy and collectively generate motion or mechanical stresses. However cells and ants differ from fish and birds in that they can support static loads. This is because cells and ants can be entangled, so that individual units are bound by transient links. Entanglement gives cells and ants a set of remarkable properties usually not found together, such as the ability to flow like a fluid, spring back like an elastic solid, and self-heal. In this review, we present the biology, mechanics and dynamics of both entangled cells and ants. We apply concepts from soft matter physics and wetting to characterize these systems as well as to point out their differences, which arise from their differences in size. We hope that our viewpoints will spur further investigations into cells and ants as active materials, and inspire the fabrication of synthetic active matter.

  20. Field techniques for sampling ants

    USDA-ARS?s Scientific Manuscript database

    Ants occur in most environments and ecologists ask a diverse array of questions involving ants. Thus, a key consideration in ant studies is to match the environment and question (and associated environmental variables) to the ant sampling technique. Since each technique has distinct limitations, usi...

  1. The effect of disturbance on an ant-plant mutualism.

    PubMed

    Piovia-Scott, Jonah

    2011-06-01

    Protective ant-plant mutualisms-where plants provide food or shelter to ants and ants protect the plants from herbivores-are a common feature in many ecological communities, but few studies have examined the effect of disturbance on these interactions. Disturbance may affect the relationship between plants and their associated ant mutualists by increasing the plants' susceptibility to herbivores, changing the amount of reward provided for the ants, and altering the abundance of ants and other predators. Pruning was used to simulate the damage to buttonwood mangrove (Conocarpus erectus) caused by hurricanes. Pruned plants grew faster than unpruned plants, produced lower levels of physical anti-herbivore defenses (trichomes, toughness), and higher levels of chemical defenses (tannins) and extrafloral nectaries. Thus, simulated hurricane damage increased plant growth and the amount of reward provided to ant mutualists, but did not have consistent effects on other anti-herbivore defenses. Both herbivores and ants increased in abundance on pruned plants, indicating that the effects of simulated hurricane damage on plant traits were propagated to higher trophic levels. Ant-exclusion led to higher leaf damage on both pruned and upruned plants. The effect of ant-exclusion did not differ between pruned and unpruned plants, despite the fact that pruned plants had higher ant and herbivore densities, produced more extrafloral nectaries, and had fewer physical defenses. Another common predator, clubionid spiders, increased in abundance on pruned plants from which ants had been excluded. I suggest that compensatory predation by these spiders diminished the effect of ant-exclusion on pruned plants.

  2. Wolbachia transmission dynamics in Formica wood ants

    PubMed Central

    2008-01-01

    the ants were infected irrespective of the family structure of their societies gives no support to the proposed hypotheses that the spreading of Wolbachia in ants might be associated to the types of their societies. PMID:18291041

  3. Long-term persistence of a neotropical ant-plant population in the absence of obligate plant-ants.

    PubMed

    Moraes, Sinara C; Vasconcelos, Heraldo L

    2009-09-01

    Interactions between ants and ant-plants are considered classic examples of obligate mutualisms. Previous studies have indicated that for many ant-plants the loss of ant colonies results in severe defoliation or mortality. Although individual plants can persist for some period of time without their mutualistic partners, to date populations of ant-free plants have only been recorded at high altitudes or on remote islands where herbivores are also scarce. We studied the interaction between ants, herbivores, and the ant-plant Tococa guianensis in the Cerrado region of central Brazil. Using a survey conducted across a large geographic region, we show that there is interpopulation variation in ant occupancy across sites and habitats. At most sites surveyed, plants were inhabited by Allomerus octoarticulatus, an obligate plant-ant. Plants with obligate ants had significantly lower standing levels of herbivore damage than plants with opportunistic ants and plants with no ant occupants. Furthermore, experimental removal of A. octoarticulatus resulted in increased levels of damage in both young and mature leaves. Despite the protection provided by obligate ants, populations of T. guianensis were found to persist without these ants in some areas. Plants without A. octoarticulatus had significantly greater leaf toughness and trichome density than those with A. octoarticulatus. Furthermore, trichome density in plants with A. octoarticulatus increased after ants were removed, probably as a response induced by increased levels of herbivore damage. To our knowledge, this is the first record of the occurrence of native myrmecophyte populations without their mutualistic ants in mainland low-elevation sites. Several factors may help to explain the long-term persistence of T. guianensis populations without plant-ants in some areas of the Brazilian Cerrado, including its potential for induced morphological defenses against insect herbivores and selection for increased levels of

  4. Ants and ant scent reduce bumblebee pollination of artificial flowers.

    PubMed

    Cembrowski, Adam R; Tan, Marcus G; Thomson, James D; Frederickson, Megan E

    2014-01-01

    Ants on flowers can disrupt pollination by consuming rewards or harassing pollinators, but it is difficult to disentangle the effects of these exploitative and interference forms of competition on pollinator behavior. Using highly rewarding and quickly replenishing artificial flowers that simulate male or female function, we allowed bumblebees (Bombus impatiens) to forage (1) on flowers with or without ants (Myrmica rubra) and (2) on flowers with or without ant scent cues. Bumblebees transferred significantly more pollen analogue both to and from ant-free flowers, demonstrating that interference competition with ants is sufficient to modify pollinator foraging behavior. Bees also removed significantly less pollen analogue from ant-scented flowers than from controls, making this the first study to show that bees can use ant scent to avoid harassment at flowers. Ant effects on pollinator behavior, possibly in addition to their effects on pollen viability, may contribute to the evolution of floral traits minimizing ant visitation.

  5. Rationality in collective decision-making by ant colonies

    PubMed Central

    Edwards, Susan C.; Pratt, Stephen C.

    2009-01-01

    Economic models of animal behaviour assume that decision-makers are rational, meaning that they assess options according to intrinsic fitness value and not by comparison with available alternatives. This expectation is frequently violated, but the significance of irrational behaviour remains controversial. One possibility is that irrationality arises from cognitive constraints that necessitate short cuts like comparative evaluation. If so, the study of whether and when irrationality occurs can illuminate cognitive mechanisms. We applied this logic in a novel setting: the collective decisions of insect societies. We tested for irrationality in colonies of Temnothorax ants choosing between two nest sites that varied in multiple attributes, such that neither site was clearly superior. In similar situations, individual animals show irrational changes in preference when a third relatively unattractive option is introduced. In contrast, we found no such effect in colonies. We suggest that immunity to irrationality in this case may result from the ants’ decentralized decision mechanism. A colony's choice does not depend on site comparison by individuals, but instead self-organizes from the interactions of multiple ants, most of which are aware of only a single site. This strategy may filter out comparative effects, preventing systematic errors that would otherwise arise from the cognitive limitations of individuals. PMID:19625319

  6. Resource redistribution in polydomous ant nest networks: local or global?

    PubMed Central

    Franks, Daniel W.; Robinson, Elva J.H.

    2014-01-01

    An important problem facing organisms in a heterogeneous environment is how to redistribute resources to where they are required. This is particularly complex in social insect societies as resources have to be moved both from the environment into the nest and between individuals within the nest. Polydomous ant colonies are split between multiple spatially separated, but socially connected, nests. Whether, and how, resources are redistributed between nests in polydomous colonies is unknown. We analyzed the nest networks of the facultatively polydomous wood ant Formica lugubris. Our results indicate that resource redistribution in polydomous F. lugubris colonies is organized at the local level between neighboring nests and not at the colony level. We found that internest trails connecting nests that differed more in their amount of foraging were stronger than trails between nests with more equal foraging activity. This indicates that resources are being exchanged directly from nests with a foraging excess to nests that require resources. In contrast, we found no significant relationships between nest properties, such as size and amount of foraging, and network measures such as centrality and connectedness. This indicates an absence of a colony-level resource exchange. This is a clear example of a complex behavior emerging as a result of local interactions between parts of a system. PMID:25214755

  7. Social coercion of larval development in an ant species

    NASA Astrophysics Data System (ADS)

    Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

    2016-04-01

    Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

  8. Marking individual ants for behavioral sampling in a laboratory colony.

    PubMed

    Holbrook, C Tate

    2009-07-01

    Ant societies are tractable and malleable, two features that make them ideal models for probing the organization of complex biological systems. The ability to identify specific individuals while they function as part of a colony permits an integrative analysis of social complexity, including self-organizational processes (i.e., how individual-level properties and social interactions give rise to emergent, colony-level attributes such as division of labor and collective decision making). Effects of genotype, nutrition, and physiology on individual behavior and the organization of work also can be investigated in this manner, through correlative and manipulative approaches. Moreover, aspects of colony demography (e.g., colony size, and age and size distributions of workers) can be altered experimentally to examine colony development and regulatory mechanisms underlying colony homeostasis and resiliency. This protocol describes how to sample the behavior of ants living in a colony under laboratory conditions. Specifically, it outlines how to identify and observe individuals within a colony, an approach that can be used to quantify individual- and colony-level patterns of behavior. When a lower-resolution measure of overall group behavior is desired, individual identities might not be required. Given the diversity of ants and their study, this protocol provides a very general methodology; the details can be modified according to the body size, colony size, and ecology of the focal species, as well as to specific research aims. These basic techniques can also be extended to more advanced experimental designs such as manipulation of colony demography and hormone treatment.

  9. Drowning out the protection racket: partner manipulation or drought can strengthen ant-plant mutualism.

    PubMed

    Denison, R Ford

    2014-07-01

    Two recent reports discuss interactions between plants and ants that defend them from herbivores. Acacia trees provide their ant bodyguards with a diet that reduces their ability to benefit from alternate hosts. Provisioning of ants by Cordia trees during drought may buy insurance against extreme defoliation events, not just average-year benefits. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Cultural Development through the Interaction between Education, the Community, and Society at Large. Contributions of Education to Cultural Development.

    ERIC Educational Resources Information Center

    Engstrom, K.

    Museums play an important role in the transmission of culture and traditions and provide a collective memory of a community. A number of museum related institutions, known as the Science Centra, have arisen to offer self-directed learning activities in problem solving and understanding the processes related to everyday life. In a modern society,…

  11. Ant behaviour and seed morphology: a missing link of myrmecochory.

    PubMed

    Gómez, Crisanto; Espadaler, Xavier; Bas, Josep M

    2005-12-01

    Seed dispersal by ants (myrmecochory) is mediated by the presence of a lipid-rich appendage (elaiosome) on the seed that induces a variety of ants to collect the diaspores. When seeds mature or fall onto the ground, these ant species transport them to their nest. After eating the elaiosome, the seed is discarded in nest galleries or outside, in the midden or farther away, where seeds can potentially germinate. The final location of seeds with their elaiosomes removed was evaluated to assess the importance of possible handles (structures that ants can grasp to carry) in transporting ants during re-dispersal experiments of seeds from nests of six species of ants. The results indicate that seeds remained within the nest because the ants were not able to transport them out of the nest. As a consequence of the elaiosome being removed, small ant species could not take Euphorbia characias seeds out of their nests. Only large ant species could remove E. characias seeds from their nests. Attaching an artificial handle to E. characias seeds allowed small ant species to redistribute the seeds from their nests. On the other hand, Rhamnus alaternus seeds that have a natural handle after the elaiosome removal were removed from the nests by both groups of ant species. If a seed has an element that acts as a handle, it will eventually get taken out of the nest. The ants' size and their mandible gap can determine the outcome of the interaction (i.e. the pattern of the final seed shadow) and as a consequence, could influence the events that take place after the dispersal process.

  12. Alate susceptibility in ants

    PubMed Central

    Ho, Eddie K H; Frederickson, Megan E

    2014-01-01

    Pathogens are predicted to pose a particular threat to eusocial insects because infections can spread rapidly in colonies with high densities of closely related individuals. In ants, there are two major castes: workers and reproductives. Sterile workers receive no direct benefit from investing in immunity, but can gain indirect fitness benefits if their immunity aids the survival of their fertile siblings. Virgin reproductives (alates), on the other hand, may be able to increase their investment in reproduction, rather than in immunity, because of the protection they receive from workers. Thus, we expect colonies to have highly immune workers, but relatively more susceptible alates. We examined the survival of workers, gynes, and males of nine ant species collected in Peru and Canada when exposed to the entomopathogenic fungus Beauveria bassiana. For the seven species in which treatment with B. bassiana increased ant mortality relative to controls, we found workers were significantly less susceptible compared with both alate sexes. Female and male alates did not differ significantly in their immunocompetence. Our results suggest that, as with other nonreproductive tasks in ant colonies like foraging and nest maintenance, workers have primary responsibility for colony immunity, allowing alates to specialize on reproduction. We highlight the importance of colony-level selection on individual immunity in ants and other eusocial organisms. PMID:25540683

  13. Nectar Theft and Floral Ant-Repellence: A Link between Nectar Volume and Ant-Repellent Traits?

    PubMed Central

    Ballantyne, Gavin; Willmer, Pat

    2012-01-01

    As flower visitors, ants rarely benefit a plant. They are poor pollinators, and can also disrupt pollination by deterring other flower visitors, or by stealing nectar. Some plant species therefore possess floral ant-repelling traits. But why do particular species have such traits when others do not? In a dry forest in Costa Rica, of 49 plant species around a third were ant-repellent at very close proximity to a common generalist ant species, usually via repellent pollen. Repellence was positively correlated with the presence of large nectar volumes. Repellent traits affected ant species differently, some influencing the behaviour of just a few species and others producing more generalised ant-repellence. Our results suggest that ant-repellent floral traits may often not be pleiotropic, but instead could have been selected for as a defence against ant thieves in plant species that invest in large volumes of nectar. This conclusion highlights to the importance of research into the cost of nectar production in future studies into ant-flower interactions. PMID:22952793

  14. Utilization of Anting-Anting (Acalypha indica) Leaves as Antibacterial

    NASA Astrophysics Data System (ADS)

    Batubara, Irmanida; Wahyuni, Wulan Tri; Firdaus, Imam

    2016-01-01

    Anting-anting (Acalypha indica) plants is a species of plant having catkin type of inflorescence. This research aims to utilize anting-anting as antibacterial toward Streptococcus mutans and degradation of biofilm on teeth. Anting-anting leaves were extracted by maceration technique using methanol, chloroform, and n-hexane. Antibacterial and biofilm degradation assays were performed using microdilution technique with 96 well. n-Hexane extracts of anting-anting leaves gave the best antibacterial potency with minimum inhibitory concentration and minimum bactericidal concentration value of 500 μg/mL and exhibited good biofilm degradation activity. Fraction of F3 obtained from fractionation of n-hexane's extract with column chromatography was a potential for degradation of biofilm with IC50 value of 56.82 μg/mL. Alkaloid was suggested as antibacterial and degradation of biofilm in the active fraction.

  15. Fossil evidence for the early ant evolution

    NASA Astrophysics Data System (ADS)

    Perrichot, Vincent; Lacau, Sébastien; Néraudeau, Didier; Nel, André

    2008-02-01

    Ants are one of the most studied insects in the world; and the literature devoted to their origin and evolution, systematics, ecology, or interactions with plants, fungi and other organisms is prolific. However, no consensus yet exists on the age estimate of the first Formicidae or on the origin of their eusociality. We review the fossil and biogeographical record of all known Cretaceous ants. We discuss the possible origin of the Formicidae with emphasis on the most primitive subfamily Sphecomyrminae according to its distribution and the Early Cretaceous palaeogeography. And we review the evidence of true castes and eusociality of the early ants regarding their morphological features and their manner of preservation in amber. The mid-Cretaceous amber forest from south-western France where some of the oldest known ants lived, corresponded to a moist tropical forest close to the shore with a dominance of gymnosperm trees but where angiosperms (flowering plants) were already diversified. This palaeoenvironmental reconstruction supports an initial radiation of ants in forest ground litter coincident with the rise of angiosperms, as recently proposed as an ecological explanation for their origin and successful evolution.

  16. Field tests of interspecific competition in ant assemblages: revisiting the dominant red wood ants.

    PubMed

    Gibb, Heloise; Johansson, Therese

    2011-05-01

    1. There has been considerable debate on the importance of competition in ecological communities, but its importance in structuring ant assemblages has often been uncritically accepted. Here, we briefly review field experiments examining competition in ant assemblages and use a removal experiment to test the effect of the classical territorial dominant ant, Formica aquilonia. Ants of this species group are thought to structure communities through a dominance hierarchy. 2. First, we used pitfall traps to compare the abundance of other ants in replicated sites with low and high densities of F. aquilonia. We found differences in community composition, in particular, Camponotus herculeanus was more common in low-density sites, in accordance with predictions. Differences in ant assemblages were not owing to differences in measured habitat variables. 3. We removed F. aquilonia from a set of high-density sites, using physical and chemical methods, and repeated these procedures at procedural control sites. One year after removal, abundances of F. aquilonia at removal sites were similar to those at low-density sites. However, the composition of other species did not change in response to F. aquilonia removal. Replication rates were identical in the mensurative and experimental components of this study, so this is unlikely to be owing to the analysis being insufficiently powerful. 4. We suggest three possibilities for the lack of difference. First, the study may have been too short term or small scale to detect differences. However, previous studies have shown effects on smaller spatial- and temporal-scales. Second, priority effects may be important in the successful colonisation by F. aquilonia. Thirdly, boreal ant assemblages may be too depauperate for redundancy in ecological roles and for competition to play an important structuring role. 5. We thus recommend that long-term large-scale experiments be considered essential if we are to distinguish between competing

  17. Odorous house ants (Tapinoma sessile) as back-seat drivers of localized ant decline in urban habitats.

    PubMed

    Salyer, Adam; Bennett, Gary W; Buczkowski, Grzegorz A

    2014-01-01

    Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile), within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers) threats as instigators or secondary (passengers) threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74%) and abundance (81%). Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban 'invasion'. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a "back

  18. Odorous House Ants (Tapinoma sessile) as Back-Seat Drivers of Localized Ant Decline in Urban Habitats

    PubMed Central

    Salyer, Adam; Bennett, Gary W.; Buczkowski, Grzegorz A.

    2014-01-01

    Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile), within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers) threats as instigators or secondary (passengers) threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74%) and abundance (81%). Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban ‘invasion’. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a

  19. Amphotis marginata (Coleoptera: Nitidulidae) a highwayman of the ant Lasius fuliginosus.

    PubMed

    Hölldobler, Bert; Kwapich, Christina L

    2017-01-01

    The space occupied by evolutionarily advanced ant societies can be subdivided into functional sites, such as broodchambers; peripheral nest chambers; kitchen middens; and foraging routes. Many predators and social parasites are specially adapted to make their living inside specific niches created by ants. In particular, the foraging paths of certain ant species are frequented by predatory and kleptoparasitic arthropods, including one striking example, the nitidulid beetle, Amphotis marginata. Adults of this species obtain the majority of their nutrition by acting as a kind of "highwayman" on the foraging trails of the ant Lasius fuliginosus, where they solicit regurgitation from food laden ant-workers by mimicking the ant's food-begging signals. Employing food labeled with the radio isotope 32P, we assessed the quantities of food the beetles siphoned-off of food-laden ants, and we investigated the site preferences, behavioral mechanisms and possible morphological adaptations underlying the food kleptoparasitism of A. marginata.

  20. Ant functional responses along environmental gradients.

    PubMed

    Arnan, Xavier; Cerdá, Xim; Retana, Javier

    2014-11-01

    functional traits may modulate the responses of ant species to the environment. Since these traits act as the link between species distributions and the environment, they could potentially be used to predict community changes under future global change scenarios. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

  1. Routing Vehicles with Ants

    NASA Astrophysics Data System (ADS)

    Tan, Wen Fang; Lee, Lai Soon; Majid, Zanariah Abdul; Seow, Hsin Vonn

    Routing vehicles involve the design of an optimal set of routes for a fleet of vehicles to serve a number of customers with known demands. This research develops an Ant Colony Optimization for the vehicle routing with one central depot and identical vehicles. The procedure simulates the behavior of real ants that always find the shortest path between their nest and a food source through a form of communication, pheromone trail. Finally, preliminary results on the learning of the algorithm testing on benchmark data set will be presented in this paper.

  2. The ants go marching millions by millions: invasive ant research

    USDA-ARS?s Scientific Manuscript database

    Invasive ants are a worldwide problem that is expanding both geographically and in intensity. Population explosions of invasive ants can overrun landscapes and inundate structures. Pest management professionals are often the first responders to complaints about invading ants. This session will fo...

  3. The Ants Go Marching Millions by Millions: Invasive Ant Research

    USDA-ARS?s Scientific Manuscript database

    Invasive ants are a worldwide problem that is expanding both geographically and in intensity. Population explosions of invasive ants can overrun landscapes and inundate structures. Pest management professionals are often the first responders to complaints about invading ants. This session will fo...

  4. Are variations in cuticular hydrocarbons of queens and workers a reliable signal of fertility in the ant Harpegnathos saltator?

    PubMed Central

    Liebig, Jürgen; Peeters, Christian; Oldham, Neil J.; Markstädter, Claus; Hölldobler, Bert

    2000-01-01

    One of the key features of insect societies is the division of labor in reproduction between one or a few fertile individuals and many sterile nestmates that function as helpers. The behavioral and physiological mechanisms regulating reproduction in ant societies are still not very well understood, especially in species in which all colony members are reproductively totipotent. In the ponerine ant Harpegnathos saltator, queen-worker dimorphism is very limited, and a few mated workers reproduce (“gamergates”) once the founding queen becomes senescent. Worker oviposition is regulated by highly directed aggressive interactions among nestmates, who can recognize different levels of ovarian activity. We show that variations in cuticular hydrocarbons (CHC) correlate with oogenesis, both for queens and workers. 13,23-Dimethylheptatriacontane is present in egg-layers, but not in infertile workers and queens. Proportions of other CHCs vary as well, resulting in clear separation of the ants in a multivariate analysis. Egg-layers are characterized by an elongation of the chain length of CHCs. We used solid-phase microextraction to measure CHCs in live ants that were experimentally induced to start producing eggs. Over a period of 118 days, CHC profiles of infertile workers changed completely to that of reproductives. The effect of age can be excluded in this modification. This striking correlation of ovarian activity with CHC variation and its correspondence with the observed recognition behavior exhibited by the workers toward egg-laying nestmates suggests that CHCs serve as a fertility signal in the ant H. saltator, a reliable basis for regulating reproduction. PMID:10760282

  5. Ant species identity mediates reproductive traits and allocation in an ant-garden bromeliad

    PubMed Central

    Leroy, Céline; Corbara, Bruno; Pélozuelo, Laurent; Carrias, Jean-François; Dejean, Alain; Céréghino, Régis

    2012-01-01

    Background and Aims Determining the sources of variation in floral morphology is crucial to understanding the mechanisms underlying Angiosperm evolution. The selection of floral and reproductive traits is influenced by the plant's abiotic environment, florivores and pollinators. However, evidence that variations in floral traits result from mutualistic interactions with insects other than pollinators is lacking in the published literature and has rarely been investigated. We aimed to determine whether the association with either Camponotus femoratus or Pachycondyla goeldii (both involved in seed dispersal and plant protection) mediates the reproductive traits and allocation of Aechmea mertensii, an obligatory ant-garden tank-bromeliad, differently. Methods Floral and reproductive traits were compared between the two A. mertensii ant-gardens. The nitrogen flux from the ants to the bromeliads was investigated through experimental enrichments with stable isotopes (15N). Key Results Camponotus femoratus-associated bromeliads produced inflorescences up to four times longer than did P. goeldii-associated bromeliads. Also, the numbers of flowers and fruits were close to four times higher, and the number of seeds and their mass per fruit were close to 1·5 times higher in C. femoratus than in P. goeldii-associated bromeliads. Furthermore, the 15N-enrichment experiment showed that C. femoratus-associated bromeliads received more nitrogen from ants than did P. goeldii-associated bromeliads, with subsequent positive repercussions on floral development. Greater benefits were conferred to A. mertensii by the association with C. femoratus compared with P. goeldii ants. Conclusions We show for the first time that mutualistic associations with ants can result in an enhanced reproductive allocation for the bromeliad A. mertensii. Nevertheless, the strength and direction of the selection of floral and fruit traits change based on the ant species and were not related to light

  6. Can the Argentine ant ( Linepithema humile Mayr) replace native ants in myrmecochory?

    NASA Astrophysics Data System (ADS)

    Gómez, Crisanto; Oliveras, Jordi

    2003-04-01

    We analyse the influence of the Argentine ant ( Linepithema humile Mayr) on the seed dispersal process of the myrmecochorous plants Euphorbia characias, E. biumbellata, Genista linifolia, G. triflora, G. monspessulana and Sarothamnus arboreus. The observations were made in two study plots of Mediterranean cork-oak secondary forest (invaded and non-invaded by L. humile). The presence of L. humile implies the displacement of all native ant species that disperse seeds. Seed transports in the non-invaded zone were carried out by eight ant species. In the invaded zone, L. humile workers removed and transported seeds to the nest. In vertebrate exclusion trials, we observed the same level of seed removal in the invaded and non-invaded zones. Two findings could explain this result. Although mean time to seed localization was higher for native ants (431.7 s) than that for L. humile (150.5 s), the mean proportion of seeds transported after being detected was higher (50.1%) in non-invaded than in invaded (16.8%) zones. The proportion of seeds removed and transported into an ant nest after an ant-seed interaction had dramatically reduced from non-invaded (41.9%) to invaded (7.4%) zones. The levels of seed dispersal by ants found prior to invasion are unlikely to be maintained in invaded zones. However, total replacement of seed dispersal function is possible if contact iteration finally offers similar levels or quantities of seeds reaching the nests. The results obtained confirm that the Argentine ant invasion may affect myrmecochory dramatically in the Mediterranean biome.

  7. Army ants: an evolutionary bestseller?

    PubMed

    Berghoff, Stefanie M

    2003-09-02

    Army ants are characterized by a complex combination of behavioral and morphological traits. Molecular data now indicate that army ant behavior has a unique evolutionary origin and has been conserved for over more than 100 million years.

  8. Self-organized structures in a superorganism: do ants “behave” like molecules?

    NASA Astrophysics Data System (ADS)

    Detrain, Claire; Deneubourg, Jean-Louis

    2006-09-01

    While the striking structures (e.g. nest architecture, trail networks) of insect societies may seem familiar to many of us, the understanding of pattern formation still constitutes a challenging problem. Over the last two decades, self-organization has dramatically changed our view on how collective decision-making and structures may emerge out of a population of ant workers having each their own individuality as well as a limited access to information. A variety of collective behaviour spontaneously outcome from multiple interactions between nestmates, even when there is no directing influence imposed by an external template, a pacemaker or a leader. By focussing this review on foraging structures, we show that ant societies display some properties which are usually considered in physico-chemical systems, as typical signatures of self-organization. We detail the key role played by feed-back loops, fluctuations, number of interacting units and sensitivity to environmental factors in the emergence of a structured collective behaviour. Nonetheless, going beyond simple analogies with non-living self-organized patterns, we stress on the specificities of social structures made of complex living units of which the biological features have been selected throughout the evolution depending on their adaptive value. In particular, we consider the ability of each ant individual to process information about environmental and social parameters, to accordingly tune its interactions with nestmates and ultimately to determine the final pattern emerging at the collective level. We emphasize on the parsimony and simplicity of behavioural rules at the individual level which allow an efficient processing of information, energy and matter within the whole colony.

  9. Recognition of Social Identity in Ants

    PubMed Central

    Bos, Nick; d’Ettorre, Patrizia

    2012-01-01

    Recognizing the identity of others, from the individual to the group level, is a hallmark of society. Ants, and other social insects, have evolved advanced societies characterized by efficient social recognition systems. Colony identity is mediated by colony specific signature mixtures, a blend of hydrocarbons present on the cuticle of every individual (the “label”). Recognition occurs when an ant encounters another individual, and compares the label it perceives to an internal representation of its own colony odor (the “template”). A mismatch between label and template leads to rejection of the encountered individual. Although advances have been made in our understanding of how the label is produced and acquired, contradictory evidence exists about information processing of recognition cues. Here, we review the literature on template acquisition in ants and address how and when the template is formed, where in the nervous system it is localized, and the possible role of learning. We combine seemingly contradictory evidence in to a novel, parsimonious theory for the information processing of nestmate recognition cues. PMID:22461777

  10. Do extrafloral nectar resources, species abundances, and body sizes contribute to the structure of ant-plant mutualistic networks?

    PubMed

    Chamberlain, Scott A; Kilpatrick, Jeffrey R; Holland, J Nathaniel

    2010-11-01

    Recent research has shown that many mutualistic communities display non-random structures. While our understanding of the structural properties of mutualistic communities continues to improve, we know little of the biological variables resulting in them. Mutualistic communities include those formed between ants and extrafloral (EF) nectar-bearing plants. In this study, we examined the contributions of plant and ant abundance, plant and ant size, and plant EF nectar resources to the network structures of nestedness and interaction frequency of ant-plant networks across five sites within one geographic locality in the Sonoran Desert. Interactions between ant and plant species were largely symmetric. That is, ant and plant species exerted nearly equivalent quantitative interaction effects on one another, as measured by their frequency of interaction. The mutualistic ant-plant networks also showed nested patterns of structure, in which there was a central core of generalist ant and plant species interacting with one another and few specialist-specialist interactions. Abundance and plant size and ant body size were the best predictors of symmetric interactions between plants and ants, as well as nestedness. Despite interactions in these communities being ultimately mediated by EF nectar resources, the number of EF nectaries had a relatively weak ability to explain variation in symmetric interactions and nestedness. These results suggest that different mechanisms may contribute to structure of bipartite networks. Moreover, our results for ant-plant mutualistic networks support the general importance of species abundances for the structure of species interactions within biological communities.

  11. Wood-nesting ants and their parasites in forests and coffee agroecosystems.

    PubMed

    De La Mora, Aldo; Philpott, Stacy M

    2010-10-01

    Agricultural intensification is linked to reduced species richness and may limit the effectiveness of predators in agricultural systems. We studied the abundance, diversity, and species composition of wood-nesting ants and frequency of parasitism of poneromorph ants in coffee agroeco systems and a forest fragment in Chiapas, Mexico. In three farms differing in shade management and in a nearby forest fragment, we surveyed ants nesting in rotten wood. We collected pupae of all poneromorph ants encountered, and incubated pupae for 15 d to recover emerging ant parasites. If no parasites emerged, we dissected pupae to examine for parasitism. Overall, we found 63 ant morphospecies, 29 genera, and 7 subfamilies from 520 colonies. There were no significant differences in ant richness or abundance between the different sites. However, there were significant differences in the species composition of ants sampled in the four different sites. The parasitism rates of ants differed according to site; in the forest 77.7% of species were parasitized, and this number declined with increasing intensification in traditional polyculture (40%),commercial polyculture (25%), and shade monoculture (16.6%). For three of four poneromorph species found in >1 habitat, parasitism rates were higher in the more vegetatively complex sites. The result that both ant species composition and ant parasitism differed among by site indicates that coffee management intensification affects wood-nesting ant communities. Further, coffee intensification may significantly alter interactions between ants and their parasites, with possible implications for biological control in coffee agroecosystems.

  12. Tiny, Powerful, Awesome Ants!

    ERIC Educational Resources Information Center

    Tate, Kathleen

    2007-01-01

    Peering through a thematic science lens--elementary students embarked on a one-week study of ants during a month-long summer school program. This integrated unit addressed reading and writing skills while developing the science-process skills of observation, inferring, and communicating in a motivating and authentic way. Pre- and post-assessments…

  13. Tiny, Powerful, Awesome Ants!

    ERIC Educational Resources Information Center

    Tate, Kathleen

    2007-01-01

    Peering through a thematic science lens--elementary students embarked on a one-week study of ants during a month-long summer school program. This integrated unit addressed reading and writing skills while developing the science-process skills of observation, inferring, and communicating in a motivating and authentic way. Pre- and post-assessments…

  14. Coevolution between attine ants and actinomycete bacteria: a reevaluation.

    PubMed

    Mueller, Ulrich G; Dash, Debadutta; Rabeling, Christian; Rodrigues, Andre

    2008-11-01

    insufficient support for the reverse, modifications of the bacteria resulting from the interaction with attine ants. The defining feature of coevolution--reciprocal modification--therefore remains to be established for the attine ant-actinomycete mutualism.

