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Sample records for acromyrmex leaf-cutting ants

  1. Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae

    Mariane Aparecida Nickele

    2012-09-01

    Full Text Available Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae. Colony migration is a poorly studied phenomenon in leaf-cutting ants. Here we report on the emigration of a colony of the leaf-cutting ant A. heyeri in Brazil. The colony emigrated to a new location 47.4 m away from the original nest site, possibly because it had undergone considerable stress due to competitive interactions with a colony of Acromyrmex crassispinus.

  2. Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae)

    Mariane Aparecida Nickele; Marcio Roberto Pie; Wilson Reis Filho

    2012-01-01

    Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae). Colony migration is a poorly studied phenomenon in leaf-cutting ants. Here we report on the emigration of a colony of the leaf-cutting ant A. heyeri in Brazil. The colony emigrated to a new location 47.4 m away from the original nest site, possibly because it had undergone considerable stress due to competitive interactions with a colony of Acromyrmex crassispinus.

  3. LEAF-CUTTING ANTS Acromyrmex niger SMITH, 1858 (HYMENOPTERA; FORMICIDAE) USED AS BIOINDICATORS OF AGROTOXICS RESIDUES

    Liriana Belizário Cantagalli; Denise Alves Lopes; Ana Lúcia Paes Barateiro Stuchi; Maria Claudia Colla Ruvolo Takasusuki

    2013-01-01

    Despite the condition of leaf-cutting ant pests in agroecosystems, it is undeniable the benefits they can bring in certain situations or environments. The leaf-cutting ants of the genus Acromyrmex attack mainly leaves of vegetables and fruit trees exposing not only to the agrochemicals used for their control as well as to those used for the control of other pests. Due to the bioindicator potential of environmental quality of the ants and their frequent exposure to agrochemicals such as organo...

  4. Specificity of the mutualistic association between actinomycete bacteria and two sympatric species of Acromyrmex leaf-cutting ants

    Poulsen, M; Cafaro, M; Boomsma, J J;

    2005-01-01

    Acromyrmex leaf-cutting ants maintain two highly specialized, vertically transmitted mutualistic ectosymbionts: basidiomycete fungi that are cultivated for food in underground gardens and actinomycete Pseudonocardia bacteria that are reared on the cuticle to produce antibiotics that suppress...

  5. High recombination frequency creates genotypic diversity in colonies of the leaf-cutting ant Acromyrmex echinatior

    Sirviö, A.; Gadau, J.; Rueppell, O.;

    2006-01-01

    demonstrated that variation in division of labour and pathogen resistance has a genetic component and that genotypic diversity among workers may thus give colonies of this leaf-cutting ant a functional advantage. The present result is therefore consistent with the hypothesis that complex social life can select...... tested in other social insects. Here, we present a linkage map and an estimate of the recombination rate for Acromyrmex echinatior, a leaf-cutting ant that resembles the honeybee in having multiple mating of queens and colonies of approximately the same size. A map of 145 AFLP markers in 22 linkage...

  6. CONTROL OF THE BLACK LEAF CUTTING ANT, Acromyrmex crassispinus, WITH POWDERED FORMICIDES

    Henrique Moreira Link

    2009-09-01

    Full Text Available Four experiments  were carried out to evaluate the efficiency of some powdered formicides on the control of the black leaf cutting ant, Acromyrmex crassispinus (Forel, 1909 (Hymenoptera: Formicidae, in Santa Maria county, from 1996 until 1998. Powdered formicides containing  Fenthion at 50g a. i./kg, Imidacloprid at  4g a. i./kg, Betacyfluthrin at 2g a. i./kg, Chlorpyrifos at 20g a. i./kg and at 50g a. i./kg, Deltamethrin at  2g a. i./kg, Acephate at 750g a. i./kg and Diazinon at 10g a. i./kg were evaluated on big nests (>80cm of diameter. The big nests of this ant were efficiently controlled with 30g/nest of the commercial formulations of Fenthion, Diazinon and Chlorpyrifos (20g a. i./kg and  50g a. i./kg; with 3g/nest of the formulation of Acephate; with 5g/nest in dry season and 30g/nest in wet season of the powdered formulation of Deltamethrin.

  7. LEAF-CUTTING ANTS Acromyrmex niger SMITH, 1858 (HYMENOPTERA; FORMICIDAE USED AS BIOINDICATORS OF AGROTOXICS RESIDUES

    Liriana Belizário Cantagalli

    2013-11-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 Despite the condition of leaf-cutting ant pests in agroecosystems, it is undeniable the benefits they can bring in certain situations or environments. The leaf-cutting ants of the genus Acromyrmex attack mainly leaves of vegetables and fruit trees exposing not only to the agrochemicals used for their control as well as to those used for the control of other pests. Due to the bioindicator potential of environmental quality of the ants and their frequent exposure to agrochemicals such as organophosphates, neonicotinoids and growth regulators insecticide used for pest control, it is necessary to study the sublethal effects that these pesticides may cause. The electrophoresis technique was used to study the activity of esterase isozymes involved in the metabolism of xenobiotics of A. niger, combined with changes in the expression of isozymes after contamination by pesticides. A. niger  showed eight regions of esterase activity, which were called EST-1, EST-2, EST-3, EST-4, EST-5, EST-6, EST-7 and EST-8 according to the electrophoretic mobility. As the specificity to α  and β -naphthyl acetate substrates, the Est-7 and Est-8 may be classified as α -esterase and the others as αβ  esterases. EST-5 is considered an enzyme of the type cholinesterase II and the others are of the type carboxilesterase. The electrophoretic analysis showed partial inhibition to all esterases subjected to the contact with Malathion organophosforate at the concentrations 1 x10-3  % and 5 x 10-3  %, which may be considered as a biomarker for the presence of residues of this insecticide in the environment. The regression analysis for sublethal effects of the tested pesticides demonstrated correlation between dose and mortality only for Thiametoxam neonicotinoid pesticide. Utilización de hormigas cortadoras Acromyrmex niger Smith,1858 (Hymenoptera; Formicidae como bioindicadoresde residuos

  8. Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae) Emigração de uma colônia da formiga cortadeira Acromyrmex heyeri Forel (Hymenoptera, Formicidae)

    Mariane Aparecida Nickele; Marcio Roberto Pie; Wilson Reis Filho

    2012-01-01

    Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae). Colony migration is a poorly studied phenomenon in leaf-cutting ants. Here we report on the emigration of a colony of the leaf-cutting ant A. heyeri in Brazil. The colony emigrated to a new location 47.4 m away from the original nest site, possibly because it had undergone considerable stress due to competitive interactions with a colony of Acromyrmex crassispinus.Emigração de uma colônia da form...

  9. Symbiont recognition of mutualistic bacteria by Acromyrmex leaf-cutting ants

    Zhang, Mingzi; Poulsen, Michael; Currie, Cameron R

    2007-01-01

    actinomycete bacterial mutualist (genus Pseudonocardia). Despite the potential of being infected by phylogenetically diverse strains of parasites, each ant colony maintains only a single Pseudonocardia symbiont strain, which is primarily vertically transmitted between colonies by the founding queens. In this......Symbiont choice has been proposed to play an important role in shaping many symbiotic relationships, including the fungus-growing ant-microbe mutualism. Over millions of years, fungus-growing ants have defended their fungus gardens from specialized parasites with antibiotics produced by an...... study, we show that Acromyrmex leaf-cutter ants are able to differentiate between their native actinomycete strain and a variety of foreign strains isolated from sympatric and allopatric Acromyrmex species, in addition to strains originating from other fungus-growing ant genera. The recognition...

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

    Marsh, Sarah E.; Thomas-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...

  11. Purpureocillium lilacinum, potential agent for biological control of the leaf-cutting ant Acromyrmex lundii.

    Goffré, D; Folgarait, P J

    2015-09-01

    Many leaf-cutter ant species are well known pests in Latin America, including species of the genera Acromyrmex and Atta. An environmentally friendly strategy to reduce the number of leafcutter ants and avoid indiscriminate use of chemical pesticides is biological control. In this work we evaluated the effectiveness of a strain of the entomopathogen Purpureocillium lilacinum, against worker ants from six Acromyrmex lundii field colonies, after immersions in pure suspensions at a concentration of 1×10(6)conidiaml(-1). Survival of ants treated with P. lilacinum was significantly lower than that recorded in controls, and median lethal time (LT50) was 6-7days. P. lilacinum was responsible for 85.6% (80.6-89.7) of the mortality in inoculated ants, in which we found that the percentage of other entomopathogens that naturally infected ants decreased also, suggesting a good competitive capability of the fungus. Horizontal transmission to non-inoculated ants was also evidenced, given that 58.5% (41.9-64.2) of them died because of P. lilacinum. Moreover, we tested pathogenicity for three concentrations of this strain (1.0×10(4), 10(6) and 10(8)conidiaml(-1)) and found a significantly faster mortality of ants and greater median percentage of infection at 10(8)conidiaml(-1) of P. lilacinum. CL50 value was 2.8×10(5)conidiaml(-1). We thus propose the use of P. lilacinum as a biological control agent of leafcutter ants in crops and plantations. PMID:26205173

  12. Acromyrmex ameliae sp. n. (Hymenoptera: Formicidae): A new social parasite of leaf-cutting ants in Brazil

    DANIVAL JOS(E) DE SOUZA; ILKA MARIA FERNANDES SOARES; TEREZINHA MARIA CASTRO BELLA LUCIA

    2007-01-01

    The fungus-growing ants (Tribe Attini) are a New World group of > 200 species, all obligate symbionts with a fungus they use for food. Four attine taxa are known to be social parasites of other attines. Acromyrmex (Pseudoatto) argentina argentina and Acromyrmex (Pseudoatta) argentina platensis (parasites of Acromyrmex lundi), and Acromyrmex sp. (a parasite of Acromyrmex rugosus) produce no worker caste. In contrast, the recently discovered Acromyrmex insinuator (a parasite of Acromyrmex echinatior) does produce workers. Here, we describe a new species, Acromyrmex ameliae, a social parasite of Acromyrmex subterraneus subterraneus and Acromyrmex subterraneus brunneus in Minas Gerais, Brasil. Like A. insinuator, it produces workers and appears to be closely related to its hosts. Similar social parasites may be fairly common in the fungus-growing ants, but overlooked due to the close resemblance between parasite and host workers.

  13. Differential gene expression in Acromyrmex leaf-cutting ants after challenges with two fungal pathogens.

    Yek, Sze H; Boomsma, Jacobus J; Schiøtt, Morten

    2013-04-01

    Social insects in general and leaf-cutting ants in particular have increased selection pressures on their innate immune system due to their social lifestyle and monoclonality of the symbiotic fungal cultivar. As this symbiosis is obligate for both parties, prophylactic behavioural defences against infections are expected to increase either ant survival or fungus-garden survival, but also to possibly trade off when specific infections differ in potential danger. We examined the effectiveness of prophylactic behaviours and modulations of innate immune defences by a combination of inoculation bioassays and genome-wide transcriptomic studies (RNA-Seq), using an ant pathogen (Metarhizium brunneum) and a fungus-garden pathogen (Escovopsis weberi) and administering inoculations both directly and indirectly (via the symbiotic partner). Upon detection of pathogen conidia, ant workers responded by increasing both general activity and the frequency of specific defence behaviours (self-grooming, allo-grooming, garden-grooming) independent of the pathogen encountered. This trend was also evident in the patterns of gene expression change. Both direct and indirect (via fungus garden) inoculations with Metarhizium induced a general up-regulation of gene expression, including a number of well-known immune-related genes. In contrast, direct inoculation of the fungus garden by Escovopsis induced an overall down-regulation of ant gene expression, whereas indirect inoculation (via the ants) did not, suggesting that increased activity of ants to remove this fungus-garden pathogen is costly and involves trade-offs with the activation of other physiological pathways. PMID:23480581

  14. Ectosymbionts and immunity in the leaf-cutting ant Acromyrmex subterraneus subterraneus.

    de Souza, Danival José; Lenoir, Alain; Kasuya, Maria Catarina Megumi; Ribeiro, Myriam Marques Ramos; Devers, Séverine; Couceiro, Joel da Cruz; Della Lucia, Terezinha Maria Castro

    2013-02-01

    Associations with symbiotic organisms can serve as a strategy for social insects to resist pathogens. Antibiotics produced by attine ectosymbionts (Actinobacteria) suppress the growth of Escovopsis spp., the specialized parasite of attine fungus gardens. Our objective was to evaluate whether the presence or absence of symbiotic actinobacteria covering the whole ant cuticle is related to differential immunocompetence, respiratory rate and cuticular hydrocarbons (CHs). We evaluated these parameters in three worker groups of Acromyrmex subterraneus subterraneus: External workers (EXT), internal workers with actinobacteria covering the whole body (INB) and internal workers without actinobacteria covering the whole body (INØ). We also eliminated the actinobacteria by antibiotic treatment and examined worker encapsulation response. INB ants showed lower rates of encapsulation and respiration than did the EXT and INØ ants. The lower encapsulation rate did not seem to be a cost imposed by actinomycetes because the elimination of the actinomycetes did not increase the encapsulation rate. Instead, we propose that actinobacteria confer protection to young workers until the maturation of their immune system. Actinobacteria do not seem to change nestmate recognition in these colonies. Although it is known that actinobacteria have a specific action against Escovopsis spp., our studies, along with other independent studies, indicate that actinomycetes may also be important for the individual health of the workers. PMID:23207105

  15. Tachykinin expression levels correlate with caste-specific aggression in workers of the leaf-cutting ant Acromyrmex echinatior

    Jack eHowe

    2016-05-01

    Full Text Available The tachykinins are a family of neuropeptides that influence a range of behavioral phenotypes in both vertebrates and invertebrates; they appear to have a conserved role in the processing of stimuli, and in the control of aggression in a wide range of animals. Expression of tachykinin in a cluster of neurons was recently shown to determine the stimulus response threshold for aggressive behavior in Drosophila (1. Varying response thresholds are often implicated in division of labor within social insect colonies, so we hypothesized that Tachykinin could play a role in the organization of colony defense by affecting individual response thresholds to non-nestmate stimuli. We used quantitative-PCR in combination with behavioral assays to test for associations between the expression of Tachykinin and its receptor, and the aggressive division of labor among the castes of the leaf-cutting ant Acromyrmex echinatior, a species with multiple worker castes. After correction for differences in brain size among castes, we found that the most aggressive large worker caste had the highest Tachykinin expression levels, but that no such effect was apparent for breeding and virgin queens. To further evaluate these deviating results for the reproductive caste, we manipulated the aggression threshold of virgin-queens by removing their wings, which is known to make them express a soldier-like behavioral phenotype. Despite heightened aggression, expression levels of Tachykinin remained unaffected, suggesting that aggression levels in reproductive caste phenotypes are controlled by differential expression of other genes.

  16. Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae Emigração de uma colônia da formiga cortadeira Acromyrmex heyeri Forel (Hymenoptera, Formicidae

    Mariane Aparecida Nickele

    2012-09-01

    Full Text Available Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae. Colony migration is a poorly studied phenomenon in leaf-cutting ants. Here we report on the emigration of a colony of the leaf-cutting ant A. heyeri in Brazil. The colony emigrated to a new location 47.4 m away from the original nest site, possibly because it had undergone considerable stress due to competitive interactions with a colony of Acromyrmex crassispinus.Emigração de uma colônia da formiga cortadeira Acromyrmex heyeri Forel (Hymenoptera, Formicidae. A migração de colônias de formigas cortadeiras é um fenômeno pouco estudado. Nesse estudo, nós relatamos a emigração de uma colônia da formiga cortadeira A. heyeri no Brasil. A colônia emigrou 47,5 m de distância do seu ninho original para um novo local, provavelmente porque sofreu um estresse considerável devido à interações competitivas com uma colônia de Acromyrmex crassispinus.

  17. Examination of the immune responses of males and workers of the leaf-cutting ant Acromyrmex echinatior and the effect of infection

    Baer, Boris; Krug, A.; Boomsma, Jacobus Jan;

    2005-01-01

    defence mechanisms. These include the immune response, which, aside from in bumblebees, has been relatively little studied in social insects. Here we compare the immune responses of males and workers of the leaf-cutting ant Acromyrmex echinatior and examine the effect upon immunocompetence of prior......-cutting ant workers being more variable in age or more genetically diverse within colonies. When exposed to the entomopathogenic fungus Metarhizium, workers expressed a substantially reduced immune response 96 h after infection, suggesting that the immune system was either depleted by having to respond to the...

  18. Ectosymbionts and immunity in the leaf-cutting ant Acromyrmex subterraneus subterraneus

    José De Souza, Danival; Lenoir, Alain; Megumi Kasuya, Maria Catarina; Marques Ramos Ribeiro, Myriam; Devers, Séverine; Couceiro, Joel da Cruz; Castro Della Lucia, Terezinha Maria

    2012-01-01

    International audience Associations with symbiotic organisms can serve as a strategy for social insects to resist pathogens. Antibiotics produced by attine ectosymbionts (Actinobacteria) suppress the growth of Escovopsis spp., the specialized parasite of attine fungus gardens. Our objective was to evaluate whether the presence or absence of symbiotic actinobacteria covering the whole ant cuticle is related to differential immunocompetence, respiratory rate and cuticular hydrocarbons (CHs)....

  19. The effect of homeopathic preparations on the activity level of Acromyrmex leaf-cutting ants=Atividade de formigas cortadeiras Acromyrmex spp. submetidas a preparações homeopáticas

    Pedro Boff

    2012-10-01

    Full Text Available The effect of homeopathic preparations on the activities of the leaf-cutting ants Acromyrmex spp. was studied. A field experiment involving ant nests in six experimental areas was performed using a randomised complete block design. Within each block, every ant nest was considered to represent one repetition. The treatments consisted of the following: Belladonna homeopathic preparations of macerated or triturated Acromyrmex spp. adults, homeopathic preparations of macerated or triturated ant nest fungus (Leucoagaricus gongylophorus collected from Acromyrmex laticeps and Acromyrmex heyeri nests, a homeopathy Belladonna, and dynamised water. All of the homeopathic treatments were tested at the 30 CH (thirtieth centesimal Hahnemannian dynamisation. An untreated nest served as the control. The total number of ants from each trail was counted, including both those carrying or not-carrying green plant fragments, immediately before the daily homeopathic applications. All of the tested homeopathic preparations, except for the water, significantly reduced the activity level of Acromyrmex spp. The homeopathic preparations of Belladonna and the macerated nosodes of Acromyrmex spp. reduced the activity level of the ants beginning with the sixth day after the first treatment application; the activity level reduction effect lasted more than 20 days after the last application.O efeito de preparados homeopáticos sobre as atividades de formigas cortadeiras Acromyrmex spp. foi estudado. O experimento foi realizado no campo, utilizando formigueiros distribuídos em seis diferentes áreas. Em cada área cada, formigueiro foi considerado uma repetição. Os tratamentos consistiram de preparados homeopáticos obtidos da tintura-mãe dos triturados e macerados de adultos de Acromyrmex spp. e do fungo Leucoagaricus gongylophorus de formigueiros de Acromyrmex laticeps e Acromyrmex heyeri. A homeopatia Belladonna e água dinamizada também foram testados. Todos os

  20. Tachykinin expression levels correlate with caste-specific aggression in workers of the leaf-cutting ant Acromyrmex echinatior

    Howe, Jack; Schiøtt, Morten; Boomsma, Jacobus J.

    2016-01-01

    The tachykinins are a family of neuropeptides that influence a range of behavioral phenotypes in both vertebrates and invertebrates; they appear to have a conserved role in the processing of stimuli, and in the control of aggression in a wide range of animals. Expression of tachykinin in a cluster...... of neurons was recently shown to determine the stimulus response threshold for aggressive behavior in Drosophila (1). Varying response thresholds are often implicated in division of labor within social insect colonies, so we hypothesized that Tachykinin could play a role in the organization of colony...... defense by affecting individual response thresholds to non-nestmate stimuli. We used quantitative-PCR in combination with behavioral assays to test for associations between the expression of Tachykinin and its receptor, and the aggressive division of labor among the castes of the leaf-cutting ant...

  1. Differential resistance and the importance of antibiotic production in Acromyrmex echinatior leaf-cutting ant castes towards the entomopathogenic fungus Aspergillus nomius

    Poulsen, Michael; Hughes, William Owen Hamar; Boomsma, Jacobus Jan

    2006-01-01

    Paired exocrine metapleural glands are present in almost all ants and produce compounds with antibiotic properties towards a variety of pathogenic fungi and bacteria. In Acromyrmex leaf-cutting ants, small workers have relatively large metapleural glands compared to large workers, and thus harbour...... approximately half the number of gland cells of large workers, despite being only one-fifteenth their body mass. Here we present results showing that when the two worker castes of A. echinatior are treated with spores of the pathogenic fungus Aspergillus nomius in doses that correspond to the difference in...... glands in small workers makes this caste particularly well adapted to preventing pathogenic microorganisms from entering the colony....