  15. Spectacular Batesian mimicry in ants.

    PubMed

    Ito, Fuminori; Hashim, Rosli; Huei, Yek Sze; Kaufmann, Eva; Akino, Toshiharu; Billen, Johan

    2004-10-01

    The mechanism by which palatable species take advantage of their similarity in appearance to those that are unpalatable, in order to avoid predation, is called Batesian mimicry. Several arthropods are thought to be Batesian mimics of social insects; however, social insects that are Batesian mimics among themselves are rare. In Malaysia we found a possible Batesian mimic in an arboreal ant species, Camponotus sp., which was exclusively observed on foraging trails of the myrmicine ant Crematogaster inflata. The bright yellow and black colouring pattern, as well as the walking behaviour, were very similar in both species. We observed general interactions between the two species, and tested their palatability and the significance of the remarkably similar visual colour patterns for predator avoidance. Prey offered to C. inflata was also eaten by Camponotus workers in spite of their being attacked by C. inflata, indicating that Camponotus sp. is a commensal of C. inflata. An experiment with chicks as potential predators suggests that Camponotus sp. is palatable whereas C. inflata is unpalatable. After tasting C. inflata, the chicks no longer attacked Camponotus sp., indicating that Camponotus sp. is a Batesian mimic of Crematogaster inflata.

  16. Spectacular Batesian mimicry in ants

    NASA Astrophysics Data System (ADS)

    Ito, Fuminori; Hashim, Rosli; Huei, Yek Sze; Kaufmann, Eva; Akino, Toshiharu; Billen, Johan

    2004-10-01

    The mechanism by which palatable species take advantage of their similarity in appearance to those that are unpalatable, in order to avoid predation, is called Batesian mimicry. Several arthropods are thought to be Batesian mimics of social insects; however, social insects that are Batesian mimics among themselves are rare. In Malaysia we found a possible Batesian mimic in an arboreal ant species, Camponotus sp., which was exclusively observed on foraging trails of the myrmicine ant Crematogaster inflata. The bright yellow and black colouring pattern, as well as the walking behaviour, were very similar in both species. We observed general interactions between the two species, and tested their palatability and the significance of the remarkably similar visual colour patterns for predator avoidance. Prey offered to C. inflata was also eaten by Camponotus workers in spite of their being attacked by C. inflata, indicating that Camponotus sp. is a commensal of C. inflata. An experiment with chicks as potential predators suggests that Camponotus sp. is palatable whereas C. inflata is unpalatable. After tasting C. inflata, the chicks no longer attacked Camponotus sp., indicating that Camponotus sp. is a Batesian mimic of Crematogaster inflata.

  17. Ant allergens and hypersensitivity reactions in response to ant stings.

    PubMed

    Potiwat, Rutcharin; Sitcharungsi, Raweerat

    2015-12-01

    Hypersensitivity reactions caused by ant stings are increasingly recognized as an important cause of death by anaphylaxis. Only some species of ants ( e.g. Solenopsis spp., Myrmecia spp., and Pachycondyla spp.) cause allergic reactions. Ant species are identified by evaluating the morphologic structures of worker ants or by molecular techniques. Ant venom contains substances, including acids and alkaloids, that cause toxic reactions, and those from Solenopsis invicta or the imported fire ant have been widely studied. Piperidine alkaloids and low protein contents can cause local reactions (sterile pustules) and systemic reactions (anaphylaxis). Imported fire ant venoms are cross-reactive; for example, the Sol i 1 allergen from S. invicta has cross-reactivity with yellow jacket phospholipase. The Sol i 3 allergen is a member of the antigen 5 family that has amino acid sequence identity with vespid antigen 5. The clinical presentations of ant hypersensitivity are categorized into immediate and delayed reactions: immediate reactions, such as small local reactions, large local reactions, and systemic reactions, occur within 1-4 hours after the ant stings, whereas delayed reactions, such as serum sickness and vasculitis, usually occur more than 4 hours after the stings. Tools for the diagnosis of ant hypersensitivity are skin testing, serum specific IgE, and sting challenge tests. Management of ant hypersensitivity can be divided into immediate (epinephrine, corticosteroids), symptomatic (antihistamines, bronchodilators), supportive (fluid resuscitation, oxygen therapy), and preventive (re-sting avoidance and immunotherapy) treatments.

  18. Multiple ant species tending lac insect Kerria yunnanensis (Hemiptera: Kerriidae) provide asymmetric protection against parasitoids.

    PubMed

    Chen, Youqing; Lu, Zhixing; Li, Qiao; Hoffmann, Benjamin D; Zhang, Wei

    2014-01-01

    This study investigated the effects of ant attendance on the parasitoid community and parasitism of lac insect Kerria yunnanensis aggregations in Yunnan province, China. We manipulated ant attendance to establish three treatments: (1) ant exclusion; (2) low ant attendance by several ant species; and (3) high ant attendance by Crematogaster macaoensis. Five parasitoid species were collected, with two species contributing 82.7 and 13.2% of total abundance respectively. Total parasitoid abundance was lowest in the February sample when K. yunnanensis was in its younger life stage, being significantly lower in the ant exclusion treatment. In April, all three treatments had significantly different parasitoid abundances, being highest in the ant exclusion treatment and the lowest in the high ant attendance treatment. When ants were present, there were strong negative relationships between total parasitoid abundance and ant abundance, with the relationships being dependent upon the ant species composition and abundance. The patterns of total parasitoid abundance were driven by the two most abundant parasitoid species. Parasitoid species richness did not differ among treatments or between sample times, however, multivariate analysis confirmed that overall parasitoid community structure differed significantly among treatments and between sample times, with the high ant attendance treatment differing most from the other two treatments. Interestingly the absence of ants did not result in increased parasitism from four of the five parasitoids. Ants in lac insect farming systems have a clear role for agricultural pest management. A full understanding of the asymmetric abilities of ants to influence parasitoid communities, and affect parasitism of hosts will require further experimental manipulation to assess the relative roles of 1) the abundance of each individual ant species on parasitoid access to hosts, 2) competition among parasitoids, and 3) the interaction between the

  19. Ecology of microfungal communities in gardens of fungus-growing ants (Hymenoptera: Formicidae): a year-long survey of three species of attine ants in Central Texas.

    PubMed

    Rodrigues, Andre; Mueller, Ulrich G; Ishak, Heather D; Bacci, Maurício; Pagnocca, Fernando C

    2011-11-01

    We profiled the microfungal communities in gardens of fungus-growing ants to evaluate possible species-specific ant-microfungal associations and to assess the potential dependencies of microfungal diversity on ant foraging behavior. In a 1-year survey, we isolated microfungi from nests of Cyphomyrmex wheeleri, Trachymyrmex septentrionalis and Atta texana in Central Texas. Microfungal prevalence was higher in gardens of C. wheeleri (57%) than in the gardens of T. septentrionalis (46%) and A. texana (35%). Culture-dependent methods coupled with a polyphasic approach of species identification revealed diverse and changing microfungal communities in all the sampling periods. Diversity analyses showed no obvious correlations between the number of observed microfungal species, ant species, or the ants' changing foraging behavior across the seasons. However, both correspondence analysis and 5.8S-rRNA gene unifrac analyses suggested structuring of microfungal communities by ant host. These host-specific differences may reflect in part the three different environments where ants were collected. Most interestingly, the specialized fungal parasite Escovopsis was not isolated from any attine garden in this study near the northernmost limit of the range of attine ants, contrasting with previous studies that indicated a significant incidence of this parasite in ant gardens from Central and South America. The observed differences of microfungal communities in attine gardens suggest that the ants are continuously in contact with a diverse microfungal species assemblage. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  20. Colony-level impacts of parasitoid flies on fire ants.

    PubMed Central

    Mehdiabadi, Natasha J; Gilbert, Lawrence E

    2002-01-01

    The red imported fire ant is becoming a global ecological problem, having invaded the United States, Puerto Rico, New Zealand and, most recently, Australia. In its established areas, this pest is devastating natural biodiversity. Early attempts to halt fire ant expansion with pesticides actually enhanced its spread. Phorid fly parasitoids from South America have now been introduced into the United States as potential biological control agents of the red imported fire ant, but the impact of these flies on fire ant populations is currently unknown. In the laboratory, we show that an average phorid density of as little as one attacking fly per 200 foraging ants decreased colony protein consumption nearly twofold and significantly reduced numbers of large-sized workers 50 days later. The high impact of a single phorid occurred mainly because ants decreased foraging rates in the presence of the flies. Our experiments, the first (to our knowledge) to link indirect and direct effects of phorids on fire ants, demonstrate that colonies can be stressed with surprisingly low parasitoid densities. We interpret our findings with regard to the more complex fire ant-phorid interactions in the field. PMID:12204130

  1. Mexican Society of Bioelectromagnetism

    SciTech Connect

    Canedo, Luis

    2008-08-11

    In July 2007 physicians, biologists and physicists that have collaborated in previous meetings of the medical branch of the Mexican Physical Society constituted the Mexican Society of Bioelectromagnetism with the purpose of promote scientific study of the interaction of electromagnetic energy (at frequencies ranging from zero Hertz through those of visible light) and acoustic energy with biological systems. A second goal was to increase the contribution of medical and biological professionals in the meetings of the medical branch of the Mexican Physical Society. The following paragraphs summarize some objectives of the Mexican Society of Bioelectromagnetism for the next two years.

  2. The Dynamics of Foraging Ants

    NASA Astrophysics Data System (ADS)

    Baxter, G. William

    2009-03-01

    We experimentally study the foraging of small black ants, Formicinae lasius flavus, in order to describe their foraging behavior mathematically. Individual ants are allowed to forage on a two-dimensional surface in the absence of any food sources. The position of the ant as a function of time is determined using a high-resolution digital camera. Analysis of the average square displacements of many ants suggests that the foraging strategy is a non-reversing random walk. Moreover, the ants do not retrace their steps to return home but instead continue the random walk until it brings them back near their starting point.

  3. Ants and the fossil record.

    PubMed

    LaPolla, John S; Dlussky, Gennady M; Perrichot, Vincent

    2013-01-01

    The dominance of ants in the terrestrial biosphere has few equals among animals today, but this was not always the case. The oldest ants appear in the fossil record 100 million years ago, but given the scarcity of their fossils, it is presumed they were relatively minor components of Mesozoic insect life. The ant fossil record consists of two primary types of fossils, each with inherent biases: as imprints in rock and as inclusions in fossilized resins (amber). New imaging technology allows ancient ant fossils to be examined in ways never before possible. This is particularly helpful because it can be difficult to distinguish true ants from non-ants in Mesozoic fossils. Fossil discoveries continue to inform our understanding of ancient ant morphological diversity, as well as provide insights into their paleobiology.

  4. Ant association facilitates the evolution of diet breadth in a lycaenid butterfly.

    PubMed

    Forister, Matthew L; Gompert, Zachariah; Nice, Chris C; Forister, Glen W; Fordyce, James A

    2011-05-22

    The role of mutualistic interactions in adaptive diversification has not been thoroughly examined. Lycaenid butterflies provide excellent systems for exploring mutualistic interactions, as more than half of this family is known to use ants as a resource in interactions that range from parasitism to mutualism. We investigate the hypothesis that protection from predators offered to caterpillars by ants might facilitate host-range evolution. Specifically, experiments with the butterfly Lycaeides melissa investigated the role of ant association in the use of a novel host, alfalfa, Medicago sativa, which is a sub-optimal host for larval development. Survival on alfalfa is increased by the presence of ants, thus supporting the hypothesis that interaction with ants might be important for host-range evolution. Using a demographic model to explore ecological conditions associated with host-range expansion in L. melissa, we conclude that the presence of ants might be an essential component for populations persisting on the novel, sub-optimal host.

  5. Electric ants: A cross-disciplinary approach to understanding insect behavior

    SciTech Connect

    Slowik, T.J.; Thorvilson, H.G.; Green, B.L.

    1996-12-31

    The response and attraction of the red imported fire ant, Solenopsis invicta, to electrical equipment was examined using an interdisciplinary approach. Entomologists specializing in fire ant behavior combined expertise with electrical engineers to investigate the economically damaging interaction of fire ants with electrical circuitry. Knowledge from the realms of physics, engineering, and biology were integrated in experimentation to test for a fire ant response to electric fields and magnetic fields associated with electrical equipment. It was determined that fire ants react to electrified conductive material and the alternating-current magnetic fields associated with electricity.

  6. Planetary Society

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Carl Sagan, Bruce Murray and Louis Friedman founded the non-profit Planetary Society in 1979 to advance the exploration of the solar system and to continue the search for extraterrestrial life. The Society has its headquarters in Pasadena, California, but is international in scope, with 100 000 members worldwide, making it the largest space interest group in the world. The Society funds a var...

  7. Ant-mediated seed dispersal in a warmed world.

    PubMed

    Stuble, Katharine L; Patterson, Courtney M; Rodriguez-Cabal, Mariano A; Ribbons, Relena R; Dunn, Robert R; Sanders, Nathan J

    2014-01-01

    Climate change affects communities both directly and indirectly via changes in interspecific interactions. One such interaction that may be altered under climate change is the ant-plant seed dispersal mutualism common in deciduous forests of eastern North America. As climatic warming alters the abundance and activity levels of ants, the potential exists for shifts in rates of ant-mediated seed dispersal. We used an experimental temperature manipulation at two sites in the eastern US (Harvard Forest in Massachusetts and Duke Forest in North Carolina) to examine the potential impacts of climatic warming on overall rates of seed dispersal (using Asarum canadense seeds) as well as species-specific rates of seed dispersal at the Duke Forest site. We also examined the relationship between ant critical thermal maxima (CTmax) and the mean seed removal temperature for each ant species. We found that seed removal rates did not change as a result of experimental warming at either study site, nor were there any changes in species-specific rates of seed dispersal. There was, however, a positive relationship between CTmax and mean seed removal temperature, whereby species with higher CTmax removed more seeds at hotter temperatures. The temperature at which seeds were removed was influenced by experimental warming as well as diurnal and day-to-day fluctuations in temperature. Taken together, our results suggest that while temperature may play a role in regulating seed removal by ants, ant plant seed-dispersal mutualisms may be more robust to climate change than currently assumed.

  8. Lipid-Loving ANTs: Molecular Simulations of Cardiolipin Interactions and the Organization of the Adenine Nucleotide Translocase in Model Mitochondrial Membranes

    PubMed Central

    2016-01-01

    The exchange of ADP and ATP across the inner mitochondrial membrane is a fundamental cellular process. This exchange is facilitated by the adenine nucleotide translocase, the structure and function of which are critically dependent on the signature phospholipid of mitochondria, cardiolipin (CL). Here we employ multiscale molecular dynamics simulations to investigate CL interactions within a membrane environment. Using simulations at both coarse-grained and atomistic resolutions, we identify three CL binding sites on the translocase, in agreement with those seen in crystal structures and inferred from nuclear magnetic resonance measurements. Characterization of the free energy landscape for lateral lipid interaction via potential of mean force calculations demonstrates the strength of interaction compared to those of binding sites on other mitochondrial membrane proteins, as well as their selectivity for CL over other phospholipids. Extending the analysis to other members of the family, yeast Aac2p and mouse uncoupling protein 2, suggests a degree of conservation. Simulation of large patches of a model mitochondrial membrane containing multiple copies of the translocase shows that CL interactions persist in the presence of protein–protein interactions and suggests CL may mediate interactions between translocases. This study provides a key example of how computational microscopy may be used to shed light on regulatory lipid–protein interactions. PMID:27786441

  9. Forest edges and fire ants alter the seed shadow of an ant-dispersed plant.

    PubMed

    Ness, J H

    2004-02-01

    Exotic species invade fragmented, edge-rich habitats readily, yet the distinct impacts of habitat edges and invaders on native biota are rarely distinguished. Both appear detrimental to ant-dispersed plants such as bloodroot, Sanguinaria canadensis. Working in northeastern Georgia (USA), an area characterized by a rich ant-dispersed flora, fragmented forests, and invasions by the red imported fire ant, Solenopsis invicta, I monitored the interactions between ants and S. canadensis seeds in uninvaded forest interiors, uninvaded forest edges, invaded forest interiors, and invaded forest edges. I observed 95% of the seed dispersal events that occurred within the 60-min observation intervals. Seed collection rates were similar among all four (habitat x invasion) groups. The presence of invasive ants had a strong effect on seed dispersal distance: S. invicta collected most seeds in invaded sites, but was a poorer disperser than four of five native ant taxa. Habitat type (interior versus edge) had no effect on seed dispersal distance, but it had a strong effect on seed dispersal direction. Dispersal towards the edge was disproportionately rare in uninvaded forest edges, and ants in those habitats moved the average dispersed seed approximately 70 cm away from that edge. Dispersal direction was also skewed away from the edge in uninvaded forest interiors and invaded forest edges, albeit non-significantly. This biased dispersal may help explain the rarity of myrmecochorous plants in younger forests and edges, and their poor ability to disperse between fragments. This is the first demonstration that forest edges and S. invicta invasion influence seed dispersal destination and distance, respectively. These forces act independently.

  10. The Frugal Cosmic Ant

    NASA Astrophysics Data System (ADS)

    2007-09-01

    Using ESO's Very Large Telescope Interferometer and its unique ability to see small details, astronomers have uncovered a flat, nearly edge-on disc of silicates in the heart of the magnificent Ant Nebula. The disc seems, however, too 'skinny' to explain how the nebula got its intriguing ant-like shape. ESO PR Photo 42/07 ESO PR Photo 42/07 A Disc in the Ant Nebula The Ant Nebula is one of the most striking planetary nebulae known. Planetary nebulae - whose name arises because most are spherical and looked like planets when they were first discovered through older, less powerful telescopes - are glowing structures of gas cast off by solar-like stars at the ends of their lives. The morphology of the Ant Nebula - a bright core, three nested pairs of bipolar lobes and a ring-like outflow - is so unique that it was nicknamed the 'Chamber of Horrors' of planetary nebulae in the late 1950s. But how can a spherical star produce such complex structures? The answer, many astronomers think, requires understanding of the discs surrounding the central star. By their nature, these discs bear witness to the phenomena that lead to the asymmetrical structures of planetary nebulae. "The challenge is to actually detect these discs," explains team leader Olivier Chesneau, from the Observatoire de la Côte d'Azur, France. "Most astronomical instruments do not have a sharp enough view to find, let alone study them. The Very Large Telescope Interferometer however, with its exceptionally high spatial resolution, is a powerful disc-hunter." The disc of the Ant Nebula, which cannot be detected with a single 8.2-m VLT Unit Telescope, was uncovered in the interferometric mode where two 8.2-m Unit Telescopes were used to combine light, through the MID-infrared Interferometric instrument (MIDI). The observations reveal a flat, nearly edge-on disc whose major axis is perpendicular to the axis of the bipolar lobes. The disc extends from about 9 times the mean distance between the Earth and the

  11. Interspecific competition and coexistence between ants and land hermit crabs on small Bahamian islands

    NASA Astrophysics Data System (ADS)

    Morrison, Lloyd W.

    2002-08-01

    Numerous studies have demonstrated the existence of intra- and interspecific competition among ants, but few have investigated direct competitive interactions between ants and other taxa. In this paper, I present the first evidence of direct competitive interactions between ants and crabs. Evidence of competition for food between ants and the land hermit crab, Coenobita clypeatus (Herbst), was derived from observations and experiments in an archipelago of small islands in the central Exumas, Bahamas. Correlational evidence of competition for food based on occurrences at baits was found between ants and hermit crabs in multiple years. Observations at baits over time revealed species turnover occurred due to aggressive interactions. C. clypeatus discovered food items rapidly, but lost control of food over time, particularly to the ant Brachymyrmex obscurior Forel, which took longer to find food items but recruited large numbers of workers that drove off hermit crabs. A second ant species, Dorymyrmex pyramicus Roger, discovered baits quickly but did not recruit to baits in large numbers, and was not a superior competitor to either C. clypeatus or B. obscurior. Competition between ants and land hermit crabs was not intense enough to cause complementary distributions, and mechanisms of coexistence apparently include temporal variation in foraging activity and complementary foraging strategies when ants and crabs are active at the same time. Because of the widespread distributions and generalist scavenger diets of many ants and crabs, such competitive interactions are likely to be a common facet of many tropical and subtropical insular and coastal communities.

  12. Trade-offs in an ant-plant-fungus mutualism.

    PubMed

    Orivel, Jérôme; Malé, Pierre-Jean; Lauth, Jérémie; Roux, Olivier; Petitclerc, Frédéric; Dejean, Alain; Leroy, Céline

    2017-03-15

    Species engaged in multiple, simultaneous mutualisms are subject to trade-offs in their mutualistic investment if the traits involved in each interaction are overlapping, which can lead to conflicts and affect the longevity of these associations. We investigate this issue via a tripartite mutualism involving an ant plant, two competing ant species and a fungus the ants cultivate to build galleries under the stems of their host plant to capture insect prey. The use of the galleries represents an innovative prey capture strategy compared with the more typical strategy of foraging on leaves. However, because of a limited worker force in their colonies, the prey capture behaviour of the ants results in a trade-off between plant protection (i.e. the ants patrol the foliage and attack intruders including herbivores) and ambushing prey in the galleries, which has a cascading effect on the fitness of all of the partners. The quantification of partners' traits and effects showed that the two ant species differed in their mutualistic investment. Less investment in the galleries (i.e. in fungal cultivation) translated into more benefits for the plant in terms of less herbivory and higher growth rates and vice versa. However, the greater vegetative growth of the plants did not produce a positive fitness effect for the better mutualistic ant species in terms of colony size and production of sexuals nor was the mutualist compensated by the wider dispersal of its queens. As a consequence, although the better ant mutualist is the one that provides more benefits to its host plant, its lower host-plant exploitation does not give this ant species a competitive advantage. The local coexistence of the ant species is thus fleeting and should eventually lead to the exclusion of the less competitive species.

  13. The Regulation of Ant Colony Foraging Activity without Spatial Information

    PubMed Central

    Prabhakar, Balaji; Dektar, Katherine N.; Gordon, Deborah M.

    2012-01-01

    Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus) colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony. PMID:22927811

  14. The regulation of ant colony foraging activity without spatial information.

    PubMed

    Prabhakar, Balaji; Dektar, Katherine N; Gordon, Deborah M

    2012-01-01

    Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus) colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.

  15. Assessing ant seed predation in threatened plants: a case study

    NASA Astrophysics Data System (ADS)

    Albert, María José; Escudero, Adrián; Iriondo, José María

    2005-11-01

    Erodium paularense is a threatened plant species that is subject to seed predation by the granivorous ant Messor capitatus. In this paper we assessed the intensity and pattern of ant seed predation and looked for possible adaptive strategies at the seed and plant levels to cope with this predation. Seed predation was estimated in 1997 and 1998 at the population level by comparing total seed production and ant consumption, assessed by counting seed hulls in refuse piles. According to this method, ant seed predation ranged between 18% and 28%. A more detailed and direct assessment conducted in 1997 raised this estimate to 43%. In this assessment spatial and temporal patterns of seed predation by ants were studied by mapping all nest entrances in the studied area and marking the mature fruits of 109 reproductive plants with a specific colour code throughout the seed dispersal period. Intact fruit coats were later recovered from the refuse piles, and their mother plants and time of dispersal were identified. Seeds dispersed at the end of the dispersal period had a greater probability of escaping from ant seed predation. Similarly, in plants with late dispersal a greater percentage of seeds escaped from ant predation. Optimum dispersal time coincided with the maximum activity of granivorous ants because, at this time, ants focused their harvest on other plant species of the community. It was also observed that within-individual seed dispersal asynchrony minimised seed predation. From a conservation perspective, results show that the granivorous ant-plant interaction cannot be assessed in isolation and that the intensity of its effects basically depends on the seed dispersal pattern of the other members of the plant community. Furthermore, this threat must be assessed by considering the overall situation of the target population. Thus, in E. paularense, the strong limitation of safe-sites for seedling establishment reduces the importance of seed predation.

  16. Distributed nestmate recognition in ants.

    PubMed

    Esponda, Fernando; Gordon, Deborah M

    2015-05-07

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response.

  17. Distributed nestmate recognition in ants

    PubMed Central

    Esponda, Fernando; Gordon, Deborah M.

    2015-01-01

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response. PMID:25833853

  18. "Ant-egg" cataract revisited.

    PubMed

    Clemmensen, Kåre; Enghild, Jan J; Ivarsen, Anders; Riise, Ruth; Vorum, Henrik; Heegaard, Steffen

    2017-01-01

    Hereditary congenital cataract varies immensely concerning location and form of the lens opacities. A specific and very rare phenotype is called "ant-egg" cataract first described in 1900. "Ant-eggs" have previously been examined using light microscopy, backscattered electron imaging and X-ray scans and electron microscopy. The purpose of this study was to further characterize "ant-egg" cataract using modern technology and display the history of the "ant-eggs" after cataract extraction. "Ant-eggs" were examined using Heidelberg SPECTRALIS Optical Coherence Tomography (OCT)(Heidelberg Engineering, Heidelberg, Germany). Ten "ant-eggs" were extracted; four of these as well as control tissue were analyzed by mass spectrometry (AB Sciex). Proteins were identified and their approximate abundances were determined. Immunohistochemical staining was carried out on the remaining "ant-eggs" for cytokeratin and S100. In anterior OCT-images, the "ant-egg" structures are localized on the iris. Comparative pictures showed that they stayed in the same location for more than 45 years. Mass spectrometry of "ant-eggs" yielded a proteome of 56 different proteins. Eighteen of the 56 "ant-egg" proteins (32 %) were neither present in our controls nor in a known fetal lens proteome. Among these were cytokeratin and Matrix-Gla protein. Immunohistochemical reactions were positive for cytokeratin and S100. This study demonstrates the previously unknown protein composition of the "ant-egg" structures in "ant-egg" cataract. Eighteen of these proteins are not natively found in the human lens. Moreover, "ant-eggs" do not vary over time, after cataract extraction, regarding size and location.

  19. A phylogenetic perspective on the association between ants (Hymenoptera: Formicidae) and black yeasts (Ascomycota: Chaetothyriales).

    PubMed

    Vasse, Marie; Voglmayr, Hermann; Mayer, Veronika; Gueidan, Cécile; Nepel, Maximilian; Moreno, Leandro; de Hoog, Sybren; Selosse, Marc-André; McKey, Doyle; Blatrix, Rumsaïs

    2017-03-15

    The frequency and the geographical extent of symbiotic associations between ants and fungi of the order Chaetothyriales have been highlighted only recently. Using a phylogenetic approach based on seven molecular markers, we showed that ant-associated Chaetothyriales are scattered through the phylogeny of this order. There was no clustering according to geographical origin or to the taxonomy of the ant host. However, strains tended to be clustered according to the type of association with ants: strains from ant-made carton and strains from plant cavities occupied by ants ('domatia') rarely clustered together. Defining molecular operational taxonomic units (MOTUs) with an internal transcribed spacer sequence similarity cut-off of 99% revealed that a single MOTU could be composed of strains collected from various ant species and from several continents. Some ant-associated MOTUs also contained strains isolated from habitats other than ant-associated structures. Altogether, our results suggest that the degree of specialization of the interactions between ants and their fungal partners is highly variable. A better knowledge of the ecology of these interactions and a more comprehensive sampling of the fungal order are needed to elucidate the evolutionary history of mutualistic symbioses between ants and Chaetothyriales. © 2017 The Author(s).

  20. Tetramorium tsushimae Ants Use Methyl Branched Hydrocarbons of Aphids for Partner Recognition.

    PubMed

    Sakata, Itaru; Hayashi, Masayuki; Nakamuta, Kiyoshi

    2017-10-04

    In mutualisms, partner discrimination is often the most important challenge for interacting organisms. The interaction between ants and aphids is a model system for studying mutualisms; ants are provided with honeydew by aphids and, in turn, the ants offer beneficial services to the aphids. To establish and maintain this system, ants must discriminate mutualistic aphid species correctly. Although recent studies have shown that ants recognize aphids as mutualistic partners based on their cuticular hydrocarbons (CHCs), it was unclear which CHCs are involved in recognition. Here, we tested whether the n-alkane or methylalkane fraction, or both, of aphid CHCs were utilized as partner recognition cues by measuring ant aggressiveness toward these fractions. When workers of Tetramorium tsushimae ants were presented with dummies coated with n-alkanes of their mutualistic aphid Aphis craccivora, ants displayed higher levels of aggression than to dummies treated with total CHCs or methyl alkanes of A. craccivora; responses to dummies treated with n-alkanes of A. craccivora were similar to those to control dummies or dummies treated with the CHCs of the non-mutualistic aphid Acyrthosiphon pisum. By contrast, ants exhibited lower aggression to dummies treated with either total CHCs or the methylalkane fraction of the mutualistic aphid than to control dummies or dummies treated with CHCs of the non-mutualistic aphid. These results suggest that T. tsushimae ants use methylalkanes of the mutualistic aphid's CHCs to recognize partners, and that these ants do not recognize aphids as partners on the basis of n-alkanes.

  1. The acacia ants revisited: convergent evolution and biogeographic context in an iconic ant/plant mutualism.

    PubMed

    Ward, Philip S; Branstetter, Michael G

    2017-03-15

    Phylogenetic and biogeographic analyses can enhance our understanding of multispecies interactions by placing the origin and evolution of such interactions in a temporal and geographical context. We use a phylogenomic approach-ultraconserved element sequence capture-to investigate the evolutionary history of an iconic multispecies mutualism: Neotropical acacia ants (Pseudomyrmex ferrugineus group) and their associated Vachellia hostplants. In this system, the ants receive shelter and food from the host plant, and they aggressively defend the plant against herbivores and competing plants. We confirm the existence of two separate lineages of obligate acacia ants that convergently occupied Vachellia and evolved plant-protecting behaviour, from timid ancestors inhabiting dead twigs in rainforest. The more diverse of the two clades is inferred to have arisen in the Late Miocene in northern Mesoamerica, and subsequently expanded its range throughout much of Central America. The other lineage is estimated to have originated in southern Mesoamerica about 3 Myr later, apparently piggy-backing on the pre-existing mutualism. Initiation of the Pseudomyrmex/Vachellia interaction involved a shift in the ants from closed to open habitats, into an environment with more intense plant herbivory. Comparative studies of the two lineages of mutualists should provide insight into the essential features binding this mutualism. © 2017 The Author(s).

  2. Amphotis marginata (Coleoptera: Nitidulidae) a highwayman of the ant Lasius fuliginosus

    PubMed Central

    Hölldobler, Bert

    2017-01-01

    The space occupied by evolutionarily advanced ant societies can be subdivided into functional sites, such as broodchambers; peripheral nest chambers; kitchen middens; and foraging routes. Many predators and social parasites are specially adapted to make their living inside specific niches created by ants. In particular, the foraging paths of certain ant species are frequented by predatory and kleptoparasitic arthropods, including one striking example, the nitidulid beetle, Amphotis marginata. Adults of this species obtain the majority of their nutrition by acting as a kind of “highwayman” on the foraging trails of the ant Lasius fuliginosus, where they solicit regurgitation from food laden ant-workers by mimicking the ant’s food-begging signals. Employing food labeled with the radio isotope 32P, we assessed the quantities of food the beetles siphoned-off of food-laden ants, and we investigated the site preferences, behavioral mechanisms and possible morphological adaptations underlying the food kleptoparasitism of A. marginata. PMID:28783744

  3. Kin-informative recognition cues in ants.

    PubMed

    Nehring, Volker; Evison, Sophie E F; Santorelli, Lorenzo A; d'Ettorre, Patrizia; Hughes, William O H

    2011-07-07

    Although social groups are characterized by cooperation, they are also often the scene of conflict. In non-clonal systems, the reproductive interests of group members will differ and individuals may benefit by exploiting the cooperative efforts of other group members. However, such selfish behaviour is thought to be rare in one of the classic examples of cooperation--social insect colonies--because the colony-level costs of individual selfishness select against cues that would allow workers to recognize their closest relatives. In accord with this, previous studies of wasps and ants have found little or no kin information in recognition cues. Here, we test the hypothesis that social insects do not have kin-informative recognition cues by investigating the recognition cues and relatedness of workers from four colonies of the ant Acromyrmex octospinosus. Contrary to the theoretical prediction, we show that the cuticular hydrocarbons of ant workers in all four colonies are informative enough to allow full-sisters to be distinguished from half-sisters with a high accuracy. These results contradict the hypothesis of non-heritable recognition cues and suggest that there is more potential for within-colony conflicts in genetically diverse societies than previously thought.