  2. Novel fungal disease in complex leaf-cutting ant societies

    Hughes, David Peter; Evans, Harry C.; Hywel-Jones, Nigel;

    2009-01-01

    1. The leaf-cutting ants practise an advanced system of mycophagy where they grow a fungus as a food source. As a consequence of parasite threats to their crops, they have evolved a system of morphological, behavioural, and chemical defences, particularly against fungal pathogens (mycopathogens). 2....... Specific fungal diseases of the leaf-cutting ants themselves have not been described, possibly because broad spectrum anti-fungal defences against mycopathogens have reduced their susceptibility to entomopathogens. 3. Using morphological and molecular tools, the present study documents three rare infection...... events of Acromyrmex and Atta leaf-cutting ants by Ophiocordyceps fungi, agenus of entomopathogens that is normally highly specific in its host choice. 4. As leaf-cutting ants have been intensively studied, the absence of prior records of Ophiocordyceps suggests that these infections may be a novel event...

  3. Adaptive social immunity in leaf-cutting ants

    Walker, Tom N.; Hughes, William O. H.

    2009-01-01

    Social insects have evolved a suite of sophisticated defences against parasites. In addition to the individual physiological immune response, social insects also express ‘social immunity’ consisting of group-level defences and behaviours that include allogrooming. Here we investigate whether the social immune response of the leaf-cutting ant Acromyrmex echinatior reacts adaptively to the virulent fungal parasite, Metarhizium anisopliae. We ‘immunized’ mini-nests of the ants by exposing them t...

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

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

    2015-01-01

    Background 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 a...

  5. Leaf-cutting ant attack in initial pine plantations and growth of defoliated plants

    Mariane Aparecida Nickele; Wilson Reis Filho; Edilson Batista Oliveira; Edson Tadeu Iede; Nádia Caldato; Priscila Strapasson

    2012-01-01

    The objective of this work was to evaluate the natural attack by Acromyrmex crassispinus in initial Pinus taeda plantations without control measures against ants, as well as the effect of defoliation in seedlings of P. taeda. Evaluations of the attack of leaf-cutting ants on P. taeda plantations were done monthly in the first six months, then 9 and 12 months after planting. The percentages of plants that were naturally attacked by ants were registered. The effect of defoliation was evaluated ...

  6. Exposure to creosote bush phenolic resin causes avoidance in the leaf-cutting ant Acromyrmex lobicornis (Formicidae: Attini La exposición a la resina fenólica de jarilla causa deterrencia en la hormiga cortadora de hojas Acromyrmex lobicornis (Formicidae: Attini

    ANA I MEDINA

    2012-06-01

    Full Text Available We focused our study on the effects of Larrea cuneifolia phenolic resin on leaf-cutting ants from two populations (Sierra de las Quijadas National Park and San Roque of Acromyrmex lobicornis in San Luis, Argentina. We conducted two bioassays of food choice (field and laboratory to compare the effects of phenolic resin on ant workers from these two populations. Results of the field experiment indicated that there were no differences in preference for either leaves treated with resin or untreated leaves among colonies from both localities. However, results of the laboratory experiments with individual ants indicated a significant effect of population and treatment on the time spent in different treatments. While leaf-cutting individual workers from Quijadas preferred the phenolic resin, workers from San Roque avoided it. These results evidence that ants respond according to time of exposure to chemicals from plants (presence or absence and that the effects of resin among a population can be observed and measured on individual ant workers, even in the absence of fungus garden influences in the nest.Este estudio se ha centrado en los efectos que produce la resina fenólica de Larrea cuneifolia sobre dos poblaciones distintas (Parque Nacional de Sierra de las Quijadas y la localidad de San Roque de Acromyrmex lobicornis en San Luis, Argentina. Se disenaron dos tipos de bioensayos (a campo y en laboratorio para comparar los efectos de la resina fenólica sobre las hormigas obreras de estas dos poblaciones. Los resultados de los experimentos de elección de la oferta alimentaria en el campo, indicaron que no hubo ninguna diferencia de preferencia entre las colonias, ni por las hojas tratadas con resina ni por las hojas sin tratar para ambas localidades. Sin embargo, los resultados de los experimentos de laboratorio con las hormigas obreras individualmente indicaron efectos significativos entre las poblaciones y entre los tratamientos. Mientras que las

  7. Differences in Forage-Acquisition and Fungal Enzyme Activity Contribute to Niche Segregation in Panamanian Leaf-Cutting Ants

    Kooij, Pepijn W.; Joanito Liberti; Konstantinos Giampoudakis; Morten Schiøtt; Boomsma, Jacobus J.

    2014-01-01

    The genera Atta and Acromyrmex are often grouped as leaf-cutting ants for pest management assessments and ecological surveys, although their mature colony sizes and foraging niches may differ substantially. Few studies have addressed such interspecific differences at the same site, which prompted us to conduct a comparative study across six sympatric leaf- cutting ant species in Central Panama. We show that foraging rates during the transition between dry and wet season differ about 60 fold b...

  8. An Overview of Integrated Management of Leaf-Cutting Ants (Hymenoptera: Formicidae) in Brazilian Forest Plantations

    Ronald Zanetti; José Cola Zanuncio; Juliana Cristina Santos; Willian Lucas Paiva da Silva; Genésio Tamara Ribeiro; Pedro Guilherme Lemes

    2014-01-01

    Brazilian forest producers have developed integrated management programs to increase the effectiveness of the control of leaf-cutting ants of the genera Atta and Acromyrmex. These measures reduced the costs and quantity of insecticides used in the plantations. Such integrated management programs are based on monitoring the ant nests, as well as the need and timing of the control methods. Chemical control employing baits is the most commonly used method, however, biological, mechanical and cul...

  9. The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens

    Moller, Isabel Eva; de Fine Licht, Henrik Hjarvard; Harholt, Jesper;

    2011-01-01

    The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus...... map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste...... material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial...

  10. The genome of the leaf-cutting ant Acromyrmex echinatior suggests key adaptations to advanced social life and fungus farming

    Nygaard, Sanne; Zhang, Guojie; Schiøtt, Morten; Li, Cai; Wurm, Yannick; Hu, Haofu; Zhou, Jiajian; Ji, Lu; Qiu, Feng; Rasmussen, Morten; Pan, Hailin; Hauser, Frank; Krogh, Anders; Grimmelikhuijzen, Cornelis J P; Wang, Jun; Boomsma, Jacobus J

    2011-01-01

    . The third is sex determination, where we could identify only a single homolog of the feminizer gene. As other ants and the honeybee have duplications of this gene, we hypothesize that this may partly explain the frequent production of diploid male larvae in A. echinatior. The fourth is the evolution...... agricultural food production 50 million years ago, and the transition from single to multiple queen mating 10 million years ago....

  11. The role of symbiont genetic distance and potential adaptability in host preference towards Pseudonocardia symbionts in Acromyrmex leaf-cutting ants

    Poulsen, Michael; Maynard, Janielle; Roland, Damien;

    2011-01-01

    two non-native strains, elucidating the role of genetic distance on preference between strains and Pseudonocardia origin. Our findings suggest that ants tend to prefer bacteria more closely related to their native bacterium and that genetic similarity is probably more important than whether symbionts...... to the role of adaptive recognition, potential ecological flexibility in symbiont preference, and more broadly, in relation to self versus non-self recognition....

  12. Variabilidade genética interespecífica em formigas cortadeiras do gênero Acromyrmex que ocorrem no Estado do Rio Grande do Sul Inter-specific genetic variability of leaf cutting ants (Acromyrmex genus from Rio Grande do Sul State

    Douglas Daniel Grutzmacher

    2007-08-01

    Full Text Available São poucos os taxonomistas que atuam na identificação de formigas cortadeiras. Os métodos morfométricos utilizados nem sempre permitem uma identificação confiável, em função do acentuado polimorfismo dentro do mesmo formigueiro. O objetivo do trabalho foi testar a possibilidade do uso da ferramenta da biologia molecular para auxiliar na identificação das espécies de formigas cortadeiras do gênero Acromyrmex que ocorrem no Estado do Rio Grande do Sul. O estudo foi realizado com seis espécies de formigas do gênero Acromyrmex coletadas em quatro regiões do RS. Utilizaram-se as técnicas RAPD e AFLP, testando-se inicialmente 50 primers, dos quais apenas 13 foram selecionados por terem amplificado com sucesso fragmentos de todas as espécies estudadas. Embora os 13 primers selecionados tenham produzido fragmentos que permitem várias alternativas de seu uso para a identificação das espécies A. heyeri, A. ambiguus, A. crassispinus, A. striatus, A. laticeps e A. aspersus, a identificação das mesmas poderá ser realizada utilizando-se apenas os primers UBC 354, UBC 348 e UBC 356, que apresentaram fragmentos bem visíveis, que permitem uma identificação segura. Os resultados obtidos com o dendograma e as características morfológicas analisadas mostram que as espécies A. striatus e A. laticeps são menos relacionadas com as demais espécies estudadas, enquanto maior proximidade genética foi observada entre as espécies A. ambiguus e A. crassispinus. Através deste trabalho, pode-se concluir que a identificação das espécies de Acromyrmex pode ser realizada de maneira segura pelas técnicas RAPD e AFLP.At present, a few number of taxonomists work on identification of leaf cutting ants. Morphological-based methods do not always produce a reliable identification, due to the strong polymorphism observed even in the same colony. This fact leads to hypothesize that, besides those variations, others may also occur related to

  13. Immune defense in leaf-cutting ants

    Armitage, Sophie A O; Broch, Jens F; Marín, Hermogenes Fernández;

    2011-01-01

    To ameliorate the impact of disease, social insects combine individual innate immune defenses with collective social defenses. This implies that there are different levels of selection acting on investment in immunity, each with their own trade-offs. We present the results of a cross......-fostering experiment designed to address the influences of genotype and social rearing environment upon individual and social immune defenses. We used a multiply mating leaf-cutting ant, enabling us to test for patriline effects within a colony, as well as cross-colony matriline effects. The worker's father influenced...... both individual innate immunity (constitutive antibacterial activity) and the size of the metapleural gland, which secretes antimicrobial compounds and functions in individual and social defense, indicating multiple mating could have important consequences for both defense types. However, the primarily...

  14. The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens.

    Isabel E Moller

    Full Text Available The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants.

  15. Leaf-cutting ant fungi produce cell wall degrading pectinase complexes reminiscent of phytopathogenic fungi

    Boomsma Jacobus J

    2010-12-01

    Full Text Available Abstract Background Leaf-cutting (attine ants use their own fecal material to manure fungus gardens, which consist of leaf material overgrown by hyphal threads of the basidiomycete fungus Leucocoprinus gongylophorus that lives in symbiosis with the ants. Previous studies have suggested that the fecal droplets contain proteins that are produced by the fungal symbiont to pass unharmed through the digestive system of the ants, so they can enhance new fungus garden growth. Results We tested this hypothesis by using proteomics methods to determine the gene sequences of fecal proteins in Acromyrmex echinatior leaf-cutting ants. Seven (21% of the 33 identified proteins were pectinolytic enzymes that originated from the fungal symbiont and which were still active in the fecal droplets produced by the ants. We show that these enzymes are found in the fecal material only when the ants had access to fungus garden food, and we used quantitative polymerase chain reaction analysis to show that the expression of six of these enzyme genes was substantially upregulated in the fungal gongylidia. These unique structures serve as food for the ants and are produced only by the evolutionarily advanced garden symbionts of higher attine ants, but not by the fungi reared by the basal lineages of this ant clade. Conclusions Pectinolytic enzymes produced in the gongylidia of the fungal symbiont are ingested but not digested by Acromyrmex leaf-cutting ants so that they end up in the fecal fluid and become mixed with new garden substrate. Substantial quantities of pectinolytic enzymes are typically found in pathogenic fungi that attack live plant tissue, where they are known to breach the cell walls to allow the fungal mycelium access to the cell contents. As the leaf-cutting ant symbionts are derived from fungal clades that decompose dead plant material, our results suggest that their pectinolytic enzymes represent secondarily evolved adaptations that are convergent to

  16. An Overview of Integrated Management of Leaf-Cutting Ants (Hymenoptera: Formicidae in Brazilian Forest Plantations

    Ronald Zanetti

    2014-03-01

    Full Text Available Brazilian forest producers have developed integrated management programs to increase the effectiveness of the control of leaf-cutting ants of the genera Atta and Acromyrmex. These measures reduced the costs and quantity of insecticides used in the plantations. Such integrated management programs are based on monitoring the ant nests, as well as the need and timing of the control methods. Chemical control employing baits is the most commonly used method, however, biological, mechanical and cultural control methods, besides plant resistance, can reduce the quantity of chemicals applied in the plantations.

  17. Chemical basis of the synergism and antagonism in microbial communities in the nests of leaf-cutting ants.

    Schoenian, Ilka; Spiteller, Michael; Ghaste, Manoj; Wirth, Rainer; Herz, Hubert; Spiteller, Dieter

    2011-02-01

    Leaf-cutting ants cultivate the fungus Leucoagaricus gongylophorus, which serves as a major food source. This symbiosis is threatened by microbial pathogens that can severely infect L. gongylophorus. Microbial symbionts of leaf-cutting ants, mainly Pseudonocardia and Streptomyces, support the ants in defending their fungus gardens against infections by supplying antimicrobial and antifungal compounds. The ecological role of microorganisms in the nests of leaf-cutting ants can only be addressed in detail if their secondary metabolites are known. Here, we use an approach for the rapid identification of established bioactive compounds from microorganisms in ecological contexts by combining phylogenetic data, database searches, and liquid chromatography electrospray ionisation high resolution mass spectrometry (LC-ESI-HR-MS) screening. Antimycins A(1)-A(4), valinomycins, and actinomycins were identified in this manner from Streptomyces symbionts of leaf-cutting ants. Matrix-assisted laser desorption ionization (MALDI) imaging revealed the distribution of valinomycin directly on the integument of Acromyrmex echinatior workers. Valinomycins and actinomycins were also directly identified in samples from the waste of A. echinatior and A. niger leaf-cutting ants, suggesting that the compounds exert their antimicrobial and antifungal potential in the nests of leaf-cutting ants. Strong synergistic effects of the secondary meta-bolites produced by ant-associated Streptomyces were observed in the agar diffusion assay against Escovopsis weberi. Actinomycins strongly inhibit soil bacteria as well as other Streptomyces and Pseudonocardia symbionts. The antifungal antimycins are not only active against pathogenic fungi but also the garden fungus L. gongylophorus itself. In conclusion, secondary metabolites of microbial symbionts of leaf-cutting ants contribute to shaping the microbial communities within the nests of leaf-cutting ants. PMID:21245311

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

    Breum Andersen, Sandra; Yek, Sze Huei; Nash, David R.;

    2015-01-01

    Background: 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 garde...... mutual co-adaptation within a single ant population.......Background: 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...

  19. Leaf-cutting ant attack in initial pine plantations and growth of defoliated plants

    Mariane Aparecida Nickele

    2012-07-01

    Full Text Available The objective of this work was to evaluate the natural attack by Acromyrmex crassispinus in initial Pinus taeda plantations without control measures against ants, as well as the effect of defoliation in seedlings of P. taeda. Evaluations of the attack of leaf-cutting ants on P. taeda plantations were done monthly in the first six months, then 9 and 12 months after planting. The percentages of plants that were naturally attacked by ants were registered. The effect of defoliation was evaluated by artificial defoliation, simulating the natural patterns of attack by A. crassispinus on P. taeda seedlings. The natural attack of A. crassispinus was greater during the first months after planting, being more intense in the first 30 days. Artificial defoliation indicated that there were no significant losses in diameter and height in plants with less than 75% defoliation. However, there were significant losses in diameter and height in plants with 100% defoliation, independently of the cut of the apical meristem, and also plant death. The control of leaf-cutting ants in P. taeda plantings, in which A. crassispinus is the most frequent leaf-cutting ant, should be intense only at the beginning of planting, since the most severe attacks occur during this time.

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

    Breum Andersen, Sandra; Yek, Sze Huei; Nash, David R.;

    2015-01-01

    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......Background: 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...... 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.Results: We show that Pseudonocardia readily...

  1. Ephemeral windows of opportunity for horizontal transmission of fungal symbionts in leaf-cutting ants

    Poulsen, Michael; Fernández-Marín, Hermógenes; Currie, Cameron R.;

    2009-01-01

    Evolutionary theory predicts that hosts are selected to prevent mixing of genetically different symbionts when competition among lineages reduces the productivity of a mutualism. The symbionts themselves may also defend their interests: recent studies of Acromyrmex leaf-cutting ants showed that s...... droplets remain compatible with alternative strains during the early stage of colony founding. We discuss how brief stages of low commitment between partners may increase the evolutionary stability of ancient coevolved mutualisms.......Evolutionary theory predicts that hosts are selected to prevent mixing of genetically different symbionts when competition among lineages reduces the productivity of a mutualism. The symbionts themselves may also defend their interests: recent studies of Acromyrmex leaf-cutting ants showed that...... original symbiont, and by the ant species the novel symbiont came from. The colony founding stage may thus provide an efficient but transient window for horizontal transmission, in which the fungus is unable to actively defend its partnership position before the host feeds on it, so that host fecal...

  2. Differences in forage-acquisition and fungal enzyme activity contribute to niche segregation in Panamanian leaf-cutting ants.

    Pepijn W Kooij

    Full Text Available The genera Atta and Acromyrmex are often grouped as leaf-cutting ants for pest management assessments and ecological surveys, although their mature colony sizes and foraging niches may differ substantially. Few studies have addressed such interspecific differences at the same site, which prompted us to conduct a comparative study across six sympatric leaf-cutting ant species in Central Panama. We show that foraging rates during the transition between dry and wet season differ about 60 fold between genera, but are relatively constant across species within genera. These differences appear to match overall differences in colony size, especially when Atta workers that return to their nests without leaves are assumed to carry liquid food. We confirm that Panamanian Atta specialize primarily on tree-leaves whereas Acromyrmex focus on collecting flowers and herbal leaves and that species within genera are similar in these overall foraging strategies. Species within genera tended to be spaced out over the three habitat categories that we distinguished (forest, forest edge, open grassland, but each of these habitats normally had only a single predominant Atta and Acromyrmex species. We measured activities of twelve fungus garden decomposition enzymes, belonging to the amylases, cellulases, hemicellulases, pectinases and proteinases, and show that average enzyme activity per unit of fungal mass in Atta gardens is lower than in Acromyrmex gardens. Expression profiles of fungal enzymes in Atta also appeared to be more specialized than in Acromyrmex, possibly reflecting variation in forage material. Our results suggest that species- and genus-level identities of leaf-cutting ants and habitat-specific foraging profiles may give predictable differences in the expression of fungal genes coding for decomposition enzymes.

  3. Differences in forage-acquisition and fungal enzyme activity contribute to niche segregation in Panamanian leaf-cutting ants.

    Kooij, Pepijn W; Liberti, Joanito; Giampoudakis, Konstantinos; Schiøtt, Morten; Boomsma, Jacobus J

    2014-01-01

    The genera Atta and Acromyrmex are often grouped as leaf-cutting ants for pest management assessments and ecological surveys, although their mature colony sizes and foraging niches may differ substantially. Few studies have addressed such interspecific differences at the same site, which prompted us to conduct a comparative study across six sympatric leaf-cutting ant species in Central Panama. We show that foraging rates during the transition between dry and wet season differ about 60 fold between genera, but are relatively constant across species within genera. These differences appear to match overall differences in colony size, especially when Atta workers that return to their nests without leaves are assumed to carry liquid food. We confirm that Panamanian Atta specialize primarily on tree-leaves whereas Acromyrmex focus on collecting flowers and herbal leaves and that species within genera are similar in these overall foraging strategies. Species within genera tended to be spaced out over the three habitat categories that we distinguished (forest, forest edge, open grassland), but each of these habitats normally had only a single predominant Atta and Acromyrmex species. We measured activities of twelve fungus garden decomposition enzymes, belonging to the amylases, cellulases, hemicellulases, pectinases and proteinases, and show that average enzyme activity per unit of fungal mass in Atta gardens is lower than in Acromyrmex gardens. Expression profiles of fungal enzymes in Atta also appeared to be more specialized than in Acromyrmex, possibly reflecting variation in forage material. Our results suggest that species- and genus-level identities of leaf-cutting ants and habitat-specific foraging profiles may give predictable differences in the expression of fungal genes coding for decomposition enzymes. PMID:24718261

  4. Contact rate modulates foraging efficiency in leaf cutting ants

    S. Bouchebti; Ferrere, S.; Vittori, K.; LATIL, G.; Dussutour, A; Fourcassié, V.

    2015-01-01

    Lane segregation is rarely observed in animals that move in bidirectional flows. Consequently, these animals generally experience a high rate of head-on collisions during their journeys. Although these collisions have a cost (each collision induces a delay resulting in a decrease of individual speed), they could also have a benefit by promoting information transfer between individuals. Here we explore the impact of head-on collisions in leaf-cutting ants moving on foraging trails by artificia...

  5. Fungal-Fungal Interactions in Leaf-Cutting Ant Agriculture

    Sunshine A. Van Bael

    2011-01-01

    Full Text Available Many organisms participate in symbiotic relationships with other organisms, yet studies of symbioses typically have focused on the reciprocal costs and benefits within a particular host-symbiont pair. Recent studies indicate that many ecological interactions involve alliances of symbionts acting together as mutualistic consortia against other consortia. Such interacting consortia are likely to be widespread in nature, even if the interactions often occur in a cryptic fashion. Little theory and empirical data exist concerning how these complex interactions shape ecological outcomes in nature. Here, we review recent work on fungal-fungal interactions between two consortia: (i leaf-cutting ants and their symbiotic fungi (the latter grown as a food crop by the former and (ii tropical plants and their foliar endophytes (the cryptic symbiotic fungi within leaves of the former. Plant characteristics (e.g., secondary compounds or leaf physical properties of leaves are involved in leaf-cutting ant preferences, and a synthesis of published information suggests that these plant traits could be modified by fungal presence. We discuss potential mechanisms for how fungal-fungal interactions proceed in the leaf-cutting ant agriculture and suggest themes for future research.

  6. Genetic royal cheats in leaf-cutting ant societies

    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...... 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...... 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...

  7. Preliminary in vitro insights into the use of natural fungal pathogens of leaf-cutting ants as biocontrol agents.

    Folgarait, Patricia; Gorosito, Norma; Poulsen, Michael; Currie, Cameron R

    2011-09-01

    Leaf-cutting ants are one of the main herbivores of the Neotropics, where they represent an important agricultural pest. These ants are particularly difficult to control because of the complex network of microbial symbionts. Leaf-cutting ants have traditionally been controlled through pesticide application, but there is a need for alternative, more environmentally friendly, control methods such as biological control. Potential promising biocontrol candidates include the microfungi Escovopsis spp. (anamorphic Hypocreales), which are specialized pathogens of the fungi the ants cultivate for food. These pathogens are suppressed through ant behaviors and ant-associated antibiotic-producing Actinobacteria. In order to be an effective biocontrol agent, Escovopsis has to overcome these defenses. Here, we evaluate, using microbial in vitro assays, whether defenses in the ant-cultivated fungus strain (Leucoagaricus sp.) and Actinobacteria from the ant pest Acromyrmex lundii have the potential to limit the use of Escovopsis in biocontrol. We also explore, for the first time, possible synergistic biocontrol between Escovopsis and the entomopathogenic fungus Lecanicillium lecanii. All strains of Escovopsis proved to overgrow A. lundii cultivar in less than 7 days, with the Escovopsis strain isolated from a different leaf-cutting ant species being the most efficient. Escovopsis challenged with a Streptomyces strain isolated from A. lundii did not exhibit significant growth inhibition. Both results are encouraging for the use of Escovopsis as a biocontrol agent. Although we found that L. lecanii can suppress the growth of the cultivar, it also had a negative impact on Escovopsis, making the success of simultaneous use of these two fungi for biocontrol of A. lundii questionable. PMID:21739253

  8. Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius)

    Roberto da Silva Camargo; Juliane F. S. Lopes; Luiz Carlos Forti

    2013-01-01

    Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius). During nest excavation, leaf-cutting ant workers undergo reduction in their body reserve, particularly carbohydrates. In order to estimate the energetic cost of digging, groups of 30 workers of the leaf-cutting ant Atta sexdens were sealed in a hermetic chamber for 24, 48 and 72 hours, with and without soil for digging, and had the CO2 concentration measured using respirometric chambers as well as ...

  9. Laccase detoxification mediates the nutritional alliance between leaf-cutting ants and fungus-garden symbionts

    De Fine Licht, Henrik; Schiøtt, Morten; Rogowska-Wrzesinska, Adelina;

    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...... 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....

  10. Energy substrate used by workers of leaf-cutting ants during nest excavation

    Roberto S. Camargo; Juliane F. S. Lopes; Luiz C. Forti; Somera, Alexandre F.; Mauricio Bacci Jr

    2013-01-01

    Energy substrate used by workers of leaf-cutting ants during nest excavation. In this study we aimed to ascertain whether leaf-cutting ant workers lose body reserves (fat or sugars) as a function of nest excavation. For each treatment, we isolated 10 workers of Atta sexdens into two experimental groups, Control (C- without excavation) and Soil (S- with excavation), which were kept for different time intervals (0, 24, 48 or 72 hours), totaling 700 tested workers. We then determined the concent...

  11. Chemical basis of the synergism and antagonism in microbial communities in the nests of leaf-cutting ants

    Schoenian, Ilka; Spiteller, Michael; Ghaste, Manoj; Wirth, Rainer; Herz, Hubert; Spiteller, Dieter

    2011-01-01

    Leaf-cutting ants cultivate the fungus Leucoagaricus gongylophorus, which serves as a major food source. This symbiosis is threatened by microbial pathogens that can severely infect L. gongylophorus. Microbial symbionts of leaf-cutting ants, mainly Pseudonocardia and Streptomyces, support the ants in defending their fungus gardens against infections by supplying antimicrobial and antifungal compounds. The ecological role of microorganisms in the nests of leaf-cutting ants can only be addresse...

  12. The thermoregulatory function of thatched nests in the South American grass-cutting ant, Acromyrmex heyeri.

    Bollazzi, Martin; Roces, Flavio

    2010-01-01

    The construction of mound-shaped nests by ants is considered as a behavioral adaptation to low environmental temperatures, i.e., colonies achieve higher and more stables temperatures than those of the environment. Besides the well-known nests of boreal Formica wood-ants, several species of South American leaf-cutting ants of the genus Acromyrmex construct thatched nests. Acromyrmex workers import plant fragments as building material, and arrange them so as to form a thatch covering a central chamber, where the fungus garden is located. Thus, the degree of thermoregulation attained by the fungus garden inside the thatched nest largely depends on how the thatch affects the thermal relations between the fungus and the environment. This work was aimed at studying the thermoregulatory function of the thatched nests built by the grass-cutting ant Acromyrmex heyeri Forel (Hymenoptera: Formicidae: Myrmicinae). Nest and environmental temperatures were measured as a function of solar radiation on the long-term. The thermal diffusivity of the nest thatch was measured and compared to that of the surrounding soil, in order to assess the influence of the building material on the nest's thermoregulatory ability. The results showed that the average core temperature of thatched nests was higher than that of the environment, but remained below values harmful for the fungus. This thermoregulation was brought about by the low thermal diffusivity of the nest thatch built by workers with plant fragments, instead of the readily-available soil particles that have a higher thermal diffusivity. The thatch prevented diurnal nest overheating by the incoming solar radiation, and avoided losses of the accumulated daily heat into the cold air during the night. The adaptive value of thatching behavior in Acromyrmex leaf-cutting ants occurring in the southernmost distribution range is discussed. PMID:20883129

  13. Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers.

    Daniela Römer

    Full Text Available During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density

  14. Leaf-cutting ant fungi produce cell wall degrading pectinase complexes reminiscent of phytopathogenic fungi

    Schiøtt, Morten; Rogowska-Wrzesinska, Adelina; Roepstorff, Peter;

    2010-01-01

    Leaf-cutting (attine) ants use their own fecal material to manure fungus gardens, which consist of leaf material overgrown by hyphal threads of the basidiomycete fungus Leucocoprinus gongylophorus that lives in symbiosis with the ants. Previous studies have suggested that the fecal droplets conta...

  15. Leaf endophyte load and fungal garden development in leaf-cutting ants

    Previous work has shown that leaf-cutting ants prefer to cut leaf material that is relatively low in fungal endophyte content. Such a preference suggests that fungal endophytes exact a cost on the ants or on the development of their colonies. We hypothesized that endophytes may play a role in thei...

  16. Regulation and specificity of antifungal metapleural gland secretion in leaf-cutting ants

    Yek, Sze Huei; Nash, David Richard; Jensen, Annette Bruun;

    2012-01-01

    Ants have paired metapleural glands (MGs) to produce secretions for prophylactic hygiene. These exocrine glands are particularly well developed in leaf-cutting ants, but whether the ants can actively regulate MG secretion is unknown. In a set of controlled experiments using conidia of five fungi...... significantly larger for ants challenged with virulent and mild pathogens/weeds than for controls and Escovopsis-challenged ants. We conclude that the MG defence system of leaf-cutting ants has characteristics reminiscent of an additional cuticular immune system, with specific and non-specific components, of......, we show that the ants adjust the amount of MG secretion to the virulence of the fungus with which they are infected. We further applied fixed volumes of MG secretion of ants challenged with constant conidia doses to agar mats of the same fungal species. This showed that inhibition halos were...

  17. Shared Escovopsis parasites between leaf-cutting and non-leaf-cutting ants in the higher attine fungus-growing ant symbiosis.

    Meirelles, Lucas A; Solomon, Scott E; Bacci, Mauricio; Wright, April M; Mueller, Ulrich G; Rodrigues, Andre

    2015-09-01

    Fungus-gardening (attine) ants grow fungus for food in protected gardens, which contain beneficial, auxiliary microbes, but also microbes harmful to gardens. Among these potentially pathogenic microorganisms, the most consistently isolated are fungi in the genus Escovopsis, which are thought to co-evolve with ants and their cultivar in a tripartite model. To test clade-to-clade correspondence between Escovopsis and ants in the higher attine symbiosis (including leaf-cutting and non-leaf-cutting ants), we amassed a geographically comprehensive collection of Escovopsis from Mexico to southern Brazil, and reconstructed the corresponding Escovopsis phylogeny. Contrary to previous analyses reporting phylogenetic divergence between Escovopsis from leafcutters and Trachymyrmex ants (non-leafcutter), we found no evidence for such specialization; rather, gardens from leafcutters and non-leafcutters genera can sometimes be infected by closely related strains of Escovopsis, suggesting switches at higher phylogenetic levels than previously reported within the higher attine symbiosis. Analyses identified rare Escovopsis strains that might represent biogeographically restricted endemic species. Phylogenetic patterns correspond to morphological variation of vesicle type (hyphal structures supporting spore-bearing cells), separating Escovopsis with phylogenetically derived cylindrical vesicles from ancestral Escovopsis with globose vesicles. The new phylogenetic insights provide an improved basis for future taxonomic and ecological studies of Escovopsis. PMID:26473050

  18. Generation of Nutrients and Detoxification: Possible Roles of Yeasts in Leaf-Cutting Ant Nests

    Pagnocca, Fernando C.; Ifeloju Dayo-Owoyemi; Marson, Fernando A L; Mendes, Thais D.; André Rodrigues

    2012-01-01

    The possible roles played by yeasts in attine ant nests are mostly unknown. Here we present our investigations on the plant polysaccharide degradation profile of 82 yeasts isolated from fungus gardens of Atta and Acromyrmex species to demonstrate that yeasts found in ant nests may play the role of making nutrients readily available throughout the garden and detoxification of compounds that may be deleterious to the ants and their fungal cultivar. Among the yeasts screened, 65% exhibited cellu...

  19. Correlation between virulence and genetic structure of Escovopsis strains from leaf-cutting ant colonies in Costa Rica.

    Wallace, Diego E Elizondo; Asensio, Juan G Vargas; Tomás, Adrián A Pinto

    2014-08-01

    Leaf-cutting ants (genera Atta and Acromyrmex) cultivate a specialized fungus for food in underground chambers employing cut plant material as substrate. Parasitism occurs in this agricultural system and plays an important role in colony fitness. The microfungi Escovopsis, a specialized mycoparasite of the fungal cultivar, is highly prevalent among colonies. In this study, we tested the antagonistic activity of several Escovopsis strains from different geographical areas in Costa Rica. We employed a combination of laboratory tests to evaluate virulence, including pure culture challenges, toxicity to fungus garden pieces and subcolony bioassays. We also performed a phylogenetic analysis of these strains in order to correlate their virulence with the genetic structure of this population. The bioassays yielded results consistent between each other and showed significant differences in antagonistic activity among the parasites evaluated. However, no significant differences were found when comparing the results of the bioassays according to the source of the ants' fungal cultivar. The phylogenetic analyses were consistent with these results: whilst the fungal cultivar phylogeny showed a single clade with limited molecular variation, the Escovopsis phylogeny yielded several clades with the most virulent isolates grouping in the same well-supported clade. These results indicate that there are Escovopsis strains better suited to establish their antagonistic effect, whilst the genetic homogeneity of the fungal cultivars limits their ability to modulate Escovopsis antagonism. These findings should be taken into consideration when evaluating the potential of Escovopsis isolates as biocontrol agents for this important agricultural pest in the Neotropics. PMID:24836623

  20. Low host-pathogen specificity in the leaf-cutting ant-microbe symbiosis.

    Taerum, Stephen J; Cafaro, Matías J; Little, Ainslie E F; Schultz, Ted R; Currie, Cameron R

    2007-08-22

    Host-parasite associations are shaped by coevolutionary dynamics. One example is the complex fungus-growing ant-microbe symbiosis, which includes ancient host-parasite coevolution. Fungus-growing ants and the fungi they cultivate for food have an antagonistic symbiosis with Escovopsis, a specialized microfungus that infects the ants' fungus gardens. The evolutionary histories of the ant, cultivar and Escovopsis are highly congruent at the deepest phylogenetic levels, with specific parasite lineages exclusively associating with corresponding groups of ants and cultivar. Here, we examine host-parasite specificity at finer phylogenetic levels, within the most derived clade of fungus-growing ants, the leaf-cutters (Atta spp. and Acromyrmex spp.). Our molecular phylogeny of Escovopsis isolates from the leaf-cutter ant-microbe symbiosis confirms specificity at the broad phylogenetic level, but reveals frequent host-switching events between species and genera of leaf-cutter ants. Escovopsis strains isolated from Acromyrmex and Atta gardens occur together in the same clades, and very closely related strains can even infect the gardens of both ant genera. Experimental evidence supports low host-parasite specificity, with phylogenetically diverse strains of Escovopsis being capable of overgrowing all leaf-cutter cultivars examined. Thus, our findings indicate that this host-pathogen association is shaped by the farming ants having to protect their cultivated fungus from phylogenetically diverse Escovopsis garden pathogens. PMID:17550881

  1. Density-dependence and within-host competition in a semelparous parasite of leaf-cutting ants

    Thomsen Lene

    2004-11-01

    Full Text Available Abstract Background Parasite heterogeneity and within-host competition are thought to be important factors influencing the dynamics of host-parasite relationships. Yet, while there have been many theoretical investigations of how these factors may act, empirical data is more limited. We investigated the effects of parasite density and heterogeneity on parasite virulence and fitness using four strains of the entomopathogenic fungus, Metarhizium anisopliae var. anisopliae, and its leaf-cutting ant host Acromyrmex echinatior as the model system. Results The relationship between parasite density and infection was sigmoidal, with there being an invasion threshold for an infection to occur (an Allee effect. Although spore production was positively density-dependent, parasite fitness decreased with increasing parasite density, indicating within-host scramble competition. The dynamics differed little between the four strains tested. In mixed infections of three strains the infection-growth dynamics were unaffected by parasite heterogeneity. Conclusions The strength of within-host competition makes dispersal the best strategy for the parasite. Parasite heterogeneity may not have effected virulence or the infection dynamics either because the most virulent strain outcompeted the others, or because the interaction involved scramble competition that was impervious to parasite heterogeneity. The dynamics observed may be common for virulent parasites, such as Metarhizium, that produce aggregated transmission stages. Such parasites make useful models for investigating infection dynamics and the impact of parasite competition.

  2. Leaf endophyte load influences fungal garden development in leaf-cutting ants

    Van Bael Sunshine A

    2012-11-01

    Full Text Available Abstract Background Previous work has shown that leaf-cutting ants prefer to cut leaf material with relatively low fungal endophyte content. This preference suggests that fungal endophytes exact a cost on the ants or on the development of their colonies. We hypothesized that endophytes may play a role in their host plants’ defense against leaf-cutting ants. To measure the long-term cost to the ant colony of fungal endophytes in their forage material, we conducted a 20-week laboratory experiment to measure fungal garden development for colonies that foraged on leaves with low or high endophyte content. Results Colony mass and the fungal garden dry mass did not differ significantly between the low and high endophyte feeding treatments. There was, however, a marginally significant trend toward greater mass of fungal garden per ant worker in the low relative to the high endophyte treatment. This trend was driven by differences in the fungal garden mass per worker from the earliest samples, when leaf-cutting ants had been foraging on low or high endophyte leaf material for only 2 weeks. At two weeks of foraging, the mean fungal garden mass per worker was 77% greater for colonies foraging on leaves with low relative to high endophyte loads. Conclusions Our data suggest that the cost of endophyte presence in ant forage material may be greatest to fungal colony development in its earliest stages, when there are few workers available to forage and to clean leaf material. This coincides with a period of high mortality for incipient colonies in the field. We discuss how the endophyte-leaf-cutter ant interaction may parallel constitutive defenses in plants, whereby endophytes reduce the rate of colony development when its risk of mortality is greatest.

  3. A colony-level response to disease control in a leaf-cutting ant

    Brown, Mark

    2002-01-01

    PUBLISHED Parasites and pathogens often impose significant costs on their hosts. This is particularly true for social organisms, where the genetic structure of groups and the accumulation of contaminated waste facilitate disease transmission. In response, hosts have evolved many mechanisms of defence against parasites. Here we present evidence that Atta colombica, a leaf-cutting ant, may combat Escovopsis, a dangerous parasite of Atta?s garden fungus, through a colony-level behavioural res...

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

    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 p...

  5. Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius

    Roberto da Silva Camargo

    2013-12-01

    Full Text Available Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius. During nest excavation, leaf-cutting ant workers undergo reduction in their body reserve, particularly carbohydrates. In order to estimate the energetic cost of digging, groups of 30 workers of the leaf-cutting ant Atta sexdens were sealed in a hermetic chamber for 24, 48 and 72 hours, with and without soil for digging, and had the CO2 concentration measured using respirometric chambers as well as volume of soil excavated (g. As expected, the worker groups that carried out soil excavation expelled more carbon dioxide than the groups that did not excavate. Therefore, a worker with body mass of 9.65 ± 1.50 mg dug in average 0.85 ± 0.27 g of soil for 24 hours, consuming ca. 0.58 ± 0.23 J. In this study, we calculate that the energetic cost of excavation per worker per day in the experimental set-up was ca. 0.58 J.

  6. Leucoagaricus gongylophorus uses leaf-cutting ants to vector proteolytic enzymes towards new plant substrate

    Kooij, Pepijn Wilhelmus; Rogowska-Wrzesinska, Adelina; Hoffmann, Daniel;

    2014-01-01

    The mutualism between leaf-cutting ants and their fungal symbionts revolves around processing and inoculation of fresh leaf pulp in underground fungus gardens, mediated by ant fecal fluid deposited on the newly added plant substrate. As herbivorous feeding often implies that growth is nitrogen...... fluid at pH values of 5-7, but the aspartic proteases were inactive across a pH range of 3-10. Protease activity disappeared when the ants were kept on a sugar water diet without fungus. Relative to normal mycelium, both metalloendoproteases, both serine proteases and one aspartic protease were...... leaf pulp that the ants add to the fungus garden, but regulatory functions such as activation of proenzymes are also possible, particularly for the aspartic proteases that were present but without showing activity. The proteases had high sequence similarities to proteolytic enzymes of phytopathogenic...

  7. The diversity of microorganisms associated with Acromyrmex leafcutter ants

    Boomsma Jacobus J

    2002-05-01

    Full Text Available Abstract Background Molecular biological techniques are dramatically changing our view of microbial diversity in almost any environment that has so far been investigated. This study presents a systematic survey of the microbial diversity associated with a population of Acromyrmex leafcutter ants. In contrast to previous studies on social insects, which targeted specific groups of symbionts occurring in the gut (termites, Tetraponera ants or in specialised cells (Camponotus ants the objective of our present study was to do a total screening of all possible micro-organisms that can be found inside the bodies of these leafcutter ants. Results We amplified, cloned and sequenced SSU rRNA encoding gene fragments from 9 microbial groups known to have insect-associated representatives, and show that: (1 representatives of 5 out of 9 tested groups are present, (2 mostly several strains per group are present, adding up to a total of 33 different taxa. We present the microbial taxa associated with Acromymex ants in a phylogenetic context (using sequences from GenBank to assess and illustrate to which known microorganisms they are closely related. The observed microbial diversity is discussed in the light of present knowledge on the evolutionary history of Acromyrmex leafcutter ants and their known mutualistic and parasitic symbionts. Conclusions The major merits of the screening approach documented here is its high sensitivity and specificity, which allowed us to identify several microorganisms that are promising candidates for further study of their interactions with Acromyrmex leafcutter ants or their gardens.

  8. Sequential Soil Transport and Its Influence on the Spatial Organisation of Collective Digging in Leaf-Cutting Ants

    Steffen Pielström; Flavio Roces

    2013-01-01

    The Chaco leaf-cutting ant Atta vollenweideri (Forel) inhabits large and deep subterranean nests composed of a large number of fungus and refuse chambers. The ants dispose of the excavated soil by forming small pellets that are carried to the surface. For ants in general, the organisation of underground soil transport during nest building remains completely unknown. In the laboratory, we investigated how soil pellets are formed and transported, and whether their occurrence influences the spat...

  9. Mating biology of the leaf-cutting ants Atta colombica and A. cephalotes

    Baer, Boris; Boomsma, Jacobus J

    2006-01-01

    Copulation behavior has often been shaped by sexually selected sperm competition or cryptic female choice. However, manipulation of previously deposited ejaculates is unknown in the social Hymenoptera and the degree to which sperm competes after insemination or is actively selected by females has...... remained ambiguous. We studied the mating process in the leaf-cutting ants Atta colombica and A. cephalotes, which belong to one of the few derived social insect lineages where obligate multiple mating has evolved. As copulations often occur at night and in remote places, direct observations were...... impossible, so we had to reconstruct the sequential copulation events by morphological analysis of the male and female genitalia and by tracking the process of sperm transfer and sperm storage. We show that Atta male genitalia have two external rows of spiny teeth, which fit into a specialized pouch organ in...