  4. The global expansion of a single ant supercolony

    PubMed Central

    Van Wilgenburg, Ellen; Torres, Candice W; Tsutsui, Neil D

    2010-01-01

    Ants are among the most damaging invasive species, and their success frequently arises from the widespread cooperation displayed by introduced populations, often across hundreds of kilometers. Previous studies of the invasive Argentine ant (Linepithema humile) have shown that introduced populations on different continents each contain a single, vast supercolony and, occasionally, smaller secondary colonies. Here, we perform inter-continental behavioral analyses among supercolonies in North America, Europe, Asia, Hawaii, New Zealand and Australia and show that these far-flung supercolonies also recognize and accept each other as if members of a single, globally distributed supercolony. Furthermore, populations also possess similar genetic and chemical profiles. However, these ants do show aggression toward ants from South Africa and the smaller secondary colonies that occur in Hawaii and California. Thus, the largest and most dominant introduced populations are likely descended from the same ancestral colony and, despite having been established more than 100 years ago, have diverged very little. This apparent evolutionary stasis is surprising because, in other species, some of the most rapid rates of evolutionary change have occurred in introduced populations. Given the spatial extent of the Argentine ant society we report here, there can be little doubt that this intercontinental supercolony represents the most populous known animal society. PMID:25567914

  5. The global expansion of a single ant supercolony.

    PubMed

    Van Wilgenburg, Ellen; Torres, Candice W; Tsutsui, Neil D

    2010-03-01

    Ants are among the most damaging invasive species, and their success frequently arises from the widespread cooperation displayed by introduced populations, often across hundreds of kilometers. Previous studies of the invasive Argentine ant (Linepithema humile) have shown that introduced populations on different continents each contain a single, vast supercolony and, occasionally, smaller secondary colonies. Here, we perform inter-continental behavioral analyses among supercolonies in North America, Europe, Asia, Hawaii, New Zealand and Australia and show that these far-flung supercolonies also recognize and accept each other as if members of a single, globally distributed supercolony. Furthermore, populations also possess similar genetic and chemical profiles. However, these ants do show aggression toward ants from South Africa and the smaller secondary colonies that occur in Hawaii and California. Thus, the largest and most dominant introduced populations are likely descended from the same ancestral colony and, despite having been established more than 100 years ago, have diverged very little. This apparent evolutionary stasis is surprising because, in other species, some of the most rapid rates of evolutionary change have occurred in introduced populations. Given the spatial extent of the Argentine ant society we report here, there can be little doubt that this intercontinental supercolony represents the most populous known animal society.

  6. A case of ant anaphylaxis.

    PubMed

    Mehr, Sam; Brown, Simon

    2012-03-01

    A four-year-old girl developed anaphylaxis following ant stings at her parent's property in country New South Wales. The offending insect was identified by an entomologist as the green head ant. Ant sting anaphylactic reactions in Australia, the importance of identifying the offending insect following sting anaphylaxis and the signs of insect sting anaphylaxis are further discussed. © 2010 The Authors. Journal of Paediatrics and Child Health © 2010 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  7. A novel interference behaviour: invasive wasps remove ants from resources and drop them from a height

    PubMed Central

    Grangier, Julien; Lester, Philip J.

    2011-01-01

    This study reports a novel form of interference behaviour between the invasive wasp Vespula vulgaris and the New Zealand native ant Prolasius advenus. By videotaping interactions at bait stations, we found that wasps commonly remove ant competitors from food resources by picking up the workers in their mandibles, flying backward and dropping them unharmed some distance from the food. Both the frequency and the efficiency of the wasp behaviour significantly increased with the abundance of ant competitors. Ant removals were the most common interference events initiated by wasps when ants were numerous, while intraspecific conflicts among wasps were prominent when few ants were present. The ‘ant-dropping’ behaviour emphasizes how asymmetry in body sizes between competitors can lead to a pronounced form of interference, related to asymmetric locomotion modes. PMID:21450726

  8. A novel interference behaviour: invasive wasps remove ants from resources and drop them from a height.

    PubMed

    Grangier, Julien; Lester, Philip J

    2011-10-23

    This study reports a novel form of interference behaviour between the invasive wasp Vespula vulgaris and the New Zealand native ant Prolasius advenus. By videotaping interactions at bait stations, we found that wasps commonly remove ant competitors from food resources by picking up the workers in their mandibles, flying backward and dropping them unharmed some distance from the food. Both the frequency and the efficiency of the wasp behaviour significantly increased with the abundance of ant competitors. Ant removals were the most common interference events initiated by wasps when ants were numerous, while intraspecific conflicts among wasps were prominent when few ants were present. The 'ant-dropping' behaviour emphasizes how asymmetry in body sizes between competitors can lead to a pronounced form of interference, related to asymmetric locomotion modes.

  9. Studying the Complex Communities of Ants and Their Symbionts Using Ecological Network Analysis.

    PubMed

    Ivens, Aniek B F; von Beeren, Christoph; Blüthgen, Nico; Kronauer, Daniel J C

    2016-01-01

    Ant colonies provide well-protected and resource-rich environments for a plethora of symbionts. Historically, most studies of ants and their symbionts have had a narrow taxonomic scope, often focusing on a single ant or symbiont species. Here we discuss the prospects of studying these assemblies in a community ecology context using the framework of ecological network analysis. We introduce three basic network metrics that we consider particularly relevant for improving our knowledge of ant-symbiont communities: interaction specificity, network modularity, and phylogenetic signal. We then discuss army ant symbionts as examples of large and primarily parasitic communities, and symbiotic sternorrhynchans as examples of generally smaller and primarily mutualistic communities in the context of these network analyses. We argue that this approach will provide new and complementary insights into the evolutionary and ecological dynamics between ants and their many associates, and will facilitate comparisons across different ant-symbiont assemblages as well as across different types of ecological networks.

  10. Filamentous fungi vectored by ants (Hymenoptera: Formicidae) in a public hospital in North-Eastern Brazil.

    PubMed

    Aquino, R S S; Silveira, S S; Pessoa, W F B; Rodrigues, A; Andrioli, J L; Delabie, J H C; Fontana, R

    2013-03-01

    The increase in opportunistic fungal infections has led to the search for putative sources of contamination in hospital environments. Ants in a public hospital in Itabuna, north-eastern Brazil were examined for carriage of filamentous fungi. During a year-long survey, ants from different hospital areas were sampled. Preference was given to locations where it was possible to observe ants actively foraging. The fungi found on the ants' integument were cultured and identified. A total of 106 ant workers belonging to 12 species in 11 genera were collected. A total of 47 fungal strains was isolated from 40% of the ants (N = 42). We found 16 fungal species in 13 genera associated with the ant workers. The prevalent fungal genera were Aspergillus, Purpureocillium and Fusarium. The ants Tapinoma melanocephalum, Paratrechina longicornis and Pheidole megacephala were associated with six fungal genera; and four genera of fungi were associated with Solenopsis saevissima workers. Fungal diversity was higher in the following hospital areas: nursery, hospital beds, breastmilk bank and paediatrics. Ants act as carriers of soil and airborne fungal species, and ant control in hospital areas is necessary to prevent the dissemination of such micro-organisms. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  11. Exploring whether and how ants affect reproductive fitness in Senna mexicana var. chapmanii

    USDA-ARS?s Scientific Manuscript database

    Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and ants. Ant-plant mutualisms are keystone associations, occurring within a complex web of biotic interactions. As such, these interactions may affect plant fitness in a number of ways, both positive and negative. In S...

  12. Stridulations Reveal Cryptic Speciation in Neotropical Sympatric Ants

    PubMed Central

    Ferreira, Ronara Souza; Poteaux, Chantal; Delabie, Jacques Hubert Charles; Fresneau, Dominique; Rybak, Fanny

    2010-01-01

    The taxonomic challenge posed by cryptic species underlines the importance of using multiple criteria in species delimitation. In the current paper we tested the use of acoustic analysis as a tool to assess the real diversity in a cryptic species complex of Neotropical ants. In order to understand the potential of acoustics and to improve consistency in the conclusions by comparing different approaches, phylogenetic relationships of all the morphs considered were assessed by the analysis of a fragment of the mitochondrial DNA cytochrome b. We observed that each of the cryptic morph studied presents a morphologically distinct stridulatory organ and that all sympatric morphs produce distinctive stridulations. This is the first evidence of such a degree of specialization in the acoustic organ and signals in ants, which suggests that stridulations may be among the cues used by these ants during inter-specific interactions. Mitochondrial DNA variation corroborated the acoustic differences observed, confirming acoustics as a helpful tool to determine cryptic species in this group of ants, and possibly in stridulating ants in general. Congruent morphological, acoustic and genetic results constitute sufficient evidence to propose each morph studied here as a valid new species, suggesting that P. apicalis is a complex of at least 6 to 9 species, even if they present different levels of divergence. Finally, our results highlight that ant stridulations may be much more informative than hitherto thought, as much for ant communication as for integrative taxonomists. PMID:21203529

  13. Wasps robbing food from ants: a frequent behavior?

    NASA Astrophysics Data System (ADS)

    Lapierre, Louis; Hespenheide, Henry; Dejean, Alain

    2007-12-01

    Food robbing, or cleptobiosis, has been well documented throughout the animal kingdom. For insects, intrafamilial food robbing is known among ants, but social wasps (Vespidae; Polistinae) taking food from ants has, to the best of our knowledge, never been reported. In this paper, we present two cases involving social wasps robbing food from ants associated with myrmecophytes. (1) Polybioides tabida F. (Ropalidiini) rob pieces of prey from Tetraponera aethiops Smith (Formicidae; Pseudomyrmecinae) specifically associated with Barteria fistulosa Mast. (Passifloraceae). (2) Charterginus spp. (Epiponini) rob food bodies from myrmecophytic Cecropia (Cecropiaceae) exploited by their Azteca mutualists (Formicidae; Dolichoderinae) or by opportunistic ants (that also attack cleptobiotic wasps). We note here that wasps gather food bodies (1) when ants are not yet active; (2) when ants are active, but avoiding any contact with them by flying off when attacked; and (3) through the coordinated efforts of two to five wasps, wherein one of them prevents the ants from leaving their nest, while the other wasps freely gather the food bodies. We suggest that these interactions are more common than previously thought.

  14. Cotton Rats Alter Foraging in Response to an Invasive Ant

    PubMed Central

    Darracq, Andrea K.; Conner, L. Mike; Brown, Joel S.; McCleery, Robert A.

    2016-01-01

    We assessed the effects of red imported fire ants (Solenopsis invicta; hereafter fire ant) on the foraging of hispid cotton rats (Sigmodon hispidus). We used a manipulative experiment, placing resource patches with a known amount of millet seed within areas with reduced (RIFA [–]) or ambient (RIFA [+]) numbers of fire ants. We measured giving up densities (the amount of food left within each patch) within the resource patches for 4 days to quantify the effects of fire ants on cotton rat foraging. We assessed the effects of fire ant treatment (RIFA), Day, and their interaction on cotton rat giving up densities. Giving up densities on RIFA [+] grids were nearly 2.2 times greater across all foraging days and ranged from 1.6 to 2.3 times greater from day 1 to day 4 than the RIFA [–] grids. From day 1 to day 4, mean giving up densities decreased significantly faster for the RIFA [–] than RIFA [+] treatments, 58% and 13%, respectively. Our results demonstrate that cotton rats perceive a risk of injury from fire ants, which is likely caused by interference competition, rather than direct predation. Envenomation from ants likely decrease the foraging efficiency of cotton rats resulting in more time spent foraging. Increased time spent foraging is likely stressful in terms of the opportunity for direct injury and encounters with other predators. These indirect effects may reduce an individual cotton rat’s fitness and translate into lowered population abundances. PMID:27655320

  15. Cotton Rats Alter Foraging in Response to an Invasive Ant.

    PubMed

    Darracq, Andrea K; Conner, L Mike; Brown, Joel S; McCleery, Robert A

    We assessed the effects of red imported fire ants (Solenopsis invicta; hereafter fire ant) on the foraging of hispid cotton rats (Sigmodon hispidus). We used a manipulative experiment, placing resource patches with a known amount of millet seed within areas with reduced (RIFA [-]) or ambient (RIFA [+]) numbers of fire ants. We measured giving up densities (the amount of food left within each patch) within the resource patches for 4 days to quantify the effects of fire ants on cotton rat foraging. We assessed the effects of fire ant treatment (RIFA), Day, and their interaction on cotton rat giving up densities. Giving up densities on RIFA [+] grids were nearly 2.2 times greater across all foraging days and ranged from 1.6 to 2.3 times greater from day 1 to day 4 than the RIFA [-] grids. From day 1 to day 4, mean giving up densities decreased significantly faster for the RIFA [-] than RIFA [+] treatments, 58% and 13%, respectively. Our results demonstrate that cotton rats perceive a risk of injury from fire ants, which is likely caused by interference competition, rather than direct predation. Envenomation from ants likely decrease the foraging efficiency of cotton rats resulting in more time spent foraging. Increased time spent foraging is likely stressful in terms of the opportunity for direct injury and encounters with other predators. These indirect effects may reduce an individual cotton rat's fitness and translate into lowered population abundances.

  16. A model for collective dynamics in ant raids.

    PubMed

    Ryan, Shawn D

    2016-05-01

    Ant raiding, the process of identifying and returning food to the nest or bivouac, is a fascinating example of collective motion in nature. During such raids ants lay pheromones to form trails for others to find a food source. In this work a coupled PDE/ODE model is introduced to study ant dynamics and pheromone concentration. The key idea is the introduction of two forms of ant dynamics: foraging and returning, each governed by different environmental and social cues. The model accounts for all aspects of the raiding cycle including local collisional interactions, the laying of pheromone along a trail, and the transition from one class of ants to another. Through analysis of an order parameter measuring the orientational order in the system, the model shows self-organization into a collective state consisting of lanes of ants moving in opposite directions as well as the transition back to the individual state once the food source is depleted matching prior experimental results. This indicates that in the absence of direct communication ants naturally form an efficient method for transporting food to the nest/bivouac. The model exhibits a continuous kinetic phase transition in the order parameter as a function of certain system parameters. The associated critical exponents are found, shedding light on the behavior of the system near the transition.

  17. Alkaloid venom weaponry of three Megalomyrmex thief ants and the behavioral response of Cyphomyrmex costatus host ants.

    PubMed

    Adams, Rachelle M M; Jones, Tappey H; Longino, John T; Weatherford, Robert G; Mueller, Ulrich G

    2015-04-01

    Social parasites exploit other societies by invading and stealing resources. Some enter protected nests using offensive chemical weaponry made from alkaloid-based venom. We characterized the venoms of three Megalomyrmex thief ant species (M. mondabora, M. mondaboroides, and M. silvestrii) that parasitize the fungus-growing ants, and developed an ethogram to describe host ant reactions to raiding M. mondaboroides and M. silvestrii parasites. We compared piperidine, pyrrolidine, and pyrolizidine venom alkaloid structures with synthetic samples from previous studies, and describe the novel stereochemistry of trans 2-hexyl-5-[8-oxononyl]-pyrrolidine (3) from M. mondabora. We showed that workers of Cyphomyrmex costatus, the host of M. mondaboroides and M. silvestrii, react to a sting by Megalomyrmex parasites mainly with submissive behavior, playing dead or retreating. Host submission also followed brief antennal contact. The behavior of C. costatus ants observed in this study was similar to that of Cyphomyrmex cornutus, host of M. mondabora, suggesting that the alkaloidal venoms with pyrrolidines from M. mondabora, piperidines from M. mondaboroides, and pyrolizidines from M. silvestrii may function similarly as appeasement and repellent allomones against host ants, despite their different chemical structure. With the use of these chemical weapons, the Megalomyrmex thief ants are met with little host resistance and easily exploit host colony resources.

  18. Benefits for plants in ant-plant protective mutualisms: a meta-analysis.

    PubMed

    Trager, Matthew D; Bhotika, Smriti; Hostetler, Jeffrey A; Andrade, Gilda V; Rodriguez-Cabal, Mariano A; McKeon, C Seabird; Osenberg, Craig W; Bolker, Benjamin M

    2010-12-22

    Costs and benefits for partners in mutualistic interactions can vary greatly, but surprisingly little is known about the factors that drive this variation across systems. We conducted a meta-analysis of ant-plant protective mutualisms to quantify the effects of ant defenders on plant reproductive output, to evaluate if reproductive effects were predicted from reductions in herbivory and to identify characteristics of the plants, ants and environment that explained variation in ant protection. We also compared our approach with two other recent meta-analyses on ant-plant mutualisms, emphasizing differences in our methodology (using a weighted linear mixed effects model) and our focus on plant reproduction rather than herbivore damage. Based on 59 ant and plant species pairs, ant presence increased plant reproductive output by 49% and reduced herbivory by 62%. The effects on herbivory and reproduction within systems were positively correlated, but the slope of this relationship (0.75) indicated that tolerance to foliar herbivory may be a common plant response to absence of ant guards. Furthermore, the relationship between foliar damage and reproduction varied substantially among systems, suggesting that herbivore damage is not a reliable surrogate for fitness consequences of ant protection. Studies that experimentally excluded ants reported a smaller effect of ant protection on plant reproduction than studies that relied upon natural variation in ant presence, suggesting that study methods can affect results in these systems. Of the ecological variables included in our analysis, only plant life history (i.e., annual or perennial) explained variation in the protective benefit of mutualistic ants: presence of ants benefitted reproduction of perennials significantly more than that of annuals. These results contrast with other quantitative reviews of these relationships that did not include plant life history as an explanatory factor and raise several questions to guide

  19. Benefits for Plants in Ant-Plant Protective Mutualisms: A Meta-Analysis

    PubMed Central

    Trager, Matthew D.; Bhotika, Smriti; Hostetler, Jeffrey A.; Andrade, Gilda V.; Rodriguez-Cabal, Mariano A.; McKeon, C. Seabird; Osenberg, Craig W.; Bolker, Benjamin M.

    2010-01-01

    Costs and benefits for partners in mutualistic interactions can vary greatly, but surprisingly little is known about the factors that drive this variation across systems. We conducted a meta-analysis of ant-plant protective mutualisms to quantify the effects of ant defenders on plant reproductive output, to evaluate if reproductive effects were predicted from reductions in herbivory and to identify characteristics of the plants, ants and environment that explained variation in ant protection. We also compared our approach with two other recent meta-analyses on ant-plant mutualisms, emphasizing differences in our methodology (using a weighted linear mixed effects model) and our focus on plant reproduction rather than herbivore damage. Based on 59 ant and plant species pairs, ant presence increased plant reproductive output by 49% and reduced herbivory by 62%. The effects on herbivory and reproduction within systems were positively correlated, but the slope of this relationship (0.75) indicated that tolerance to foliar herbivory may be a common plant response to absence of ant guards. Furthermore, the relationship between foliar damage and reproduction varied substantially among systems, suggesting that herbivore damage is not a reliable surrogate for fitness consequences of ant protection. Studies that experimentally excluded ants reported a smaller effect of ant protection on plant reproduction than studies that relied upon natural variation in ant presence, suggesting that study methods can affect results in these systems. Of the ecological variables included in our analysis, only plant life history (i.e., annual or perennial) explained variation in the protective benefit of mutualistic ants: presence of ants benefitted reproduction of perennials significantly more than that of annuals. These results contrast with other quantitative reviews of these relationships that did not include plant life history as an explanatory factor and raise several questions to guide

  20. Creative Drama and Agricultural Societies.

    ERIC Educational Resources Information Center

    Courtney, Richard

    1989-01-01

    Discusses the interaction of culture and creative drama. Examines agricultural societies under three conditions: historically, from neolithic times; contemporary American Southwest Indian and Polynesian; and modern farming subcultures of European industrial societies. Asks how far agricultural life influences creative drama in agrarian societies.…

  1. Indirect benefits of symbiotic coccoids for an ant-defended myrmecophytic tree.

    PubMed

    Pringle, Elizabeth G; Dirzo, Rodolfo; Gordon, Deborah M

    2011-01-01

    The net benefits of mutualism depend directly on the costs and effectiveness of mutualistic services and indirectly on the interactions that affect those services. We examined interactions among Cordia alliodora myrmecophytic trees, their symbiotic ants Azteca pittieri, coccoid hemipterans, and foliar herbivores in two Neotropical dry forests. The tree makes two investments in symbiotic ants: it supplies nesting space, as domatia, and it provides phloem to coccoids, which then produce honeydew that is consumed by ants. Although higher densities of coccoids should have higher direct costs for trees, we asked whether higher densities of coccoids can also have higher indirect benefits for trees by increasing the effectiveness of ant defense against foliar herbivores. We found that trees benefited from ant defense against herbivores. Ants defended trees effectively only when colonies reached high densities within trees, and ant and coccoid densities within trees were strongly positively correlated. The benefits of reduced foliar herbivory by larger ant colonies were therefore indirectly controlled by the number of coccoids. Coccoid honeydew supply also affected per capita ant aggression against tree herbivores. Ants experimentally fed a carbohydrate-rich diet, analogous to sugar obtained from coccoids, were more aggressive against caterpillars per capita than ants fed a carbohydrate-poor diet. Ant defense was more effective on more valuable and vulnerable young leaves than on older leaves. Young domatia, associated with young leaves, contained higher coccoid densities than older domatia, which suggests that coccoids may also drive spatially favorable ant defense of the tree. If higher investments by one mutualistic partner are tied to higher benefits received from the other, there may be positive feedback between partners that will stabilize the mutualism. These results suggest that higher investment by trees in coccoids leads to more effective defense by ants against

  2. Fire ant microsporidia acquired by parasitoid flies of fire ants

    USDA-ARS?s Scientific Manuscript database

    The microsporidium Kneallhazia (formerly Thelohania) solenopsae and parasitoid flies in the genus Pseudacteon are natural enemies of the invasive fire ant, Solenopsis invicta. Pseudacteon flies oviposit into adult fire ants, where maggots that eclose from eggs migrate to the ants’ head, pupate, and...

  3. Interactions and Interventions: Current Research on Improving Informal Astronomy Education via the Astronomical Society of the Pacific (ASP)

    NASA Astrophysics Data System (ADS)

    Manning, James G.; Gurton, S.; Hurst, A.; Berendsen, M.; Storksdieck, M.; Haley-Goldman, K.; Stein, J.; Pompea, S.; Garmany, C.; Sparks, R.; Pollock, W.

    2007-12-01

    In building national capacity for better informal astronomy education and public outreach (EPO), what sorts of professional development interactions are most effective in what situations--and what interventions for improvement can be effectively applied? Building on previous experience, the ASP, in conjunction with its partners, is conducting two National Science Foundation (NSF) funded projects investigating astronomy teaching and learning in informal contexts to explore these questions in both museum-based and amateur astronomy club settings. "Astronomy from the Ground Up" (AfGU) develops capacity for hands-on astronomy education in small and medium-sized science centers and nature centers through on-site and online professional development workshops and the establishment of a "community of practice" network. The ASP, in collaboration with the National Optical Astronomy Observatory (NOAO) and the Association of Science and Technology Centers (ASTC), is investigating which model--face-to-face or online professional development--works best and will be sustainable for that target group. "Sharing the Universe" (STU) builds on the Night Sky Network in which amateur astronomy clubs, through the ASP with financial and logistical support from NASA and its missions, are provided tools and training to conduct EPO activities with their public audiences. The ASP, in collaboration with the Institute for Learning Innovation (ILI), launched a national survey in late 2007 to investigate the factors that either support or discourage sustained amateur astronomer EPO efforts, followed by an in-depth study of a subset of both successful and struggling clubs, and leading to the development of interventions that support amateur astronomy outreach within the context of a nurturing club environment. The presentation will offer some early and initial results of the AfGU project--which reveal some interesting and unforeseen advantages of the online model over the on-site model--and some

  4. Native predators living in invaded areas: responses of terrestrial amphibian species to an Argentine ant invasion.

    PubMed

    Alvarez-Blanco, Paloma; Caut, Stephane; Cerdá, Xim; Angulo, Elena

    2017-08-22

    Predator-prey interactions play a key role in the success and impacts of invasive species. However, the effects of invasive preys on native predators have been poorly studied. Here, we first reviewed hypotheses describing potential relationships between native predators and invasive preys. Second, we examined how an invasive prey, the Argentine ant (Linepithema humile), affected a native terrestrial amphibian community. In the field, we looked at the structure of the amphibian community in invaded versus uninvaded areas and characterized amphibian trophic ecology. The amphibian community sampled seemed to show a species-dependent response in abundance to invasion: adults of the natterjack toad (Bufo calamita), the species demonstrating the highest degree of ant specialization, were less abundant in invaded areas. Although available ant biomass was significantly greater in invaded than in uninvaded areas (only Argentine ants occurred in the former), amphibians consumed relatively fewer ants in invaded areas. In the lab, we quantified amphibian consumption of Argentine ants versus native ants and assessed whether consumption patterns could have been influenced by prior exposure to the invader. The lab experiments corroborated the field results: amphibians preferred native ants over Argentine ants, and prior exposure did not influence consumption. Differences in preference explained why amphibians consumed fewer Argentine ants in spite of their greater relative availability; they might also explain why the most ant-specialized amphibians seemed to avoid invaded areas. Our results suggest the importance to account for predator feeding capacities and dietary ranges to understand the effects of invasive species at higher trophic levels.

  5. Ants have a negative rather than a positive effect on extrafloral nectaried Crotalaria pallida performance

    NASA Astrophysics Data System (ADS)

    Pereira, Marcela Fernandes; Trigo, José Roberto

    2013-08-01

    Crotalaria pallida (Fabaceae) is a pantropical plant with extrafloral nectaries (EFNs) near the reproductive structures. EFN-visiting ants attack and remove arctiid moth Utetheisa ornatrix larvae, the main pre-dispersal seed predator, but the impact of ants on C. pallida fitness is unknown. To assess this impact, we controlled ant presence on plants and evaluated the reproductive output of C. pallida with and without ants. Predatory wasps also visit EFNs, prey upon U. ornatrix larvae, and may be driven out by ants during EFN feeding. Does this agonistic interaction affect the multitrophic interaction outcome? We found it difficult to evaluate the effect of both visitors because cages excluding wasps affect plant growth and do not allow U. ornatrix oviposition. Therefore, we verified whether ant presence inhibited wasp EFN visitation and predicted that (1) if ants confer a benefit for C. pallida, any negative effect of ants on wasps would be negligible for the plant because ants would be the best guardians, and (2) if ants are poor guardians, they would negatively affect wasps and negatively impact the fitness of C. pallida. Surprisingly, we found that the number of seeds/pods significantly increased, ca. 4.7 times, after ant removal. Additionally, we unexpectedly verified that controls showed a higher percentage of herbivore bored pods than ant-excluded plants. We found that wasps spent less time visiting EFNs patrolled by ants (ca. 299 s less). These results support our second prediction and suggest that the outcome of multitrophic interactions may vary with natural enemy actors.

  6. Individual-based ant-plant networks: diurnal-nocturnal structure and species-area relationship.

    PubMed

    Dáttilo, Wesley; Fagundes, Roberth; Gurka, Carlos A Q; Silva, Mara S A; Vieira, Marisa C L; Izzo, Thiago J; Díaz-Castelazo, Cecília; Del-Claro, Kleber; Rico-Gray, Victor

    2014-01-01

    Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available) in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants' composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this "night-turnover" suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night) at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences.

  7. Competitive assembly of South Pacific invasive ant communities

    PubMed Central

    Lester, Philip J; Abbott, Kirsti L; Sarty, Megan; Burns, KC

    2009-01-01

    Background The relative importance of chance and determinism in structuring ecological communities has been debated for nearly a century. Evidence for determinism or assembly rules is often evaluated with null models that randomize the occurrence of species in particular locales. However, analyses of the presence or absence of species ignores the potential influence of species abundances, which have long been considered of major importance on community structure. Here, we test for community assembly rules in ant communities on small islands of the Tokelau archipelago using both presence-absence and abundance data. We conducted three sets of analyses on two spatial scales using three years of sampling data from 39 plots on 11 islands. Results First, traditional null model tests showed support for negative species co-occurrence patterns among plots within islands, but not among islands. A plausible explanation for this result is that analyses at larger spatial scales merge heterogeneous habitats that have considerable effects on species occurrences. Second, analyses of ant abundances showed that samples with high ant abundances had fewer species than expected by chance, both within and among islands. One ant species, the invasive yellow crazy ant Anoplolepis gracilipes, appeared to have a particularly strong effect on community structure correlated with its abundance. Third, abundances of most ant species were inversely correlated with the abundances of all other ants at both spatial scales. This result is consistent with competition theory, which predicts species distributions are affected by diffuse competition with suites of co-occurring species. Conclusion Our results support a pluralistic explanation for ant species abundances and assembly. Both stochastic and deterministic processes interact to determine ant community assembly, though abundance patterns clearly drive the deterministic patterns in this community. These deterministic patterns were observed at two

  8. Exploration versus exploitation in polydomous ant colonies.

    PubMed

    Cook, Zoe; Franks, Daniel W; Robinson, Elva J H

    2013-04-21

    In socially foraging species resource information can be shared between individuals, increasing foraging success. In ant colonies, nestmate recruitment allows high exploitation rates at known resources however, to maximise foraging efficiency this must be balanced with searching for new resources. Many ant species form colonies inhabiting two or more spatially separated but socially connected nests: this type of organisation is known as polydomy. Polydomous colonies may benefit from increased foraging efficiency by carrying out dispersed-central place foraging. However, decentralisation of the colony may affect recruitment success by limiting interaction between ants based in separate nests. We use an agent-based model which compares the foraging success of monodomous and polydomous colonies in different food environments, incorporating recruitment through pheromone trails and group foraging. In contrast to previous results we show that polydomy is beneficial in some but not all cases. Polydomous colonies discover resources at a higher rate, making them more successful when food is highly dispersed, but their relative success can be lowered by limitations on recruitment success. Monodomous colonies can have higher foraging efficiency than polydomous colonies by exploiting food more rapidly. The results show the importance of interactions between recruitment strategy, colony size, and colony organisation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Using VisANT to Analyze Networks

    PubMed Central

    Hu, Zhenjun

    2014-01-01

    VisANT is a Web-based workbench for the integrative analysis of biological networks with unique features such as exploratory navigation of interaction network and multi-scale visualization and inference with integrated hierarchical knowledge. It provides functionalities for convenient construction, visualization, and analysis of molecular and higher order networks based on functional (e.g., expression profiles, phylogenetic profiles) and physical (e.g., yeast two-hybrid, chromatin-immunoprecipitation and drug target) relations from either the Predictome database or user-defined data sets. Analysis capabilities include network structure analysis, overrepresentation analysis, expression enrichment analysis etc. Additionally, network can be saved, accessed, and shared online. VisANT is able to develop and display meta-networks for meta-nodes that are structural complexes or pathways or any kind of subnetworks. Further, VisANT supports a growing number of standard exchange formats and database referencing standards, e.g., PSI-MI, KGML, BioPAX, SBML(in progress) Multiple species are supported to the extent that interactions or associations are available (i.e., public datasets or Predictome database). PMID:25422679

  10. Seed odor mediates an obligate ant-plant mutualism in Amazonian rainforests.

    PubMed

    Youngsteadt, Elsa; Nojima, Satoshi; Häberlein, Christopher; Schulz, Stefan; Schal, Coby

    2008-03-25

    Seed dispersal mutualisms are essential for the survival of diverse plant species and communities worldwide. Among invertebrates, only ants have a major role in seed dispersal, and thousands of plant species produce seeds specialized for ant dispersal in "diffuse" multispecies interactions. An outstanding but poorly understood ant-seed mutualism occurs in the Amazonian rainforest, where arboreal ants collect seeds of several epiphyte species and cultivate them in nutrient-rich nests, forming abundant and conspicuous hanging gardens known as ant-gardens (AGs). AG ants and plants are dominant members of lowland Amazonian ecosystems, and their interaction is both specific and obligate, but the means by which ants locate, recognize, and accept their mutualist seeds while rejecting other seeds is unknown. Here we address the chemical and behavioral basis of the AG interaction. We show that workers of the AG ant Camponotus femoratus are attracted to odorants emanating from seeds of the AG plant Peperomia macrostachya, and that chemical cues also elicit seed-carrying behavior. We identify five compounds from P. macrostachya seeds that, as a blend, attract C. femoratus workers. This report of attractive odorants from ant-dispersed seeds illustrates the intimacy and complexity of the AG mutualism and begins to illuminate the chemical basis of this important and enigmatic interaction.

  11. Water stress strengthens mutualism among ants, trees, and scale insects.

    PubMed

    Pringle, Elizabeth G; Akçay, Erol; Raab, Ted K; Dirzo, Rodolfo; Gordon, Deborah M

    2013-11-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  12. Dominance Hierarchies in Leptothorax Ants

    NASA Astrophysics Data System (ADS)

    Cole, Blaine J.

    1981-04-01

    The social organization of Leptothorax allardycei is unique among ant species thus far studied. The workers form linear dominance hierarchies characterized by routine displays of dominance, avoidance behavior, and even fighting. The high-ranking ants are favored in liquid food exchange, have greater ovarian development, and produce 20 percent of the eggs.

  13. Temperature: Human Regulating, Ants Conforming

    ERIC Educational Resources Information Center

    Clopton, Joe R.

    2007-01-01

    Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

  14. Temperature: Human Regulating, Ants Conforming

    ERIC Educational Resources Information Center

    Clopton, Joe R.

    2007-01-01

    Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

  15. The effects of ant nests on soil fertility and plant performance: a meta-analysis.

    PubMed

    Farji-Brener, Alejandro G; Werenkraut, Victoria

    2017-07-01

    , which may balance their known influence as primary consumers. Fourth, the effects of ant nests as fertility islands are larger in arid lands, possibly because fertility is intrinsically lower in these habitats. Overall, this study provide novel and quantitative evidence confirming that ant nests are key soil modifiers, emphasizing their role as ecological engineers. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  16. Specialization and group size: brain and behavioural correlates of colony size in ants lacking morphological castes

    PubMed Central

    Amador-Vargas, Sabrina; Gronenberg, Wulfila; Wcislo, William T.; Mueller, Ulrich

    2015-01-01

    Group size in both multicellular organisms and animal societies can correlate with the degree of division of labour. For ants, the task specialization hypothesis (TSH) proposes that increased behavioural specialization enabled by larger group size corresponds to anatomical specialization of worker brains. Alternatively, the social brain hypothesis proposes that increased levels of social stimuli in larger colonies lead to enlarged brain regions in all workers, regardless of their task specialization. We tested these hypotheses in acacia ants (Pseudomyrmex spinicola), which exhibit behavioural but not morphological task specialization. In wild colonies, we marked, followed and tested ant workers involved in foraging tasks on the leaves (leaf-ants) and in defensive tasks on the host tree trunk (trunk-ants). Task specialization increased with colony size, especially in defensive tasks. The relationship between colony size and brain region volume was task-dependent, supporting the TSH. Specifically, as colony size increased, the relative size of regions within the mushroom bodies of the brain decreased in trunk-ants but increased in leaf-ants; those regions play important roles in learning and memory. Our findings suggest that workers specialized in defence may have reduced learning abilities relative to leaf-ants; these inferences remain to be tested. In societies with monomorphic workers, brain polymorphism enhanced by group size could be a mechanism by which division of labour is achieved. PMID:25567649

  17. Specialization and group size: brain and behavioural correlates of colony size in ants lacking morphological castes.

    PubMed

    Amador-Vargas, Sabrina; Gronenberg, Wulfila; Wcislo, William T; Mueller, Ulrich

    2015-02-22

    Group size in both multicellular organisms and animal societies can correlate with the degree of division of labour. For ants, the task specialization hypothesis (TSH) proposes that increased behavioural specialization enabled by larger group size corresponds to anatomical specialization of worker brains. Alternatively, the social brain hypothesis proposes that increased levels of social stimuli in larger colonies lead to enlarged brain regions in all workers, regardless of their task specialization. We tested these hypotheses in acacia ants (Pseudomyrmex spinicola), which exhibit behavioural but not morphological task specialization. In wild colonies, we marked, followed and tested ant workers involved in foraging tasks on the leaves (leaf-ants) and in defensive tasks on the host tree trunk (trunk-ants). Task specialization increased with colony size, especially in defensive tasks. The relationship between colony size and brain region volume was task-dependent, supporting the TSH. Specifically, as colony size increased, the relative size of regions within the mushroom bodies of the brain decreased in trunk-ants but increased in leaf-ants; those regions play important roles in learning and memory. Our findings suggest that workers specialized in defence may have reduced learning abilities relative to leaf-ants; these inferences remain to be tested. In societies with monomorphic workers, brain polymorphism enhanced by group size could be a mechanism by which division of labour is achieved.

  18. Stigmergic construction and topochemical information shape ant nest architecture

    PubMed Central

    Khuong, Anaïs; Gautrais, Jacques; Perna, Andrea; Sbaï, Chaker; Combe, Maud; Kuntz, Pascale; Jost, Christian; Theraulaz, Guy

    2016-01-01

    The nests of social insects are not only impressive because of their sheer complexity but also because they are built from individuals whose work is not centrally coordinated. A key question is how groups of insects coordinate their building actions. Here, we use a combination of experimental and modeling approaches to investigate nest construction in the ant Lasius niger. We quantify the construction dynamics and the 3D structures built by ants. Then, we characterize individual behaviors and the interactions of ants with the structures they build. We show that two main interactions are involved in the coordination of building actions: (i) a stigmergic-based interaction that controls the amplification of depositions at some locations and is attributable to a pheromone added by ants to the building material; and (ii) a template-based interaction in which ants use their body size as a cue to control the height at which they start to build a roof from existing pillars. We then develop a 3D stochastic model based on these individual behaviors to analyze the effect of pheromone presence and strength on construction dynamics. We show that the model can quantitatively reproduce key features of construction dynamics, including a large-scale pattern of regularly spaced pillars, the formation and merging of caps over the pillars, and the remodeling of built structures. Finally, our model suggests that the lifetime of the pheromone is a highly influential parameter that controls the growth and form of nest architecture. PMID:26787857

  19. Competition can lead to unexpected patterns in tropical ant communities

    NASA Astrophysics Data System (ADS)

    Ellwood, M. D. Farnon; Blüthgen, Nico; Fayle, Tom M.; Foster, William A.; Menzel, Florian

    2016-08-01

    Ecological communities are structured by competitive, predatory, mutualistic and parasitic interactions combined with chance events. Separating deterministic from stochastic processes is possible, but finding statistical evidence for specific biological interactions is challenging. We attempt to solve this problem for ant communities nesting in epiphytic bird's nest ferns (Asplenium nidus) in Borneo's lowland rainforest. By recording the frequencies with which each and every single ant species occurred together, we were able to test statistically for patterns associated with interspecific competition. We found evidence for competition, but the resulting co-occurrence pattern was the opposite of what we expected. Rather than detecting species segregation-the classical hallmark of competition-we found species aggregation. Moreover, our approach of testing individual pairwise interactions mostly revealed spatially positive rather than negative associations. Significant negative interactions were only detected among large ants, and among species of the subfamily Ponerinae. Remarkably, the results from this study, and from a corroborating analysis of ant communities known to be structured by competition, suggest that competition within the ants leads to species aggregation rather than segregation. We believe this unexpected result is linked with the displacement of species following asymmetric competition. We conclude that analysing co-occurrence frequencies across complete species assemblages, separately for each species, and for each unique pairwise combination of species, represents a subtle yet powerful way of detecting structure and compartmentalisation in ecological communities.

  20. Stigmergic construction and topochemical information shape ant nest architecture.

    PubMed

    Khuong, Anaïs; Gautrais, Jacques; Perna, Andrea; Sbaï, Chaker; Combe, Maud; Kuntz, Pascale; Jost, Christian; Theraulaz, Guy

    2016-02-02

    The nests of social insects are not only impressive because of their sheer complexity but also because they are built from individuals whose work is not centrally coordinated. A key question is how groups of insects coordinate their building actions. Here, we use a combination of experimental and modeling approaches to investigate nest construction in the ant Lasius niger. We quantify the construction dynamics and the 3D structures built by ants. Then, we characterize individual behaviors and the interactions of ants with the structures they build. We show that two main interactions are involved in the coordination of building actions: (i) a stigmergic-based interaction that controls the amplification of depositions at some locations and is attributable to a pheromone added by ants to the building material; and (ii) a template-based interaction in which ants use their body size as a cue to control the height at which they start to build a roof from existing pillars. We then develop a 3D stochastic model based on these individual behaviors to analyze the effect of pheromone presence and strength on construction dynamics. We show that the model can quantitatively reproduce key features of construction dynamics, including a large-scale pattern of regularly spaced pillars, the formation and merging of caps over the pillars, and the remodeling of built structures. Finally, our model suggests that the lifetime of the pheromone is a highly influential parameter that controls the growth and form of nest architecture.

  1. Social isolation and brain development in the ant Camponotus floridanus

    NASA Astrophysics Data System (ADS)

    Seid, Marc A.; Junge, Erich

    2016-06-01

    Social interactions play a key role in the healthy development of social animals and are most pronounced in species with complex social networks. When developing offspring do not receive proper social interaction, they show developmental impairments. This effect is well documented in mammalian species but controversial in social insects. It has been hypothesized that the enlargement of the mushroom bodies, responsible for learning and memory, observed in social insects is needed for maintaining the large social networks and/or task allocation. This study examines the impact of social isolation on the development of mushroom bodies of the ant Camponotus floridanus. Ants raised in isolation were shown to exhibit impairment in the growth of the mushroom bodies as well as behavioral differences when compared to ants raised in social groups. These results indicate that social interaction is necessary for the proper development of C. floridanus mushroom bodies.

  2. Imidacloprid seed treatments affect individual ant behavior and community structure but not egg predation, pest abundance or soybean yield.

    PubMed

    Penn, Hannah J; Dale, Andrew M

    2017-08-01

    Neonicotinoid seed treatments are under scrutiny because of their variable efficacy against crop pests and for their potential negative impacts on non-target organisms. Ants provide important biocontrol services in agroecosystems and can be indicators of ecosystem health. This study tested for effects of exposure to imidacloprid plus fungicide or fungicide-treated seeds on individual ant survival, locomotion and foraging capabilities and on field ant community structure, pest abundance, ant predation and yield. Cohorts of ants exposed to either type of treated seed had impaired locomotion and a higher incidence of morbidity and mortality but no loss of foraging capacity. In the field, we saw no difference in ant species richness, regardless of seed treatment. Blocks with imidacloprid did have higher species evenness and diversity, probably owing to variable effects of the insecticide on different ant species, particularly Tetramorium caespitum. Ant predation on sentinel eggs, pest abundance and soybean growth and yield were similar in the two treatments. Both seed treatments had lethal and sublethal effects on ant individuals, and the influence of imidacloprid seed coating in the field was manifested in altered ant community composition. Those effects, however, were not strong enough to affect egg predation, pest abundance or soybean yield in field blocks. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  3. Temporal Variation in the Abundance and Richness of Foliage-Dwelling Ants Mediated by Extrafloral Nectar

    PubMed Central

    Belchior, Ceres; Sendoya, Sebastián F.

    2016-01-01

    Plants bearing extrafloral nectaries (EFNs) are common in the Brazilian cerrado savanna, where climatic conditions having marked seasonality influence arboreal ant fauna organization. These ant-plant interactions have rarely been studied at community level. Here, we tested whether: 1) EFN-bearing plants are more visited by ants than EFN-lacking plants; 2) ant visitation is higher in the rainy season than in dry season; 3) plants producing young leaves are more visited than those lacking young leaves in the rainy season; 4) during the dry season, plants with old leaves and flowers are more visited than plants with young leaves and bare of leaves or flowers; 5) the composition of visiting ant fauna differs between plants with and without EFNs. Field work was done in a cerrado reserve near Uberlândia, MG State, Brazil, along ten transects (total area 3,000 m2), in the rainy (October-January) and dry seasons (April-July) of 2010–2011. Plants (72 species; 762 individuals) were checked three times per season for ant presence. Results showed that 21 species (29%) and 266 individuals (35%) possessed EFNs. These plants attracted 38 ant species (36 in rainy, 26 in dry season). In the rainy season, plants with EFNs had higher ant abundance/richness than plants without EFNs, but in the dry season, EFN presence did not influence ant visitation. Plant phenology affected ant richness and abundance in different ways: plants with young leaves possessed higher ant richness in the rainy season, but in the dry season ant abundance was higher on plants possessing old leaves or flowers. The species composition of plant-associated ant communities, however, did not differ between plants with and without EFNs in either season. These findings suggest that the effect of EFN presence on a community of plant-visiting ants is context dependent, being conditioned to seasonal variation. PMID:27438722

  4. Effects of habitat fragmentation and degradation on flocks of African ant-following birds.

    PubMed

    Peters, Marcell K; Likare, Smith; Kraemer, Manfred

    2008-06-01

    Tropical rain forests are rapidly cleared, fragmented, and degraded in sub-Saharan Africa; however, little is known about the response of species and even of key ecological groups to these processes. One of the most intriguing (but often neglected) ecological phenomena in African rain forests is the interaction between swarm-raiding army ants and ant-following birds. Similar to their well-known Neotropical representatives, ant-following birds in Africa track the massive swarm raids of army ants and feed on arthropods flushed by the ants. In this study we analyzed the effect of habitat fragmentation and degradation of a mid-altitude Congo-Guinean rain forest in western Kenya on the structure of ant-following bird flocks. Significant numbers of swarm raids were located in all forest fragments and in both undegraded and degraded forest. Fifty-six different species of birds followed army ant raids, forming bird flocks of one to 15 species. We quantitatively differentiated the bird community into five species of specialized ant-followers and 51 species of opportunistic ant-followers. Species richness and size of bird flocks decreased with decreasing size of forest fragments and was higher in undegraded than in degraded habitat. This was caused by the decrease of the species richness and number of specialized ant-followers at swarms, while the group of opportunistic ant-followers was affected little by habitat fragmentation and degradation. The composition of bird flocks was more variable in small fragments and degraded forest, compared to undegraded habitat in large fragments. The effect of habitat fragmentation on flock structure was best explained by the strong decline of the abundance of specialized ant-followers in small forest fragments. To conserve the association of army ants and ant-following birds in its natural state, vast areas of unfragmented and undegraded tropical rain forest are necessary.

  5. Myrmecophily in Hesperiidae. The case of Vettius tertianus in ant gardens.

    PubMed

    Orivel, J; Dejean, A

    2000-08-01

    The larvae of the hesperiid butterfly Vettius tertianus develop by eating the leaves of Aechmea mertensii, a bromeliad epiphyte restricted to ant gardens. The relationships between ants and V. tertianus larvae highlight the preferential association of the caterpillars with Pachycondyla goeldii (Ponerinae), an ant-garden initiator. The oviposition strategy of V. tertianus may thus imply the identification of the inhabiting ant species and not only the identification of the host plant. The caterpillars neither provide secretions to the ants, nor possess defensive devices (i.e. hairs or appendices) against ants. Their activity rhythm does not isolate them from foraging workers of P. goeldii and their shelters are also attainable by the ants. Moreover, as the cuticular lipid profiles of V. tertianus larvae are clearly different from those of the ants and also from the leaf-surface of A. mertensii, acceptance is not due to mimicry between larvae and plants or ants. However, the caterpillars deposit, on the leaf they eat, silk containing a mixture of substances very similar to those found on their own cuticle. No interaction with ants was recorded during observations, even though the ant gardens were patrolled by numerous P. goeldii individuals during their activity period. But when confronted with the caterpillar, none of the tested ant species reacted aggressively. These results suggest the existence of compounds, other than cuticular lipids, responsible for the absence of aggressiveness in the ants. The case of V. tertianus is relatively new as myrmecophily within Hesperiidae has been described only once. Moreover, it preferentially involves a member of the Ponerinae, a subfamily in which interactions with other arthropods are exceptional.

  6. Human Adenine Nucleotide Translocase (ANT) Modulators Identified by High-Throughput Screening of Transgenic Yeast.

    PubMed

    Zhang, Yujian; Tian, Defeng; Matsuyama, Hironori; Hamazaki, Takashi; Shiratsuchi, Takayuki; Terada, Naohiro; Hook, Derek J; Walters, Michael A; Georg, Gunda I; Hawkinson, Jon E

    2016-04-01

    Transport of ADP and ATP across mitochondria is one of the primary points of regulation to maintain cellular energy homeostasis. This process is mainly mediated by adenine nucleotide translocase (ANT) located on the mitochondrial inner membrane. There are four human ANT isoforms, each having a unique tissue-specific expression pattern and biological function, highlighting their potential as drug targets for diverse clinical indications, including male contraception and cancer. In this study, we present a novel yeast-based high-throughput screening (HTS) strategy to identify compounds inhibiting the function of ANT. Yeast strains generated by deletion of endogenous proteins with ANT activity followed by insertion of individual human ANT isoforms are sensitive to cell-permeable ANT inhibitors, which reduce proliferation. Screening hits identified in the yeast proliferation assay were characterized in ADP/ATP exchange assays employing recombinant ANT isoforms expressed in isolated yeast mitochondria and Lactococcus lactis as well as by oxygen consumption rate in mammalian cells. Using this approach, closantel and CD437 were identified as broad-spectrum ANT inhibitors, whereas leelamine was found to be a modulator of ANT function. This yeast "knock-out/knock-in" screening strategy is applicable to a broad range of essential molecular targets that are required for yeast survival. © 2016 Society for Laboratory Automation and Screening.

  7. Bacterial community composition and diversity in an ancestral ant fungus symbiosis.

    PubMed

    Kellner, Katrin; Ishak, Heather D; Linksvayer, Timothy A; Mueller, Ulrich G

    2015-07-01

    Fungus-farming ants (Hymenoptera: Formicidae, Attini) exhibit some of the most complex microbial symbioses because both macroscopic partners (ants and fungus) are associated with a rich community of microorganisms. The ant and fungal microbiomes are thought to serve important beneficial nutritional and defensive roles in these symbioses. While most recent research has investigated the bacterial communities in the higher attines (e.g. the leaf-cutter ant genera Atta and Acromyrmex), which are often associated with antibiotic-producing Actinobacteria, very little is known about the microbial communities in basal lineages, labeled as 'lower attines', which retain the ancestral traits of smaller and more simple societies. In this study, we used 16S amplicon pyrosequencing to characterize bacterial communities of the lower attine ant Mycocepurus smithii among seven sampling sites in central Panama. We discovered that ant and fungus garden-associated microbiota were distinct from surrounding soil, but unlike the situation in the derived fungus-gardening ants, which show distinct ant and fungal microbiomes, microbial community structure of the ants and their fungi were similar. Another surprising finding was that the abundance of actinomycete bacteria was low and instead, these symbioses were characterized by an abundance of Lactobacillus and Pantoea bacteria. Furthermore, our data indicate that Lactobacillus strains are acquired from the environment rather than acquired vertically.

  8. The role of tending ants in host plant selection and egg parasitism of two facultative myrmecophilous butterflies.

    PubMed

    Bächtold, Alexandra; Alves-Silva, Estevão; Kaminski, Lucas A; Del-Claro, Kleber

    2014-11-01

    Ovipositing adult females of myrmecophilous lycaenids are expected to select plants based on ant presence in order to maximize the survivorship of immature stages. Usually, larvae feed ants with honey-like solutions and, in turn, ants ward off parasitoids. Nonetheless, a rarely investigated approach is whether ant partners can also extend their protective behavior towards lycaenids eggs. Here, we investigated the ant-related oviposition pattern of Allosmaitia strophius and Rekoa marius; then, we compared egg parasitism according to the presence of ants. Lycaenid oviposition and egg parasitism (in percent) were experimentally compared in ant-present and ant-excluded treatments. The study plant, Heteropterys byrsonimifolia, is an extrafloral nectaried shrub which supports several ant species. We sampled 280 eggs, of which 39.65 % belonged to A. strophius and 60.35 % to R. marius. Both lycaenids eggs were significantly more abundant on branches with ants, especially those with Camponotus crassus and Camponotus blandus, two ant species known to attend to lycaenids. A. strophius and R. marius parasitism was 4.5- and 2.4-fold higher, respectively, in ant-present treatments, but the results were not statistically significant. Our study shows that ant-mediated host plant selection in lycaenids might be much more widespread than previously thought, and not restricted to obligate myrmecophilous species. Tending ants may be inefficient bodyguards of lycaenid eggs, because unlike larvae which release sugared liquids, eggs do not offer obvious rewards to ants. Ants can ward off parasitoids of larvae, as observed elsewhere, but our findings show that positive ant-lycaenid interactions are conditional and depend on immature ontogeny.

  9. A Systematic Review of Global Drivers of Ant Elevational Diversity

    PubMed Central

    Szewczyk, Tim; McCain, Christy M.

    2016-01-01

    Ant diversity shows a variety of patterns across elevational gradients, though the patterns and drivers have not been evaluated comprehensively. In this systematic review and reanalysis, we use published data on ant elevational diversity to detail the observed patterns and to test the predictions and interactions of four major diversity hypotheses: thermal energy, the mid-domain effect, area, and the elevational climate model. Of sixty-seven published datasets from the literature, only those with standardized, comprehensive sampling were used. Datasets included both local and regional ant diversity and spanned 80° in latitude across six biogeographical provinces. We used a combination of simulations, linear regressions, and non-parametric statistics to test multiple quantitative predictions of each hypothesis. We used an environmentally and geometrically constrained model as well as multiple regression to test their interactions. Ant diversity showed three distinct patterns across elevations: most common were hump-shaped mid-elevation peaks in diversity, followed by low-elevation plateaus and monotonic decreases in the number of ant species. The elevational climate model, which proposes that temperature and precipitation jointly drive diversity, and area were partially supported as independent drivers. Thermal energy and the mid-domain effect were not supported as primary drivers of ant diversity globally. The interaction models supported the influence of multiple drivers, though not a consistent set. In contrast to many vertebrate taxa, global ant elevational diversity patterns appear more complex, with the best environmental model contingent on precipitation levels. Differences in ecology and natural history among taxa may be crucial to the processes influencing broad-scale diversity patterns. PMID:27175999

  10. Individual-Based Ant-Plant Networks: Diurnal-Nocturnal Structure and Species-Area Relationship

    PubMed Central

    Dáttilo, Wesley; Fagundes, Roberth; Gurka, Carlos A. Q.; Silva, Mara S. A.; Vieira, Marisa C. L.; Izzo, Thiago J.; Díaz-Castelazo, Cecília; Del-Claro, Kleber; Rico-Gray, Victor

    2014-01-01

    Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available) in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants’ composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this “night-turnover” suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night) at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences. PMID:24918750

  11. FORMIDABEL: The Belgian Ants Database

    PubMed Central

    Brosens, Dimitri; Vankerkhoven, François; Ignace, David; Wegnez, Philippe; Noé, Nicolas; Heughebaert, André; Bortels, Jeannine; Dekoninck, Wouter

    2013-01-01

    Abstract FORMIDABEL is a database of Belgian Ants containing more than 27.000 occurrence records. These records originate from collections, field sampling and literature. The database gives information on 76 native and 9 introduced ant species found in Belgium. The collection records originated mainly from the ants collection in Royal Belgian Institute of Natural Sciences (RBINS), the ‘Gaspar’ Ants collection in Gembloux and the zoological collection of the University of Liège (ULG). The oldest occurrences date back from May 1866, the most recent refer to August 2012. FORMIDABEL is a work in progress and the database is updated twice a year. The latest version of the dataset is publicly and freely accessible through this url: http://ipt.biodiversity.be/resource.do?r=formidabel. The dataset is also retrievable via the GBIF data portal through this link: http://data.gbif.org/datasets/resource/14697 A dedicated geo-portal, developed by the Belgian Biodiversity Platform is accessible at: http://www.formicidae-atlas.be Purpose: FORMIDABEL is a joint cooperation of the Flemish ants working group “Polyergus” (http://formicidae.be) and the Wallonian ants working group “FourmisWalBru” (http://fourmiswalbru.be). The original database was created in 2002 in the context of the preliminary red data book of Flemish Ants (Dekoninck et al. 2003). Later, in 2005, data from the Southern part of Belgium; Wallonia and Brussels were added. In 2012 this dataset was again updated for the creation of the first Belgian Ants Atlas (Figure 1) (Dekoninck et al. 2012). The main purpose of this atlas was to generate maps for all outdoor-living ant species in Belgium using an overlay of the standard Belgian ecoregions. By using this overlay for most species, we can discern a clear and often restricted distribution pattern in Belgium, mainly based on vegetation and soil types. PMID:23794918

  12. No sex in fungus-farming ants or their crops

    PubMed Central

    Himler, Anna G.; Caldera, Eric J.; Baer, Boris C.; Fernández-Marín, Hermógenes; Mueller, Ulrich G.

    2009-01-01

    Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi for food. Degenerate female mating anatomy, extensive field and laboratory surveys, and DNA fingerprinting implicate complete asexuality in this widespread ant species. Maternally inherited bacteria (e.g. Wolbachia, Cardinium) and the fungal cultivars can be ruled out as agents inducing asexuality. M. smithii societies of clonal females provide a unique system to test theories of parent–offspring conflict and reproductive policing in social insects. Asexuality of both ant farmer and fungal crop challenges traditional views proposing that sexual farmer ants outpace coevolving sexual crop pathogens, and thus compensate for vulnerabilities of their asexual crops. Either the double asexuality of both farmer and crop may permit the host to fully exploit advantages of asexuality for unknown reasons or frequent switching between crops (symbiont reassociation) generates novel ant–fungus combinations, which may compensate for any evolutionary handicaps of asexuality in M. smithii. PMID:19369264

  13. Specialized myrmecophily at the ecological dawn of modern ants.

    PubMed

    Parker, Joseph; Grimaldi, David A

    2014-10-20

    Myrmecophiles--species that depend on ant societies--include some of the most morphologically and behaviorally specialized animals known. Remarkable adaptive characters enable these creatures to bypass fortress-like security, integrate into colony life, and exploit abundant resources and protection inside ant nests. Such innovations must result from intimate coevolution with hosts, but a scarcity of definitive fossil myrmecophiles obscures when and how this lifestyle arose. Here, we report the earliest known morphologically specialized and apparently obligate myrmecophile, in Early Eocene (∼ 52 million years old) Cambay amber from India. Protoclaviger trichodens gen. et sp. nov. is a stem-group member of Clavigeritae, a speciose supertribe of pselaphine rove beetles (Coleoptera: Staphylinidae) heavily modified for myrmecophily via reduced mouthparts for trophallaxis with worker ants, brush-like trichomes that exude appeasement compounds, and fusions of many body and antennal segments. Protoclaviger captures a transitional stage in the evolutionary development of this novel body plan, most evident in its still-distinct abdominal tergites. The Cambay paleobiota marks one of the first occurrences in the fossil record of a significant presence of modern ants. Protoclaviger reveals that sophisticated social parasites were nest intruders throughout, and probably before, the ascent of ants to ecological dominance, with ancient groups such as Clavigeritae primed to radiate as their hosts became increasingly ubiquitous.

  14. Optimal construction of army ant living bridges.

    PubMed

    Graham, Jason M; Kao, Albert B; Wilhelm, Dylana A; Garnier, Simon

    2017-09-20

    Integrating the costs and benefits of collective behaviors is a fundamental challenge to understanding the evolution of group living. These costs and benefits can rarely be quantified simultaneously due to the complexity of the interactions within the group, or even compared to each other because of the absence of common metrics between them. The construction of 'living bridges' by New World army ants - which they use to shorten their foraging trails - is a unique example of a collective behavior where costs and benefits have been experimentally measured and related to each other. As a result, it is possible to make quantitative predictions about when and how the behavior will be observed. In this paper, we extend a previous mathematical model of these costs and benefits to much broader domain of applicability. Specifically, we exhibit a procedure for analyzing the optimal formation, and final configuration, of army ant living bridges given a means to express the geometrical configuration of foraging path obstructions. Using this procedure, we provide experimentally testable predictions of the final bridge position, as well as the optimal formation process for certain cases, for a wide range of scenarios, which more closely resemble common terrain obstacles that ants encounter in nature. As such, our framework offers a rare benchmark for determining the evolutionary pressures governing the evolution of a naturally occurring collective animal behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Action of Ants on Vertebrate Carcasses and Blow Flies (Calliphoridae).

    PubMed

    Paula, Michele C; Morishita, Gustavo M; Cavarson, Carolina H; Gonçalves, Cristiano R; Tavares, Paulo R A; Mendonça, Angélica; Súarez, Yzel R; Antonialli-Junior, William F

    2016-11-01

    Forensic entomology is a science that uses insect fauna as a tool to assist in criminal investigations and civil proceedings. Although the most researched insects are the Diptera and Coleoptera, ants may be present in all stages of decomposition. The aim of this study was to evaluate the role of ants and their action on blow flies during the decomposition process. Experiments were performed in which four pig carcasses were exposed in the cold and dry season (November/2012 and March/2013) and four in the hot and wet season (May/2013 and August/2013). Flies were the first insects to detect and interact with the carcasses, and six species of the Calliphoridae family were identified. Ants (Hymenoptera: Formicidae) were the second group, with six subfamilies identified. Myrmycinae represented 42% of the species, followed by Formicinae (28%), Ectatominae and Ponerinae (both 10%), and Ecitoninae and Dolichoderinae (both 5%). The ants acted on the carcasses as predators of visiting species, omnivores, and necrophagous, in all cases significantly affecting the decomposition time, slowing it down when the ants preyed on adult and immature insects consuming the carcass, or accelerating it by consuming the carcass and creating holes that could serve as gateways for the action of other organisms. The ants also generated artifacts that could lead to forensic misinterpretation.

  16. An invasive slug exploits an ant-seed dispersal mutualism.

    PubMed

    Meadley Dunphy, Shannon A; Prior, Kirsten M; Frederickson, Megan E

    2016-05-01

    Plant-animal mutualisms, such as seed dispersal, are often vulnerable to disruption by invasive species. Here, we show for the first time how a non-ant invasive species negatively affects seed dispersal by ants. We examined the effects of several animal species that co-occur in a temperate deciduous forest-including native and invasive seed-dispersing ants (Aphaenogaster rudis and Myrmica rubra, respectively), an invasive slug (Arion subfuscus), and native rodents-on a native myrmecochorous plant, Asarum canadense. We experimentally manipulated ant, slug, and rodent access to seed depots and measured seed removal. We also video-recorded depots to determine which other taxa interact with seeds. We found that A. rudis was the main disperser of seeds and that A. subfuscus consumed elaiosomes without dispersing seeds. Rodent visitation was rare, and rodent exclusion had no significant effect on seed or elaiosome removal. We then used data obtained from laboratory and field mesocosm experiments to determine how elaiosome robbing by A. subfuscus affects seed dispersal by A. rudis and M. rubra. We found that elaiosome robbing by slugs reduced seed dispersal by ants, especially in mesocosms with A. rudis, which picks up seeds more slowly than M. rubra. Taken together, our results show that elaiosome robbing by an invasive slug reduces seed dispersal by ants, suggesting that invasive slugs can have profound negative effects on seed dispersal mutualisms.

  17. Imported fire ants in the southeast

    Treesearch

    David F. Williams

    1998-01-01

    Two species of imported fire ants were introduced into the U.S. at Mobile, Alabama. The black imported fire ant, Solenopsis richteri Forel, was introduced around the early 1900's while the red imported fire ant, Solenopsis invicta Buren entered in the late 1930' or early 1940's. The red imported fire ant is the most...