  10. A colony-level response to disease control in a leaf-cutting ant

    Hart, Adam; Bot, A. N. M.; Brown, Mark

    2002-03-01

    Parasites and pathogens often impose significant costs on their hosts. This is particularly true for social organisms, where the genetic structure of groups and the accumulation of contaminated waste facilitate disease transmission. In response, hosts have evolved many mechanisms of defence against parasites. Here we present evidence that Atta colombica, a leaf-cutting ant, may combat Escovopsis, a dangerous parasite of Atta's garden fungus, through a colony-level behavioural response. In A. colombica, garden waste is removed from within the colony and transported to the midden - an external waste dump - where it is processed by a group of midden workers. We found that colonies infected with Escovopsis have higher numbers of workers on the midden, where Escovopsis is deposited. Further, midden workers are highly effective in dispersing newly deposited waste away from the dumping site. Thus, the colony-level task allocation strategies of the Atta superorganism may change in response to the threat of disease to a third, essential party.

  11. Energy substrate used by workers of leaf-cutting ants during nest excavation

    Roberto S. Camargo

    2013-12-01

    Full Text Available Energy substrate used by workers of leaf-cutting ants during nest excavation. In this study we aimed to ascertain whether leaf-cutting ant workers lose body reserves (fat or sugars as a function of nest excavation. For each treatment, we isolated 10 workers of Atta sexdens into two experimental groups, Control (C- without excavation and Soil (S- with excavation, which were kept for different time intervals (0, 24, 48 or 72 hours, totaling 700 tested workers. We then determined the concentration of soluble carbohydrates and total lipid content in them. The total carbohydrates were determined colorimetrically, based on the reaction between carbohydrates and sulfuric acid-phenol. For determination of lipids, the insects were immersed in organic solvent until they reached a constant weight. Our results showed that carbohydrates are consumed during nest excavation activities. In the experimental groups S24, S48 and S72, there was an average reduction of 5.82 (20.42%, 14.31 (44.96% and 13.27 (43.96% µ.mg-1 in soluble sugar when compared with the experimental groups that did not excavate. Furthermore, the lipids were not used during this activity. With respect to dry mass of the workers, their values were C0 = 8%, C24 = 10.4%, C48 = 9.2%, C72 = 10%, S24 = 9.2%, S48 = 8.7% and S72 = 8.5%. Our results show experimentally that the source of energy for nest excavation is carbohydrates, whereas lipids are conserved for other activities.

  12. Immune defense in leaf-cutting ants: a cross-fostering approach.

    Armitage, Sophie A O; Broch, Jens F; Marín, Hermogenes Fernández; Nash, David R; Boomsma, Jacobus J

    2011-06-01

    To ameliorate the impact of disease, social insects combine individual innate immune defenses with collective social defenses. This implies that there are different levels of selection acting on investment in immunity, each with their own trade-offs. We present the results of a cross-fostering experiment designed to address the influences of genotype and social rearing environment upon individual and social immune defenses. We used a multiply mating leaf-cutting ant, enabling us to test for patriline effects within a colony, as well as cross-colony matriline effects. The worker's father influenced both individual innate immunity (constitutive antibacterial activity) and the size of the metapleural gland, which secretes antimicrobial compounds and functions in individual and social defense, indicating multiple mating could have important consequences for both defense types. However, the primarily social defense, a Pseudonocardia bacteria that helps to control pathogens in the ants' fungus garden, showed a significant colony of origin by rearing environment interaction, whereby ants that acquired the bacteria of a foster colony obtained a less abundant cover of bacteria: one explanation for this pattern would be co-adaptation between host colonies and their vertically transmitted mutualist. These results illustrate the complexity of the selection pressures that affect the expression of multilevel immune defenses. PMID:21644963

  13. Ultrastructure and physiology of the CO2 sensitive sensillum ampullaceum in the leaf-cutting ant Atta sexdens

    Kleineidam, Christoph; Romani, Roberto; Tautz, Jürgen; Isidoro, Nunzio

    2000-01-01

    The sensilla ampullacea on the apical antennomere of the leaf cutting ant Atta sexdens were investigated regarding both their responses to CO2 and their ultrastructure. By staining the sensillum during recording, we confirmed that the sensilla ampullacea are responsible for CO2 perception. We showed that the sensory neurons of the sensilla ampullacea are continuously active without adaptation during stimulation with CO2 (test duration: 1 h). This feature should enable ants to assess the absol...

  14. Combate sistemático de formigas-cortadeiras com iscas granuladas, em eucaliptais com cultivo mínimo Systematic control of leaf-cutting ants in areas with eucalyptus stands under minimum cultivation system

    Ronald Zanetti

    2003-06-01

    Full Text Available Avaliou-se a eficiência do combate sistemático de formigas-cortadeiras em áreas de reforma de eucalipto com cultivo mínimo, na Celulose Nipo-Brasileira S.A., em Belo Oriente, Minas Gerais, de setembro a dezembro de 1996. Os tratamentos consistiram na aplicação de uma isca granulada com sulfluramida (0,3% de forma sistemática, a granel ou com microporta-iscas, na dosagem de 5 g a cada 6 m² e 10 g a cada 12 m², respectivamente. A mortalidade das colônias de formigas-cortadeiras foi avaliada 30 dias após a aplicação da isca. Foram encontradas até 396,3, 285,2, 59,3, 55,6, 29,6 e 14,8 colônias de Mycocepurus goeldii, Sericomyrmex sp., Acromyrmex subterraneus molestans, Atta spp., Acromyrmex balzani e Acromyrmex niger (Hymenoptera: Formicidae por hectare, respectivamente. A eficiência da isca granulada no combate sistemático variou com o método empregado e com a espécie de formiga-cortadeira. A maior eficiência foi obtida para A. subterraneus molestans, com 69,2% de suas colônias mortas com a isca aplicada a granel e 62,5% com microporta-iscas, o que indica que a distribuição entre dois pontos com isca nos plantios de eucalipto foi maior que a área de forrageamento das formigas-cortadeiras encontradas e, ou, que a dosagem aplicada por ponto foi insuficiente.The efficiency of a systematic application of baits against leaf-cutting ants was evaluated in a eucalypus plantation under a minimum cultivation system, in areas owned by Celulose Nipo-Brasileira S.A. (CENIBRA, in Belo Oriente, Minas Gerais, Brazil, from September to December 1996. Treatments consisted of applying a granulated bait with sulfluramide (0.3% in a systematic manner in bulk and plastic bags at a dose of five grams every 6 m² (T1 and 10 grams at each 12 m² (T2. Mortality of colonies of leaf-cutting ants was evaluated 30 days after bait application. A. maximum of 396.3; 285.2; 59.3; 55.6; 29.6 and 14.8 colonies of Mycocepurus goeldii, Sericomyrmex sp

  15. The Postpharyngeal Gland: Specialized Organ for Lipid Nutrition in Leaf-Cutting Ants.

    Decio, Pâmela; Vieira, Alexsandro Santana; Dias, Nathalia Baptista; Palma, Mario Sergio; Bueno, Odair Correa

    2016-01-01

    There are several hypotheses about the possible functions of the postpharyngeal gland (PPG) in ants. The proposed functions include roles as cephalic or gastric caeca and diverticulum of the digestive tract, mixing of hydrocarbons, nestmate recognition, feeding larvae, and the accumulation of lipids inside this gland, whose origin is contradictory. The current study aimed to investigate the functions of these glands by examining the protein expression profile of the PPGs of Atta sexdens rubropilosa (Hymenoptera, Formicidae). Mated females received lipid supplementation and their glands were extracted and analyzed using a proteomic approach. The protocol used combined two-dimensional electrophoresis and shotgun strategies, followed by mass spectrometry. We also detected lipid β-oxidation by immunofluorescent marking of acyl-CoA dehydrogenase. Supplying ants with lipids elicited responses in the glandular cells of the PPG; these included increased expression of proteins related to defense mechanisms and signal transduction and reorganization of the cytoskeleton due to cell expansion. In addition, some proteins in PPG were overexpressed, especially those involved in lipid and energy metabolism. Part of the lipids may be reduced, used for the synthesis of fatty alcohol, transported to the hemolymph, or may be used as substrate for the synthesis of acetyl-CoA, which is oxidized to form molecules that drive oxidative phosphorylation and produce energy for cellular metabolic processes. These findings suggest that this organ is specialized for lipid nutrition of adult leaf-cutting ants and characterized like a of diverticulum foregut, with the ability to absorb, store, metabolize, and mobilize lipids to the hemolymph. However, we do not rule out that the PPG may have other functions in other species of ants. PMID:27149618

  16. The Postpharyngeal Gland: Specialized Organ for Lipid Nutrition in Leaf-Cutting Ants

    Decio, Pâmela; Vieira, Alexsandro Santana; Dias, Nathalia Baptista; Palma, Mario Sergio; Bueno, Odair Correa

    2016-01-01

    There are several hypotheses about the possible functions of the postpharyngeal gland (PPG) in ants. The proposed functions include roles as cephalic or gastric caeca and diverticulum of the digestive tract, mixing of hydrocarbons, nestmate recognition, feeding larvae, and the accumulation of lipids inside this gland, whose origin is contradictory. The current study aimed to investigate the functions of these glands by examining the protein expression profile of the PPGs of Atta sexdens rubropilosa (Hymenoptera, Formicidae). Mated females received lipid supplementation and their glands were extracted and analyzed using a proteomic approach. The protocol used combined two-dimensional electrophoresis and shotgun strategies, followed by mass spectrometry. We also detected lipid β-oxidation by immunofluorescent marking of acyl-CoA dehydrogenase. Supplying ants with lipids elicited responses in the glandular cells of the PPG; these included increased expression of proteins related to defense mechanisms and signal transduction and reorganization of the cytoskeleton due to cell expansion. In addition, some proteins in PPG were overexpressed, especially those involved in lipid and energy metabolism. Part of the lipids may be reduced, used for the synthesis of fatty alcohol, transported to the hemolymph, or may be used as substrate for the synthesis of acetyl-CoA, which is oxidized to form molecules that drive oxidative phosphorylation and produce energy for cellular metabolic processes. These findings suggest that this organ is specialized for lipid nutrition of adult leaf-cutting ants and characterized like a of diverticulum foregut, with the ability to absorb, store, metabolize, and mobilize lipids to the hemolymph. However, we do not rule out that the PPG may have other functions in other species of ants. PMID:27149618

  17. Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants

    Fernández-Marín, Hermógenes; Nash, David Richard; Higginbotham, Sarah;

    2015-01-01

    derived leaf-cutting ants are less sensitive to PAA than strains from phylogenetically more basal fungus-farming ants, consistent with the dynamics of an evolutionary arms race between virulence and control for Escovopsis, but not Metarhizium. Atta ants form larger colonies with more extreme caste...... differentiation relative to other attines, in societies characterized by an almost complete absence of reproductive conflicts.We hypothesize that these changes are associatedwith unique evolutionary innovations in chemical pest management that appear robust against selection pressure for resistance by specialized...

  18. Nest Enlargement in Leaf-Cutting Ants: Relocated Brood and Fungus Trigger the Excavation of New Chambers

    Daniela Römer; Flavio Roces

    2014-01-01

    During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory,...

  19. Towards a molecular understanding of symbiont function: Identification of a fungal gene for the degradation of xylan in the fungus gardens of leaf-cutting ants

    Lange Lene

    2008-02-01

    Full Text Available Abstract Background Leaf-cutting ants live in symbiosis with a fungus that they rear for food by providing it with live plant material. Until recently the fungus' main inferred function was to make otherwise inaccessible cell wall degradation products available to the ants, but new studies have shed doubt on this idea. To provide evidence for the cell wall degrading capacity of the attine ant symbiont, we designed PCR primers from conserved regions of known xylanase genes, to be used in PCR with genomic DNA from the symbiont as template. We also measured xylanase, cellulase and proteinase activities in the fungus gardens in order to investigate the dynamics of degradation activities. Results We cloned a xylanase gene from the mutualistic fungus of Acromyrmex echinatior, determined its protein sequence, and inserted it in a yeast expression vector to confirm its substrate specificity. Our results show that the fungus has a functional xylanase gene. We also show by lab experiments in vivo that the activity of fungal xylanase and cellulase is not evenly distributed, but concentrated in the lower layer of fungus gardens, with only modest activity in the middle layer where gongylidia are produced and intermediate activity in the newly established top layer. This vertical distribution appears to be negatively correlated with the concentration of glucose, which indicates a directly regulating role of glucose, as has been found in other fungi and has been previously suggested for the ant fungal symbiont. Conclusion The mutualistic fungus of Acromyrmex echinatior has a functional xylanase gene and is thus presumably able to at least partially degrade the cell walls of leaves. This finding supports a saprotrophic origin of the fungal symbiont. The observed distribution of enzyme activity leads us to propose that leaf-substrate degradation in fungus gardens is a multi-step process comparable to normal biodegradation of organic matter in soil ecosystems

  20. Isolation and molecular characterization of symbiotic fungus from Acromyrmex ambiguus and Acromyrmex heyeri ants of Rio Grande do Sul State, Brazil

    Daniela Isabel Brayer Pereira

    2015-07-01

    Full Text Available Leaf-cutting ants of the genera Atta and Acromyrmex determine serious agricultural problems and live on symbiosis with Leucoagaricus gongylophorus. The aim of this study is to identify morphological and molecularly, as well as to verify the genotypic variability of the symbiotic fungus cultivated by A. heyeri and A. ambiguus from three different regions of the state of Rio Grande do Sul, Brazil. Fungus gardens were collected and fragments of mycelia were grown in selective medium. Total DNA was extracted and amplification of the ITS region was performed by PCR using universal primers. After DNA sequencing, the chromatograms were assembled and phylogenetic analyzes were performed by the Neighbor-Joining method. A total of six isolates of L. gongylophorus were obtained and their identities were confirmed by molecular analyses. Phylogenetic analysis of the ITS region showed a tree with two distinct groups regarding the fungus isolates from A. heiyeri and A. ambiguous. In this study, it was verified that A. heyeri and A. ambiguous, cultivate the same fungus. Additionally, the molecular marker used in this study showed variations in L. gongylophorus, evidencing two distinct branches in the phylogenetic tree, according to the ant species that cultivate L. gongylophorus. However, other studies involving the inclusion of a great number of isolates of L. gongylophorus, as well as the use of other molecular markers to validate the possible variations in the phylogenetic relationship of this symbiotic fungus are required.

  1. Representation of thermal information in the antennal lobe of leaf-cutting ants

    Markus eRuchty

    2010-11-01

    Full Text Available Insects are equipped with various types of antennal sensilla, which house thermosensitive neurons adapted to receive different parameters of the thermal environment for a variety of temperature-guided behaviors. In the leaf-cutting ant Atta vollenweideri, the physiology and the morphology of the thermosensitive sensillum coeloconicum (Sc has been thoroughly investigated. However, the central projections of its receptor neurons are unknown. Here we selectively stained the three neurons found in single Sc and tracked their axons into the brain of Atta vollenweideri workers. Each of the three axons terminates in a single glomerulus of the antennal lobe (Sc-glomeruli. Two of the innervated glomeruli are adjacent to each other and are located laterally, while the third one is clearly separated and located medially in the antennal lobe. Using two-photon Ca2+ imaging of antennal lobe projection neurons, we studied where in the antennal lobe thermal information is represented. In the 11 investigated antennal lobes, we found up to 10 different glomeruli in a single specimen responding to temperature stimulation. Both, warm- and cold-sensitive glomeruli could be identified. The thermosensitive glomeruli were mainly located in the medial part of the antennal lobe. Based on the general representation of thermal information in the antennal lobe and functional data on the Sc-glomeruli we conclude that temperature stimuli received by Sc are processed in the medial of the three target glomeruli. The present study reveals an important role of the antennal lobe in temperature processing and links a specific thermosensitive neuron to its central target glomerulus.

  2. Leaf-cutting ants toxicity of limonexic acid and degraded limonoids from Raulinoa echinata: X-ray structure of epoxy-fraxinellone

    Phytochemical survey of roots extracts of the South Brazilian endemic plant Raulinoa echinata Cowan, Rutaceae led to the isolation of known degraded limonoids: fraxinellone, fraxinellonone and epoxy-fraxinellone. The latter was previously isolated also from the stems, but the relative configuration could not be solved by NMR experiments. This paper deals with the X-ray diffraction analysis of epoxy-fraxinellone and its toxicity to leaf-cutting ants, describes the isolation of fraxinellonone and fraxinellone for the first time in Raulinoa. Epoxy-fraxinellone showed no toxicity to the leaf-cutting ants (Atta sexdens rubropilosa). The limonoid limonexic acid, isolated from stems, presented high toxicity to the leaf-cutting ants, diminishing considerably their longevity. (author)

  3. Leaf-cutting ants toxicity of limonexic acid and degraded limonoids from Raulinoa echinata: X-ray structure of epoxy-fraxinellone

    Biavatti, Maique W.; Westerlon, Rosangela [Universidade do Vale do Itajai, SC (Brazil). Programa de Pos-Graduacao em Ciencias Farmaceuticas]. E-mail: maique@univali.br; Vieira, Paulo C.; Silva, M. Fatima G.F. da; Fernandes, Joao B. [Sao Carlos Univ., SP (Brazil). Dept. de Quimica; Penaflor, M. Fernanda G.V.; Bueno, Odair C. [UNESP, Rio Claro, SP (Brazil). Centro de Estudos de Insetos Sociais; Ellena, Javier [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica

    2005-11-15

    Phytochemical survey of roots extracts of the South Brazilian endemic plant Raulinoa echinata Cowan, Rutaceae led to the isolation of known degraded limonoids: fraxinellone, fraxinellonone and epoxy-fraxinellone. The latter was previously isolated also from the stems, but the relative configuration could not be solved by NMR experiments. This paper deals with the X-ray diffraction analysis of epoxy-fraxinellone and its toxicity to leaf-cutting ants, describes the isolation of fraxinellonone and fraxinellone for the first time in Raulinoa. Epoxy-fraxinellone showed no toxicity to the leaf-cutting ants (Atta sexdens rubropilosa). The limonoid limonexic acid, isolated from stems, presented high toxicity to the leaf-cutting ants, diminishing considerably their longevity. (author)

  4. Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants.

    Fernández-Marín, Hermógenes; Nash, David R; Higginbotham, Sarah; Estrada, Catalina; van Zweden, Jelle S; d'Ettorre, Patrizia; Wcislo, William T; Boomsma, Jacobus J

    2015-05-22

    Fungus-farming ant colonies vary four to five orders of magnitude in size. They employ compounds from actinomycete bacteria and exocrine glands as antimicrobial agents. Atta colonies have millions of ants and are particularly relevant for understanding hygienic strategies as they have abandoned their ancestors' prime dependence on antibiotic-based biological control in favour of using metapleural gland (MG) chemical secretions. Atta MGs are unique in synthesizing large quantities of phenylacetic acid (PAA), a known but little investigated antimicrobial agent. We show that particularly the smallest workers greatly reduce germination rates of Escovopsis and Metarhizium spores after actively applying PAA to experimental infection targets in garden fragments and transferring the spores to the ants' infrabuccal cavities. In vitro assays further indicated that Escovopsis strains isolated from evolutionarily derived leaf-cutting ants are less sensitive to PAA than strains from phylogenetically more basal fungus-farming ants, consistent with the dynamics of an evolutionary arms race between virulence and control for Escovopsis, but not Metarhizium. Atta ants form larger colonies with more extreme caste differentiation relative to other attines, in societies characterized by an almost complete absence of reproductive conflicts. We hypothesize that these changes are associated with unique evolutionary innovations in chemical pest management that appear robust against selection pressure for resistance by specialized mycopathogens. PMID:25925100

  5. Prevalence of the genus Cladosporium on the integument of leaf-cutting ants characterized by 454 pyrosequencing.

    Duarte, A P M; Ferro, M; Rodrigues, A; Bacci, M; Nagamoto, N S; Forti, L C; Pagnocca, F C

    2016-09-01

    The relationship of attine ants with their mutualistic fungus and other microorganisms has been studied during the last two centuries. However, previous studies about the diversity of fungi in the ants' microenvironment are based mostly on culture-dependent approaches, lacking a broad characterization of the fungal ant-associated community. Here, we analysed the fungal diversity found on the integument of Atta capiguara and Atta laevigata alate ants using 454 pyrosequencing. We obtained 35,453 ITS reads grouped into 99 molecular operational taxonomic units (MOTUs). Data analysis revealed that A. capiguara drones had the highest diversity of MOTUs. Besides the occurrence of several uncultured fungi, the mycobiota analysis revealed that the most abundant taxa were the Cladosporium-complex, Cryptococcus laurentii and Epicoccum sp. Taxa in the genus Cladosporium were predominant in all samples, comprising 67.9 % of all reads. The remarkable presence of the genus Cladosporium on the integument of leaf-cutting ants alates from distinct ant species suggests that this fungus is favored in this microenvironment. PMID:27307255

  6. Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase

    Edypo Jacob Silva

    2014-12-01

    Full Text Available Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase. This study evaluated the crude protein content of queens of Atta sexdens before the nuptial flight and after the claustral phase in laboratory and field colonies. The hypothesis was that protein is used for survival of the queen and for early colony growth during the claustral phase. Additionally, the nest morphology, live biomass and adult population of field colonies were evaluated. Crude protein was determined by digestion of the organic material with sulfuric acid at high temperatures. The mean crude protein content was 123.23 ± 11.20 mg for females before the nuptial flight and 70.44 ± 12.21 mg for laboratory-reared queens after the claustral phase. The post-claustral crude protein content of field-collected queen was 55.90 ± 9.18 mg. With respect to the loss of crude protein as a function of duration of the claustral phase, laboratory-reared queens lost 52.79 mg and field-collected queens lost 67.33 mg compared to females before the nuptial flight. A positive linear correlation was observed between the weight of field-collected queens (256.4 ± 36.3 mg and colony biomass (13.02 ± 9.12 g, but there was no correlation between biomass and nest depth (13.11 ± 3.82 cm. As expected, the present results support the hypothesis that protein is used for survival of the queen and for early colony growth, as demonstrated by the reduction in crude protein content as a function of duration of the claustral phase. To our knowledge, this is the first study to provide data of the dynamics of protein reserves in leaf-cutting ant queens during the claustral phase.