  18. Ants Use Partner Specific Odors to Learn to Recognize a Mutualistic Partner

    PubMed Central

    Hojo, Masaru K.; Yamamoto, Ari; Akino, Toshiharu; Tsuji, Kazuki; Yamaoka, Ryohei

    2014-01-01

    Regulation via interspecific communication is an important for the maintenance of many mutualisms. However, mechanisms underlying the evolution of partner communication are poorly understood for many mutualisms. Here we show, in an ant-lycaenid butterfly mutualism, that attendant ants selectively learn to recognize and interact cooperatively with a partner. Workers of the ant Pristomyrmex punctatus learn to associate cuticular hydrocarbons of mutualistic Narathura japonica caterpillars with food rewards and, as a result, are more likely to tend the caterpillars. However, the workers do not learn to associate the cuticular hydrocarbons of caterpillars of a non-ant-associated lycaenid, Lycaena phlaeas, with artificial food rewards. Chemical analysis revealed cuticular hydrocarbon profiles of the mutualistic caterpillars were complex compared with those of non-ant-associated caterpillars. Our results suggest that partner-recognition based on partner-specific chemical signals and cognitive abilities of workers are important mechanisms underlying the evolution and maintenance of mutualism with ants. PMID:24489690

  19. Ants use partner specific odors to learn to recognize a mutualistic partner.

    PubMed

    Hojo, Masaru K; Yamamoto, Ari; Akino, Toshiharu; Tsuji, Kazuki; Yamaoka, Ryohei

    2014-01-01

    Regulation via interspecific communication is an important for the maintenance of many mutualisms. However, mechanisms underlying the evolution of partner communication are poorly understood for many mutualisms. Here we show, in an ant-lycaenid butterfly mutualism, that attendant ants selectively learn to recognize and interact cooperatively with a partner. Workers of the ant Pristomyrmex punctatus learn to associate cuticular hydrocarbons of mutualistic Narathura japonica caterpillars with food rewards and, as a result, are more likely to tend the caterpillars. However, the workers do not learn to associate the cuticular hydrocarbons of caterpillars of a non-ant-associated lycaenid, Lycaena phlaeas, with artificial food rewards. Chemical analysis revealed cuticular hydrocarbon profiles of the mutualistic caterpillars were complex compared with those of non-ant-associated caterpillars. Our results suggest that partner-recognition based on partner-specific chemical signals and cognitive abilities of workers are important mechanisms underlying the evolution and maintenance of mutualism with ants.

  20. Soil surface searching and transport of Euphorbia characias seeds by ants

    NASA Astrophysics Data System (ADS)

    Espadaler, Xavier; Gómez, Crisanto

    The intensity of exploring the soil surface by ants was studied for the four species involved in the dispersal and predation of seeds of the West-Mediterranean myrmecochorous plant Euphorbia characias. During the dehiscence period (June) the whole soil surface is sccanned in 43 minutes. Not all ants that find a seed take it to the nest. For the four ant species studied ( Pheidole pallidula, Aphaenogaster senilis, Tapinoma nigerrimum, Messor barbarus) the proportion of ants that finally take the seed is 67.6%. In spite of this, the high level of soil surface searching explains the rather short time that seeds remain on the soil before being removed. The presence of an elaiosome is a key element in the outcome of the ant-seed interaction: a seed with elaiosome has a seven-fold increase in probability of being taken to the nest if found by a non-granivorous ant. The predator-avoidance hypothesis for myrmecochory is supported.

  1. Behavioral Strategies of Phorid Parasitoids and Responses of Their Hosts, the Leaf-Cutting Ants

    PubMed Central

    Elizalde, Luciana; Folgarait, Patricia Julia

    2012-01-01

    Host-searching and oviposition behaviors of parasitoids, and defensive responses of the hosts, are fundamental in shaping the ecology of host-parasitoid interactions. In order to uncover key behavioral features for the little known interactions between phorid parasitoids (Diptera: Phoridae) and their leaf-cutting ant hosts (Formicidae: Attini), host-related behavioral strategies (i.e., host searching and oviposition) for 13 phorid species, and host defensive responses (i.e., hitchhikers and particular body postures) for 11 ant species, were studied. Data was collected at 14 localities, one of them characterized by its high species richness for this host-parasitoid system. Phorid species showed both great variation and specificity in attacking behaviors. Some chose their hosts using either an ambush or an actively searching strategy, while some species attacked ants on different body parts, and specialized on ants performing different tasks, such as when ants were foraging, removing wastes to refuse piles, or repairing the nest. Combining all the behaviors recorded, most phorid species differed in performance in at least one, making it possible to recognize species in the field through their behavior. Phorid species that attacked hosts with greater activity levels showed overall higher attack rates, although there was no significant correlation between attack rates by most phorid species and ant activity outside the nest while parasitoids were attacking. The presence of phorids was a significant determinant for the presence of defensive behaviors by the ants. Although ant species varied in the incidence levels of these defensive behaviors, most ant species reacted against different phorids by utilizing similar behaviors, in contrast to what parasitoids do. General features of the observed phorid-ant interactions were parasitoid specialization and corresponding high interspecific variation in their behaviors, while their hosts showed generalized responses to attacks

  2. Specific, non-nutritional association between an ascomycete fungus and Allomerus plant-ants

    PubMed Central

    Ruiz-González, Mario X.; Malé, Pierre-Jean G.; Leroy, Céline; Dejean, Alain; Gryta, Hervé; Jargeat, Patricia; Quilichini, Angélique; Orivel, Jérôme

    2011-01-01

    Ant–fungus associations are well known from attine ants, whose nutrition is based on a symbiosis with basidiomycete fungi. Otherwise, only a few non-nutritional ant–fungus associations have been recorded to date. Here we focus on one of these associations involving Allomerus plant-ants that build galleried structures on their myrmecophytic hosts in order to ambush prey. We show that this association is not opportunistic because the ants select from a monophyletic group of closely related fungal haplotypes of an ascomycete species from the order Chaetothyriales that consistently grows on and has been isolated from the galleries. Both the ants' behaviour and an analysis of the genetic population structure of the ants and the fungus argue for host specificity in this interaction. The ants' behaviour reveals a major investment in manipulating, growing and cleaning the fungus. A molecular analysis of the fungus demonstrates the widespread occurrence of one haplotype and many other haplotypes with a lower occurrence, as well as significant variation in the presence of these fungal haplotypes between areas and ant species. Altogether, these results suggest that such an interaction might represent an as-yet undescribed type of specific association between ants and fungus in which the ants cultivate fungal mycelia to strengthen their hunting galleries. PMID:21084334

  3. Density-Dependent Benefits in Ant-Hemipteran Mutualism? The Case of the Ghost Ant Tapinoma melanocephalum (Hymenoptera: Formicidae) and the Invasive Mealybug Phenacoccus solenopsis (Hemiptera: Pseudococcidae)

    PubMed Central

    Zhou, Aiming; Kuang, Beiqing; Gao, Yingrui; Liang, Guangwen

    2015-01-01

    Although density-dependent benefits to hemipterans from ant tending have been measured many times, few studies have focused on integrated effects such as interactions between ant tending, natural enemy density, and hemipteran density. In this study, we tested whether the invasive mealybug Phenacoccus solenopsis is affected by tending by ghost ants (Tapinoma melanocephalum), the presence of parasitoids, mealybug density, parasitoid density and interactions among these factors. Our results showed that mealybug colony growth rate and percentage parasitism were significantly affected by ant tending, parasitoid presence, and initial mealybug density separately. However, there were no interactions among the independent factors. There were also no significant interactions between ant tending and parasitoid density on either mealybug colony growth rate or percentage parasitism. Mealybug colony growth rate showed a negative linear relationship with initial mealybug density but a positive linear relationship with the level of ant tending. These results suggest that benefits to mealybugs are density-independent and are affected by ant tending level. PMID:25886510

  4. Behavioral Plasticity in Ant Queens: Environmental Manipulation Induces Aggression among Normally Peaceful Queens in the Socially Polymorphic Ant Leptothorax acervorum

    PubMed Central

    Trettin, Jürgen; Seyferth, Thomas; Heinze, Jürgen

    2014-01-01

    The behavioral traits that shape the structure of animal societies vary considerably among species but appear to be less flexible within species or at least within populations. Populations of the ant Leptothorax acervorum differ in how queens interact with other queens. Nestmate queens from extended, homogeneous habitats tolerate each other and contribute quite equally to the offspring of the colony (polygyny: low reproductive skew). In contrast, nestmate queens from patchy habitats establish social hierarchies by biting and antennal boxing, and eventually only the top-ranking queen of the colony lays eggs (functional monogyny: high reproductive skew). Here we investigate whether queen-queen behavior is fixed within populations or whether aggression and high skew can be elicited by manipulation of socio-environmental factors in colonies from low skew populations. An increase of queen/worker ratio and to a lesser extent food limitation elicited queen-queen antagonism in polygynous colonies from Nürnberger Reichswald similar to that underlying social and reproductive hierarchies in high-skew populations from Spain, Japan, and Alaska. In manipulated colonies, queens differed more in ovarian status than in control colonies. This indicates that queens are in principle capable of adapting the magnitude of reproductive skew to environmental changes in behavioral rather than evolutionary time. PMID:24743352

  5. A specialist herbivore uses chemical camouflage to overcome the defenses of an ant-plant mutualism.

    PubMed

    Whitehead, Susan R; Reid, Ellen; Sapp, Joseph; Poveda, Katja; Royer, Anne M; Posto, Amanda L; Kessler, André

    2014-01-01

    Many plants and ants engage in mutualisms where plants provide food and shelter to the ants in exchange for protection against herbivores and competitors. Although several species of herbivores thwart ant defenses and extract resources from the plants, the mechanisms that allow these herbivores to avoid attack are poorly understood. The specialist insect herbivore, Piezogaster reclusus (Hemiptera: Coreidae), feeds on Neotropical bull-horn acacias (Vachellia collinsii) despite the presence of Pseudomyrmex spinicola ants that nest in and aggressively defend the trees. We tested three hypotheses for how P. reclusus feeds on V. collinsii while avoiding ant attack: (1) chemical camouflage via cuticular surface compounds, (2) chemical deterrence via metathoracic defense glands, and (3) behavioral traits that reduce ant detection or attack. Our results showed that compounds from both P. reclusus cuticles and metathoracic glands reduce the number of ant attacks, but only cuticular compounds appear to be essential in allowing P. reclusus to feed on bull-horn acacia trees undisturbed. In addition, we found that ant attack rates to P. reclusus increased significantly when individuals were transferred between P. spinicola ant colonies. These results are consistent with the hypothesis that chemical mimicry of colony-specific ant or host plant odors plays a key role in allowing P. reclusus to circumvent ant defenses and gain access to important resources, including food and possibly enemy-free space. This interaction between ants, acacias, and their herbivores provides an excellent example of the ability of herbivores to adapt to ant defenses of plants and suggests that herbivores may play an important role in the evolution and maintenance of mutualisms.

  6. A Specialist Herbivore Uses Chemical Camouflage to Overcome the Defenses of an Ant-Plant Mutualism

    PubMed Central

    Whitehead, Susan R.; Reid, Ellen; Sapp, Joseph; Poveda, Katja; Royer, Anne M.; Posto, Amanda L.; Kessler, André

    2014-01-01

    Many plants and ants engage in mutualisms where plants provide food and shelter to the ants in exchange for protection against herbivores and competitors. Although several species of herbivores thwart ant defenses and extract resources from the plants, the mechanisms that allow these herbivores to avoid attack are poorly understood. The specialist insect herbivore, Piezogaster reclusus (Hemiptera: Coreidae), feeds on Neotropical bull-horn acacias (Vachellia collinsii) despite the presence of Pseudomyrmex spinicola ants that nest in and aggressively defend the trees. We tested three hypotheses for how P. reclusus feeds on V. collinsii while avoiding ant attack: (1) chemical camouflage via cuticular surface compounds, (2) chemical deterrence via metathoracic defense glands, and (3) behavioral traits that reduce ant detection or attack. Our results showed that compounds from both P. reclusus cuticles and metathoracic glands reduce the number of ant attacks, but only cuticular compounds appear to be essential in allowing P. reclusus to feed on bull-horn acacia trees undisturbed. In addition, we found that ant attack rates to P. reclusus increased significantly when individuals were transferred between P. spinicola ant colonies. These results are consistent with the hypothesis that chemical mimicry of colony-specific ant or host plant odors plays a key role in allowing P. reclusus to circumvent ant defenses and gain access to important resources, including food and possibly enemy-free space. This interaction between ants, acacias, and their herbivores provides an excellent example of the ability of herbivores to adapt to ant defenses of plants and suggests that herbivores may play an important role in the evolution and maintenance of mutualisms. PMID:25047551

  7. Widespread Chemical Detoxification of Alkaloid Venom by Formicine Ants.

    PubMed

    LeBrun, Edward G; Diebold, Peter J; Orr, Matthew R; Gilbert, Lawrence E

    2015-10-01

    The ability to detoxify defensive compounds of competitors provides key ecological advantages that can influence community-level processes. Although common in plants and bacteria, this type of detoxification interaction is extremely rare in animals. Here, using laboratory behavioral assays and analyses of videotaped interactions in South America, we report widespread venom detoxification among ants in the subfamily Formicinae. Across both data sets, nine formicine species, representing all major clades, used a stereotyped grooming behavior to self-apply formic acid (acidopore grooming) in response to fire ant (Solenopsis invicta and S. saevissima) venom exposure. In laboratory assays, this behavior increased the survivorship of species following exposure to S. invicta venom. Species expressed the behavior when exposed to additional alkaloid venoms, including both compositionally similar piperidine venom of an additional fire ant species and the pyrrolidine/pyrroline alkaloid venom of a Monomorium species. In addition, species expressed the behavior following exposure to the uncharacterized venom of a Crematogaster species. However, species did not express acidopore grooming when confronted with protein-based ant venoms or when exposed to monoterpenoid-based venom. This pattern, combined with the specific chemistry of the reaction of formic acid with venom alkaloids, indicates that alkaloid venoms are targets of detoxification grooming. Solenopsis thief ants, and Monomorium species stand out as brood-predators of formicine ants that produce piperidine, pyrrolidine, and pyrroline venom, providing an important ecological context for the use of detoxification behavior. Detoxification behavior also represents a mechanism that can influence the order of assemblage dominance hierarchies surrounding food competition. Thus, this behavior likely influences ant-assemblages through a variety of ecological pathways.

  8. Pan-Eurasian Experiment (PEEX): towards a holistic understanding of the feedbacks and interactions in the land-atmosphere-ocean-society continuum in the northern Eurasian region

    NASA Astrophysics Data System (ADS)

    Lappalainen, Hanna K.; Kerminen, Veli-Matti; Petäjä, Tuukka; Kurten, Theo; Baklanov, Aleksander; Shvidenko, Anatoly; Bäck, Jaana; Vihma, Timo; Alekseychik, Pavel; Andreae, Meinrat O.; Arnold, Stephen R.; Arshinov, Mikhail; Asmi, Eija; Belan, Boris; Bobylev, Leonid; Chalov, Sergey; Cheng, Yafang; Chubarova, Natalia; de Leeuw, Gerrit; Ding, Aijun; Dobrolyubov, Sergey; Dubtsov, Sergei; Dyukarev, Egor; Elansky, Nikolai; Eleftheriadis, Kostas; Esau, Igor; Filatov, Nikolay; Flint, Mikhail; Fu, Congbin; Glezer, Olga; Gliko, Aleksander; Heimann, Martin; Holtslag, Albert A. M.; Hõrrak, Urmas; Janhunen, Juha; Juhola, Sirkku; Järvi, Leena; Järvinen, Heikki; Kanukhina, Anna; Konstantinov, Pavel; Kotlyakov, Vladimir; Kieloaho, Antti-Jussi; Komarov, Alexander S.; Kujansuu, Joni; Kukkonen, Ilmo; Duplissy, Ella-Maria; Laaksonen, Ari; Laurila, Tuomas; Lihavainen, Heikki; Lisitzin, Alexander; Mahura, Alexsander; Makshtas, Alexander; Mareev, Evgeny; Mazon, Stephany; Matishov, Dmitry; Melnikov, Vladimir; Mikhailov, Eugene; Moisseev, Dmitri; Nigmatulin, Robert; Noe, Steffen M.; Ojala, Anne; Pihlatie, Mari; Popovicheva, Olga; Pumpanen, Jukka; Regerand, Tatjana; Repina, Irina; Shcherbinin, Aleksei; Shevchenko, Vladimir; Sipilä, Mikko; Skorokhod, Andrey; Spracklen, Dominick V.; Su, Hang; Subetto, Dmitry A.; Sun, Junying; Terzhevik, Arkady Y.; Timofeyev, Yuri; Troitskaya, Yuliya; Tynkkynen, Veli-Pekka; Kharuk, Viacheslav I.; Zaytseva, Nina; Zhang, Jiahua; Viisanen, Yrjö; Vesala, Timo; Hari, Pertti; Christen Hansson, Hans; Matvienko, Gennady G.; Kasimov, Nikolai S.; Guo, Huadong; Bondur, Valery; Zilitinkevich, Sergej; Kulmala, Markku

    2016-11-01

    The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-atmosphere-aquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context.

  9. World-wide satellite night-light data as a proxy of society-hydrology interaction and vulnerability to flood risk

    NASA Astrophysics Data System (ADS)

    Ceola, S.; Laio, F.; Montanari, A.

    2013-12-01

    The study and the analysis of the interactions and feedbacks between hydrology and society constitute the main issue of socio-hydrology. Recent flood events, which occurred across the globe, highlighted once again that mitigation strategies are needed to reduce flood risk. In particular, quick procedures for the identification of vulnerable human settlements and flood prone areas are a necessary tool to identify priorities for flood risk management. To this aim, a 19-year long period of world-wide night light data, as a proxy of human population, and the global river network have been examined. The spatio-temporal evolution of artificial luminosity depending on the distance from the river network has been assessed in order to quantitatively identify the likelihood for a populated pixel to be reached by water. The analysis focuses both on a global and on a local scale. Hotspots, such as highly illuminated areas and developing regions, have been also examined. The analysis shows an increment of yearly-averaged artificial luminosity from 1992 to 2010 (i.e. the time period of satellite data availability), whereas light intensity tends to decrease with increasing distance from the river network. The results thus reveal an increased vulnerability of human settlements to flooding events. A nearly 70-year long period of peace and the economic development after the Second World War could reasonably explain the observed enhancement of human population proximity to water bodies.

  10. Neuroretinitis following bull ant sting

    PubMed Central

    Ullrich, Katja; Saha, Niladri; Lake, Stewart

    2012-01-01

    Cat scratch disease causes the majority of cases of neuroretinitis. Neuroretinitis is characterised by clinical features of papillitis, macular oedema and macular star. We report a case study of infection with Bartonella henselae most likely transmitted by a bull ant sting. The patient presented with blurred vision and reduced visual acuity after being stung by an ant in her garden some 7 days earlier. Further testing revealed positive serology to B henselae and the patient improved with appropriate treatment. PMID:22865803

  11. New mutualism for old: indirect disruption and direct facilitation of seed dispersal following Argentine ant invasion.

    PubMed

    Rowles, Alexei D; O'Dowd, Dennis J

    2009-01-01

    The indirect effects of biological invasions on native communities are poorly understood. Disruption of native ant communities following invasion by the Argentine ant (Linepithema humile) is widely reported to lead indirectly to the near complete collapse of seed dispersal services. In coastal scrub in southeastern Australia, we examined seed dispersal and handling of two native and two invasive alien plant species at Argentine ant-invaded or -uninvaded sites. The Argentine ant virtually eliminates the native keystone disperser Rhytidoponera victoriae, but seed dispersal did not collapse following invasion. Indeed, Argentine ants directly accounted for 92% of all ant-seed interactions and sustained overall seed dispersal rates. Nevertheless, dispersal quantity and quality among seed species differed between Argentine ant-invaded and -uninvaded sites. Argentine ants removed significantly fewer native Acacia retinodes seeds, but significantly more small seeds of invasive Polygala myrtifolia than did native ants at uninvaded sites. They also handled significantly more large seeds of A. sophorae, but rarely moved them >5 cm, instead recruiting en masse, consuming elaiosomes piecemeal and burying seeds in situ. In contrast, Argentine ants transported and interred P. myrtifolia seeds in their shallow nests. Experiments with artificial diaspores that varied in diaspore and elaiosome masses, but kept seed morphology and elaiosome quality constant, showed that removal by L. humile depended on the interaction of seed size and percentage elaiosome reward. Small diaspores were frequently taken, independent of high or low elaiosome reward, but large artificial diaspores with high reward instead elicited mass recruitment by Argentine ants and were rarely moved. Thus, Argentine ants appear to favour some diaspore types and reject others based largely on diaspore size and percentage reward. Such variability in response indirectly reduces native seed dispersal and can directly

  12. Plant-derived differences in the composition of aphid honeydew and their effects on colonies of aphid-tending ants.

    PubMed

    Pringle, Elizabeth G; Novo, Alexandria; Ableson, Ian; Barbehenn, Raymond V; Vannette, Rachel L

    2014-11-01

    In plant-ant-hemipteran interactions, ants visit plants to consume the honeydew produced by phloem-feeding hemipterans. If genetically based differences in plant phloem chemistry change the chemical composition of hemipteran honeydew, then the plant's genetic constitution could have indirect effects on ants via the hemipterans. If such effects change ant behavior, they could feed back to affect the plant itself. We compared the chemical composition of honeydews produced by Aphis nerii aphid clones on two milkweed congeners, Asclepias curassavica and Asclepias incarnata, and we measured the responses of experimental Linepithema humile ant colonies to these honeydews. The compositions of secondary metabolites, sugars, and amino acids differed significantly in the honeydews from the two plant species. Ant colonies feeding on honeydew derived from A. incarnata recruited in higher numbers to artificial diet, maintained higher queen and worker dry weight, and sustained marginally more workers than ants feeding on honeydew derived from A. curassavica. Ants feeding on honeydew from A. incarnata were also more exploratory in behavioral assays than ants feeding from A. curassavica. Despite performing better when feeding on the A. incarnata honeydew, ant workers marginally preferred honeydew from A. curassavica to honeydew from A. incarnata when given a choice. Our results demonstrate that plant congeners can exert strong indirect effects on ant colonies by means of plant-species-specific differences in aphid honeydew chemistry. Moreover, these effects changed ant behavior and thus could feed back to affect plant performance in the field.

  13. Effects of substrate, ant and fungal species on plant fiber degradation in a fungus-gardening ant symbiosis.

    PubMed

    DeMilto, Alexandria M; Rouquette, Monte; Mueller, Ulrich G; Kellner, Katrin; Seal, Jon N

    2017-02-11

    fungal species grown by T. arizonensis colonies, hemicellulose utilization was higher in T. arizonensis colonies growing a derived leaf-cutting ant fungal symbiont than when growing a native type of symbiont. The results of this study demonstrate that fiber digestion in fungus-gardening ants is an outcome of ant-fungal interaction.

  14. Cryptozoology Society

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    Reports of Loch Ness monsters, Bigfoot, and the Yeti spring u p from time to time, sparking scientific controversy about the veracity of these observations. Now an organization has been established to help cull, analyze, and disseminate information on the alleged creatures. The International Society of Cryptozoology, formed at a January meeting at the U.S. National Museum of Natural History of the Smithsonian Institution, will serve as the focal point for the investigation, analysis, publication, and discussion of animals of unexpected form or size or of unexpected occurrences in time or space.

  15. Trap-mulching Argentine ants.

    PubMed

    Silverman, Jules; Sorenson, Clyde E; Waldvogel, Michael G

    2006-10-01

    Argentine ant, Linepithema humile (Mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. Management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. This concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band of pine (Pinus spp.) needle mulch (trap) within a much larger patch of repellent aromatic cedar (Juniperus spp.) mulch. After ants reestablished around the trees, the pine needle mulch band was treated with 0.06% fipronil (Termidor). Poor results were obtained when the trap extended from the tree trunk to the edge of the mulched area. When the trap was applied as a circular band around the tree trunk reductions in the number of foraging ants were recorded through 14 d compared with an untreated mulch control, but not for longer periods. Reductions in the number of ant nests within mulch were no different between the trap mulch and any of the other treatments. We conclude that trap-mulching offers limited benefits, and that successful management of Argentine ants will require implementation of complementary or perhaps alternative strategies.

  16. Measuring activity in ant colonies

    NASA Astrophysics Data System (ADS)

    Noda, C.; Fernández, J.; Pérez-Penichet, C.; Altshuler, E.

    2006-12-01

    Ants, as paradigm of social insects, have become a recurrent example of efficient problem solvers via self-organization. In spite of the simple behavior of each individual, the colony as a whole displays "swarm intelligence:" the organization of ant trails for foraging is a typical output of it. But conventional techniques of observation can hardly record the amount of data needed to get a detailed understanding of self-organization of ant swarms in the wild. Here we are presenting a measurement system intended to monitor ant activity in the field comprising massive data acquisition and high sensitivity. A central role is played by an infrared sensor devised specifically to monitor relevant parameters to the activity of ants through the exits of the nest, although other sensors detecting temperature and luminosity are added to the system. We study the characteristics of the activity sensor and its performance in the field. Finally, we present massive data measured at one exit of a nest of Atta insularis, an ant endemic to Cuba, to illustrate the potential of our system.

  17. Science and Society Colloquium

    ScienceCinema

    None

    2016-07-12

    Mr. Randi will give an update of his lecture to the American Physical Society on the occasion of his award of the 1989 Forum Prize. The citation said: "for his unique defense of Science and the scientific method in many disciplines, including physics, against pseudoscience, frauds and charlatans. His use of scientific techniques has contributed to refuting suspicious and fraudulent claims of paranormal results. He has contributed significantly to public understanding of important issues where science and society interact". He is a professional magician and author of many books. He worked with John Maddox, the Editor of Nature to investigate the claims of "water with memory".

  18. Science and Society Colloquium

    SciTech Connect

    2008-03-10

    Mr. Randi will give an update of his lecture to the American Physical Society on the occasion of his award of the 1989 Forum Prize. The citation said: "for his unique defense of Science and the scientific method in many disciplines, including physics, against pseudoscience, frauds and charlatans. His use of scientific techniques has contributed to refuting suspicious and fraudulent claims of paranormal results. He has contributed significantly to public understanding of important issues where science and society interact". He is a professional magician and author of many books. He worked with John Maddox, the Editor of Nature to investigate the claims of "water with memory".

  19. Specificity and transmission mosaic of ant nest-wall fungi

    PubMed Central

    Schlick-Steiner, Birgit C.; Steiner, Florian M.; Konrad, Heino; Seifert, Bernhard; Christian, Erhard; Moder, Karl; Stauffer, Christian; Crozier, Ross H.

    2008-01-01

    Mutualism, whereby species interact to their mutual benefit, is extraordinary in a competitive world. To recognize general patterns of origin and maintenance from the plethora of mutualistic associations proves a persisting challenge. The simplest situation is believed to be that of a single mutualist specific to a single host, vertically transmitted from one host generation to the next. We characterized ascomycete fungal associates cultured for nest architecture by the ant subgenera Dendrolasius and Chthonolasius. The ants probably manage their fungal mutualists by protecting them against fungal competitors. The ant subgenera display different ant-to-fungus specificity patterns, one-to-two and many-to-one, and we infer vertical transmission, in the latter case overlaid by horizontal transmission. Possible evolutionary trajectories include a reversal from fungiculture by other Lasius subgenera and inheritance of fungi through life cycle interactions of the ant subgenera. The mosaic indicates how specificity patterns can be shaped by an interplay between host life-cycles and transmission adaptations. PMID:18195358

  20. Glass-like dynamics in confined and congested ant traffic.

    PubMed

    Gravish, Nick; Gold, Gregory; Zangwill, Andrew; Goodisman, Michael A D; Goldman, Daniel I

    2015-09-07

    The collective movement of animal groups often occurs in confined spaces. As animal groups are challenged to move at high density, their mobility dynamics may resemble the flow of densely packed non-living soft materials such as colloids, grains, or polymers. However, unlike inert soft-materials, self-propelled collective living systems often display social interactions whose influence on collective mobility are only now being explored. In this paper, we study the mobility of bi-directional traffic flow in a social insect (the fire ant Solenopsis invicta) as we vary the diameter of confining foraging tunnels. In all tunnel diameters, we observe the emergence of spatially heterogeneous regions of fast and slow traffic that are induced through two phenomena: physical obstruction, arising from the inability of individual ants to interpenetrate, and time-delay resulting from social interaction in which ants stop to briefly antennate. Density correlation functions reveal that the relaxation dynamics of high density traffic fluctuations scale linearly with fluctuation size and are sensitive to tunnel diameter. We separate the roles of physical obstruction and social interactions in traffic flow using cellular automata based simulation. Social interaction between ants is modeled as a dwell time (Tint) over which interacting ants remain stationary in the tunnel. Investigation over a range of densities and Tint reveals that the slowing dynamics of collective motion in social living systems are consistent with dynamics near a fragile glass transition in inert soft-matter systems. In particular, flow is relatively insensitive to density until a critical density is reached. As social interaction affinity is increased (increasing Tint) traffic dynamics change and resemble a strong glass transition. Thus, social interactions play an important role in the mobility of collective living systems at high density. Our experiments and model demonstrate that the concepts of soft

  1. Assessing ecological specialization of an ant-seed dispersal mutualism through a wide geographic range.

    PubMed

    Manzaneda, Antonio J; Rey, Pedro J

    2009-11-01

    Specialization in species interactions is of central importance for understanding the ecological structure and evolution of plant-animal mutualisms. Most plant-animal mutualisms are facultative and strongly asymmetric. In particular, myrmecochory (seed dispersal by ants) has been regarded as a very generalized interaction. Although some recent studies have suggested that only a few ant species are really important for dispersal, no rigorous measurement of the specialization in ant-seed dispersal mutualisms has been performed. Here, we use individual plants as basic units for replication to investigate the generalization-specialization of the herb Helleborus foetidus on its ant dispersers over a considerable part of its geographical range. We define generalization in terms of diversity components (species richness and evenness) of the ant visitor that realizes dispersal by removing diaspores. We obtain truly comparable values of ant visitor diversity, distinguishing among different functional groups of visitors and identifying incidental visitors and real ant dispersers. Using null model approaches, we test the null hypothesis that ant-mediated dispersal is a generalized mutualism. At least two premises should be confirmed to validate the hypothesis: (1) diaspores are dispersed by multiple ant-visitor species, and (2) diaspore dispersal is significantly equitable. Though up to 37 ant species visited diaspores across 10 populations, only two large formicines, Camponotus cruentatus and Formica lugubris, were responsible for the vast majority of visits resulting in dispersal in most populations and years, which strongly suggests that ant seed dispersal in H. foetidus is ecologically specialized. Interestingly, specialization degree was unrelated to dispersal success across populations. Our study offers new insights into the spatiotemporal dynamics of myrmecochory. We propose the existence of an alternative scenario to extensive generalization. In this new scenario

  2. Rapid modification in the olfactory signal of ants following a change in reproductive status

    NASA Astrophysics Data System (ADS)

    Cuvillier-Hot, Virginie; Renault, Valérie; Peeters, Christian

    2005-02-01

    In insect societies, the presence and condition of egg-layers can be assessed with pheromones. Exocrine secretions are expected to vary in time in order to give up-to-date information on an individual’s reproductive physiology. In the queenless monogynous ant Streblognathus peetersi, we allowed a previously infertile high-ranking worker to accede to the alpha rank, thus triggering the onset of her oogenesis (15 replicates). We then studied her interactions with an established egg-layer from the same colony after different durations, ranging from 20 h to several days. Even though her eggs are only ready to be laid after 30 days, the new alpha was recognised within 1 2 days. Detection occurred at a distance of a few millimetres, suggesting the involvement of a pheromone with low volatility, such as cuticular hydrocarbons. When the new alpha had differentiated for >48 h, she was attacked by the established egg-layer. In all cases, low-ranking workers eventually immobilised one of the two alphas: the new alpha was the target if she had differentiated only recently, suggesting that police workers select the dominant worker with the “less fertile” odour. Using the behaviour of ants as our measure, we demonstrate that a dominant’s olfactory signal changes rapidly with a modification in her social status, and it occurs well before the onset of egg-laying.

  3. Differential host use in two highly specialized ant-plant associations: evidence from stable isotopes.

    PubMed

    Trimble, S T; Sagers, C L

    2004-01-01

    Carbon and nitrogen stable isotopes were used to examine variation in ant use of plant resources in the Cecropia obtusifolia / Azteca spp. association in Costa Rica. Tissue of ants, host plants and symbiotic pseudococcids were collected along three elevation transects on the Pacific slope of Costa Rica's Cordillera Central, and were analyzed for carbon and nitrogen isotopic composition. Worker carbon and nitrogen signatures were found to vary with elevation and ant colony size, and between Azteca species groups. Ants in the A. constructor species group appear to be opportunistic foragers at low elevations, but rely more heavily on their host plants at high elevations, whereas ants in the A. alfari species group consume a more consistent diet across their distribution. Further, isotope values indicate that both ant species groups acquire more nitrogen from higher trophic levels at low elevation and when ant colonies are small. Provisioning by the host is a substantial ecological cost to the interaction, and it may vary, even in a highly specialized association. Nonetheless, not all specialized interactions are equivalent; where interaction with one ant species group appears conditional upon the environment, the other is not. Differential host use within the Cecropia-Azteca association suggests that the ecological and evolutionary benefits and costs of association may vary among species pairs.

  4. Comparative dating of attine ant and lepiotaceous cultivar phylogenies reveals coevolutionary synchrony and discord.

    PubMed

    Mikheyev, Alexander S; Mueller, Ulrich G; Abbot, Patrick

    2010-06-01

    The mutualistic symbiosis between fungus-gardening ants and their cultivars has made fundamental contributions to our understanding of the coevolution of complex species interactions. Reciprocal specialization and vertical symbiont cotransmission are thought to promote a pattern of largely synchronous coevolutionary diversification in attines. Here we test this hypothesis by inferring the first time-calibrated multigene phylogeny of the lepiotaceous attine cultivars and comparing it with the recently published fossil-anchored phylogeny of the attine ants. While this comparison reveals some possible cases of synchronous origins of ant and fungal clades, there were a number of surprising asynchronies. For example, leaf-cutter cultivars appear to be significantly younger than the corresponding ant genera. Similarly, a clade of fungi interacting with primitive fungus-gardening ants--thought to be ancestral to the more derived leaf-cutter symbionts--appears instead to be a more recent acquisition from free-living stock. These macroevolutionary patterns are consistent with recent population-level studies suggesting occasional acquisition of novel cultivar types from environmental sources and horizontal transmission of cultivars between different ant species. Horizontal transmission events, even if rare, appear to form loose ecological connections between diffusely coevolving ant and fungus lineages that permit punctuated changes in the topology of the mutualistic ant-fungus interaction network.

  5. Ant exclusion in citrus over an 8-year period reveals a pervasive yet changing effect of ants on a Mediterranean spider assemblage.

    PubMed

    Mestre, L; Piñol, J; Barrientos, J A; Espadaler, X

    2013-09-01

    Ants and spiders are ubiquitous generalist predators that exert top-down control on herbivore populations. Research shows that intraguild interactions between ants and spiders can negatively affect spider populations, but there is a lack of long-term research documenting the strength of such interactions and the potentially different effects of ants on the diverse array of species in a spider assemblage. Similarly, the suitability of family-level surrogates for finding patterns revealed by species-level data (taxonomic sufficiency) has almost never been tested in spider assemblages. We present a long-term study in which we tested the impact of ants on the spider assemblage of a Mediterranean citrus grove by performing sequential 1-year experimental exclusions on tree canopies for 8 years. We found that ants had a widespread influence on the spider assemblage, although the effect was only evident in the last 5 years of the study. During those years, ants negatively affected many spiders, and effects were especially strong for sedentary spiders. Analyses at the family level also detected assemblage differences between treatments, but they concealed the different responses to ant exclusion shown by some related spider species. Our findings show that the effects of experimental manipulations in ecology can vary greatly over time and highlight the need for long-term studies to document species interactions.

  6. Thermoregulation strategies in ants in comparison to other social insects, with a focus on red wood ants ( Formica rufa group)

    PubMed Central

    Kadochová, Štěpánka; Frouz, Jan

    2014-01-01

    Temperature influences every aspect of ant biology, especially metabolic rate, growth and development. Maintenance of high inner nest temperature increases the rate of sexual brood development and thereby increases the colony fitness. Insect societies can achieve better thermoregulation than solitary insects due to the former’s ability to build large and elaborated nests and display complex behaviour. In ants and termites the upper part of the nest, the mound, often works as a solar collector and can also have an efficient ventilation system. Two thermoregulatory strategies could be applied. Firstly the ants use an increased thermal gradient available in the mound for brood relocation. Nurse workers move the brood according to the thermal gradients to ensure the ideal conditions for development. A precise perception of temperature and evolution of temperature preferences are needed to make the correct choices. A second thermoregulatory strategy used by mound nesting ants is keeping a high temperature inside large nests. The unique thermal and insulation properties of the nest material help to maintain stable conditions, which is the case of the Wood ant genus Formica. Ants can regulate thermal loss by moving nest aggregation and alternating nest ventilation. Metabolic heat produced by ant workers or associated micro organisms is an important additional source of heat which helps to maintain thermal homeostasis in the nest. PMID:24715967

  7. Thermoregulation strategies in ants in comparison to other social insects, with a focus on red wood ants ( Formica rufa group).

    PubMed

    Kadochová, Stěpánka; Frouz, Jan

    2013-01-01

    Temperature influences every aspect of ant biology, especially metabolic rate, growth and development. Maintenance of high inner nest temperature increases the rate of sexual brood development and thereby increases the colony fitness. Insect societies can achieve better thermoregulation than solitary insects due to the former's ability to build large and elaborated nests and display complex behaviour. In ants and termites the upper part of the nest, the mound, often works as a solar collector and can also have an efficient ventilation system. Two thermoregulatory strategies could be applied. Firstly the ants use an increased thermal gradient available in the mound for brood relocation. Nurse workers move the brood according to the thermal gradients to ensure the ideal conditions for development. A precise perception of temperature and evolution of temperature preferences are needed to make the correct choices. A second thermoregulatory strategy used by mound nesting ants is keeping a high temperature inside large nests. The unique thermal and insulation properties of the nest material help to maintain stable conditions, which is the case of the Wood ant genus Formica. Ants can regulate thermal loss by moving nest aggregation and alternating nest ventilation. Metabolic heat produced by ant workers or associated micro organisms is an important additional source of heat which helps to maintain thermal homeostasis in the nest.

  8. VideoANT: Extending Online Video Annotation beyond Content Delivery

    ERIC Educational Resources Information Center

    Hosack, Bradford

    2010-01-01

    This paper expands the boundaries of video annotation in education by outlining the need for extended interaction in online video use, identifying the challenges faced by existing video annotation tools, and introducing Video-ANT, a tool designed to create text-based annotations integrated within the time line of a video hosted online. Several…

  9. VideoANT: Extending Online Video Annotation beyond Content Delivery

    ERIC Educational Resources Information Center

    Hosack, Bradford

    2010-01-01

    This paper expands the boundaries of video annotation in education by outlining the need for extended interaction in online video use, identifying the challenges faced by existing video annotation tools, and introducing Video-ANT, a tool designed to create text-based annotations integrated within the time line of a video hosted online. Several…

  10. Multiple functions of fire ant, Solenopsis invicta, mandibular gland products

    USDA-ARS?s Scientific Manuscript database

    : Alarm pheromones are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality in social insects. Recently, we identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of the fire ant, Solenopsis invicta. We continu...

  11. Monoculture of Leafcutter Ant Gardens

    PubMed Central

    Mueller, Ulrich G.; Scott, Jarrod J.; Ishak, Heather D.; Cooper, Michael; Rodrigues, Andre

    2010-01-01

    Background Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. Methodology/Principal Findings Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens) and extended lifespans (10–20 years). In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells), and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. Conclusions/Significance Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants), an analog of artificial selection. PMID:20844760

  12. Few Ant Species Play a Central Role Linking Different Plant Resources in a Network in Rupestrian Grasslands

    PubMed Central

    Mello, Marco A. R.; Bronstein, Judith L.; Guerra, Tadeu J.; Muylaert, Renata L.; Leite, Alice C.; Neves, Frederico S.

    2016-01-01

    Ant-plant associations are an outstanding model to study the entangled ecological interactions that structure communities. However, most studies of plant-animal networks focus on only one type of resource that mediates these interactions (e.g, nectar or fruits), leading to a biased understanding of community structure. New approaches, however, have made possible to study several interaction types simultaneously through multilayer networks models. Here, we use this approach to ask whether the structural patterns described to date for ant-plant networks hold when multiple interactions with plant-derived food rewards are considered. We tested whether networks characterized by different resource types differ in specialization and resource partitioning among ants, and whether the identity of the core ant species is similar among resource types. We monitored ant interactions with extrafloral nectaries, flowers, and fruits, as well as trophobiont hemipterans feeding on plants, for one year, in seven rupestrian grassland (campo rupestre) sites in southeastern Brazil. We found a highly tangled ant-plant network in which plants offering different resource types are connected by a few central ant species. The multilayer network had low modularity and specialization, but ant specialization and niche overlap differed according to the type of resource used. Beyond detecting structural differences across networks, our study demonstrates empirically that the core of most central ant species is similar across them. We suggest that foraging strategies of ant species, such as massive recruitment, may determine specialization and resource partitioning in ant-plant interactions. As this core of ant species is involved in multiple ecosystem functions, it may drive the diversity and evolution of the entire campo rupestre community. PMID:27911919

  13. Few Ant Species Play a Central Role Linking Different Plant Resources in a Network in Rupestrian Grasslands.

    PubMed

    Costa, Fernanda V; Mello, Marco A R; Bronstein, Judith L; Guerra, Tadeu J; Muylaert, Renata L; Leite, Alice C; Neves, Frederico S

    2016-01-01

    Ant-plant associations are an outstanding model to study the entangled ecological interactions that structure communities. However, most studies of plant-animal networks focus on only one type of resource that mediates these interactions (e.g, nectar or fruits), leading to a biased understanding of community structure. New approaches, however, have made possible to study several interaction types simultaneously through multilayer networks models. Here, we use this approach to ask whether the structural patterns described to date for ant-plant networks hold when multiple interactions with plant-derived food rewards are considered. We tested whether networks characterized by different resource types differ in specialization and resource partitioning among ants, and whether the identity of the core ant species is similar among resource types. We monitored ant interactions with extrafloral nectaries, flowers, and fruits, as well as trophobiont hemipterans feeding on plants, for one year, in seven rupestrian grassland (campo rupestre) sites in southeastern Brazil. We found a highly tangled ant-plant network in which plants offering different resource types are connected by a few central ant species. The multilayer network had low modularity and specialization, but ant specialization and niche overlap differed according to the type of resource used. Beyond detecting structural differences across networks, our study demonstrates empirically that the core of most central ant species is similar across them. We suggest that foraging strategies of ant species, such as massive recruitment, may determine specialization and resource partitioning in ant-plant interactions. As this core of ant species is involved in multiple ecosystem functions, it may drive the diversity and evolution of the entire campo rupestre community.

  14. Genetic compatibility affects division of labor in the Argentine ant Linepithema humile.

    PubMed

    Libbrecht, Romain; Keller, Laurent

    2013-02-01

    Division of labor is central to the organization of insect societies. Within-colony comparisons between subfamilies of workers (patrilines or matrilines) revealed genetic effects on division of labor in many social insect species. Although this has been taken as evidence for additive genetic effects on division of labor, it has never been experimentally tested. To determine the relative roles of additive and nonadditive genetic effects (e.g., genetic compatibility, epistasis, and parent-of-origin imprinting effects) on worker behavior, we performed controlled crosses using the Argentine ant Linepithema humile. Three of the measured behaviors (the efficiency to collect pupae, the foraging propensity, and the distance between non-brood-tenders and brood) were affected by the maternal genetic background and the two others (the efficiency to feed larvae and the distance between brood-tenders and brood) by the paternal genetic background. Moreover, there were significant interactions between the maternal and paternal genetic backgrounds for three of the five behaviors. These results are most consistent with parent-of-origin and genetic compatibility effects on division of labor. The finding of nonadditive genetic effects is in strong contrast with the current view and has important consequences for our understanding of division of labor in insect societies. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  15. Fluvial landscapes - human societies interactions during the last 2000 years: the Middle Loire River and its embanking since the Middle Ages (France)

    NASA Astrophysics Data System (ADS)

    Castanet, Cyril; Carcaud, Nathalie

    2015-04-01

    This research deals with the study of fluvial landscapes, heavily and precociously transformed by societies (fluvial anthroposystems). It aims to characterize i), fluvial responses to climate, environmental and anthropogenic changes ii), history of hydraulical constructions relative to rivers iii), history of fluvial origin risks and their management - (Program: AGES Ancient Geomorphological EvolutionS of the Loire River hydrosystem). The Middle Loire River valley in the Val d'Orléans was strongly and precociously occupied, particularly during historical periods. Hydrosedimentary flows are there irregular. The river dykes were built during the Middle Ages (dykes named turcies) and the Modern Period, but ages and localizations of the oldest dykes were not precisely known. A systemic and multi-scaled approach aimed to characterize i), palaeo-hydrographical, -hydrological and -hydraulical evolutions of the Loire River, fluvial risks (palaeo-hazards and -vulnerabilities) and their management. It is based on an integrated approach, in and out archaeological sites: morpho-stratigraphy, sedimentology, geophysics, geochemistry, geomatics, geochronology, archaeology. Spatio-temporal variability of fluvial hazards is characterized. A model of the Loire River fluvial activity is developed: multicentennial scale variability, with higher fluvial activity episodes during the Gallo-Roman period, IX-XIth centuries and LIA. Fluvial patterns changes are indentified. Settlement dynamics and hydraulical constructions of the valley are specified. We establish the ages and localizations of the oldest discovered dikes of the Middle Loire River: after the Late Antiquity and before the end of the Early Middle Ages (2 dated dykes), between Bou and Orléans cities. During historical periods, we suggest 2 main thresholds concerning socio-environmental interactions: the first one during the Early Middle Ages (turcies: small scattered dykes), the second during the Modern Period (levees: high

  16. Parabiotic associations between tropical ants: equal partnership or parasitic exploitation?

    PubMed

    Menzel, F; Blüthgen, N

    2010-01-01

    1. The huge diversity of symbiotic associations among animals and/or plants comprises both mutualisms and parasitisms. Most symbioses between social insect species, however, involve social parasites, while mutual benefits have been only suspected for some parabiotic associations - two colonies that share a nest. 2. In the rainforest of Borneo, we studied parabiotic associations between the ants Crematogaster modiglianii and Camponotus rufifemur. Parabiotic nests were regularly found inside hollow tree trunks, most likely initiated by Cr. modiglianii. This species frequently nested without its partner, whereas we never found non-parabiotic Ca. rufifemur nests. We experimentally investigated potential benefits, potential interference competition for food (as a probable cost), and foraging niches of both species. 3. The two species never showed aggressive interactions and amicably shared food resources. However, Cr. modiglianii had a wider temporal and spatial foraging range than Ca. rufifemur, always found baits before Ca. rufifemur and recruited more efficiently. Camponotus rufifemur probably benefited from following pheromone trails of Cr. modiglianii. In turn, Ca. rufifemur was significantly more successful in defending the nest against alien ants. Crematogaster modiglianii hence may profit from its partner's defensive abilities. 4. In neotropical parabioses, epiphytes grown in 'ant-gardens' play a crucial role in the association, e.g. by stabilization of nests. Hemiepiphytic Poikilospermum cordifolium (Cecropiaceae) seedlings and saplings frequently grew in the entrances of parabiotic nests in Borneo, obviously dispersed by the ants. In cafeteria experiments, both parabiotic ants carried its elaiosome-bearing seeds into the nest. However, P. cordifolium does not provide additional nest space, contrasting with neotropical ant-gardens. 5. The parabiotic association appears beneficial for both ant species, the main benefits being nest initiation by Cr. modiglianii

  17. Development of virtual bait stations to control Argentine ants (Hymenoptera: Formicidae) in environmentally sensitive habitats.

    PubMed

    Choe, Dong-Hwan; Vetter, Richard S; Rust, Michael K

    2010-10-01

    A novel bait station referred to as a virtual bait station was developed and tested against field populations of the invasive Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), at White Beach, Camp Pendleton, in Oceanside, CA. White Beach is a nesting habitat for an endangered seabird, the California least tern (Sterna antillarum browni Mearns). The beach is heavily infested with Argentine ants, one of the threats for the California least tern chicks. Conventional pest control strategies are prohibited because of the existence of the protected bird species and the site's proximity to the ocean. The bait station consisted of a polyvinyl chloride pipe that was treated on the inside with fipronil insecticide at low concentrations to obtain delayed toxicity against ants. The pipe was provisioned with an inverted bottle of 25% sucrose solution, then capped, and buried in the sand. Foraging ants crossed the treated surface to consume the sucrose solution. The delayed toxicity of fipronil deposits allowed the ants to continue foraging on the sucrose solution and to interact with their nestmates, killing them within 3-5 d after exposure. Further modification of the bait station design minimized the accumulation of dead ants in the sucrose solution, significantly improving the longevity and efficacy of the bait station. The virtual bait station exploits the foraging behavior of the ants and provides a low impact approach to control ants in environmentally sensitive habitats. It excluded all insects except ants, required only milligram quantities of toxicant, and eliminated the problem of formulating toxicants into aqueous sugar baits.

  18. Species-Specific Seed Dispersal in an Obligate Ant-Plant Mutualism

    PubMed Central

    Youngsteadt, Elsa; Baca, Jeniffer Alvarez; Osborne, Jason; Schal, Coby

    2009-01-01

    Throughout lowland Amazonia, arboreal ants collect seeds of specific plants and cultivate them in nutrient-rich nests, forming diverse yet obligate and species-specific symbioses called Neotropical ant-gardens (AGs). The ants depend on their symbiotic plants for nest stability, and the plants depend on AGs for substrate and nutrients. Although the AGs are limited to specific participants, it is unknown at what stage specificity arises, and seed fate pathways in AG epiphytes are undocumented. Here we examine the specificity of the ant-seed interaction by comparing the ant community observed at general food baits to ants attracted to and removing seeds of the AG plant Peperomia macrostachya. We also compare seed removal rates under treatments that excluded vertebrates, arthropods, or both. In the bait study, only three of 70 ant species collected P. macrostachya seeds, and 84% of observed seed removal by ants was attributed to the AG ant Camponotus femoratus. In the exclusion experiment, arthropod exclusion significantly reduced seed removal rates, but vertebrate exclusion did not. We provide the most extensive empirical evidence of species specificity in the AG mutualism and begin to quantify factors that affect seed fate in order to understand conditions that favor its departure from the typical diffuse model of plant-animal mutualism. PMID:19194502

  19. Bacteria may contribute to distant species recognition in ant-aphid mutualistic relationships.

    PubMed

    Fischer, Christophe Y; Detrain, Claire; Thonart, Philippe; Haubruge, Eric; Francis, Frédéric; Verheggen, François J; Lognay, Georges C

    2017-04-01

    Mutualistic interactions between ant and aphid species have been the subject of considerable historical and contemporary investigations, the primary benefits being cleaning and protection for the aphids and carbohydrate-rich honeydew for the ants. Questions remained, however, as to the volatile semiochemical factor influencing this relationship. A recent study highlighted the role of bacterial honeydew volatile compounds in ant attraction. Here, ant's ability to distantly discriminate 2 aphid species was investigated based on bacterial honeydew semiochemicals emissions using a two-way olfactometer. Both the mutualistic aphid Aphis fabae L. and the nonmyrmecophilous aphid Acyrthosiphon pisum Harris were found to be attractive for the ant Lasius niger L. The level of attraction was similar in both assays (control vs. one of the aphid species). However, when given a choice between these 2 aphid species, ants showed a significant preference for Aphis fabae. Honeydew volatiles, mostly from bacterial origins, are known to be a key element in ant attraction. Using the same olfactometry protocol, the relative attractiveness of volatiles emitted by honeydews collected from each aphid species and by bacteria isolated from each honeydew was investigated. Again, ants significantly preferred volatiles released by Aphis fabae honeydew and bacteria. This information suggests that microbial honeydew volatiles enable ants to distantly discriminate aphid species. These results strengthen the interest of studying the occurrence and potential impact of microorganisms in insect symbioses. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  20. Species-specific seed dispersal in an obligate ant-plant mutualism.

    PubMed

    Youngsteadt, Elsa; Baca, Jeniffer Alvarez; Osborne, Jason; Schal, Coby

    2009-01-01

    Throughout lowland Amazonia, arboreal ants collect seeds of specific plants and cultivate them in nutrient-rich nests, forming diverse yet obligate and species-specific symbioses called Neotropical ant-gardens (AGs). The ants depend on their symbiotic plants for nest stability, and the plants depend on AGs for substrate and nutrients. Although the AGs are limited to specific participants, it is unknown at what stage specificity arises, and seed fate pathways in AG epiphytes are undocumented. Here we examine the specificity of the ant-seed interaction by comparing the ant community observed at general food baits to ants attracted to and removing seeds of the AG plant Peperomia macrostachya. We also compare seed removal rates under treatments that excluded vertebrates, arthropods, or both. In the bait study, only three of 70 ant species collected P. macrostachya seeds, and 84% of observed seed removal by ants was attributed to the AG ant Camponotus femoratus. In the exclusion experiment, arthropod exclusion significantly reduced seed removal rates, but vertebrate exclusion did not. We provide the most extensive empirical evidence of species specificity in the AG mutualism and begin to quantify factors that affect seed fate in order to understand conditions that favor its departure from the typical diffuse model of plant-animal mutualism.

  1. Biotic and abiotic controls of Argentine ant invasion success at local and landscape scales.

    PubMed

    Menke, S B; Fisher, R N; Jetz, W; Holway, D A

    2007-12-01

    Although the ecological success of introduced species hinges on biotic interactions and physical conditions, few experimental studies--especially on animals--have simultaneously investigated the relative importance of both types of factors. The lack of such research may stem from the common assumption that native and introduced species exhibit similar environmental tolerances. Here we combine experimental and spatial modeling approaches (1) to determine the relative importance of biotic and abiotic controls of Argentine ant (Linepithema humile) invasion success, (2) to examine how the importance of these factors changes with spatial scale in southern California (USA), and (3) to assess how Argentine ants differ from native ants in their environmental tolerances. A factorial field experiment that combined native ant removal with irrigation revealed that Argentine ants failed to invade any dry plots (even those lacking native ants) but readily invaded all moist plots. Native ants slowed the spread of Argentine ants into irrigated plots but did not prevent invasion. In areas without Argentine ants, native ant species showed variable responses to irrigation. At the landscape scale, Argentine ant occurrence was positively correlated with minimum winter temperature (but not precipitation), whereas native ant diversity increased with precipitation and was negatively correlated with minimum winter temperature. These results are of interest for several reasons. First, they demonstrate that fine-scale differences in the physical environment can eclipse biotic resistance from native competitors in determining community susceptibility to invasion. Second, our results illustrate surprising complexities with respect to how the abiotic factors limiting invasion can change with spatial scale, and third, how native and invasive species can differ in their responses to the physical environment. Idiosyncratic and scale-dependent processes complicate attempts to forecast where

  2. Steep Decline and Cessation in Seed Dispersal by Myrmica rubra Ants.

    PubMed

    Bologna, Audrey; Detrain, Claire

    2015-01-01

    Myrmecochorous diaspores bear a nutrient-rich appendage, the elaiosome, attractive to ant workers that retrieve them into the nest, detach the elaiosome and reject the seed intact. While this interaction is beneficial for the plant partner by ensuring its seed dispersal, elaiosome consumption has various effects -positive, negative or none - on ants' demography and survival, depending on both the ant/plant species involved. In this context, the contribution of ants to seed dispersal strongly varies according to the ant/plant pairs considered. In this paper, we investigate whether the dynamics of myrmecochory also vary on a temporal scale, for a given pair of partners: Myrmica rubra ants and Viola odorata seeds. During their first encounter with seeds, ants collect all the diaspores and eat the majority of elaiosomes. Both the harvesting effort and the elaiosome consumption decline when seeds are offered on the next week and completely cease for the following weeks. This is related to a decrease in the number of foragers reaching the food source, as well as to a reduced probability for an ant contacting a seed to retrieve it. Seed retrieval is not reactivated after seven weeks without any encounter with V. odorata seeds. By contrast, naive ant colonies only fed with fruit flies do not show a decline of prey harvesting of which the speed of retrieval even increases over the successive weeks. Myrmecochory may thus be labile at the scale of a fruiting season due to the ability of ants to steeply tune and cease for several months the harvesting of these seemingly poorly rewarding items and to maintain cessation of seed exploitation. The present study emphasizes the importance of a long-lasting follow up of the myrmecochory process, to assess the stability of this ant-plant partnership and to identify mechanisms of adaptive harvesting in ants.

  3. Monopolization of resources by ground-nesting ants foraging on trees in Mediterranean forests

    NASA Astrophysics Data System (ADS)

    Martinez, Jean-Jacques Itzhak

    2015-05-01

    Ant communities are generally structured by territoriality, dominance and resource monopolization, but in Mediterranean hot grassland thermal tolerance plays a more important role. The main purposes of the present research were to investigate the hypothesis that in cooler Mediterranean forests resource monopolization structures the generalist ground-nesting ant community while foraging on trees, and to learn if tree heterogeneity plays any role in this structure. In Mediterranean forests in Israel, I visually recorded and trapped ants on the forest floor and those climbing on trees of five species. Ants of 27 species were detected, while the Chao2 index indicated an asymptotic richness estimation of 31 ± 8.1 species (mean ± S.D.). The numerically dominant species were Crematogaster lorteti and Tapinoma simrothi followed by Tapinoma israele and Crematogaster scutellaris. In more than 80% of the cases, specimens of only one ant species climbed at the same time on any individual tree, and no tree was occupied by more than three species. The C-score of climbing ants was statistically higher than simulated indexes when resources were individual trees, indicating that the ants strongly monopolized each tree. No difference was detected between observed and simulated C-scores when resources were tree species. The observed index of Pianka's niche overlap indicated no species specific interaction between trees and ants. In conclusion, this study confirms that ant mosaic structure may be formed by ground-nesting ants while foraging on trees. Tree species heterogeneity did not have a selective impact on the ants nor a central role in the ant community structure.

  4. Macroevolutionary assembly of ant/plant symbioses: Pseudomyrmex ants and their ant-housing plants in the Neotropics.

    PubMed

    Chomicki, Guillaume; Ward, Philip S; Renner, Susanne S

    2015-11-22

    Symbioses include some of the clearest cases of coevolution, but their origin, loss or reassembly with different partners can rarely be inferred. Here we use ant/plant symbioses involving three plant clades to investigate the evolution of symbioses. We generated phylogenies for the big-eyed arboreal ants (Pseudomyrmecinae), including 72% of their 286 species, as well as for five of their plant host groups, in each case sampling more than 61% of the species. We show that the ant-housing Vachellia (Mimosoideae) clade and its ants co-diversified for the past 5 Ma, with some species additionally colonized by younger plant-nesting ant species, some parasitic. An apparent co-radiation of ants and Tachigali (Caesalpinioideae) was followed by waves of colonization by the same ant clade, and subsequent occupation by a younger ant group. Wide crown and stem age differences between the ant-housing genus Triplaris (Polygonaceae) and its obligate ant inhabitants, and stochastic trait mapping, indicate that its domatium evolved earlier than the ants now occupying it, suggesting previous symbioses that dissolved. Parasitic ant species evolved from generalists, not from mutualists, and are younger than the mutualistic systems they parasitize. Our study illuminates the macroevolutionary assembly of ant/plant symbioses, which has been highly dynamic, even in very specialized systems.

  5. Macroevolutionary assembly of ant/plant symbioses: Pseudomyrmex ants and their ant-housing plants in the Neotropics

    PubMed Central

    Chomicki, Guillaume; Ward, Philip S.; Renner, Susanne S.

    2015-01-01

    Symbioses include some of the clearest cases of coevolution, but their origin, loss or reassembly with different partners can rarely be inferred. Here we use ant/plant symbioses involving three plant clades to investigate the evolution of symbioses. We generated phylogenies for the big-eyed arboreal ants (Pseudomyrmecinae), including 72% of their 286 species, as well as for five of their plant host groups, in each case sampling more than 61% of the species. We show that the ant-housing Vachellia (Mimosoideae) clade and its ants co-diversified for the past 5 Ma, with some species additionally colonized by younger plant-nesting ant species, some parasitic. An apparent co-radiation of ants and Tachigali (Caesalpinioideae) was followed by waves of colonization by the same ant clade, and subsequent occupation by a younger ant group. Wide crown and stem age differences between the ant-housing genus Triplaris (Polygonaceae) and its obligate ant inhabitants, and stochastic trait mapping, indicate that its domatium evolved earlier than the ants now occupying it, suggesting previous symbioses that dissolved. Parasitic ant species evolved from generalists, not from mutualists, and are younger than the mutualistic systems they parasitize. Our study illuminates the macroevolutionary assembly of ant/plant symbioses, which has been highly dynamic, even in very specialized systems. PMID:26582029

  6. Army Ants as Research and Collection Tools

    PubMed Central

    Smith, Adrian A.; Haight, Kevin L.

    2008-01-01

    Ants that fall prey to the raids of army ants commonly respond by evacuating their nests. This documented behavior has been underexploited by researchers as an efficient research tool. This study focuses on the evacuation response of the southwestern desert ant Aphaenogaster cockerelli André (Hymenoptera: Formicidae) to the army ant Newamyrmex nigrescens Cresson. It is shown that army ants can be used to collect mature colonies of ants. The applicability of this tool to ecologically meaningful areas of research is discussed. PMID:20302457

  7. The influence of space and time on the evolution of altruistic defence: the case of ant slave rebellion.

    PubMed

    Metzler, D; Jordan, F; Pamminger, T; Foitzik, S

    2016-05-01

    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. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  8. Wind and sky as compass cues in desert ant navigation

    NASA Astrophysics Data System (ADS)

    Müller, Martin; Wehner, Rüdiger

    2007-07-01

    While integrating their foraging and homing paths, desert ants, Cataglyphis fortis, depend on external compass cues. Whereas recent research in bees and ants has focused nearly exclusively on the polarization compass, two other compass systems—the sun compass and the wind (anemo) compass—as well as the mutual interactions of all these compass systems have received little attention. In this study, we show that of the two visual compass systems, it is only the polarization compass that invariably outcompetes the wind compass, while the sun compass does so only under certain conditions. If the ants are experimentally deprived of their polarization compass system, but have access simultaneously to both their sun compass and their wind compass, they steer intermediate courses. The intermediate courses shift the more towards the wind compass course, the higher the elevation of the sun is in the sky.

  9. Neuromodulation of Nestmate Recognition Decisions by Pavement Ants

    PubMed Central

    Bubak, Andrew N.; Yaeger, Jazmine D. W.; Renner, Kenneth J.; Swallow, John G.; Greene, Michael J.

    2016-01-01

    Ant colonies are distributed systems that are regulated in a non-hierarchical manner. Without a central authority, individuals inform their decisions by comparing information in local cues to a set of inherent behavioral rules. Individual behavioral decisions collectively change colony behavior and lead to self-organization capable of solving complex problems such as the decision to engage in aggressive societal conflicts with neighbors. Despite the relevance to colony fitness, the mechanisms that drive individual decisions leading to cooperative behavior are not well understood. Here we show how sensory information, both tactile and chemical, and social context—isolation, nestmate interaction, or fighting non-nestmates—affects brain monoamine levels in pavement ants (Tetramorium caespitum). Our results provide evidence that changes in octopamine and serotonin in the brains of individuals are sufficient to alter the decision by pavement ants to be aggressive towards non-nestmate ants whereas increased brain levels of dopamine correlate to physical fighting. We propose a model in which the changes in brain states of many workers collectively lead to the self-organization of societal aggression between neighboring colonies of pavement ants. PMID:27846261

  10. Neuromodulation of Nestmate Recognition Decisions by Pavement Ants.

    PubMed

    Bubak, Andrew N; Yaeger, Jazmine D W; Renner, Kenneth J; Swallow, John G; Greene, Michael J

    2016-01-01

    Ant colonies are distributed systems that are regulated in a non-hierarchical manner. Without a central authority, individuals inform their decisions by comparing information in local cues to a set of inherent behavioral rules. Individual behavioral decisions collectively change colony behavior and lead to self-organization capable of solving complex problems such as the decision to engage in aggressive societal conflicts with neighbors. Despite the relevance to colony fitness, the mechanisms that drive individual decisions leading to cooperative behavior are not well understood. Here we show how sensory information, both tactile and chemical, and social context-isolation, nestmate interaction, or fighting non-nestmates-affects brain monoamine levels in pavement ants (Tetramorium caespitum). Our results provide evidence that changes in octopamine and serotonin in the brains of individuals are sufficient to alter the decision by pavement ants to be aggressive towards non-nestmate ants whereas increased brain levels of dopamine correlate to physical fighting. We propose a model in which the changes in brain states of many workers collectively lead to the self-organization of societal aggression between neighboring colonies of pavement ants.