  7. Social life and sanitary risks: evolutionary and current ecological conditions determine waste management in leaf-cutting ants.

    Farji-Brener, Alejandro G; Elizalde, Luciana; Fernández-Marín, Hermógenes; Amador-Vargas, Sabrina

    2016-05-25

    Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions. PMID:27226469

  8. Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

    Ivens, Aniek B. F.; Nash, David R.; Poulsen, Michael; Boomsma, Jacobus J.

    2009-01-01

    The interaction between leaf-cutting ants and their fungus garden mutualists is ideal for studying the evolutionary stability of interspecific cooperation. Although the mutualism has a long history of diffuse coevolution, there is ample potential for conflicts between the partners over the mixing an

  9. Expressed sequence tags from Atta laevigata and identification of candidate genes for the control of pest leaf-cutting ants

    Henrique-Silva Flávio

    2011-06-01

    Full Text Available Abstract Background Leafcutters are the highest evolved within Neotropical ants in the tribe Attini and model systems for studying caste formation, labor division and symbiosis with microorganisms. Some species of leafcutters are agricultural pests controlled by chemicals which affect other animals and accumulate in the environment. Aiming to provide genetic basis for the study of leafcutters and for the development of more specific and environmentally friendly methods for the control of pest leafcutters, we generated expressed sequence tag data from Atta laevigata, one of the pest ants with broad geographic distribution in South America. Results The analysis of the expressed sequence tags allowed us to characterize 2,006 unique sequences in Atta laevigata. Sixteen of these genes had a high number of transcripts and are likely positively selected for high level of gene expression, being responsible for three basic biological functions: energy conservation through redox reactions in mitochondria; cytoskeleton and muscle structuring; regulation of gene expression and metabolism. Based on leafcutters lifestyle and reports of genes involved in key processes of other social insects, we identified 146 sequences potential targets for controlling pest leafcutters. The targets are responsible for antixenobiosis, development and longevity, immunity, resistance to pathogens, pheromone function, cell signaling, behavior, polysaccharide metabolism and arginine kynase activity. Conclusion The generation and analysis of expressed sequence tags from Atta laevigata have provided important genetic basis for future studies on the biology of leaf-cutting ants and may contribute to the development of a more specific and environmentally friendly method for the control of agricultural pest leafcutters.

  10. Towards a molecular understanding of symbiont function: Identification of a fungal gene for the degradation of xylan in the fungus gardens of leaf-cutting ants

    Lange Lene; De Fine Licht Henrik H; Schiøtt Morten; Boomsma Jacobus J

    2008-01-01

    Abstract Background Leaf-cutting ants live in symbiosis with a fungus that they rear for food by providing it with live plant material. Until recently the fungus' main inferred function was to make otherwise inaccessible cell wall degradation products available to the ants, but new studies have shed doubt on this idea. To provide evidence for the cell wall degrading capacity of the attine ant symbiont, we designed PCR primers from conserved regions of known xylanase genes, to be used in PCR w...

  11. Antagonistic interactions between garden yeasts and microfungal garden pathogens of leaf-cutting ants.

    Rodrigues, Andre; Cable, Rachel N; Mueller, Ulrich G; Bacci, Maurício; Pagnocca, Fernando C

    2009-10-01

    We investigate the diversity of yeasts isolated in gardens of the leafcutter ant Atta texana. Repeated sampling of gardens from four nests over a 1-year time period showed that gardens contain a diverse assemblage of yeasts. The yeast community in gardens consisted mostly of yeasts associated with plants or soil, but community composition changed between sampling periods. In order to understand the potential disease-suppressing roles of the garden yeasts, we screened isolates for antagonistic effects against known microfungal garden contaminants. In vitro assays revealed that yeasts inhibited the mycelial growth of two strains of Escovopsis (a specialized attine garden parasite), Syncephalastrum racemosum (a fungus often growing in gardens of leafcutter lab nests), and the insect pathogen Beauveria bassiana. These garden yeasts add to the growing list of disease-suppressing microbes in attine nests that may contribute synergistically, together with actinomycetes and Burkholderia bacteria, to protect the gardens and the ants against diseases. Additionally, we suggest that garden immunity against problem fungi may therefore derive not only from the presence of disease-suppressing Pseudonocardia actinomycetes, but from an enrichment of multiple disease-suppressing microorganisms in the garden matrix. PMID:19449210

  12. Soil Moisture and Excavation Behaviour in the Chaco Leaf-Cutting Ant (Atta vollenweideri): Digging Performance and Prevention of Water Inflow into the Nest

    Steffen Pielström; Flavio Roces

    2014-01-01

    The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behavio...

  13. Considerations for assessing maximum critical temperatures in small ectothermic animals: insights from leaf-cutting ants.

    Pedro Leite Ribeiro

    Full Text Available The thermal limits of individual animals were originally proposed as a link between animal physiology and thermal ecology. Although this link is valid in theory, the evaluation of physiological tolerances involves some problems that are the focus of this study. One rationale was that heating rates shall influence upper critical limits, so that ecological thermal limits need to consider experimental heating rates. In addition, if thermal limits are not surpassed in experiments, subsequent tests of the same individual should yield similar results or produce evidence of hardening. Finally, several non-controlled variables such as time under experimental conditions and procedures may affect results. To analyze these issues we conducted an integrative study of upper critical temperatures in a single species, the ant Atta sexdens rubropiosa, an animal model providing large numbers of individuals of diverse sizes but similar genetic makeup. Our specific aims were to test the 1 influence of heating rates in the experimental evaluation of upper critical temperature, 2 assumptions of absence of physical damage and reproducibility, and 3 sources of variance often overlooked in the thermal-limits literature; and 4 to introduce some experimental approaches that may help researchers to separate physiological and methodological issues. The upper thermal limits were influenced by both heating rates and body mass. In the latter case, the effect was physiological rather than methodological. The critical temperature decreased during subsequent tests performed on the same individual ants, even one week after the initial test. Accordingly, upper thermal limits may have been overestimated by our (and typical protocols. Heating rates, body mass, procedures independent of temperature and other variables may affect the estimation of upper critical temperatures. Therefore, based on our data, we offer suggestions to enhance the quality of measurements, and offer

  14. Caste-specific expression of genetic variation in the size of antibiotic-producing glands of leaf-cutting ants

    Hughes, W O H; Bot, A N M; Boomsma, J J

    2010-01-01

    Social insect castes represent some of the most spectacular examples of phenotypic plasticity, with each caste being associated with different environmental conditions during their life. Here we examine the level of genetic variation in different castes of two polyandrous species of Acromyrmex le...

  15. Differences in forage-acquisition and fungal enzyme activity contribute to niche segregation in Panamanian leaf-cutting ants

    Kooij, Pepijn Wilhelmus; Liberti, Joanito; Giampoudakis, Konstantinos;

    2014-01-01

    activities of twelve fungus garden decomposition enzymes, belonging to the amylases, cellulases, hemicellulases, pectinases and proteinases, and show that average enzyme activity per unit of fungal mass in Atta gardens is lower than in Acromyrmex gardens. Expression profiles of fungal enzymes in Atta also...... decomposition enzymes....

  16. Worker laying in leafcutter ant Acromyrmex subterraneus brunneus (Formicidae, Attini)

    ROBERTO S. CAMARGO; LUIZ C FORTI; JULIANE F. S. LOPES; NEWTON C. NORONHA; ANGELO L. T. OTTATI

    2007-01-01

    We studied the process of offspring production in queenless colonies of Acromyrmex subterraneus brunneus, and particularly evaluated the ovary development of workers as a function of their age. For this, subcolonies were set up and evaluated at different periods of isolation from the queen (2, 4 and 6 months), besides individually labeled age groups. The subcolonies were assessed according to offspring production and ovaries containing oocytes or not. The evaluations showed worker oviposition and development of males originating from worker-laid eggs. At 2 months' absence ofthe queen, eggs and larvae were found, with eggs in a higher proportion than larvae. After 4 months, the proportion of eggs had reduced while larvae had increased, and a pupa was found in one subcolony. At 6 months, besides a higher share of larvae, one pupa and one adult male were found. Dissection of workers revealed ovaries containing oocytes during the periods of evaluation. Only a group of medium-sized and large workers, 23.3%, 20.9% and 37.5% of the population from each period assessed in queenless subcolonies respectively, presented developed oocytes in the ovary. The same was observed in colonies with a queen, with 17.6%, 19.6% and 7.8% of the group of dissected workers from each time period, respectively. With respect to worker age, we observed by dissection of the ovary, that the greatest percentage of individuals with ovarioles containing oocytes occurred at 45 days (6 weeks) up to 90 days (12 weeks). These results probably are associated with the workers reproduction and the laying of trophic and reproductive eggs in colonies with and without a queen; these eggs have distinct functions in each situation.

  17. Dynamic Wolbachia prevalence in Acromyrmex leaf‐cutting ants: potential for a nutritional symbiosis

    Andersen, S. B.; Boye, Mette; Nash, D. R.;

    2012-01-01

    ‐cutting ant Acromyrmex octospinosus across developmental stages of sterile workers. We confirm that workers are infected with one or two widespread wsp genotypes of Wolbachia, show that colony prevalence is always 100% and characterize two rare recombinant genotypes. One dominant genotype is always present...... and most abundant, whereas another only proliferates in adult workers of some colonies and is barely detectable in larvae and pupae. An explanation may be that Wolbachia genotypes compete for host resources in immature stages while adult tissues provide substantially more niche space. Tissue...

  18. Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

    Ivens, Aniek B.F.; Nash, David R.; Poulsen, Michael;

    2009-01-01

    and transmission of symbionts. Symbiont transmission is vertical by default, and both the ants and resident fungus actively protect the fungal monoculture growing in their nest against secondary introductions of genetically dissimilar symbionts from other colonies. An earlier study showed that...... mixtures of major and minor Acromyrmex workers eliminate alien fungus fragments even in subcolonies where their resident symbiont is not present. We hypothesize that the different tasks and behaviors performed by majors and minors are likely to select for differential responses to alien fungi. Major...

  19. Antifungals of acromyrmex, allomerus, and tetraponera ant- and cultivarassociated bacteria

    Barke, Joerg

    2013-01-01

    The central purpose of this thesis is to test the utility of ant-microbe associations for discovering antifungal compounds with novel molecular (sub-) structures. Novel antifungals displaying reduced adverse side-effects, increased water-solubilities, and/or strong fungicidal properties would be helpful in medical science for responding to the rising prevalence of human mycoses and for solving problems with adverse side-effects in currently used antifungal drugs. Host-symbiont systems m...

  20. Attractiveness of copperleaf-based bait to leaf-cutting ants Atratividade de iscas à base de acalifa para formigas cortadeiras

    Nilson Satoru Nagamoto

    2011-06-01

    Full Text Available Leaves of copperleaf (Acalypha spp. are greatly accepted by leaf-cutting ants and therefore used to maintain colonies in the laboratory. In order to determine the attractive potential of granulated bait of Acalypha wilkesiana leaves versus citrus pulp, currently used in commercial baits, an evaluation was performed, by using the leaf-cutting ant Atta sexdens rubropilosa as model. The handmade non-toxic baits contained powder (90% w/w of either citrus pulp or A. wilkesiana were offered simultaneously in the foraging arena until the total loading of one of them. Results showed that copperleaf baits are less attractive than the citrus ones, which invalidates the viability of the substitution.Folhas de acalifa (Acalypha spp. são de grande aceitação pelas formigas cortadeiras e, por isso, utilizadas na manutenção de colônias em laboratório. Baseado nesses fatos, procedeu-se a uma avaliação da atratividade de isca granulada feita com folhas de Acalypha wilkesiana, usando a formiga cortadeira Atta sexdens rubropilosa como modelo, com o objetivo de determinar o seu potencial atrativo frente ao citros, atualmente utilizado na formulação comercial de iscas formicidas. Foram formuladas artesanalmente iscas atóxicas, contendo pó (90% p/p de polpa cítrica ou de A. wilkesiana. As iscas foram colocadas simultaneamente em uma arena de forrageamento até o carregamento total de uma delas. Os resultados mostram que a isca de acalifa é menos atrativa que a de citros, o que inviabiliza a substituição.

  1. Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils.

    Vieira, Alexsandro Santana; Camargo-Mathias, Maria Izabel; Roces, Flavio

    2015-09-01

    Queens of leaf-cutting ants found their nests singly, each consisting of a vertical tunnel and a final horizontal chamber. Because of the claustral mode of nest founding, the queen and/or her initial fungus garden are exposed to threats imposed by several soil pathogens, and the antibiotic secretions produced by their metapleural glands are considered a main adaptation to deal with them. Nests of two Atta leaf-cutting ant species, Atta vollenweideri and Atta sexdens rubropilosa, occur in different soil types, alfisols and oxisols. Their queens are known to excavate the initial nest in different soil horizons, clayish and organic, respectively, which differ in their fertility and associated microbiota. The aim of the present study was to comparatively investigate the morpho-physiology of the metapleural glands in queens of A. vollenweideri and A. sexdens rubropilosa, addressing the question whether the distinct selective pressure imposed by the microbiota in the two different soil types led to morpho-physiological differences in the metapleural glands that were consistent with their antiseptic function. The results revealed that metapleural glands of A. sexdens rubropilosa have a larger number of secretory cells, and consequently a higher production of antibiotic secretions, which may have been selected to allow nest founding at the superficial horizon of oxisols rich in organic matter and microorganisms. Glands of A. vollenweideri, on the contrary, presented fewer secretory cells, suggesting less production of antibiotic secretions. We argue that the excavation of deep founding nests in A. vollenweideri was primarily selected for during evolution to avoid the risk posed by flooding, and further hypothesize that a reduced number of cells in their metapleural glands occurred because of a weak pathogen-driven selective pressure at the preferred soil depth. PMID:26145506

  2. Towards a molecular understanding of symbiont function: identification of a fungal gene for the degradation of xylan in the fungus gardens of leaf-cutting ants

    Schiøtt, Morten; De Fine Licht, Henrik H; Lange, Lene; Boomsma, Jacobus J

    2008-01-01

    in the fungus gardens in order to investigate the dynamics of degradation activities. RESULTS: We cloned a xylanase gene from the mutualistic fungus of Acromyrmex echinatior, determined its protein sequence, and inserted it in a yeast expression vector to confirm its substrate specificity. Our...... results show that the fungus has a functional xylanase gene. We also show by lab experiments in vivo that the activity of fungal xylanase and cellulase is not evenly distributed, but concentrated in the lower layer of fungus gardens, with only modest activity in the middle layer where gongylidia are...... produced and intermediate activity in the newly established top layer. This vertical distribution appears to be negatively correlated with the concentration of glucose, which indicates a directly regulating role of glucose, as has been found in other fungi and has been previously suggested for the ant...

  3. Cytogenetic data on six leafcutter ants of the genus Acromyrmex Mayr, 1865 (Hymenoptera, Formicidae, Myrmicinae): insights into chromosome evolution and taxonomic implications

    Barros, Luísa Antônia Campos; de Aguiar, Hilton Jeferson Alves Cardoso; Mariano, Cléa dos Santos Ferreira; Andrade-Souza, Vanderly; Costa, Marco Antonio; Delabie, Jacques Hubert Charles; Pompolo, Silvia das Graças

    2016-01-01

    Abstract Cytogenetic data for the genus Acromyrmex Mayr, 1865 are available, to date, for a few species from Brazil and Uruguay, which have uniform chromosome numbers (2n = 38). The recent cytogenetic data of Acromyrmex striatus (Roger, 1863), including its banding patterns, showed a distinct karyotype (2n = 22), similar to earlier studied Atta Fabricius, 1804 species. Karyological data are still scarce for the leafcutter ants and many gaps are still present for a proper understanding of this group. Therefore, this study aimed at increasing cytogenetic knowledge of the genus through the characterization of other six species: Acromyrmex balzani (Emery, 1890), Acromyrmex coronatus Fabricius, 1804, Acromyrmex disciger (Mayr, 1887), Acromyrmex echinatior (Forel, 1899), Acromyrmex niger (Smith, 1858) and Acromyrmex rugosus (Smith, 1858), all of which were collected in Minas Gerais – Brazil, except for Acromyrmex echinatior which was collected in Barro Colorado – Panama. The number and morphology of the chromosomes were studied and the following banding techniques were applied: C-banding, fluorochromes CMA3 and DAPI, as well as the detection of 45S rDNA using FISH technique. All the six species had the same chromosome number observed for already studied species, i.e. 2n = 38. Acromyrmex balzani had a different karyotype compared with other species mainly due to the first metacentric pair. The heterochromatin distribution also showed interspecific variation. Nevertheless, all the studied species had a pair of bands in the short arm of the first subtelocentric pair. The fluorochrome CMA3 visualized bands in the short arm of the first subtelocentric pair for all the six species, while Acromyrmex rugosus and Acromyrmex niger also demonstrated in the other chromosomes. The AT-rich regions with differential staining using DAPI were not observed. 45S ribosomal genes were identified by FISH in the short arm of the first subtelocentric pair in Acromyrmex coronatus, Acromyrmex

  4. Spatially Heterogeneous Nest-Clearing Behavior Coincides with Rain Event in the Leaf-Cutting Ant Atta cephalotes (L.) (Hymenoptera: Formicidae).

    Stephan, J G; Wirth, R; Leal, I R; Meyer, S T

    2015-04-01

    Leaf-cutting ants of the genus Atta construct the probably largest nests among ants and are ecosystem engineers because they alter light and nutrient availability at nest sites. Besides creating canopy gaps in the forest, workers remove all vegetation from atop their nest mounds. Here, we examined the extent and spatial distribution of this nest-clearing behavior by transplanting Licania tomentosa seedlings on Atta cephalotes (Linnaeus) nest mounds in the Atlantic forest in northeast Brazil and documented defoliation patterns by the workers. Within 9 days, workers removed around 53% of the total leaf area planted per colony. All colonies showed a synchronized start of defoliation after a rain event in the fifth night after the seedlings had been transplanted. Defoliation increased with time elapsed since transplanting and with the number of entrances surrounding each seedling. In addition, workers started defoliation on the top of the mound. In contrast, the distance to the next entrance and the size of the seedling did not affect the defoliation pattern. Defoliation was not part of the colony foraging activities but was identified as an element of nest maintenance. Possible cues triggering nest-clearing behavior and the potential link between nest-clearing activities and the control of microclimate of ant nests are discussed. PMID:26013129

  5. Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants

    Fernández-Marín, Hermógenes; Nash, David R.; Higginbotham, Sarah; Estrada, Catalina; Jelle S van Zweden; D'Ettorre, Patrizia; Wcislo, William T.; Boomsma, Jacobus J.

    2015-01-01

    Fungus-farming ant colonies vary four to five orders of magnitude in size. They employ compounds from actinomycete bacteria and exocrine glands as antimicrobial agents. Atta colonies have millions of ants and are particularly relevant for understanding hygienic strategies as they have abandoned their ancestors' prime dependence on antibiotic-based biological control in favour of using metapleural gland (MG) chemical secretions. Atta MGs are unique in synthesizing large quantities of phenylace...

  6. [Occurrence and biological characteristics of parasitoid phorids (Diptera: Phoridae) of the leaf-cutting ant Atta laevigata (Smith) (Hymenoptera: Formicidae) in Porto Nacional, TO, Brazil].

    Bragança, Marcos A L; Medeiros, Zodja C S

    2006-01-01

    The purpose of this study was to verify the occurrence of parasitism in Atta laevigata (Smith) by phorids in Porto Nacional, Tocantins, Brazil and to evaluate some biological characteristics of those flies. From October/2002 to September/2003, at 15-day intervals, 22 samplings were carried out (149.5 +/- 82.9 workers each) comprising 3,704 ants. In the laboratory, the ants were distributed in groups of five individuals per petri dish and maintained at temperature of 25 +/- 1 masculineC and 80 +/- 5% of RH. They were fed daily with a 50% honey solution until death. The total of 106 workers (2.8%), collected with or without load (plant fragment), were parasitized by phorids: 72 workers (68%) were parasitized by Apocephalus vicosae Disney, 28 individuals (26.4%) by Neodohrniphora erthali Brown, and six (5.6%) by Apocephalus attophilus Borgmeier. The higher parasitism rates by A. vicosae (3.9-5.4%) were observed during the dry season (June-August), while the parasitism by N. erthali was lower than 2.3% throughout the year. The bigger workers were parasitized by bigger parasitoid N. erthali or by parasitoid with larger number of larvae A. attophilus. The occurrence of three phorid species in Tocantins broadens the distribution of these flies in Brazil. The development of A. vicosae larva within the thorax of the host as well as the rupture between the ant pronotum and propleuron so that the emergence of the fly can take place are characteristics not yet described on parasitism of leaf-cutting ants by phorids. PMID:18575704

  7. A mixed community of actinomycetes produce multiple antibiotics for the fungus farming ant Acromyrmex octospinosus

    Barke Jörg

    2010-08-01

    Full Text Available Abstract Background Attine ants live in an intensely studied tripartite mutualism with the fungus Leucoagaricus gongylophorus, which provides food to the ants, and with antibiotic-producing actinomycete bacteria. One hypothesis suggests that bacteria from the genus Pseudonocardia are the sole, co-evolved mutualists of attine ants and are transmitted vertically by the queens. A recent study identified a Pseudonocardia-produced antifungal, named dentigerumycin, associated with the lower attine Apterostigma dentigerum consistent with the idea that co-evolved Pseudonocardia make novel antibiotics. An alternative possibility is that attine ants sample actinomycete bacteria from the soil, selecting and maintaining those species that make useful antibiotics. Consistent with this idea, a Streptomyces species associated with the higher attine Acromyrmex octospinosus was recently shown to produce the well-known antifungal candicidin. Candicidin production is widespread in environmental isolates of Streptomyces, so this could either be an environmental contaminant or evidence of recruitment of useful actinomycetes from the environment. It should be noted that the two possibilities for actinomycete acquisition are not necessarily mutually exclusive. Results In order to test these possibilities we isolated bacteria from a geographically distinct population of A. octospinosus and identified a candicidin-producing Streptomyces species, which suggests that they are common mutualists of attine ants, most probably recruited from the environment. We also identified a Pseudonocardia species in the same ant colony that produces an unusual polyene antifungal, providing evidence for co-evolution of Pseudonocardia with A. octospinosus. Conclusions Our results show that a combination of co-evolution and environmental sampling results in the diversity of actinomycete symbionts and antibiotics associated with attine ants.

  8. Soil moisture and excavation behaviour in the Chaco leaf-cutting ant (Atta vollenweideri: digging performance and prevention of water inflow into the nest.

    Steffen Pielström

    Full Text Available The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed.

  9. Damage caused by different levels of artificial defoliation, simulating the leaf-cutting ants attack on young plantations of Pinus taeda and Eucalyptus grandis Danos causados por diferentes níveis de desfolha artificial para simulação do ataque de formigas cortadeiras em Pinus taeda e Eucalyptus grandis

    Wilson Reis Filho; Franciele dos Santos; Priscila Strapasson; Mariane Aparecida Nickele

    2011-01-01

    The artificial defoliation allows to measure the defoliation intensity caused by insects. The objectives of this work were to evaluate the damages caused by leaf-cutting ants in young plantations of Pinus taeda and Eucalyptus grandis using different levels of artificial defoliation. A classification was established according to defoliation levels that were caused by leaf-cutting ants in P. taeda: level 1: 50%, level 2: 75%, level 3: 100% and ...

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

    Poulsen, Michael; Erhardt, Daniel P; Molinaro, Daniel J;

    2007-01-01

    . 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...... 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...

  11. The origin of the chemical profiles of fungal symbionts and their significance for nestmate recognition in Acromyrmex leaf-cutting ants

    Richard, Freddie-Jeanne; Poulsen, Michael; Hefetz, Abraham;

    2007-01-01

    less aggression when they are later introduced into that colony. It appears, therefore, that fungus gardens are an independent and significant source of chemical compounds, potentially contributing a richer and more abundant blend of recognition cues to the colony ¿gestalt¿ than the innate chemical...

  12. Registro de Acromyrmex disciger Mayr, 1887 (Hymenoptera: Formicidae em Cinnamomum zeylanicum (Lauraceae no Município de Braço do Trombudo, Santa Catarina, Brasil

    Tiago Pikart

    2010-11-01

    Abstract. Cinnamomum zeylanicum Blume (Lauraceae is cultivated for production of leaves, bark and roots, due to its aromatic and spice proprieties. But despite being a resistant plant, C. zeylanicum is subject to attack by various insects and mites during their development, and these pests are responsible for considerable reduction in crop yields. The aim of this study was to record and characterize the attack by leaf-cutting ants in plants of C. zeylanicum in Braço do Trombudo, Santa Catarina State, Brazil between January and March 2010. Damage were characterized by cutting young leaves and shoots of plants of C. zeylanicum with height between 1.0 to 1.5 m and total defoliation of plants less than 1.0 m. The attack in adult plants was not observed. This is the first record of leaf-cutting ant Acromyrmex disciger Mayr damaging plants of C. zeylanicum in Brazil.

  13. Ant parasite queens revert to mating singly

    Sumner, Seirian; Hughes, William Owen Hamar; Pedersen, Jes Søe;

    2004-01-01

    A parasitic ant has abandoned the multiple mating habit of the queens of its related host. Multiple mating (polyandry) is widespread among animal groups, particularly insects 1 . But the factors that maintain it and underlie its evolution are hard to verify because benefits and costs are not easily...... quantified and they tend to be similar in related species. Here we compare the mating strategies of the leaf-cutting ant Acromyrmex echinatior and its recently derived social parasite Acromyrmex insinuator, which is also its closest relative 2 (see Fig. 1 ). We find that although the host queens mate with up...... to a dozen different males, the social parasite mates only singly. This rapid and surprising reversion to single mating in a socially parasitic ant indicates that the costs of polyandry are probably specific to a free-living lifestyle....

  14. Self-restraint and sterility in workers of Acromyrmex and Atta leafcutter ants

    Dijkstra, Michiel Bendert; Nash, David Richard; Boomsma, Jacobus Jan

    2005-01-01

    large workers) lay eggs that are similar in size to queen-laid eggs, but mostly with a reduced amount of yolk. Trophic eggs appear to be an important source of food for larvae in Acromyrmex (especially in Ac. echinatior), but not in Atta. Five (0.8) of 616 dissected Ac. echinatior workers but no Ac...

  15. Atratividade da isca granulada de polpa de fruto do jatobá para saúva-limão, no campo Attractiveness of the granulated bait of jatobá's fruit pulp to the leaf- cutting ant, in the field

    Maria Lucia França Teixeira

    2008-08-01

    Full Text Available A atratividade da polpa do fruto de jatobá para saúva-limão foi avaliada tendo como parâmetro comparativo a polpa cítrica desidratada, utilizada como veículo por diversas marcas comerciais. O experimento foi conduzido em quatro formigueiros de saúva-limão em canteiros gramados com espécies arbóreas. As iscas de jatobá e de polpa cítrica desidratada, ambas sem princípio ativo, foram confeccionadas em grânulos com formato e diâmetro semelhantes aos das iscas granuladas comerciais. As iscas de jatobá foram mais atrativas para as operárias de saúva-limão, que fizeram o primeiro contato aos 17s, em contraste com os 29s gastos para o primeiro contato com as iscas de polpa cítrica. As iscas de jatobá também começaram a ser carregadas mais cedo, aos 26s, sendo que as iscas de polpa cítrica foram carregadas 48s mais tarde. A grande aceitação do jatobá foi reforçada pelo menor tempo para o encerramento dos testes, 5min 39s, contrastando com os 11min 17s necessários para o encerramento do teste com a polpa cítrica. A polpa do fruto do jatobá foi mais atrativa para saúva-limão do que a polpa cítrica desidratada.Attractiveness of the leaf-cutting ant, Atta sexdens rubropilosa to jatobá's fruit pulp was evaluated, having the dehydrated citrus pulp as comparative parameter, used as vehicle by several commercial brands. The experiment was conducted on four nests of leaf-cutting ants on lawns with arboreal species. Jatobá baits and dehydrated citric pulp both without active principle were made into granules with form and diameter similar to the commercial granulated baits. Jatobá baits were more attractive to the laborers of leaf-cutting ants which made the first contact after 17s, contrasting with 29s before the first contact with citric pulp baits. Jatobá baits were also carried earlier, after 26s, while citric pulp baits were carried 48s later. The great acceptance of jatobá baits was strengthened by the short time to

  16. The prominent role of fungi and fungal enzymes in the ant-fungus biomass conversion symbiosis.

    Lange, L; Grell, M N

    2014-06-01

    Molecular studies have added significantly to understanding of the role of fungi and fungal enzymes in the efficient biomass conversion, which takes place in the fungus garden of leaf-cutting ants. It is now clear that the fungal symbiont expresses the full spectrum of genes for degrading cellulose and other plant cell wall polysaccharides. Since the start of the genomics era, numerous interesting studies have especially focused on evolutionary, molecular, and organismal aspects of the biological and biochemical functions of the symbiosis between leaf-cutting ants (Atta spp. and Acromyrmex spp.) and their fungal symbiont Leucoagaricus gongylophorus. Macroscopic observations of the fungus-farming ant colony inherently depict the ants as the leading part of the symbiosis (the myrmicocentric approach, overshadowing the mycocentric aspects). However, at the molecular level, it is fungal enzymes that enable the ants to access the nutrition embedded in recalcitrant plant biomass. Our hypothesis is that the evolutionary events that established fungus-farming practice were predisposed by a fascinating fungal evolution toward increasing attractiveness to ants. This resulted in the ants allowing the fungus to grow in the nests and began to supply plant materials for more fungal growth. Molecular studies also confirm that specialized fungal structures, the gongylidia, with high levels of proteins and rich blend of enzymes, are essential for symbiosis. Harvested and used as ant feed, the gongylidia are the key factor for sustaining the highly complex leaf-cutting ant colony. This microbial upgrade of fresh leaves to protein-enriched animal feed can serve as inspiration for modern biorefinery technology. PMID:24728757

  17. Diploid male production in a leaf-cutting ant

    Armitage, S.; Boomsma, J.; Baer, Boris

    2010-01-01

    1. In haplodiploid social insects where males are haploid and females are diploid, inbreeding depression is expressed as the production of diploid males when homozygosity at the sex-determining locus results in the production of diploid individuals with a male phenotype. Diploid males are often...... success would be reduced compared with haploid males if they were able to copulate. 5. We conclude that diploid male production is likely to affect the fitness of A. sexdens queens with a matched mating, as these males are produced at the cost of workers and, if the colony survives to reach mature size...

  18. Características biológicas e comportamentais de Neodohrniphora elongata Brown (Diptera, Phoridae, um parasitóide da saúva Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae Biological and behavioral characteristics of Neodohrniphora elongata Brown (Diptera, Phoridae, a parasitic fly of the leaf-cutting ant Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae

    Marcos A. L. Bragança

    2009-12-01

    foraging arena. Flies launched attacks on flies and failed four or five times before they would successfully attack ants and oviposit on the head of workers. Larvae of the parasitoid developed in the cephalic capsule of 63.8% of the 426 attacked workers; 218 flies emerged. N. elongata oviposited on bigger workers, or those with cephalic capsules 2.9 ± 0.4 mm wide. Capsule width seems to be important for the development of the parasitoid because failure in pupa formation and the non-emergence of adults occurred primarily among ants with capsules smaller than 2.9 mm. Flies that emerged in the laboratory had greater longevity when fed on honey solution at 10% than honey solution at 50%, or on distilled water only. The females emerged in laboratory had flight and attack behavior similar to those of field females, although second generation parasitoids could not be obtained. Additional studies on the impact of natural sources of carbohydrates and protein on the longevity and reproduction of N. elongate should be conducted to multiply this and other phorids of leaf-cutting ants in the laboratory.

  19. Broad Escovopsis-inhibition activity of Pseudonocardia associated with Trachymyrmex ants.

    Meirelles, Lucas A; Mendes, Thaís D; Solomon, Scott E; Bueno, Odair C; Pagnocca, Fernando C; Rodrigues, Andre

    2014-08-01

    Attine ants maintain an association with antibiotic-producing Actinobacteria found on their integuments. Evidence supports these bacteria as auxiliary symbionts that help ants to defend the fungus gardens against pathogens. Using Pseudonocardia strains isolated from Trachymyrmex ants, we tested whether the inhibitory capabilities of such strains are restricted to Escovopsis parasites that infect gardens of this ant genus. Twelve Pseudonocardia strains were tested in in vitro bioassays against Escovopsis strains derived from fungus gardens of Trachymyrmex (n = 1) and leaf-cutting ants (n = 3). Overall, significant differences were observed in the mycelial growth among each Escovopsis strain in the presence of Pseudonocardia. Particularly, Escovopsis from Acromyrmex and Trachymyrmex were the most inhibited strains in comparison to Escovopsis isolated from Atta. This result suggests that Pseudonocardia isolated from Trachymyrmex possibly secrete antimicrobial compounds effective against diverse Escovopsis strains. The fact that Trachymyrmex ants harbour Pseudonocardia strains with broad spectrum of activity and its defensive role on attine gardens are discussed. PMID:24992532

  20. Non-specific association between filamentous bacteria and fungus-growing ants.

    Kost, Christian; Lakatos, Tanja; Böttcher, Ingo; Arendholz, Wolf-Rüdiger; Redenbach, Matthias; Wirth, Rainer

    2007-10-01

    Fungus-growing ants and their fungal cultivar form a highly evolved mutualism that is negatively affected by the specialized parasitic fungus Escovopsis. Filamentous Pseudonocardia bacteria occurring on the cuticle of attine ants have been proposed to form a mutualistic interaction with these ants in which they are vertically transmitted (i.e. from parent to offspring colonies). Given a strictly vertical transmission of Pseudonocardia, the evolutionary theory predicts a reduced genetic variability of symbionts among ant lineages. The aim of this study was to verify whether actinomycetes, which occur on Acromyrmex octospinosus leaf-cutting ants, meet this expectation by comparing their genotypic variability with restriction fragment length polymorphisms. Multiple actinomycete strains could be isolated from both individual ant workers and colonies (one to seven strains per colony). The colony specificity of actinomycete communities was high: Only 15% of all strains were isolated from more than one colony, and just 5% were present in both populations investigated. Partial sequencing of 16S ribosomal deoxyribonucleic acid of two of the isolated strains assigned both of them to the genus Streptomyces. Actinomycetes could also be isolated from workers of the two non-attine ant species Myrmica rugulosa and Lasius flavus. Sixty-two percent of the strains derived from attine ants and 80% of the strains isolated from non-attine ants inhibited the growth of Escovopsis. Our data suggest that the association between attine ants and their actinomycete symbionts is less specific then previously thought. Soil-dwelling actinomycetes may have been dynamically recruited from the environment (horizontal transmission), probably reflecting an adaptation to a diverse community of microbial pathogens. PMID:17541536

  1. Damage caused by different levels of artificial defoliation, simulating the leaf-cutting ants attack on young plantations of Pinus taeda and Eucalyptus grandis Danos causados por diferentes níveis de desfolha artificial para simulação do ataque de formigas cortadeiras em Pinus taeda e Eucalyptus grandis

    Wilson Reis Filho

    2011-03-01

    Full Text Available

    The artificial defoliation allows to measure the defoliation intensity caused by insects. The objectives of this work were to evaluate the damages caused by leaf-cutting ants in young plantations of Pinus taeda and Eucalyptus grandis using different levels of artificial defoliation. A classification was established according to defoliation levels that were caused by leaf-cutting ants in P. taeda: level 1: 50%, level 2: 75%, level 3: 100% and level 4: 100%, including the cut of the apical meristem. And in E. grandis: level 1: 50% of defoliation; level 2: 75% and level 3: 100%. After one year, the P. taeda seedlings had losses in diameter and height for defoliation level above 75%. Seedlings severely defoliated (level 4, had losses of 37.0% in height and 45.4% in diameter. The E. grandis seedlings had losses since three months old and the reductions were proportional to the defoliation intensity. After one year, the losses of 13.3% in height and 20% in diameter were verified in plants with 100% of defoliation. P. taeda plants are more damaged by leaf-cutting attack.

    doi: 10.4336/2011.pfb.31.65.37

    A desfolha artificial permite mensurar a intensidade do dano devido à desfolha causada por insetos. No presente estudo, buscou-se avaliar os danos causados por formigas cortadeiras em plantios de Pinus taeda e Eucalyptus grandis com 30 dias de idade. Foi estabelecida uma classificação baseada em níveis de desfolha semelhantes aos causados por formigas cortadeiras. Para P. taeda, os níveis foram: N1: 50%, N2: 75%, N3: 100% e N4: 100% de desfolha, incluindo o corte do meristema apical. Para E. grandis, os níveis foram N1: 50%, N2: 75% e N3: 100% de desfolha, incluindo o corte do meristema apical. Após um ano, as mudas de P. taeda tiveram perdas em altura e diâmetro nos níveis de N2 a N4. Mudas de P. taeda desfolhadas no nível N4 apresentaram perdas de

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

    Michael Poulsen

    Full Text Available 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

  3. Ocorrência de formigas Acromyrmex Mayr, 1865, em alguns municípios do Brasil - DOI: 10.4025/actascibiolsci.v27i2.1322 Occurrence of ants Acromyrmex Mayr, 1865 in some cities of Brasil - DOI: 10.4025/actascibiolsci.v27i2.1322

    Luiz Carlos Forti

    2005-03-01

    Full Text Available Espécies de Acromyrmex Mayr, 1865, foram coletadas em vários municípios do Brasil, nos seguintes estados: de Santa Catarina, Paraná, São Paulo, Minas Gerais, Goiás, Mato Grosso do Sul, Mato Grosso, Rondônia, Amapá, e também no Paraguai e no Uruguai, visando atualizar a ocorrência das mesmas. Os exemplares coletados nas viagens foram identificados no laboratório da Fca/Unesp/Botucatu-SP. Foram registradas, pela primeira vez, as ocorrências de A. rugosus rugosus (F. Smith, 1858 no Paraná, em Rondônia e em Santa Catarina; de A. subterraneus subterraneus (Forel, 1893 no Amapá e na Bahia; de A. diasi (Gonçalves, 1982 no Rio Grande do Sul e no Paraná; de A. coronatus (Fabricius, 1804 no Paraná; de A. balzani (Emery, 1890 no Amapá e de A. subterraneus brunneus (Forel, 1911 em GoiásIt were collected species of Acromyrmex Mayr, 1865 in many brazilian cities from Santa Catarina, Paraná, São Paulo, Minas Gerais, Goiás, Mato Grosso do Sul, Mato Grosso, Rondônia and Amapá states and in Paraguay and Uruguay, with the purpose to bring up-to-date their occurrence. Specimens collected on trips were identified at laboratory of Fca/Unesp/Botucatu-SP. It were recorded, for the first time, the occurrence of A. rugosus rugosus (F. Smith, 1858 in Paraná, Rondônia and Santa Catarina states; A. subterraneus subterraneus (Forel, 1893 in Amapá and Bahia; A. diasi Gonçalves, 1982 in Rio Grande do Sul and Paraná states; A. coronatus (Fabricius, 1804 in Paraná; A. balzani (Emery, 1890 in Amapá and A. subterraneus brunneus (Forel, 1911 in Goiás

  4. Extrações de óleos de sementes de citros e suas atividades sobre a formiga cortadeira Atta sexdens e seu fungo simbionte Citrus seed oils extractions and their activity against leaf cutting ant Atta sexdens and its symbiotic fungus

    João B. Fernandes

    2002-12-01

    Full Text Available Seeds Citrus oils (C. sinensis, C. limon and C. reticulata extraction with hexane in a soxhlet apparatus and through supercritical fluid (CO2 were done. Besides triglycerides, the oils obtained with hexane comprised volatile compounds such as terpenes and fatty alcohols, esters, and aldehydes. However, the oils obtained by extraction with supercritical fluid presented only triglycerides. These results indicate that the extraction using supercritical fluid presents better selectivity. The activity of the oils on the development of the ant symbiotic fungus, Leucoagaricus gongylophorus, showed week activity and the topic insecticide assay showed better activity for the tangerine seed oil.

  5. The effects of age and social interactions on innate immunity in a leaf-cutting ant

    Armitage, S.A.O.; Boomsma, J.J.

    2010-01-01

    Both developmental and environmental factors shape investment in costly immune defences. Social insect workers have different selection pressures on their innate immune system compared to non-social insects because workers do not reproduce and their longevity affects the fitness of relatives....... Furthermore, hygienic behavioural defences found in social insects can result in increased survival after fungal infection, although it is not known if there is modulation in physiological immune defence associated with group living vs. solitary living. Here we investigated whether physiological immune...