  11. Ant-like task allocation and recruitment in cooperative robots

    NASA Astrophysics Data System (ADS)

    Krieger, Michael J. B.; Billeter, Jean-Bernard; Keller, Laurent

    2000-08-01

    One of the greatest challenges in robotics is to create machines that are able to interact with unpredictable environments in real time. A possible solution may be to use swarms of robots behaving in a self-organized manner, similar to workers in an ant colony. Efficient mechanisms of division of labour, in particular series-parallel operation and transfer of information among group members, are key components of the tremendous ecological success of ants. Here we show that the general principles regulating division of labour in ant colonies indeed allow the design of flexible, robust and effective robotic systems. Groups of robots using ant-inspired algorithms of decentralized control techniques foraged more efficiently and maintained higher levels of group energy than single robots. But the benefits of group living decreased in larger groups, most probably because of interference during foraging. Intriguingly, a similar relationship between group size and efficiency has been documented in social insects. Moreover, when food items were clustered, groups where robots could recruit other robots in an ant-like manner were more efficient than groups without information transfer, suggesting that group dynamics of swarms of robots may follow rules similar to those governing social insects.

  12. Ant-like task allocation and recruitment in cooperative robots.

    PubMed

    Krieger, M J; Billeter, J B; Keller, L

    2000-08-31

    One of the greatest challenges in robotics is to create machines that are able to interact with unpredictable environments in real time. A possible solution may be to use swarms of robots behaving in a self-organized manner, similar to workers in an ant colony. Efficient mechanisms of division of labour, in particular series-parallel operation and transfer of information among group members, are key components of the tremendous ecological success of ants. Here we show that the general principles regulating division of labour in ant colonies indeed allow the design of flexible, robust and effective robotic systems. Groups of robots using ant-inspired algorithms of decentralized control techniques foraged more efficiently and maintained higher levels of group energy than single robots. But the benefits of group living decreased in larger groups, most probably because of interference during foraging. Intriguingly, a similar relationship between group size and efficiency has been documented in social insects. Moreover, when food items were clustered, groups where robots could recruit other robots in an ant-like manner were more efficient than groups without information transfer, suggesting that group dynamics of swarms of robots may follow rules similar to those governing social insects.

  13. Plant-derived differences in the composition of aphid honeydew and their effects on colonies of aphid-tending ants

    PubMed Central

    Pringle, Elizabeth G; Novo, Alexandria; Ableson, Ian; Barbehenn, Raymond V; Vannette, Rachel L

    2014-01-01

    In plant–ant–hemipteran interactions, ants visit plants to consume the honeydew produced by phloem-feeding hemipterans. If genetically based differences in plant phloem chemistry change the chemical composition of hemipteran honeydew, then the plant's genetic constitution could have indirect effects on ants via the hemipterans. If such effects change ant behavior, they could feed back to affect the plant itself. We compared the chemical composition of honeydews produced by Aphis nerii aphid clones on two milkweed congeners, Asclepias curassavica and Asclepias incarnata, and we measured the responses of experimental Linepithema humile ant colonies to these honeydews. The compositions of secondary metabolites, sugars, and amino acids differed significantly in the honeydews from the two plant species. Ant colonies feeding on honeydew derived from A. incarnata recruited in higher numbers to artificial diet, maintained higher queen and worker dry weight, and sustained marginally more workers than ants feeding on honeydew derived from A. curassavica. Ants feeding on honeydew from A. incarnata were also more exploratory in behavioral assays than ants feeding from A. curassavica. Despite performing better when feeding on the A. incarnata honeydew, ant workers marginally preferred honeydew from A. curassavica to honeydew from A. incarnata when given a choice. Our results demonstrate that plant congeners can exert strong indirect effects on ant colonies by means of plant-species-specific differences in aphid honeydew chemistry. Moreover, these effects changed ant behavior and thus could feed back to affect plant performance in the field. PMID:25505534

  14. Convergent coevolution in the domestication of coral mushrooms by fungus-growing ants.

    PubMed Central

    Munkacsi, A. B.; Pan, J. J.; Villesen, P.; Mueller, U. G.; Blackwell, M.; McLaughlin, D. J.

    2004-01-01

    Comparisons of phylogenetic patterns between coevolving symbionts can reveal rich details about the evolutionary history of symbioses. The ancient symbiosis between fungus-growing ants, their fungal cultivars, antibiotic-producing bacteria and cultivar-infecting parasites is dominated by a pattern of parallel coevolution, where the symbionts of each functional group are members of monophyletic groups. However, there is one outstanding exception in the fungus-growing ant system, the unidentified cultivar grown only by ants in the Apterostigma pilosum group. We classify this cultivar in the coral-mushroom family Pterulaceae using phylogenetic reconstructions based on broad taxon sampling, including the first mushroom collected from the garden of an ant species in the A. pilosum group. The domestication of the pterulaceous cultivar is independent from the domestication of the gilled mushrooms cultivated by all other fungus-growing ants. Yet it has the same overall assemblage of coevolved ant-cultivar-parasite-bacterium interactions as the other ant-grown fungal cultivars. This indicates a pattern of convergent coevolution in the fungus-growing ant system, where symbionts with both similar and very different evolutionary histories converge to functionally identical interactions. PMID:15315892

  15. Ants medicate to fight disease.

    PubMed

    Bos, Nick; Sundström, Liselotte; Fuchs, Siiri; Freitak, Dalial

    2015-11-01

    Parasites are ubiquitous, and the ability to defend against these is of paramount importance. One way to fight diseases is self-medication, which occurs when an organism consumes biologically active compounds to clear, inhibit, or alleviate disease symptoms. Here, we show for the first time that ants selectively consume harmful substances (reactive oxygen species, ROS) upon exposure to a fungal pathogen, yet avoid these in the absence of infection. This increased intake of ROS, while harmful to healthy ants, leads to higher survival of exposed ants. The fact that ingestion of this substance carries a fitness cost in the absence of pathogens rules out compensatory diet choice as the mechanism, and provides evidence that social insects medicate themselves against fungal infection, using a substance that carries a fitness cost to uninfected individuals.

  16. The genome of the fire ant Solenopsis invicta

    PubMed Central

    Wurm, Yannick; Wang, John; Riba-Grognuz, Oksana; Corona, Miguel; Nygaard, Sanne; Hunt, Brendan G.; Ingram, Krista K.; Falquet, Laurent; Nipitwattanaphon, Mingkwan; Gotzek, Dietrich; Dijkstra, Michiel B.; Oettler, Jan; Comtesse, Fabien; Shih, Cheng-Jen; Wu, Wen-Jer; Yang, Chin-Cheng; Thomas, Jerome; Beaudoing, Emmanuel; Pradervand, Sylvain; Flegel, Volker; Cook, Erin D.; Fabbretti, Roberto; Stockinger, Heinz; Long, Li; Farmerie, William G.; Oakey, Jane; Boomsma, Jacobus J.; Pamilo, Pekka; Yi, Soojin V.; Heinze, Jürgen; Goodisman, Michael A. D.; Farinelli, Laurent; Harshman, Keith; Hulo, Nicolas; Cerutti, Lorenzo; Xenarios, Ioannis; Shoemaker, DeWayne; Keller, Laurent

    2011-01-01

    Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta, are also major pests. Here, we present a draft genome of S. invicta, assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothers. We used comparative genomic methods to obtain insight into the unique features of the S. invicta genome. For example, we found that this genome harbors four adjacent copies of vitellogenin. A phylogenetic analysis revealed that an ancestral vitellogenin gene first underwent a duplication that was followed by possibly independent duplications of each of the daughter vitellogenins. The vitellogenin genes have undergone subfunctionalization with queen- and worker-specific expression, possibly reflecting differential selection acting on the queen and worker castes. Additionally, we identified more than 400 putative olfactory receptors of which at least 297 are intact. This represents the largest repertoire reported so far in insects. S. invicta also harbors an expansion of a specific family of lipid-processing genes, two putative orthologs to the transformer/feminizer sex differentiation gene, a functional DNA methylation system, and a single putative telomerase ortholog. EST data indicate that this S. invicta telomerase ortholog has at least four spliceforms that differ in their use of two sets of mutually exclusive exons. Some of these and other unique aspects of the fire ant genome are likely linked to the complex social behavior of this species. PMID:21282665

  17. The genome of the fire ant Solenopsis invicta.

    PubMed

    Wurm, Yannick; Wang, John; Riba-Grognuz, Oksana; Corona, Miguel; Nygaard, Sanne; Hunt, Brendan G; Ingram, Krista K; Falquet, Laurent; Nipitwattanaphon, Mingkwan; Gotzek, Dietrich; Dijkstra, Michiel B; Oettler, Jan; Comtesse, Fabien; Shih, Cheng-Jen; Wu, Wen-Jer; Yang, Chin-Cheng; Thomas, Jerome; Beaudoing, Emmanuel; Pradervand, Sylvain; Flegel, Volker; Cook, Erin D; Fabbretti, Roberto; Stockinger, Heinz; Long, Li; Farmerie, William G; Oakey, Jane; Boomsma, Jacobus J; Pamilo, Pekka; Yi, Soojin V; Heinze, Jürgen; Goodisman, Michael A D; Farinelli, Laurent; Harshman, Keith; Hulo, Nicolas; Cerutti, Lorenzo; Xenarios, Ioannis; Shoemaker, Dewayne; Keller, Laurent

    2011-04-05

    Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta, are also major pests. Here, we present a draft genome of S. invicta, assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothers. We used comparative genomic methods to obtain insight into the unique features of the S. invicta genome. For example, we found that this genome harbors four adjacent copies of vitellogenin. A phylogenetic analysis revealed that an ancestral vitellogenin gene first underwent a duplication that was followed by possibly independent duplications of each of the daughter vitellogenins. The vitellogenin genes have undergone subfunctionalization with queen- and worker-specific expression, possibly reflecting differential selection acting on the queen and worker castes. Additionally, we identified more than 400 putative olfactory receptors of which at least 297 are intact. This represents the largest repertoire reported so far in insects. S. invicta also harbors an expansion of a specific family of lipid-processing genes, two putative orthologs to the transformer/feminizer sex differentiation gene, a functional DNA methylation system, and a single putative telomerase ortholog. EST data indicate that this S. invicta telomerase ortholog has at least four spliceforms that differ in their use of two sets of mutually exclusive exons. Some of these and other unique aspects of the fire ant genome are likely linked to the complex social behavior of this species.

  18. Reproductive phenologies in a diverse temperate ant fauna

    USGS Publications Warehouse

    Dunn, R.R.; Parker, C.R.; Geraghty, M.; Sanders, N.J.

    2007-01-01

    1. Ant nuptial flights are central to understanding ant life history and ecology but have been little studied. This study examined the timing of nuptial flights, the synchronicity of nuptial flights (as a potential index of mating strategy), and variation in nuptial flights with elevation and among years in a diverse temperate ant fauna. 2. Flights occurred throughout the year, but were concentrated in the beginning of summer and in early fall (autumn). Relative to the entire flight season, closely related species tended to be more likely than expected by chance to fly at similar times, perhaps because of phylogenetic constraints on life history evolution. 3. Flights were relatively synchronous within species for nearly all species considered, but synchronicity did not appear to be a robust estimate of overall mating strategy. 4. Overall patterns in nuptial flights among species and the timing of flights for individual species varied with elevation, but did not vary greatly among years. 5. Although this study is one of the most comprehensive on the reproductive flight phenologies of ants, much remains to be learned about the causes and consequences of such spatial and temporal variation in flight phenology. ?? 2007 The Royal Entomological Society.

  19. Mimetic host shifts in an endangered social parasite of ants

    PubMed Central

    Thomas, Jeremy A.; Elmes, Graham W.; Sielezniew, Marcin; Stankiewicz-Fiedurek, Anna; Simcox, David J.; Settele, Josef; Schönrogge, Karsten

    2013-01-01

    An emerging problem in conservation is whether listed morpho-species with broad distributions, yet specialized lifestyles, consist of more than one cryptic species or functionally distinct forms that have different ecological requirements. We describe extreme regional divergence within an iconic endangered butterfly, whose socially parasitic young stages use non-visual, non-tactile cues to infiltrate and supplant the brood in ant societies. Although indistinguishable morphologically or when using current mitochondrial and nuclear sequence-, or microsatellite data, Maculinea rebeli from Spain and southeast Poland exploit different Myrmica ant species and experience 100 per cent mortality with each other's hosts. This reflects major differences in the hydrocarbons synthesized from each region by the larvae, which so closely mimic the recognition profiles of their respective hosts that nurse ants afford each parasite a social status above that of their own kin larvae. The two host ants occupy separate niches within grassland; thus, conservation management must differ in each region. Similar cryptic differentiation may be common, yet equally hard to detect, among the approximately 10 000 unstudied morpho-species of social parasite that are estimated to exist, many of which are Red Data Book listed. PMID:23193127

  20. Long-term temporal variation in the organization of an ant-plant network.

    PubMed

    Díaz-Castelazo, Cecilia; Sánchez-Galván, Ingrid R; Guimarães, Paulo R; Raimundo, Rafael L Galdini; Rico-Gray, Víctor

    2013-06-01

    Functional groups of species interact and coevolve in space and time, forming complex networks of interacting species. A long-term study of temporal variation of an ant-plant network is presented with the aims of: (1) depicting its structural changes over a 20-year period; (2) detailing temporal variation in network topology, as revealed by nestedness and modularity analysis and other parameters (i.e. connectance, niche overlap); and (3) identifying long-term turnover in taxonomic structure (i.e. switches in ant resource use or plant visitor assemblages according to taxa). Fieldwork was carried out at La Mancha, Mexico, and ant-plant interactions were observed between 1989 and 1991, between 1998 and 2000, and between May 2010 and 2011. Occurrences of ants on extrafloral nectaries (EFNs) were recorded. The resulting ant-plant networks were constructed from qualitative presence-absence data determined by a species-species matrix defined by the frequency of occurrence of each pairwise ant-plant interaction. Network variation across time was stable and a persistent nested structure may have contributed to the maintenance of resilient and species-rich communities. Modularity was lower than expected, especially in the most recent networks, indicating that the community exhibited high overlap among interacting species (e.g. few species were hubs in the more recent network, being partly responsible for the nested pattern). Structurally, the connections created among modules by super-generalists gave cohesion to subsets of species that otherwise would remain unconnected. This may have allowed an increasing cascade-effect of evolutionary events among modules. Mutualistic ant-plant interactions were structured 20 years ago mainly by the subdominant nectarivorous ant species Camponotus planatus and Crematogaster brevispinosa, which monopolized the best extrafloral nectar resources and out-competed other species with broader feeding habits. Through time, these ants, which are

  1. Ants mediate the structure of phytotelm communities in an ant-garden bromeliad.

    PubMed

    Céréghino, Régis; Leroy, Céline; Dejean, Alain; Corbara, Bruno

    2010-05-01

    The main theories explaining the biological diversity of rain forests often confer a limited understanding of the contribution of interspecific interactions to the observed patterns. We show how two-species mutualisms can affect much larger segments of the invertebrate community in tropical rain forests. Aechmea mertensii (Bromeliaceae) is both a phytotelm (plant-held water) and an ant-garden epiphyte. We studied the influence of its associated ant species (Pachycondyla goeldii and Camponotus femoratus) on the physical characteristics of the plants, and, subsequently, on the diversity of the invertebrate communities that inhabit their tanks. As dispersal agents for the bromeliads, P. goeldii and C. femoratus influence the shape and size of the bromeliad by determining the location of the seedling, from exposed to partially shaded areas. By coexisting on a local scale, the two ant species generate a gradient of habitat conditions in terms of available resources (space and food) for aquatic invertebrates, the diversity of the invertebrate communities increasing with greater volumes of water and fine detritus. Two-species mutualisms are widespread in nature, but their influence on the diversity of entire communities remains largely unexplored. Because macroinvertebrates constitute an important part of animal production in all ecosystem types, further investigations should address the functional implications of such indirect effects.

  2. Chemical defense by the native winter ant (Prenolepis imparis) against the invasive Argentine ant (Linepithema humile).

    PubMed

    Sorrells, Trevor R; Kuritzky, Leah Y; Kauhanen, Peter G; Fitzgerald, Katherine; Sturgis, Shelby J; Chen, Jimmy; Dijamco, Cheri A; Basurto, Kimberly N; Gordon, Deborah M

    2011-04-19

    The invasive Argentine ant (Linepithema humile) is established worldwide and displaces native ant species. In northern California, however, the native winter ant (Prenolepis imparis) persists in invaded areas. We found that in aggressive interactions between the two species, P. imparis employs a potent defensive secretion. Field observations were conducted at P. imparis nest sites both in the presence and absence of L. humile. These observations suggested and laboratory assays confirmed that P. imparis workers are more likely to secrete when outnumbered by L. humile. Workers of P. imparis were also more likely to secrete near their nest entrances than when foraging on trees. One-on-one laboratory trials showed that the P. imparis secretion is highly lethal to L. humile, causing 79% mortality. The nonpolar fraction of the secretion was chemically analyzed with gas chromatography/mass spectrometry, and found to be composed of long-chain and cyclic hydrocarbons. Chemical analysis of dissected P. imparis workers showed that the nonpolar fraction is derived from the Dufour's gland. Based on these conclusions, we hypothesize that this chemical defense may help P. imparis to resist displacement by L. humile.

  3. Chemical Defense by the Native Winter Ant (Prenolepis imparis) against the Invasive Argentine Ant (Linepithema humile)

    PubMed Central

    Kauhanen, Peter G.; Fitzgerald, Katherine; Sturgis, Shelby J.; Chen, Jimmy; Dijamco, Cheri A.; Basurto, Kimberly N.; Gordon, Deborah M.

    2011-01-01

    The invasive Argentine ant (Linepithema humile) is established worldwide and displaces native ant species. In northern California, however, the native winter ant (Prenolepis imparis) persists in invaded areas. We found that in aggressive interactions between the two species, P. imparis employs a potent defensive secretion. Field observations were conducted at P. imparis nest sites both in the presence and absence of L. humile. These observations suggested and laboratory assays confirmed that P. imparis workers are more likely to secrete when outnumbered by L. humile. Workers of P. imparis were also more likely to secrete near their nest entrances than when foraging on trees. One-on-one laboratory trials showed that the P. imparis secretion is highly lethal to L. humile, causing 79% mortality. The nonpolar fraction of the secretion was chemically analyzed with gas chromatography/mass spectrometry, and found to be composed of long-chain and cyclic hydrocarbons. Chemical analysis of dissected P. imparis workers showed that the nonpolar fraction is derived from the Dufour's gland. Based on these conclusions, we hypothesize that this chemical defense may help P. imparis to resist displacement by L. humile. PMID:21526231

  4. Ant colony optimization: Introduction and recent trends

    NASA Astrophysics Data System (ADS)

    Blum, Christian

    2005-12-01

    Ant colony optimization is a technique for optimization that was introduced in the early 1990's. The inspiring source of ant colony optimization is the foraging behavior of real ant colonies. This behavior is exploited in artificial ant colonies for the search of approximate solutions to discrete optimization problems, to continuous optimization problems, and to important problems in telecommunications, such as routing and load balancing. First, we deal with the biological inspiration of ant colony optimization algorithms. We show how this biological inspiration can be transfered into an algorithm for discrete optimization. Then, we outline ant colony optimization in more general terms in the context of discrete optimization, and present some of the nowadays best-performing ant colony optimization variants. After summarizing some important theoretical results, we demonstrate how ant colony optimization can be applied to continuous optimization problems. Finally, we provide examples of an interesting recent research direction: The hybridization with more classical techniques from artificial intelligence and operations research.

  5. Myrmecochores can target high-quality disperser ants: variation in elaiosome traits and ant preferences for myrmecochorous Euphorbiaceae in Brazilian Caatinga.

    PubMed

    Leal, Laura Carolina; Lima Neto, Mário Correia; de Oliveira, Antônio Fernando Morais; Andersen, Alan N; Leal, Inara R

    2014-02-01

    Recent evidence suggests that the traditional view of myrmecochory as a highly diffuse interaction between diaspores and a wide range of ant species attracted to their elaiosomes may not be correct. The effectiveness of dispersal varies markedly among ant species, and combined with differential attractiveness of diaspores due to elaiosome size and composition, this raises the potential for myrmecochorous plants to target ant species that offer the highest quality dispersal services. We ask the question: Do particular physical and chemical traits of elaiosomes result in disproportionate removal of Euphorbiaceae diaspores by high-quality disperser ants in Caatinga vegetation of north-eastern Brazil? We offered seeds of five euphorb species that varied in morphological and chemical traits of elaiosomes to seed-dispersing ants. High-quality seed-disperser ants (species of Dinoponera, Ectatomma and Camponotus) were identified as those that rapidly collected and transported diaspores to their nests, often over substantial distances, whereas low-quality disperser ants (primarily species of Pheidole and Solenopsis) typically fed on elaiosomes in situ, and only ever transported diaspores very short distances. Low-quality disperser ants were equally attracted to the elaiosomes of all study species. However, high-quality dispersers showed a strong preference for diaspores with the highest elaiosome mass (and especially proportional mass). As far as we are aware, this is the first study to identify a mechanism of diaspore selection by high-quality ant dispersers based on elaiosome traits under field conditions. Our findings suggest that myrmecochorous plants can preferentially target high-quality seed-disperser ants through the evolution of particular elaiosome traits.

  6. Ant opsins: sequences from the Saharan silver ant and the carpenter ant.

    PubMed

    Popp, M P; Grisshammer, R; Hargrave, P A; Smith, W C

    1996-03-01

    cDNA clones encoding opsins from compound eyes of carpenter ant, Camponotus abdominalis, and Saharan silver ant, Cataglyphis bombycina, were isolated from cDNA libraries. The opsin cDNAs from each species code for deduced proteins with 378 amino acids which are 92% identical. Of the 30 amino acid differences between the two proteins, 13 are non-conservative. Eight of these non-conservative substitutions are within the membrane spanning domain. The presence of a potential Schiff-base counterion in helix III in both species suggests that these opsins are the protein moiety of the visible range pigments. When compared to all known opsins, these opsins are most similar to the opsin from preying mantis (76% identity at the amino acid level). Phyletic comparisons group the two ant opsins with the other arthropod long wavelength opsins.

  7. Using Ants to Investigate the Environment

    ERIC Educational Resources Information Center

    Hagevik, Rita A.

    2005-01-01

    The best place for students to begin to understand complex environmental relationships is in their own back yards. Doing investigations of ants allows students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenance, and increase their understanding of the environment and their…

  8. Using Ants To Investigate the Environment.

    ERIC Educational Resources Information Center

    Hagevik, Rita A.

    2003-01-01

    Describes three inquiry-based activities designed for students to begin to understand complex environmental relationships in their own backyard. Includes investigations of ants, which allow students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenances, and increase student…

  9. Raves & rants about invasive crazy ants

    USDA-ARS?s Scientific Manuscript database

    Crazy ants” is a name that refers to various species of ants that are characterized by erratic, scurrying, or running, behavior when disturbed. Two of these species, the yellow crazy ant and the Caribbean or Rasberry [sic] crazy ant, are invasive with extremely large populations that inundate lands...

  10. Active anting in the Puerto Rican tanager

    USGS Publications Warehouse

    King, W.B.; Kepler, C.B.

    1970-01-01

    Anting, a bird’s intentional exposure of its body surface to chemical substances secreted by ants or other agents, has been recorded in over 20 species of birds of 40 families, mostly within the order Passeriformes. Our observations of anting in the Puerto Rico tanager (Neospingus speculiferus) extend the phenomenon to a new genus and the 14th species of the Thraupidae.

  11. Using Ants To Investigate the Environment.

    ERIC Educational Resources Information Center

    Hagevik, Rita A.

    2003-01-01

    Describes three inquiry-based activities designed for students to begin to understand complex environmental relationships in their own backyard. Includes investigations of ants, which allow students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenances, and increase student…

  12. Using Ants to Investigate the Environment

    ERIC Educational Resources Information Center

    Hagevik, Rita A.

    2005-01-01

    The best place for students to begin to understand complex environmental relationships is in their own back yards. Doing investigations of ants allows students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenance, and increase their understanding of the environment and their…

  13. Bait development for Tawny Crazy Ants

    USDA-ARS?s Scientific Manuscript database

    The tawny crazy ant, Nylanderia fulva, is an invasive ant from South America that is spreading in the southern USA. As of December 2015, N. fulva was reported from at least 85 counties or parishes primarily among all the gulf coast states. In addition this ant is found on St Croix in the U.S Virgi...

  14. Foraging arena size and structural complexity affect the dynamics of food distribution in ant colonies.

    PubMed

    Buczkowski, Grzegorz; VanWeelden, Matthew

    2010-12-01

    Food acquisition by ant colonies is a complex process that starts with acquiring food at the source (i.e., foraging) and culminates with food exchange in or around the nest (i.e., feeding). While ant foraging behavior is relatively well understood, the process of food distribution has received little attention, largely because of the lack of methodology that allows for accurate monitoring of food flow. In this study, we used the odorous house ant, Tapinoma sessile (Say) to investigate the effect of foraging arena size and structural complexity on the rate and the extent of spread of liquid carbohydrate food (sucrose solution) throughout a colony. To track the movement of food, we used protein marking and double-antibody sandwich enzyme-linked immunosorbent assay, DAS-ELISA. Variation in arena size, in conjunction with different colony sizes, allowed us to test the effect of different worker densities on food distribution. Results demonstrate that both arena size and colony size have a significant effect on the spread of the food and the number of workers receiving food decreased as arena size and colony size increased. When colony size was kept constant and arena size increased, the percentage of workers testing positive for the marker decreased, most likely because of fewer trophallactic interactions resulting from lower worker density. When arena size was kept constant and colony size increased, the percentage of workers testing positive decreased. Nonrandom (clustered) worker dispersion and a limited supply of food may have contributed to this result. Overall, results suggest that food distribution is more complete is smaller colonies regardless of the size of the foraging arena and that colony size, rather than worker density, is the primary factor affecting food distribution. The structural complexity of foraging arenas ranged from simple, two-dimensional space (empty arenas) to complex, three-dimensional space (arenas filled with mulch). The structural

  15. Exploratory of society

    NASA Astrophysics Data System (ADS)

    Cederman, L.-E.; Conte, R.; Helbing, D.; Nowak, A.; Schweitzer, F.; Vespignani, A.

    2012-11-01

    A huge flow of quantitative social, demographic and behavioral data is becoming available that traces the activities and interactions of individuals, social patterns, transportation infrastructures and travel fluxes. This has caused, together with innovative computational techniques and methods for modeling social actions in hybrid (natural and artificial) societies, a qualitative change in the ways we model socio-technical systems. For the first time, society can be studied in a comprehensive fashion that addresses social and behavioral complexity. In other words we are in the position to envision the development of large data and computational cyber infrastructure defining an exploratory of society that provides quantitative anticipatory, explanatory and scenario analysis capabilities ranging from emerging infectious disease to conflict and crime surges. The goal of the exploratory of society is to provide the basic infrastructure embedding the framework of tools and knowledge needed for the design of forecast/anticipatory/crisis management approaches to socio technical systems, supporting future decision making procedures by accelerating the scientific cycle that goes from data generation to predictions.

  16. Trafficlike collective movement of ants on trails: absence of a jammed phase.

    PubMed

    John, Alexander; Schadschneider, Andreas; Chowdhury, Debashish; Nishinari, Katsuhiro

    2009-03-13

    We report experimental results on unidirectional trafficlike collective movement of ants on trails. Our work is primarily motivated by fundamental questions on the collective spatiotemporal organization in systems of interacting motile constituents driven far from equilibrium. Making use of the analogies with vehicular traffic, we analyze our experimental data for the spatiotemporal organization of ants on a trail. From this analysis, we extract the flow-density relation as well as the distributions of velocities of the ants and distance headways. Some of our observations are consistent with our earlier models of ant traffic, which are appropriate extensions of the asymmetric simple exclusion process. In sharp contrast to highway traffic and most other transport processes, the average velocity of the ants is almost independent of their density on the trail. Consequently, no jammed phase is observed.

  17. Optimal cue integration in ants

    PubMed Central

    Wystrach, Antoine; Mangan, Michael; Webb, Barbara

    2015-01-01

    In situations with redundant or competing sensory information, humans have been shown to perform cue integration, weighting different cues according to their certainty in a quantifiably optimal manner. Ants have been shown to merge the directional information available from their path integration (PI) and visual memory, but as yet it is not clear that they do so in a way that reflects the relative certainty of the cues. In this study, we manipulate the variance of the PI home vector by allowing ants (Cataglyphis velox) to run different distances and testing their directional choice when the PI vector direction is put in competition with visual memory. Ants show progressively stronger weighting of their PI direction as PI length increases. The weighting is quantitatively predicted by modelling the expected directional variance of home vectors of different lengths and assuming optimal cue integration. However, a subsequent experiment suggests ants may not actually compute an internal estimate of the PI certainty, but are using the PI home vector length as a proxy. PMID:26400741

  18. Ant Ecdysteroid Extraction and Radioimmunoassay

    USDA-ARS?s Scientific Manuscript database

    Ecdysteroids are a group of steroid compounds present in many plant and invertebrate species. In arthropods, they function primarily as hormones involved in the regulation of molting. This protocol describes how to extract ecdysteroid hormones from ant specimens and subsequently quantify circulating...

  19. Ants, Wasps, and Bees (Hymenoptera)

    USDA-ARS?s Scientific Manuscript database

    Stinging wasps, bees, and ants are a problem for farm workers, particularly at harvest when these insects are attracted to ripe fruits. Researchers at the USDA-ARS Yakima Agricultural Research Laboratory, Wapato, WA, together with personnel at Oral Roberts University compiled available information o...

  20. Optimal cue integration in ants.

    PubMed

    Wystrach, Antoine; Mangan, Michael; Webb, Barbara

    2015-10-07

    In situations with redundant or competing sensory information, humans have been shown to perform cue integration, weighting different cues according to their certainty in a quantifiably optimal manner. Ants have been shown to merge the directional information available from their path integration (PI) and visual memory, but as yet it is not clear that they do so in a way that reflects the relative certainty of the cues. In this study, we manipulate the variance of the PI home vector by allowing ants (Cataglyphis velox) to run different distances and testing their directional choice when the PI vector direction is put in competition with visual memory. Ants show progressively stronger weighting of their PI direction as PI length increases. The weighting is quantitatively predicted by modelling the expected directional variance of home vectors of different lengths and assuming optimal cue integration. However, a subsequent experiment suggests ants may not actually compute an internal estimate of the PI certainty, but are using the PI home vector length as a proxy.

  1. A selection mosaic in the facultative mutualism between ants and wild cotton.

    PubMed

    Rudgers, Jennifer A; Strauss, Sharon Y

    2004-12-07

    In protection mutualisms, one mutualist defends its partner against a natural enemy in exchange for a reward, usually food or shelter. For both partners, the costs and benefits of these interactions often vary considerably in space because the outcome (positive, negative or neutral) depends on the local abundance of at least three species: the protector, the beneficiary of protection and the beneficiary's natural enemy. In Gossypium thurberi (wild cotton), ants benefit nutritionally from the plant's extrafloral nectaries and guard plants from herbivores. Experimentally altering the availability of both ants and extrafloral nectar in three populations demonstrated that the mutualism is facultative, depending, in part, on the abundance of ants and the level of herbivore damage. The species composition of ants and a parasitic alga that clogs extrafloral nectaries were also implicated in altering the outcome of plant-ant interactions. Furthermore, experimental treatments that excluded ants (the putative selective agents) in combination with phenotypic selection analyses revealed that selection on extrafloral nectary traits was mediated by ants and, importantly, varied across populations. This work is some of the first to manipulate interactions experimentally across multiple sites and thereby document that geographically variable selection, mediated by a mutualist, can shape the evolution of plant traits.

  2. A selection mosaic in the facultative mutualism between ants and wild cotton.

    PubMed Central

    Rudgers, Jennifer A.; Strauss, Sharon Y.