  6. SPATIAL DISTRIBUTION OF LEAF-CUTTING ANT NESTS (Hymenoptera: Formicidae IN EUCALYPTUS PLANTATIONS

    Marcelo Araújo Caldeira

    2005-03-01

    Full Text Available Programs of integrated pest management in forest plantation require a sampling plan. Therefore, it is important todetermine the spatial distribution these pests, because it makes the decision process more precise, given that it takes into accounttheir local and regional spatial distribution variations. This work was carried out for evaluating the spatial distribution of antnests in eucalyptus plantations. Twelve eucalyptus stands belonging to V&M Florestal Ltd., in Bocaiúva county, Minas Gerais,were used. They were divided into 6m x 20m sub parcels, totalizing 120m2. The nests were identified, counted and measured ineach parcel. Both found and expected frequency of nests were calculated according to Poisson’s distribution, in order todetermine the type of spatial distribution of nests. The found and the expected frequency (x2; p>0.01 were similar. The result was a randomized distribution.

  7. Adventitious shoot formation on leaf cuttings in vivo, a tool in horticulture.

    Custers, J.B.M.

    1986-01-01

    Adventitious shoot formation implies the regeneration or development of shoots from fully differentiated tissue. Its application has, after the rise of in vitro culture, assumed large proportions. Then the question arose whether in vivo adventitious shoot formation could not be applied more widely in commercial horticulture. To answer this question investigations were made on the regeneration of leaf cuttings and the results are presented in this thesis.It was found that the majority of a lar...

  8. Fungal Adaptations to Mutualistic Life with Ants

    Kooij, Pepijn Wilhelmus

    Fungus-growing ants (Attini) feed off a fungus they cultivate in a mutualistic symbiosis in underground chambers by providing it substrate they collect outside the colony. The tribe of Attine ants ranges from small colonies of the paleo- and basal Attine species with a few hundred workers that...... forage on crude substrates such as insect frass and dry plant material, to large colonies of the leaf-cutting ants with several thousands to several million workers that provide live plant material to their fungus gardens. Leaf-cutting ants are the dominant herbivores of the Neo-tropics, and have a major...... estimate that approximately half of these nuclei were represented by different genomes, giving the fungus a ploidy level of 5n-6n. In mutualistic symbioses it is important the partners stay true to each other. In fungus-growing ants, new founding queens bring a piece of fungus to build up their new colony...

  9. Leaf-Cutter Ant Parasitoids: Current Knowledge

    Patricia J. Folgarait

    2013-01-01

    This review updates and summarizes the current knowledge about the interaction of leaf-cutter ants and their parasitoids by providing comparable data for Acromyrmex and Atta ants. First, an overview of the relevant aspects of the biology and taxonomy of leaf cutters and of their parasitoids is provided. Second, I show the peculiarities of the parasitoids attacking behaviors towards their host as well as the responses or ant defenses against the phorids exhibited by their hosts. Third, I discu...

  10. Slowing them down will make them lose: a role for attine ant crop fungus in defending pupae against infections?

    Armitage, Sophie A O; Fernández-Marín, Hermógenes; Boomsma, Jacobus J; Wcislo, William T

    2016-09-01

    Fungus-growing ants (Attini) have evolved an obligate dependency upon a basidiomycete fungus that they cultivate as their food. Less well known is that the crop fungus is also used by many attine species to cover their eggs, larvae and pupae. The adaptive functional significance of this brood covering is poorly understood. One hypothesis to account for this behaviour is that it is part of the pathogen protection portfolio when many thousands of sister workers live in close proximity and larvae and pupae are not protected by cells, as in bees and wasps, and are immobile. We performed behavioural observations on brood covering in the leaf-cutting ant Acromyrmex echinatior, and we experimentally manipulated mycelial cover on pupae and exposed them to the entomopathogenic fungus Metarhizium brunneum to test for a role in pathogen resistance. Our results show that active mycelial brood covering by workers is a behaviourally plastic trait that varies temporally, and across life stages and castes. The presence of a fungal cover on the pupae reduced the rate at which conidia appeared and the percentage of pupal surface that produced pathogen spores, compared to pupae that had fungal cover experimentally removed or naturally had no mycelial cover. Infected pupae with mycelium had higher survival rates than infected pupae without the cover, although this depended upon the time at which adult sister workers were allowed to interact with pupae. Finally, workers employed higher rates of metapleural gland grooming to infected pupae without mycelium than to infected pupae with mycelium. Our results imply that mycelial brood covering may play a significant role in suppressing the growth and subsequent spread of disease, thus adding a novel layer of protection to their defence portfolio. PMID:27136600

  11. Antimicrobial defense shows an abrupt evolutionary transition in the fungus-growing ants

    Hughes, William O H; Pagliarini, Roberta; Madsen, Henning Bang; Dijkstra, Michiel B; Boomsma, Jacobus J

    2008-01-01

    exception to this rule because they are a key first-line defense that are fixed in size in adults. Here we conduct a comparative analysis of the size of the gland reservoir across the fungus-growing ants (tribe Attini). Most attines have singly mated queens, but in two derived genera, the leaf-cutting ants...

  12. Low host–pathogen specificity in the leaf-cutting ant–microbe symbiosis

    Stephen J Taerum; Cafaro, Matías J.; Little, Ainslie E. F.; Schultz, Ted R.; Currie, Cameron R

    2007-01-01

    Host–parasite associations are shaped by coevolutionary dynamics. One example is the complex fungus-growing ant–microbe symbiosis, which includes ancient host–parasite coevolution. Fungus-growing ants and the fungi they cultivate for food have an antagonistic symbiosis with Escovopsis, a specialized microfungus that infects the ants' fungus gardens. The evolutionary histories of the ant, cultivar and Escovopsis are highly congruent at the deepest phylogenetic levels, with specific parasite li...

  13. Laccase gene expression as a possible key adaptation for herbivorous niche expansion in the attine fungus-growing ants

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Nygaard, Sanne;

    played an important role in allowing the leaf-cutting ants to become generalist functional herbivores. Laccases are polyphenol oxidase enzymes (PPOs) that are best known for their ability to degrade lignin in saprophytic and wood-pathogenic fungi. We found that laccase activity was primarily expressed in......Fungus garden enzyme activity is crucial for sustaining societies of attine ants. The evolutionary diversification of this clade has likely been influenced by enzymatic specialization in connection to changes in foraging niche (De Fine Licht, Schiøtt, Mueller & Boomsma, 2010, Evolution......), particularly when the ancestral leaf-cutting ants shifted from a diet of mostly fresh but shed plant material to actively cutting leaves. However, the way in which leaf-cutting ants managed to overcome the chemical defences of leaves has remained poorly understood. Here we document that laccases may have...

  14. Mandibular and postpharyngeal gland secretions of Acromyrmex landolti (Hymenoptera: Formicidae as chemical cues for nestmate recognition

    Cristina Sainz-Borgo

    2013-09-01

    Full Text Available Nestmate recognition is fundamental for the cohesiveness of the colony in social insects. Acromyrmex landolti is a higher Attini, a leaf-cutter ant with largest nest and morphological castes. We studied the location of the recognition signal of A. landolti on the whole ant body, the isolation effect on the capacity of nestmaterecognition, and the role of the mandibular (MG and post-pharyngeal glands (PPG as putative sources for chemical recognition signals in this species. We performed behavioral bioassays and chemical analyses of MG and PPG glands; MG volatiles in different castes were also characterized. In order to determine the occurrence of nestmate recognition signals, behavioral tests were performed for which the whole body, body parts or gland extracts from a nestmate and an alien worker ant, were placed on the central axis of an active field trail. Besides, the isolation effect of the nestmate chemical signal persistence was evaluated by repeating the experiments with whole ant bodies after 12h, 24h and 48h of isolation. The agonistic behavior of the ants on the trail was classified as inspection, threatening and biting. Gland volatiles were obtained by headspace solid phase microextraction, and PPG by solid sample analyses; and chemical analyses were performed using gas chromatography-mass spectrometry. Workers performed agonistic behaviors more frequently towards non-nestmate whole bodies, body parts and gland extracts, primarily those from the post-pharyngeal glands. Nestmate thoraces odorized with alien extracts were also recognized from aliens. Nestmate recognition ability persists for 12h and 24h after isolation, but decreases after 48h, suggesting that the chemical signal changes over time. Inter-colonial chemical analyses showed no differences in the PPG hydrocarbon profiles, while the relative proportions of MG compounds showed significant differences between colonies. These results showed that nestmate recognition was achieved

  15. Activities of extracts and compounds from Spiranthera odoratissima St. Hil. (Rutaceae) in leaf-cutting ants and their symbiotic fungus

    The study of the Spiranthera odoratissima St. Hil (Rutaceae) branches extracts led to the isolation of the furoquinoline (dictamine, γ-fagarine and skimmianine) and 2-arylquinoli-4-one (1-methyl-2-phenylquinoline-4-one) alkaloids and limonoids (limonexic acid and limonin). The compounds 1-methyl-2-phenylquinoline-4-one and limonexic acid were isolated for the first time from the Spiranthera. These furoquinoline and 2-arylquinoli-4-one alkaloids and limonoids showed insecticidal and/or fungicidal activity in the nest of the Atta sexdens rubropilosa. (author)

  16. Activities of extracts and compounds from Spiranthera odoratissima St. Hil. (Rutaceae) in leaf-cutting ants and their symbiotic fungus

    Terezan, Ana Paula; Fernandes, Joao B.; Silva, M. Fatima das Gracas Fernandes da; Vieira, Paulo C. [Universidade Federal de Sao Carlos (UFSCAR), Sao Carlos, SP (Brazil). Dept. de Quimica; Rossi, Raquel Andrade; Almeida, Roberta N.A.; Freitas, Tais Garcia; Bueno, Odair C.; Pagnocca, Fernando C. [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Centro de Estudos de Insetos Sociais; Pirani, Jose R., E-mail: djbf@power.ufscar.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Biociencias. Dept. de Botanica

    2010-07-01

    The study of the Spiranthera odoratissima St. Hil (Rutaceae) branches extracts led to the isolation of the furoquinoline (dictamine, gamma-fagarine and skimmianine) and 2-arylquinoli-4-one (1-methyl-2-phenylquinoline-4-one) alkaloids and limonoids (limonexic acid and limonin). The compounds 1-methyl-2-phenylquinoline-4-one and limonexic acid were isolated for the first time from the Spiranthera. These furoquinoline and 2-arylquinoli-4-one alkaloids and limonoids showed insecticidal and/or fungicidal activity in the nest of the Atta sexdens rubropilosa. (author)

  17. Density-dependence and within-host competition in a semelparous parasite of leaf-cutting ants

    Hughes, William; Petersen, Klaus; Ugelvig, Line;

    2004-01-01

    BACKGROUND:Parasite heterogeneity and within-host competition are thought to be important factors influencing the dynamics of host-parasite relationships. Yet, while there have been many theoretical investigations of how these factors may act, empirical data is more limited. We investigated the e...... stages. Such parasites make useful models for investigating infection dynamics and the impact of parasite competition....

  18. EVOLUTIONARY TRANSITIONS IN ENZYME ACTIVITY OF ANT FUNGUS GARDENS

    De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G;

    2010-01-01

    an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across...... the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens...... are targeted primarily towards partial degradation of plant cell walls, reflecting a plesiomorphic state of non-domesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major...

  19. Co-evolution of enzyme function in the attine ant-fungus symbiosis

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    have small nests with a fungus garden the size of a table-tennis ball. Only the leaf-cutting ants are specialized on using fresh leaves as substrate for their fungus gardens, whereas the more basal attine genera use substrates such as dry plant material (leaf litter and small twigs) and also insect...

  20. Kin-informative recognition cues in ants

    Nehring, Volker; Evison, Sophie E F; Santorelli, Lorenzo A;

    2011-01-01

    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...

  1. Efecto de los cortafuegos sobre el ensamble de hormigas (Hymenoptera, Formicidae en una región semiárida, Argentina Effects of firebreaks on ant density (Hymenoptera, Formicidae in a semiarid region, Argentina

    Francisco Rodrigo Tizón

    2010-09-01

    (shrubland, herbaceous cover (grass, and 80% of bare soil (firebreaks within a 12 ha study area where large herbivores were excluded. We recorded soil surface temperature, humidity, pH and degree of soil compaction in each area. The density of nests was assessed by randomly placing three transects (80 m x 5 m in each experimental unit. Soil temperature was higher in firebreaks and soil compaction was higher in the shrubland and the grassland. No differences in ant assemblage were found regarding nest density among environments. However, Acromyrmex striatus (Roger, 1863 was found mostly in firebreaks where loose soil with greater porosity allows more gas exchange and water infiltration. Our findings revealed that the construction of firebreaks favors the establishment of leaf-cutting ants, which due to their competitive advantage, could negatively affect ant and plant composition in the community.

  2. Comparative studies of the secretome of fungus-growing ants

    Linde, Tore; Grell, Morten Nedergaard; Schiøtt, Morten;

    2009-01-01

    Leafcutter ants of the species Acromyrmex echinatior live in symbiosis with the fungus Leucoagaricus gongylophorus. The ants harvest fragments of leaves and carry them to the nest where they place the material on the fungal colony. The fungus secretes a wide array of proteins to degrade the leaves...... into nutrients that the ants can feed on. The focus of this study is to discover, characterize and compare the secreted proteins. In order to do so cDNA libraries are constructed from mRNA extracted from the fungus material. The most efficient technology to screen cDNA libraries selectively for...

  3. Evolution of Fungal enzymes in the attine ant symbiosis

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    The attine ant symbiosis is characterized by ancient but varying degrees of diffuse co-evolution between the ants and their fungal cultivars. Domesticated fungi became dependent on vertical transmission by queens and the ant colonies came to rely on their symbiotic fungus for food and thus......, indirectly, on fungal enzymes to break down the plant material brought in by the ants as fungal substrate. The more than 210 extant fungus-growing ant species differ considerably in colony size, social complexity and substrate-use. Only the derived leaf-cutting ants are specialized on using fresh leaves as...... garden substrate, whereas the more basal genera use leaf litter, insect feces and insect carcasses. We hypothesized that enzyme activity of fungal symbionts has co-evolved with substrate use and we measured enzyme activities of fungus gardens in the field to test this, focusing particularly on plant...

  4. Optimal conditions to rear phorid parasitoids (Diptera: Phoridae) of Atta vollenweideri and Acromyrmex lundii (Hymenoptera: Formicidae).

    Guillade, Andrea C; Folgarait, Patricia J

    2014-04-01

    Phorid flies have been considered viable options for biological control of leaf-cutter ants because they are highly specific to these hosts, producing direct mortality and also affecting the normal functioning of colonies. Designing protocols for mass rearing of these insects requires knowing the temperature and humidity conditions that optimize their development in terms of duration, survivorship and longevity of adults. We reared Apocephalus setitarsus Brown, Eibesfeldtphora trilobata Disney, and Myrmosicarius brandaoi Disney, which are specific leaf-cutter ant parasitoids of Atta vollenweideri Forel, and Apocephalus neivai Borgmeier and Myrmosicarius catharinensis Borgmeier, which are parasitoids of Acromyrmex lundii Guérin-Méneville. Phorids were maintained under one of five different rearing conditions, 20°C high humidity (20HH), 24°C low and high humidity (24LH and 24HH), and 28°C low and high humidity (28LH and 28HH). Flies from all species could complete their development under all the conditions tested. As expected, the 20HH treatment significantly lengthened all developmental periods in all species, whereas the shortest duration was achieved under 28HH. Although pupal survivorship was highest at 24HH, the greatest longevity of adults was achieved at 20HH. Percentage of pupae obtained and pupal survivorship also exhibited the highest values at 24HH. The rearing efficiency index was highest for all species at 24HH. Therefore, we suggest this temperature and humidity combination as the most suitable for rearing these species, whereas the 20HH treatment is ideal for maintaining adults for longer periods, which would be advantageous for synchronizing matings and mass releases of adults in the field. PMID:24565267

  5. Dinâmica populacional e ecologia do forrageamento de Acromyrmex Mayr, 1865 (hymenoptera: Formicidae)

    Nickele, Mariane Aparecida

    2013-01-01

    Resumo: A tribo Attini (Hymenoptera: Formicidae) compreende 14 gêneros de formigas que estão envolvidas em um mutualismo obrigatório com fungos. As formigas cortadeiras, Atta e Acromyrmex, são consideradas as principais pragas de florestas plantadas de Pinus e Eucalyptus, no entanto, na região sul do Brasil, as espécies de Acromyrmex são mais comuns. O objetivo geral deste estudo foi avaliar a dinâmica populacional de formigas cortadeiras do gênero Acromyrmex em plantios de Pinus taeda e estu...

  6. Laccase gene expression as a possible key adaptation for herbivorous niche expansion in the attine fungus-growing ants

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    Fungus garden enzyme activity is crucial for sustaining societies of attine ants. The evolutionary diversification of this clade has likely been influenced by enzymatic specialization in connection to changes in foraging niche, particularly when the ancestral leaf-cutting ants shifted from a diet...... of mostly fresh but shed plant material to actively cutting leaves. However, the way in which these ants managed to overcome the chemical defences of leaves has remained poorly understood. Here we document that fungal laccases may have played an important role in allowing the leaf-cutting ants to...... become generalist functional herbivores. Laccases are polyphenol oxidase enzymes (PPOs) that are best known for their ability to degrade lignin in saprophytic and wood-pathogenic fungi. We found that laccase activity was primarily expressed in newly constructed garden sections where secondary leaf...

  7. From so simple a beginning: Enzymatic innovation in fungus-growing ants involved a transition from individual symbiont selection to colony-level selection

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    ants increased the share of fresh leaves in their forage. However, once in place, this novel enzyme function gave the entire mutualism a significant colony-level advantage, which allowed the leaf-cutting ants to evolve very large long-lived colonies and to become one of the most important and...... partner species. Here we document such a sequence that was connected to a major evolutionary transition in the fungus-growing ants, when the ancestor of the derived leaf-cutting ants shifted from a diet of dry vegetative material to the almost exclusive use of freshly cut leaves. This shift generated...... visible adaptations in the host ants, such as increased worker dimorphism allowing large workers to cut fresh leaves, but comparative studies of the specific fungal adaptations that accompanied the transition have not been done. Here we report the first large comparative data set on enzymatic fungus...

  8. The role of enzymes in fungus-growing ant evolution

    de Fine Licht, Henrik Hjarvard

    behaviour. Here we report the first large-scale comparative study on fungus garden enzyme profiles and show that various interesting changes can be documented. A more detailed analysis of laccase expression, an enzyme that is believed to oxidize phenols in defensive secondary plant compounds such as tannins......, showed that this enzyme is exclusively found in the gardens of leaf-cutting ants, where it is significantly upregulated in the gongylidia. I’ll discuss the possible role of this enzyme and other fungal modifications in the evolution of the leafcutter ants and their non-leafcutting attine relatives....

  9. Forage collection, substrate preparation, and diet composition in fungus-growing ants

    Licht, H.H.D.; Boomsma, J.J.

    2010-01-01

    , whereas most of the other attine species use dry and partly degraded plant material such as leaf litter and caterpillar frass, but systematic comparative studies of actual resource acquisition across the attine ants have not been done. 3. Here we review 179 literature records of diet composition across...... the extant genera of fungus-growing ants. The records confirm the dependence of leaf-cutting ants on fresh vegetation but find that flowers, dry plant debris, seeds (husks), and insect frass are used by all genera, whereas other substrates such as nectar and insect carcasses are only used by some. 4...

  10. PREFERÊNCIA DE CORTE DE Acromyrmex crassispinus (FOREL, 1909 E Acromyrmex ambiguus (EMERY, 1887 (HYMENOPTERA: FORMICIDAE POR DIFERENTES ESPÉCIES DE EUCALIPTOS EM LABORATÓRIO

    João Luis Osório Rosado

    2014-12-01

    Full Text Available A busca por novos métodos de manejo e controle de formigas-cortadeiras vem sendo enfoque de inúmeros estudos pelo país, impulsionada por aspectos econômicos e ambientais. O estabelecimento de espécies resistentes ou menos preferidas ao corte pode contribuir substancialmente neste sentido. Logo, o objetivo deste estudo foi avaliar a preferência de corte entre as espécies Corymbia citriodora, Eucalyptus benthamii, Eucalyptus camaldulensis, Eucalyptus dunnii, Eucalyptus globulus e Eucalyptus urograndis por Acromyrmex ambiguus e Acromyrmex crassispinus em laboratório. Para isso, folhas foram ofertadas, simultaneamente, para seis colônias de cada espécie em bioensaios com chance de escolha. No entanto, nos testes sem chance de escolha, apenas as espécies menos preferidas pelo teste anterior foram utilizadas. Para Acromyrmex crassispinus, as espécies Eucalyptus camaldulensis e Eucalyptus urograndis foram mais cortadas, enquanto que as espécies Corymbia citriodora, Eucalyptus dunnii e Eucalyptus globulus foram menos preferidas ao corte. Acromyrmex ambiguus apresentou padrão similar de preferência, adicionando-se Eucalyptus benthamii entre as mais preferidas e excluindo-se Eucalyptus dunnii das menos preferidas.

  11. Cassava leaf methanolic extract as an alternative to control of fall armyworm and leaf cutter ants

    Mírian Aparecida Isidro Santos; Angelita Duarte Corrêa; Ana Paula de Carvalho Alves; Anderson Assaid Simão; Dejane Santos Alves; Rodrigo Lopes de Oliveira; Adelir Aparecida Saczk; Geraldo Andrade Carvalho

    2013-01-01

    The objective of this study was to characterize phenolic compounds and evaluate the effect, under laboratory conditions, of the cassava leaf powder methanol extract on the development of fall armyworm Spodoptera frugiperda and of leaf-cutting ant Atta sexdens rubropilosa. The extract was incorporated into an artificial diet, to which the armyworm was exposed, at concentrations of 250, 500, 1,000 and 1,500 mg kg-1, in order to evaluate biological characteristics. Soon after the insects emergen...