    2004-01-01

    In protection mutualisms, one mutualist defends its partner against a natural enemy in exchange for a reward, usually food or shelter. For both partners, the costs and benefits of these interactions often vary considerably in space because the outcome (positive, negative or neutral) depends on the local abundance of at least three species: the protector, the beneficiary of protection and the beneficiary's natural enemy. In Gossypium thurberi (wild cotton), ants benefit nutritionally from the plant's extrafloral nectaries and guard plants from herbivores. Experimentally altering the availability of both ants and extrafloral nectar in three populations demonstrated that the mutualism is facultative, depending, in part, on the abundance of ants and the level of herbivore damage. The species composition of ants and a parasitic alga that clogs extrafloral nectaries were also implicated in altering the outcome of plant-ant interactions. Furthermore, experimental treatments that excluded ants (the putative selective agents) in combination with phenotypic selection analyses revealed that selection on extrafloral nectary traits was mediated by ants and, importantly, varied across populations. This work is some of the first to manipulate interactions experimentally across multiple sites and thereby document that geographically variable selection, mediated by a mutualist, can shape the evolution of plant traits. PMID:15590599

  3. Community analysis of microbial sharing and specialization in a Costa Rican ant-plant-hemipteran symbiosis.

    PubMed

    Pringle, Elizabeth G; Moreau, Corrie S

    2017-03-15

    Ants have long been renowned for their intimate mutualisms with trophobionts and plants and more recently appreciated for their widespread and diverse interactions with microbes. An open question in symbiosis research is the extent to which environmental influence, including the exchange of microbes between interacting macroorganisms, affects the composition and function of symbiotic microbial communities. Here we approached this question by investigating symbiosis within symbiosis. Ant-plant-hemipteran symbioses are hallmarks of tropical ecosystems that produce persistent close contact among the macroorganism partners, which then have substantial opportunity to exchange symbiotic microbes. We used metabarcoding and quantitative PCR to examine community structure of both bacteria and fungi in a Neotropical ant-plant-scale-insect symbiosis. Both phloem-feeding scale insects and honeydew-feeding ants make use of microbial symbionts to subsist on phloem-derived diets of suboptimal nutritional quality. Among the insects examined here, Cephalotes ants and pseudococcid scale insects had the most specialized bacterial symbionts, whereas Azteca ants appeared to consume or associate with more fungi than bacteria, and coccid scale insects were associated with unusually diverse bacterial communities. Despite these differences, we also identified apparent sharing of microbes among the macro-partners. How microbial exchanges affect the consumer-resource interactions that shape the evolution of ant-plant-hemipteran symbioses is an exciting question that awaits further research. © 2017 The Author(s).

  4. Consequences of forest clear-cuts for native and nonindigenous ants (Hymenoptera: Formicidae)

    USGS Publications Warehouse

    Zettler, J.A.; Taylor, M.D.; Allen, C.R.; Spira, T.P.

    2004-01-01

    Currently, the southern United States produces more timber than any other region in the world. Entire timber stands are removed through a harvesting method called clear-cutting. This common forestry practice may lead to the replacement of native ant communities with invasive, nonindigenous species. In four deciduous forest sites in South Carolina, we monitored the change in ant species richness, diversity, and abundance immediately after forest clearing for a period of 15 mo to 2 yr and determined the incidence of colonization of the red imported fire ant Solenopsis invicta into these four newly disturbed sites. Each site consisted of an uncut, forested plot and a logged, pine-planted plot. Fire ants were collected in clear-cuts as early as 3 mo postcutting, and by the end of the experiment, they were found in all four treatment sites. Our study is the first to document, through a controlled experiment, that clear-cutting alters ant species assemblages by increasing S. invicta and Pheidole spp. populations and significantly reducing native ant numbers. Long-term studies are needed to assess how replacing native deciduous forests with pine monocultures affects ant assemblages. ?? 2004 Entomological Society of America.

  5. Steep Decline and Cessation in Seed Dispersal by Myrmica rubra Ants

    PubMed Central

    2015-01-01

    Myrmecochorous diaspores bear a nutrient-rich appendage, the elaiosome, attractive to ant workers that retrieve them into the nest, detach the elaiosome and reject the seed intact. While this interaction is beneficial for the plant partner by ensuring its seed dispersal, elaiosome consumption has various effects −positive, negative or none − on ants’ demography and survival, depending on both the ant/plant species involved. In this context, the contribution of ants to seed dispersal strongly varies according to the ant/plant pairs considered. In this paper, we investigate whether the dynamics of myrmecochory also vary on a temporal scale, for a given pair of partners: Myrmica rubra ants and Viola odorata seeds. During their first encounter with seeds, ants collect all the diaspores and eat the majority of elaiosomes. Both the harvesting effort and the elaiosome consumption decline when seeds are offered on the next week and completely cease for the following weeks. This is related to a decrease in the number of foragers reaching the food source, as well as to a reduced probability for an ant contacting a seed to retrieve it. Seed retrieval is not reactivated after seven weeks without any encounter with V. odorata seeds. By contrast, naive ant colonies only fed with fruit flies do not show a decline of prey harvesting of which the speed of retrieval even increases over the successive weeks. Myrmecochory may thus be labile at the scale of a fruiting season due to the ability of ants to steeply tune and cease for several months the harvesting of these seemingly poorly rewarding items and to maintain cessation of seed exploitation. The present study emphasizes the importance of a long-lasting follow up of the myrmecochory process, to assess the stability of this ant-plant partnership and to identify mechanisms of adaptive harvesting in ants. PMID:26414161

  6. Experience influences aggressive behaviour in the Argentine ant

    PubMed Central

    Van Wilgenburg, Ellen; Clémencet, Johanna; Tsutsui, Neil D.

    2010-01-01

    All animals interact with conspecifics during their life, and nearly all also display some form of aggression. An enduring challenge, however, is to understand how the experiences of an individual animal influence its later behaviours. Several studies have shown that prior winning experience increases the probability of initiating fights in later encounters. Using behavioural assays in the laboratory, we provide evidence that, in Argentine ants (Linepithema humile), the mere exposure to an opponent, without the encounter escalating to a fight, also increases the probability that it will display aggression in later encounters. Argentine ant workers differ in their propensity to attack non-colonymates, with some ants repeatedly aggressive and others consistently more docile. Although 78 per cent of the workers were consistent in their behaviour from one encounter to the next, workers that did change their behaviour after an encounter with a non-colonymate more often changed from non-aggressive to aggressive, rather than the reverse. Surprisingly, a single encounter with a non-colonymate increased a worker's propensity to fight in encounters up to a week later. An encounter with a non-colonymate also increased the probability that a worker would attack ants from a colony that it had not previously encountered. Thus, these interactions lowered the overall aggression threshold, rather than stimulating a specific aggressive response to a particular foreign colony. Finally, our data suggest that aggression towards non-colonymates increases with age. PMID:19793741

  7. Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects

    PubMed Central

    Pringle, Elizabeth G.; Akçay, Erol; Raab, Ted K.; Dirzo, Rodolfo; Gordon, Deborah M.

    2013-01-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

  8. Habitat contrasts reveal a shift in the trophic position of ant assemblages.

    PubMed

    Gibb, Heloise; Cunningham, Saul A

    2011-01-01

    1. Trophic structure within a guild can be influenced by factors such as resource availability and competition. While ants occupy a wide range of positions in food webs, and ant community composition changes with habitat, it is not well understood if ant genera tend to maintain their position in the trophic structure, or if trophic position varies across habitats. 2. We used ratios of stable isotopes of carbon and nitrogen to test for differences in the trophic structure and position of assemblages of ants among habitat types. We tested for differences between assemblages in replicate sites of the land use categories: (i) pastures with old large trees; (ii) recently revegetated pastures with small young trees; and (iii) remnant woodlands. Known insect herbivores and predatory spiders provided baselines for herbivorous and predaceous arthropods. Soil samples were used to correct for the base level of isotopic enrichment at each site. 3. We found no significant interactions between land use and ant genus for isotope enrichment, indicating that trophic structure is conserved across land use categories. The fixed relative positions of genera in the trophic structure might be re-enforced by competition or some other factor. However, the entire ant assemblage had significantly lower δ(15) N values in revegetated sites, suggesting that ants feed lower down in the food chain i.e. they are more 'herbivorous' in revegetated sites. This may be a result of the high availability of plant sugars, honeydew and herbivorous arthropod prey. 4. Surprisingly, ants in remnants and pastures with trees displayed similar isotopic compositions. Interactions within ant assemblages are thus likely to be resilient to changes in land use, but ant diets in early successional habitats may reflect the simplicity of communities, which may have comparatively lower rates of saprophagy and predation.

  9. Ant-fungus species combinations engineer physiological activity of fungus gardens.

    PubMed

    Seal, J N; Schiøtt, M; Mueller, U G

    2014-07-15

    Fungus-gardening insects are among the most complex organisms because of their extensive co-evolutionary histories with obligate fungal symbionts and other microbes. Some fungus-gardening insect lineages share fungal symbionts with other members of their lineage and thus exhibit diffuse co-evolutionary relationships, while others exhibit little or no symbiont sharing, resulting in host-fungus fidelity. The mechanisms that maintain this symbiont fidelity are currently unknown. Prior work suggested that derived leaf-cutting ants in the genus Atta interact synergistically with leaf-cutter fungi (Attamyces) by exhibiting higher fungal growth rates and enzymatic activities than when growing a fungus from the sister-clade to Attamyces (so-called 'Trachymyces'), grown primarily by the non-leaf cutting Trachymyrmex ants that form, correspondingly, the sister-clade to leaf-cutting ants. To elucidate the enzymatic bases of host-fungus specialization in leaf-cutting ants, we conducted a reciprocal fungus-switch experiment between the ant Atta texana and the ant Trachymyrmex arizonensis and report measured enzymatic activities of switched and sham-switched fungus gardens to digest starch, pectin, xylan, cellulose and casein. Gardens exhibited higher amylase and pectinase activities when A. texana ants cultivated Attamyces compared with Trachymyces fungi, consistent with enzymatic specialization. In contrast, gardens showed comparable amylase and pectinase activities when T. arizonensis cultivated either fungal species. Although gardens of leaf-cutting ants are not known to be significant metabolizers of cellulose, T. arizonensis were able to maintain gardens with significant cellulase activity when growing either fungal species. In contrast to carbohydrate metabolism, protease activity was significantly higher in Attamyces than in Trachymyces, regardless of the ant host. Activity of some enzymes employed by this symbiosis therefore arises from complex interactions between the

  10. Prudent sperm use by leaf-cutter ant queens

    PubMed Central

    den Boer, Susanne P. A.; Baer, Boris; Dreier, Stephanie; Aron, Serge; Nash, David R.; Boomsma, Jacobus J.

    2009-01-01

    In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens are able to fertilize close to 100 per cent of the eggs and that the average sperm use per egg is very low, but increases with queen age. The robustness of stored sperm was found to decrease with years of storage, signifying that senescence affects sperm either directly or indirectly via the declining glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm expenditure and infer that our observed averages of sperm number, sperm robustness and sperm use are consistent with sperm depletion being a significant cause of mortality of mature colonies of Atta leaf-cutter ants. PMID:19710057

  11. Prudent sperm use by leaf-cutter ant queens.

    PubMed

    den Boer, Susanne P A; Baer, Boris; Dreier, Stephanie; Aron, Serge; Nash, David R; Boomsma, Jacobus J

    2009-11-22

    In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens are able to fertilize close to 100 per cent of the eggs and that the average sperm use per egg is very low, but increases with queen age. The robustness of stored sperm was found to decrease with years of storage, signifying that senescence affects sperm either directly or indirectly via the declining glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm expenditure and infer that our observed averages of sperm number, sperm robustness and sperm use are consistent with sperm depletion being a significant cause of mortality of mature colonies of Atta leaf-cutter ants.

  12. Isolation of a pyrazine alarm pheromone component from the fire ant, Solenopsis invicta.

    PubMed

    Vander Meer, Robert K; Preston, Catherine A; Choi, Man-Yeon

    2010-02-01

    Alarm pheromones in social insects are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality. The alarm pheromones of ants were among the first examples of animal pheromones identified, primarily because of the large amount of chemical produced and the distinctive responses of ants to the pheromone. However, the alarm pheromone of the fire ant, Solenopsis invicta, eluded identification for over four decades. We identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of S. invicta. Worker fire ants detect the pyrazine alarm pheromone at 30 pg/ml, which is comparable to alarm pheromone sensitivities reported for other ant species. The source of this alarm pheromone are the mandibular glands, which, in fire ants, are not well developed and contain only about 300 pg of the compound, much less than the microgram quantities of alarm pheromones reported for several other ant species. Female and male sexuals and workers produce the pyrazine, which suggests that it may be involved in fire ant mating flight initiation, as well as the typical worker alarm response. This is the first report of 2-ethyl-3,6-dimethylpyrazine from a Solenopsis species and the first example of this alkaloid functioning as an alarm pheromone.

  13. Exploiting a mutualism: parasite specialization on cultivars within the fungus-growing ant symbiosis.

    PubMed Central

    Gerardo, Nicole M.; Mueller, Ulrich G.; Price, Shauna L.; Currie, Cameron R.

    2004-01-01

    Fungus-growing ants, their cultivated fungi and the cultivar-attacking parasite Escovopsis coevolve as a complex community. Higher-level phylogenetic congruence of the symbionts suggests specialized long-term associations of host-parasite clades but reveals little about parasite specificity at finer scales of species-species and genotype-genotype interactions. By coupling sequence and amplified fragment length polymorphism genotyping analyses with experimental evidence, we examine (i) the host specificity of Escovopsis strains infecting colonies of three closely related ant species in the genus Cyphomyrmex, and (ii) potential mechanisms constraining the Escovopsis host range. Incongruence of cultivar and ant relationships across the three focal Cyphomyrmex spp. allows us to test whether Escovopsis strains track their cultivar or the ant hosts. Phylogenetic analyses demonstrate that the Escovopsis phylogeny matches the cultivar phylogeny but not the ant phylogeny, indicating that the parasites are cultivar specific. Cross-infection experiments establish that ant gardens can be infected by parasite strains with which they are not typically associated in the field, but that infection is more likely when gardens are inoculated with their typical parasite strains. Thus, Escovopsis specialization is shaped by the parasite's ability to overcome only a narrow range of garden-specific defences, but specialization is probably additionally constrained by ecological factors, including the other symbionts (i.e. ants and their antibiotic-producing bacteria) within the coevolved fungus-growing ant symbiosis. PMID:15315894

  14. Salticid predation as one potential driving force of ant mimicry in jumping spiders

    PubMed Central

    Huang, Jin-Nan; Cheng, Ren-Chung; Li, Daiqin; Tso, I-Min

    2011-01-01

    Many spiders possess myrmecomorphy, and species of the jumping spider genus Myrmarachne exhibit nearly perfect ant mimicry. Most salticids are diurnal predators with unusually high visual acuity that prey on various arthropods, including conspecifics. In this study, we tested whether predation pressure from large jumping spiders is one possible driving force of perfect ant mimicry in jumping spiders. The results showed that small non-ant-mimicking jumping spiders were readily treated as prey by large ones (no matter whether heterospecific or conspecific) and suffered high attack and mortality rates. The size difference between small and large jumping spiders significantly affected the outcomes of predatory interactions between them: the smaller the juvenile jumping spiders, the higher the predation risk from large ones. The attack and mortality rates of ant-mimicking jumping spiders were significantly lower than those of non-ant-mimicking jumping spiders, indicating that a resemblance to ants could provide protection against salticid predation. However, results of multivariate behavioural analyses showed that the responses of large jumping spiders to ants and ant-mimicking salticids differed significantly. Results of this study indicate that predation pressure from large jumping spiders might be one selection force driving the evolution of nearly perfect myrmecomorphy in spiders and other arthropods. PMID:20961898

  15. Salticid predation as one potential driving force of ant mimicry in jumping spiders.

    PubMed

    Huang, Jin-Nan; Cheng, Ren-Chung; Li, Daiqin; Tso, I-Min

    2011-05-07

    Many spiders possess myrmecomorphy, and species of the jumping spider genus Myrmarachne exhibit nearly perfect ant mimicry. Most salticids are diurnal predators with unusually high visual acuity that prey on various arthropods, including conspecifics. In this study, we tested whether predation pressure from large jumping spiders is one possible driving force of perfect ant mimicry in jumping spiders. The results showed that small non-ant-mimicking jumping spiders were readily treated as prey by large ones (no matter whether heterospecific or conspecific) and suffered high attack and mortality rates. The size difference between small and large jumping spiders significantly affected the outcomes of predatory interactions between them: the smaller the juvenile jumping spiders, the higher the predation risk from large ones. The attack and mortality rates of ant-mimicking jumping spiders were significantly lower than those of non-ant-mimicking jumping spiders, indicating that a resemblance to ants could provide protection against salticid predation. However, results of multivariate behavioural analyses showed that the responses of large jumping spiders to ants and ant-mimicking salticids differed significantly. Results of this study indicate that predation pressure from large jumping spiders might be one selection force driving the evolution of nearly perfect myrmecomorphy in spiders and other arthropods.

  16. The demographic consequences of mutualism: ants increase host-plant fruit production but not population growth.

    PubMed

    Ford, Kevin R; Ness, Joshua H; Bronstein, Judith L; Morris, William F

    2015-10-01

    The impact of mutualists on a partner's demography depends on how they affect the partner's multiple vital rates and how those vital rates, in turn, affect population growth. However, mutualism studies rarely measure effects on multiple vital rates or integrate them to assess the ultimate impact on population growth. We used vital rate data, population models and simulations of long-term population dynamics to quantify the demographic impact of a guild of ant species on the plant Ferocactus wislizeni. The ants feed at the plant's extrafloral nectaries and attack herbivores attempting to consume reproductive organs. Ant-guarded plants produced significantly more fruit, but ants had no significant effect on individual growth or survival. After integrating ant effects across these vital rates, we found that projected population growth was not significantly different between unguarded and ant-guarded plants because population growth was only weakly influenced by differences in fruit production (though strongly influenced by differences in individual growth and survival). However, simulations showed that ants could positively affect long-term plant population dynamics through services provided during rare but important events (herbivore outbreaks that reduce survival or years of high seedling recruitment associated with abundant precipitation). Thus, in this seemingly clear example of mutualism, the interaction may actually yield no clear benefit to plant population growth, or if it does, may only do so through the actions of the ants during rare events. These insights demonstrate the value of taking a demographic approach to studying the consequences of mutualism.

  17. Social, spatial, and temporal organization in a complex insect society.

    PubMed

    Quevillon, Lauren E; Hanks, Ephraim M; Bansal, Shweta; Hughes, David P

    2015-08-24

    High-density living is often associated with high disease risk due to density-dependent epidemic spread. Despite being paragons of high-density living, the social insects have largely decoupled the association with density-dependent epidemics. It is hypothesized that this is accomplished through prophylactic and inducible defenses termed 'collective immunity'. Here we characterise segregation of carpenter ants that would be most likely to encounter infectious agents (i.e. foragers) using integrated social, spatial, and temporal analyses. Importantly, we do this in the absence of disease to establish baseline colony organization. Behavioural and social network analyses show that active foragers engage in more trophallaxis interactions than their nest worker and queen counterparts and occupy greater area within the nest. When the temporal ordering of social interactions is taken into account, active foragers and inactive foragers are not observed to interact with the queen in ways that could lead to the meaningful transfer of disease. Furthermore, theoretical resource spread analyses show that such temporal segregation does not appear to impact the colony-wide flow of food. This study provides an understanding of a complex society's organization in the absence of disease that will serve as a null model for future studies in which disease is explicitly introduced.

  18. Methods for Casting Subterranean Ant Nests

    PubMed Central

    Tschinkel, Walter R.

    2010-01-01

    The study of subterranean ant nests has been impeded by the difficulty of rendering their structures in visible form. Here, several different casting materials are shown to make perfect casts of the underground nests of ants. Each material (dental plaster, paraffin wax, aluminum, zinc) has advantages and limitations, which are discussed. Some of the materials allow the recovery of the ants entombed in the casts, allowing a census of the ants to be connected with features of their nest architecture. The necessary equipment and procedures are described in the hope that more researchers will study this very important aspect of ant natural history. PMID:20673073

  19. Tournaments and slavery in a desert ant.

    PubMed

    Hölldobler, B

    1976-05-28

    Many species of ants engage in physical fighting when territorial borders are challenged. In contrast, colonies of the honeypot ant species Myrmecocystus mimicus conduct ritualized tournaments, in which hundreds of ants perform highly stereotyped display fights. Opposing colonies summon their worker forces to the tournament area by means of an alarm-recruitment system. When one colony is considerably stronger than the other, the tournament quickly ends, and the weaker colony is raided and its ants "enslaved." This is the first example of intraspecific slavery recorded in ants.

  20. The need for interaction between assisted reproduction technology and genetics: recommendations of the European Societies of Human Genetics and Human Reproduction and Embryology.

    PubMed

    2006-08-01

    Infertility and reproductive genetic risk are both increasing in our societies because of lifestyle changes and possibly environmental factors. Owing to the magnitude of the problem, they have implications not only at the individual and family levels but also at the community level. This leads to an increasing demand for access to assisted reproduction technology (ART) and genetic services, especially when the cause of infertility may be genetic in origin. The increasing application of genetics in reproductive medicine and vice versa requires closer collaboration between the two disciplines. ART and genetics are rapidly evolving fields where new technologies are currently introduced without sufficient knowledge of their potential long-term effects. As for any medical procedures, there are possible unexpected effects which need to be envisaged to make sure that the balance between benefits and risks is clearly on the benefit side. The development of ART and genetics as scientific activities is creating an opportunity to understand the early stages of human development, which is leading to new and challenging findings/knowledge. However, there are opinions against investigating the early stages of development in humans who deserve respect and attention. For all these reasons, these two societies, European Society of Human Genetics (ESHG) and European Society of Human Reproduction and Embryology (ESHRE), have joined efforts to explore the issues at stake and to set up recommendations to maximize the benefit for the couples in need and for the community.

  1. Quantifying ant activity using vibration measurements.

    PubMed

    Oberst, Sebastian; Baro, Enrique Nava; Lai, Joseph C S; Evans, Theodore A

    2014-01-01

    Ant behaviour is of great interest due to their sociality. Ant behaviour is typically observed visually, however there are many circumstances where visual observation is not possible. It may be possible to assess ant behaviour using vibration signals produced by their physical movement. We demonstrate through a series of bioassays with different stimuli that the level of activity of meat ants (Iridomyrmex purpureus) can be quantified using vibrations, corresponding to observations with video. We found that ants exposed to physical shaking produced the highest average vibration amplitudes followed by ants with stones to drag, then ants with neighbours, illuminated ants and ants in darkness. In addition, we devised a novel method based on wavelet decomposition to separate the vibration signal owing to the initial ant behaviour from the substrate response, which will allow signals recorded from different substrates to be compared directly. Our results indicate the potential to use vibration signals to classify some ant behaviours in situations where visual observation could be difficult.

  2. Quantifying Ant Activity Using Vibration Measurements

    PubMed Central

    Oberst, Sebastian; Baro, Enrique Nava; Lai, Joseph C. S.; Evans, Theodore A.

    2014-01-01

    Ant behaviour is of great interest due to their sociality. Ant behaviour is typically observed visually, however there are many circumstances where visual observation is not possible. It may be possible to assess ant behaviour using vibration signals produced by their physical movement. We demonstrate through a series of bioassays with different stimuli that the level of activity of meat ants (Iridomyrmex purpureus) can be quantified using vibrations, corresponding to observations with video. We found that ants exposed to physical shaking produced the highest average vibration amplitudes followed by ants with stones to drag, then ants with neighbours, illuminated ants and ants in darkness. In addition, we devised a novel method based on wavelet decomposition to separate the vibration signal owing to the initial ant behaviour from the substrate response, which will allow signals recorded from different substrates to be compared directly. Our results indicate the potential to use vibration signals to classify some ant behaviours in situations where visual observation could be difficult. PMID:24658467

  3. Beneficial Effects of Ants and Spiders on the Reproductive Value of Eriotheca gracilipes (Malvaceae) in a Tropical Savanna.

    PubMed

    Stefani, Vanessa; Pires, Tayna Lopes; Torezan-Silingardi, Helena Maura; Del-Claro, Kleber

    2015-01-01

    Predators affect plant fitness when they forage on them and reduce the action of herbivores. Our study evaluates the complementary effects of spiders and ants that visit the extrafloral nectaries of Eriotheca gracilipes (Malvaceae) on the production of fruits and viable seeds of these savanna trees. Four experimental groups were established: control group - with free access of spiders and ants; exclusion group - spiders and ants excluded; ant group - absence of spiders; and spider group - absence of ants. The presence of ants reduced the spider richness; however, the presence of spiders did not affect the ant richness. A significantly higher number of fruits per buds were found in the presence of spiders alone or spiders and ants together (control group) compared with the absence of both predators (exclusion group). The number of seeds per fruits and seed viability were higher in the control group. This is the first study showing that spiders and ants may exert a positive and complementary effect on the reproductive value of an extrafloral nectaried plant. Mostly the impact of ants and/or spiders on herbivores is considered, whereas our study reinforces the importance of evaluating the effect of multiple predators simultaneously, exploring how the interactions among predators with distinct skills may affect the herbivores and the plants on which they forage.

  4. Beneficial Effects of Ants and Spiders on the Reproductive Value of Eriotheca gracilipes (Malvaceae) in a Tropical Savanna

    PubMed Central

    2015-01-01

    Predators affect plant fitness when they forage on them and reduce the action of herbivores. Our study evaluates the complementary effects of spiders and ants that visit the extrafloral nectaries of Eriotheca gracilipes (Malvaceae) on the production of fruits and viable seeds of these savanna trees. Four experimental groups were established: control group – with free access of spiders and ants; exclusion group – spiders and ants excluded; ant group – absence of spiders; and spider group – absence of ants. The presence of ants reduced the spider richness; however, the presence of spiders did not affect the ant richness. A significantly higher number of fruits per buds were found in the presence of spiders alone or spiders and ants together (control group) compared with the absence of both predators (exclusion group). The number of seeds per fruits and seed viability were higher in the control group. This is the first study showing that spiders and ants may exert a positive and complementary effect on the reproductive value of an extrafloral nectaried plant. Mostly the impact of ants and/or spiders on herbivores is considered, whereas our study reinforces the importance of evaluating the effect of multiple predators simultaneously, exploring how the interactions among predators with distinct skills may affect the herbivores and the plants on which they forage. PMID:26168036

  5. Variation in the effectiveness of biotic defence: the case of an opportunistic ant-plant protection mutualism.

    PubMed

    Giusto, Bruno; Anstett, Marie-Charlotte; Dounias, Edmond; McKey, Doyle B

    2001-11-01

    Benefits to plants in facultative ant protection mutualisms are highly variable. This allows examination of the sources of this variation and the mechanisms by which ants protect plants. We studied opportunistic interactions between ants and an extrafloral nectary-bearing vine, Dioscorea praehensilis, during 3 different years. Variation in plant protection among years was striking. Several factors affected the effectiveness of the biotic defence. Stems recently emerged from the underground tuber were self-supporting, contacting no other plants and encountering few foraging ants. Stems then became lianescent, and contact with supporting plants greatly increased ant recruitment. Both species and number of ant workers influenced the effect of ants on the major herbivore, the chrysomelid beetle Lilioceris latipennis. Protective actions included limitation of oviposition (reduction in the number of eggs laid on the plant) and predation, leading to increased larval mortality. The probability of successful predation was strongly dependent on larval size. If temporarily low ant-patrolling activity allows larvae to grow beyond a critical size, their mechanical (thick integument) or chemical (plant-derived compounds in a fecal shield) defences become more effective against ants. Secondary metabolites derived from the host plant thus appear to be important for the anti-predator mechanisms of this beetle, being necessary for its survival and reproduction on a host plant that actively recruits ants as a biotic defence against herbivores.

  6. Dynamics of the association between a long-lived understory myrmecophyte and its specific associated ants.

    PubMed

    Orivel, Jérôme; Lambs, Luc; Malé, Pierre-Jean G; Leroy, Céline; Grangier, Julien; Otto, Thierry; Quilichini, Angélique; Dejean, Alain

    2011-02-01

    Myrmecophytic symbioses are widespread in tropical ecosystems and their diversity makes them useful tools for understanding the origin and evolution of mutualisms. Obligate ant-plants, or myrmecophytes, provide a nesting place, and, often, food to a limited number of plant-ant species. In exchange, plant-ants protect their host plants from herbivores, competitors and pathogens, and can provide them with nutrients. Although most studies to date have highlighted a similar global pattern of interactions in these systems, little is known about the temporal structuring and dynamics of most of these associations. In this study we focused on the association between the understory myrmecophyte Hirtella physophora (Chrysobalanaceae) and its obligate ant partner Allomerus decemarticulatus (Myrmicinae). An examination of the life histories and growth rates of both partners demonstrated that this plant species has a much longer lifespan (up to about 350 years) than its associated ant colonies (up to about 21 years). The size of the ant colonies and their reproductive success were strongly limited by the available nesting space provided by the host plants. Moreover, the resident ants positively affected the vegetative growth of their host plant, but had a negative effect on its reproduction by reducing the number of flowers and fruits by more than 50%. Altogether our results are important to understanding the evolutionary dynamics of ant-plant symbioses. The highly specialized interaction between long-lived plants and ants with a shorter lifespan produces an asymmetry in the evolutionary rates of the interaction which, in return, can affect the degree to which the interests of the two partners converge.

  7. Laccase detoxification mediates the nutritional alliance between leaf-cutting ants and fungus-garden symbionts.

    PubMed

    De Fine Licht, Henrik H; Schiøtt, Morten; Rogowska-Wrzesinska, Adelina; Nygaard, Sanne; Roepstorff, Peter; Boomsma, Jacobus J

    2013-01-08

    Leaf-cutting ants combine large-scale herbivory with fungus farming to sustain advanced societies. Their stratified colonies are major evolutionary achievements and serious agricultural pests, but the crucial adaptations that allowed this mutualism to become the prime herbivorous component of neotropical ecosystems has remained elusive. Here we show how coevolutionary adaptation of a specific enzyme in the fungal symbiont has helped leaf-cutting ants overcome plant defensive phenolic compounds. We identify nine putative laccase-coding genes in the fungal genome of Leucocoprinus gongylophorus cultivated by the leaf-cutting ant Acromyrmex echinatior. One of these laccases (LgLcc1) is highly expressed in the specialized hyphal tips (gongylidia) that the ants preferentially eat, and we confirm that these ingested laccase molecules pass through the ant guts and remain active when defecated on the leaf pulp that the ants add to their gardens. This accurate deposition ensures that laccase activity is highest where new leaf material enters the fungus garden, but where fungal mycelium is too sparse to produce extracellular enzymes in sufficient quantities to detoxify phenolic compounds. Phylogenetic analysis of LgLcc1 ortholog sequences from symbiotic and free-living fungi revealed significant positive selection in the ancestral lineage that gave rise to the gongylidia-producing symbionts of leaf-cutting ants and their non-leaf-cutting ant sister group. Our results are consistent with fungal preadaptation and subsequent modification of a particular laccase enzyme for the detoxification of secondary plant compounds during the transition to active herbivory in the ancestor of leaf-cutting ants between 8 and 12 Mya.

  8. Laccase detoxification mediates the nutritional alliance between leaf-cutting ants and fungus-garden symbionts

    PubMed Central

    De Fine Licht, Henrik H.; Schiøtt, Morten; Rogowska-Wrzesinska, Adelina; Nygaard, Sanne; Roepstorff, Peter; Boomsma, Jacobus J.

    2013-01-01

    Leaf-cutting ants combine large-scale herbivory with fungus farming to sustain advanced societies. Their stratified colonies are major evolutionary achievements and serious agricultural pests, but the crucial adaptations that allowed this mutualism to become the prime herbivorous component of neotropical ecosystems has remained elusive. Here we show how coevolutionary adaptation of a specific enzyme in the fungal symbiont has helped leaf-cutting ants overcome plant defensive phenolic compounds. We identify nine putative laccase-coding genes in the fungal genome of Leucocoprinus gongylophorus cultivated by the leaf-cutting ant Acromyrmex echinatior. One of these laccases (LgLcc1) is highly expressed in the specialized hyphal tips (gongylidia) that the ants preferentially eat, and we confirm that these ingested laccase molecules pass through the ant guts and remain active when defecated on the leaf pulp that the ants add to their gardens. This accurate deposition ensures that laccase activity is highest where new leaf material enters the fungus garden, but where fungal mycelium is too sparse to produce extracellular enzymes in sufficient quantities to detoxify phenolic compounds. Phylogenetic analysis of LgLcc1 ortholog sequences from symbiotic and free-living fungi revealed significant positive selection in the ancestral lineage that gave rise to the gongylidia-producing symbionts of leaf-cutting ants and their non–leaf-cutting ant sister