  12. Sperm length evolution in the fungus-growing ants

    Baer, B.; Dijkstra, M. B.; Mueller, U. G.;

    2009-01-01

    -growing ants, representing 9 of the 12 recognized genera, and mapped these onto the ant phylogeny. We show that average sperm length across species is highly variable and decreases with mature colony size in basal genera with singly mated queens, suggesting that sperm production or storage constraints affect...... the evolution of sperm length. Sperm length does not decrease further in multiply mating leaf-cutting ants, despite substantial further increases in colony size. In a combined analysis, sexual dimorphism explained 63.1% of the variance in sperm length between species. As colony size was not a...... significant predictor in this analysis, we conclude that sperm production trade-offs in males have been the major selective force affecting sperm length across the fungus-growing ants, rather than storage constraints in females. The relationship between sperm length and sexual dimorphism remained robust in...

  13. The effect of metapleural gland secretion on the growth of a mutualistic bacterium on the cuticle of leaf-cutting ants

    Poulsen, Michael; Bot, Adrianne N M; Boomsma, Jacobus J

    2003-01-01

    controlling a microfungal parasite of their fungus gardens. Interaction between this bacterium and gland secretion therefore seems unavoidable. We document the typical development of bacterial growth on the cuticle of young major workers, show that growth starts a few days after eclosion, and that the maximal...

  14. Random sperm use and genetic effects on worker caste fate in Atta colombica leaf-cutting ants

    Holman, Luke; Stürup, Marlene; Trontti, Kalevi; Boomsma, Jacobus J

    2011-01-01

    genotyping revealed how sperm number translated into paternity of eggs and adult workers. We demonstrate that fertilization success is directly related to sperm numbers, that stored sperm are well-mixed and that egg paternity is constant over time. Moreover, worker size was found to have a considerable...

  15. Ecosystem engineering in fragmented forests: Edge-mediated hyper-abundance of leaf-cutting ants and resulting impacts on forest structure, microclimate and regeneration

    Meyer, Sebastian T.

    2008-01-01

    Fragmentation of habitats, especially of tropical rainforests, ranks globally among the most pervasive man-made disturbances of ecosystems. There is growing evidence for long-term effects of forest frag-mentation and the accompanying creation of artificial edges on ecosystem functioning and forest structure, which are altered in a way that generally transforms these forests into early successional systems. Edge-induced disruption of species interactions can be among the driving mechanisms gov...

  16. Uninformed sacrifice: Evidence against long-range alarm transmission in foraging ants exposed to localized abduction

    Tejera, F.; Reyes, A.; Altshuler, E.

    2016-07-01

    It is well established that danger information can be transmitted by ants through relatively small distances, provoking either a state of alarm when they move away from potentially dangerous stimulus, or charge toward it aggressively. There is almost no knowledge if danger information can be transmitted along large distances. In this paper, we abduct leaf cutting ants of the species Atta insularis while they forage in their natural environment at a certain point of the foraging line, so ants make a "U" turn to escape from the danger zone and go back to the nest. Our results strongly suggest that those ants do not transmit "danger information" to other nestmates marching towards the abduction area. The individualistic behavior of the ants returning from the danger zone results in a depression of the foraging activity due to the systematic sacrifice of non-informed individuals.

  17. O jardim de fungo atua como um molde para a construção das câmaras em formigas cortadeiras? Fungus garden acts as a template for the construction of chambers in ants?

    Roberto da Silva Camargo

    2013-04-01

    Full Text Available Os ninhos adultos das formigas cortadeiras (gênero Atta e Acromyrmex são compostos de milhares de câmaras subterrâneas, as quais abrigam o jardim de fungo, lixo e a população desses insetos. Entretanto, como as câmaras são construídas? Para responder essa questão, nós hipotetizamos que o jardim de fungo atua como um molde para a construção das câmaras. Assim, foram utilizadas 20 colônias de 6 meses de idade, divididas em quatro séries experimentais: padrão (quantidade normal de jardim de fungo; metade de jardim de fungo; dobro de jardim de fungo e sem jardim de fungo (Testemunha. As variáveis estudadas foram: parâmetros morfológicos das estruturas (túneis e câmara formada; fluxo das atividades das operárias; volume de solo escavado. Como se esperava, o jardim de fungo atua como um molde para a construção das câmaras em formigas cortadeiras. Os resultados foram: o tratamento sem jardim de fungo não apresentou nenhuma câmara, apenas túneis, em contraposição às demais séries experimentais que apresentaram no mínimo 2 câmaras, com dimensões similares; o fluxo das operárias carregando pellet de solo por minuto durante as 72 horas diferiu estatisticamente entre as séries experimentais e, finalmente, o volume do solo escavado foi resultado da taxa de escavação das operárias, diferindo estatisticamente entre as séries experimentais. Os resultados corroboram a hipótese de que o jardim de fungo atua como um molde para a construção da câmara. A ausência de uma estrutura funcional como uma câmara, quando o jardim de fungo está ausente, comprova a hipótese.Adult nests of leaf cutting ants (genus Atta and Acromyrmex are composed of thousands of underground chambers, which harbor the fungus garden, garbage and their population. However, how the chambers are constructed? To answer this question, we hypothesized that the fungus garden acts as a template for the chambers construction. Thus, we used 20 colonies of

  18. Sex allocation in fungus-growing ants: worker or queen control without symbiont-induced female bias

    Dijkstra, Michiel B.; Boomsma, Jacobus Jan

    2008-01-01

    The fungal cultivars of fungus-growing ants are vertically transmitted by queens but not males. Selection would therefore favor cultivars that bias the ants' sex ratio towards gynes, beyond the gyne bias that is optimal for workers and queens. We measured sex allocation in 190 colonies of six......, colony fecundity, and fungal garden volume for Acromyrmex and Sericomyrmex, but not for Trachymyrmex. Year of collection, worker number and mating frequency of Acromyrmex queens did not affect the colony sex ratios. We used a novel sensitivity analysis to compare the population sex allocation ratios with...... the theoretical queen and worker optima for a range of values of k, the correction factor for sex differences in metabolic rate and fat content. The results were consistent with either worker or queen control, but never with fungal control for any realistic value of k. We conclude that the fungal...

  19. Densidade e tamanho de formigueiros de Acromyrmex crassispinus em plantios de Pinus taeda Density and size of Acromyrmex crassispinus nests in Pinus taeda plantations

    Mariane Aparecida Nickele; Wilson Reis Filho; Edilson Batista Oliveira; Edson Tadeu Iede

    2009-01-01

    O objetivo deste trabalho foi avaliar a densidade e o tamanho dos formigueiros de Acromyrmex crassispinus, ao longo do ano, em plantios de Pinus taeda de diferentes idades. Os experimentos foram realizados, em Rio Negrinho e em Três Barras, SC, em talhões de P. taeda com diferentes idades (recém-plantado, três anos e seis anos de idade). Em cada tratamento, foram demarcadas três parcelas de 1 ha. Os formigueiros foram classificados em três classes de tamanho: classe I, até 30 cm de diâmetro; ...

  20. Sperm storage induces an immunity cost in ants

    Baer, Boris; Armitage, Sophie A O; Boomsma, Jacobus J

    2006-01-01

    Ant queens are among the most long-lived insects known. They mate early in adult life and maintain millions of viable sperm in their sperm storage organ until they die many years later. Because they never re-mate, the reproductive success of queens is ultimately sperm-limited, but it is not known...... what selective forces determine the upper limit to sperm storage. Here we show that sperm storage carries a significant cost of reduced immunity during colony founding. Newly mated queens of the leaf-cutting ant Atta colombica upregulate their immune response shortly after completing their nest burrow......, probably as an adaptive response to a greater exposure to pathogens in the absence of grooming workers. However, the immune response nine days after colony founding is negatively correlated with the amount of sperm in the sperm storage organ, indicating that short-term survival is traded off against long...

  1. Mutualistic fungi control crop diversity in fungus-growing ants.

    Poulsen, Michael; Boomsma, Jacobus J

    2005-02-01

    Leaf-cutting ants rear clonal fungi for food and transmit the fungi from mother to daughter colonies so that symbiont mixing and conflict, which result from competition between genetically different clones, are avoided. Here we show that despite millions of years of predominantly vertical transmission, the domesticated fungi actively reject mycelial fragments from neighboring colonies, and that the strength of these reactions are in proportion to the overall genetic difference between these symbionts. Fungal incompatibility compounds remain intact during ant digestion, so that fecal droplets, which are used for manuring newly grown fungus, elicit similar hostile reactions when applied to symbionts from other colonies. Symbiont control over new mycelial growth by manurial imprinting prevents the rearing of multiple crops in fungus gardens belonging to the same colony. PMID:15692054

  2. Mutualistic fungi control crop diversity in fungus-growing ants

    Poulsen, Michael; Boomsma, Jacobus J

    2005-01-01

    Leaf-cutting ants rear clonal fungi for food and transmit the fungi from mother to daughter colonies so that symbiont mixing and conflict, which result from competition between genetically different clones, are avoided. Here we show that despite millions of years of predominantly vertical...... transmission, the domesticated fungi actively reject mycelial fragments from neighboring colonies, and that the strength of these reactions are in proportion to the overall genetic difference between these symbionts. Fungal incompatibility compounds remain intact during ant digestion, so that fecal droplets......, which are used for manuring newly grown fungus, elicit similar hostile reactions when applied to symbionts from other colonies. Symbiont control over new mycelial growth by manurial imprinting prevents the rearing of multiple crops in fungus gardens belonging to the same colony....

  3. Patterns of diversity and abundance of fungus-growing ants (Formicidae: Attini) in areas of the Brazilian Cerrado Padrões de diversidade e abundância de formigas cultivadoras de fungo (Formicidade: Attini) em áreas do Cerrado Brasileiro

    Heraldo L. Vasconcelos; Bruna B. Araújo; Antonio J. Mayhé-Nunes

    2008-01-01

    Fungus-growing ants (tribe Attini) are characteristic elements of the New World fauna. However, there is little information on the patterns of diversity, abundance, and distribution of attine species in their native ecosystems, especially for the so-called "lower" genera of the tribe. A survey of attine ant nests (excluding Atta Fabricus, 1804 and Acromyrmex Mayr, 1865) was conducted in a variety of savanna and forest habitats of the Cerrado biome near Uberlândia, Brazil. In total, 314 nests ...

  4. Identifying the transition between single and multiple mating of queens in fungus-growing ants

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R;

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...... is known to include evolutionarily derived genera with obligate multiple mating (the Acromyrmex and Atta leafcutter ants) as well as phylogenetically basal genera with exclusively single mating (e.g. Apterostigma, Cyphomyrmex, Myrmicocrypta). All attine genera share the unique characteristic of...... obligate dependence on symbiotic fungus gardens for food, but the sophistication of this symbiosis differs considerably across genera. The lower attine genera generally have small, short-lived colonies and relatively non-specialized fungal symbionts (capable of living independently of their ant hosts...

  5. Comparative ultrastructure of ant spermatozoa (Formicidae: Hymenoptera).

    Wheeler, D E; Crichton, E G; Krutzsch, P H

    1990-12-01

    Mature spermatozoa from spermathecae of founding queens were obtained from 5 species of ants, representing the major subfamilies Myrmicinae (Acromyrmex versicolor, Crematogaster sp.) and Dolichoderinae (Tapinoma sessile, Conomyrma insana, Conomyrma wheeleri). The ultrastructure of ant spermatozoa has many features in common with that of higher insects and is similar to that of other Hymenoptera. Structural similarities to spermatozoa of other Hymenoptera include an acrosome containing an internal rod that extends into the nucleus, two elongate mitochondrial derivatives, a centriolar adjunct, and an axonemal arrangement of 9 + 9 + 2 that includes well-developed coarse, or accessory, tubules. Spermatozoa obtained from A. versicolor, a species that is known to store and utilize viable sperm from this supply for over 10 years, show greater development of the mitochondrial derivatives than do the other species. The most distinctive feature of ant spermatozoa in comparison to other Hymenoptera is the large size of the centriolar adjunct relative to the other organelles. The centriolar adjunct is located posterior to the nucleus, anterior to the mitochondrial derivatives, and opposite the axoneme. PMID:2280410

  6. Densidade e tamanho de formigueiros de Acromyrmex crassispinus em plantios de Pinus taeda Density and size of Acromyrmex crassispinus nests in Pinus taeda plantations

    Mariane Aparecida Nickele

    2009-04-01

    Full Text Available O objetivo deste trabalho foi avaliar a densidade e o tamanho dos formigueiros de Acromyrmex crassispinus, ao longo do ano, em plantios de Pinus taeda de diferentes idades. Os experimentos foram realizados, em Rio Negrinho e em Três Barras, SC, em talhões de P. taeda com diferentes idades (recém-plantado, três anos e seis anos de idade. Em cada tratamento, foram demarcadas três parcelas de 1 ha. Os formigueiros foram classificados em três classes de tamanho: classe I, até 30 cm de diâmetro; classe II, 31 a 60 cm; e classe III, mais que 61 cm. A densidade de formigueiros de A. crassispinus foi menor no início do desenvolvimento da floresta, praticamente duplicou nos plantios com três anos, e reduziu quando a floresta estava com seis anos. A maior densidade de formigueiros ocorreu no período de dezembro a abril. Os formigueiros aumentaram de tamanho com a idade do pínus.The objective of this work was to evaluate the density and size of Acromyrmex crassispinus nests in Pinus taeda plantations along the year. The experiments were carried out in Rio Negrinho and Três Barras, SC, Brazil, in P. taeda plantations of different ages (recently planted and three and six years old. Three plots of one hectare were delimited in each treatment. The nests were classified according to three size classes: class I, up to 30 cm diameter; class II, 31 up to 60 cm; class III, above 61 cm. The density of A. crassispinus nests was low in recently planted areas, nearly twofold in three year-old plantations, and it reduced when the forest was six years old. The greatest nest density occurred in the period from December to April. The nests size increased along with the age of the P. taeda plantations.

  7. Soil ants and bromeliad-nesting ants in an Atlantic Forest area, Santa Catarina Island, southern Brazil: Species inventory and new records

    Josefina Steiner

    2008-12-01

    Full Text Available The myrmecofauna in an Atlantic Forest area was studied using various methods for soil ants and bromeliad-nesting ants. Monthly collections were performed between March 2002 and August 2004, using a Winkler extractor, pitfall traps and bromeliad individuals. One hundred and twenty-four species from nine subfamilies and 33 genera were found. The richest genera were Pheidole, Solenopsis, Crematogaster, Acromyrmex and Camponotus. More species were found in soil than in bromeliads, with 8% occurring in both habitats. Twelve species are new records for Santa Catarina State and 19 are new for the greater Florianópolis region. These results correlate with the use of new methodologies for the region, showing that the ant fauna of Santa Catarina Island still needs to be better studied.

  8. Comparative Study of Nest Architecture and Colony Structure of the Fungus-Growing Ants, Mycocepurus goeldii and M. smithii

    Rabeling, C.; Verhaagh, M.; Engels, W

    2007-01-01

    Nest architecture and demography of the non leaf-cutting fungus-growing ant species Mycocepurus goeldii and M. smithii (Attini: Formicidae) were studied in an agroforest habitat near Manaus, Brazil during the excavation of 13 nests. Both species built their nests in two different ways. The first type possessed a “tree-like” architecture, in which a vertical tunnel led downwards and lateral tunnels branched off at 90° angles from the main tunnel, with a chamber at the end of each side branch. ...

  9. [Ants (Hymenoptera: Formicidae) as vectors for bacteria in two hospitals in the municipality of Divinópolis, State of Minas Gerais].

    Santos, Paula Fernandes dos; Fonseca, Alysson Rodrigo; Sanches, Newton Moreno

    2009-01-01

    The presence of ants (Hymenoptera: Formicidae) in hospital environments may constitute a public health problem, especially since they are mechanical vectors for pathogenic organisms. This study aimed to survey the ant populations and analyze the presence of bacteria associated with them in two medium-sized regional hospitals in the municipality of Divinópolis, Minas Gerais, Brazil. Specimens were collected every monthly over a six-month period. The following ant species were found: Pheidole sp1 and sp2, Linepithema humile, Wasmannia auropunctata, Camponotus sp1 and sp2, Odontomachus sp, Solenopsis sp, Acromyrmex sp and Tapinoma melenocephalum. It was observed that these ants mechanically transported Pseudomonas aeruginosa, Enterococcus, Streptococcus, Escherichia coli and non-pathogenic and pathogenic Staphylococcus. These results show the propensity for occurrences of hospital infections at these sites caused by mechanical transmission of pathogens by ants. PMID:19967241

  10. Field evaluation of potential of alarm pheromone compounds to enhance baits for control of grass-cutting ants (Hymenoptera: Formicidae).

    Hughes, William O H; Howse, Philip E; Vilela, Evaldo F; Knapp, Jenny J; Goulson, Dave

    2002-06-01

    Leaf-cutting ants are important economic pests of the Neotropics, and the most common method of control involves the use of insecticidal baits. Baits that are currently available exhibit low attractiveness to grass-cutting species, thus there is a need to develop improved baits. The potential for using alarm pheromone compounds to enhance the attractiveness and subsequent harvest of baits was examined for two economically important species of grass-cutting ant, Atta bisphaerica (Forel) and Atta capiguara (Goncalves). Compounds of the alarm pheromone were applied to rubber septa that were then sealed inside plastic sachets together with citrus pulp-based bait. The best candidate compound for bait enhancement was 4-methyl-3-heptanone. This compound significantly increased the attractiveness of bait sachets to both species. It also appeared to improve the discovery of nearby unenhanced sachets. However, 4-methyl-3-heptanone resulted in only a slight and non-significant improvement in bait harvest. Enhanced and unenhanced bait sachets were applied at a number of positions to obtain an improvement in harvest, but without success. The possible reasons for the lack of an enhancement of harvest and the potential for using alarm pheromone compounds as leaf-cutting ant bait enhancers are discussed. PMID:12075997

  11. Occurrence of polygyny in Acromyrmex subterraneus molestans Santschi 1925 (Hymenoptera: Formicidae

    Souza Danival José de

    2004-01-01

    Full Text Available Polygyny denotes the coexistence of two or more mated and fertile queens in the colony. A colony of Acromyrmex subterraneus molestans Santschi containing 14 queens was collected on campus of the Universidade Federal de Viçosa, Brazil, aiming to verify if they were all egg-layers and fertile . The volume of the fungus garden in the nest was about 500 ml with a large number of larvae and pupae. Observation of the ovarian development and spermathecae indicates that 13 queens had copulated and ovary did not show morphological differences among them. This could indicate that polygyny is not accidental and may represent an adaptative strategy to optimize the development of the initial colony in A. subterraneus molestans.

  12. Workers of Acromyrmex echinatior leafcutter ants police worker-laid eggs, but not reproductive workers

    Dijkstra, Michiel B.; van Zweden, Jelle Stijn; Dirchsen, Maria;

    2010-01-01

    Nonreproductive workers of many eusocial Hymenoptera 'police' the colony, that is, they attack reproductive sister workers or destroy their eggs (unfertilized; developing into haploid males). Several ultimate causes of policing have been proposed, including (1) an increase in colony productivity,...... reproductive workers. We infer that relatedness incentives are the most likely ultimate cause of the evolutionary maintenance of worker-egg policing in A. echinatior. (C) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved...

  13. A comparative study of exocrine gland chemistry in Trachymyrmex and Sericomyrmex fungus-growing ants

    Adams, Rachelle Martha Marie; Jones, Tappey H.; Jeter, Andrew W.;

    2012-01-01

    -cutting ants possess many derived characteristics such as extensive leaf-cutting behavior and massive colony sizes, effectively making them major herbivores in many Neotropical habitats. This is the first comparison of the chemistry of eight Trachymyrmex and one Sericomyrmex species in a phylogenetic context....... Most of the compounds found in the Trachymyrmex species examined were terpenes. In one species, the major component was a,a-acariolide, the first example of this compound, which was only previously reported in mites, from an insect. Additionally, 3-octanol, 3-octanone, and 4-methyl-3-heptanone were...

  14. Ants can learn to forage on one-way trails.

    Pedro Leite Ribeiro

    Full Text Available The trails formed by many ant species between nest and food source are two-way roads on which outgoing and returning workers meet and touch each other all along. The way to get back home, after grasping a food load, is to take the same route on which they have arrived from the nest. In many species such trails are chemically marked by pheromones providing orientation cues for the ants to find their way. Other species rely on their vision and use landmarks as cues. We have developed a method to stop foraging ants from shuttling on two-way trails. The only way to forage is to take two separate roads, as they cannot go back on their steps after arriving at the food or at the nest. The condition qualifies as a problem because all their orientation cues -- chemical, visual or any other -- are disrupted, as all of them cannot but lead the ants back to the route on which they arrived. We have found that workers of the leaf-cutting ant Atta sexdens rubropilosa can solve the problem. They could not only find the alternative way, but also used the unidirectional traffic system to forage effectively. We suggest that their ability is an evolutionary consequence of the need to deal with environmental irregularities that cannot be negotiated by means of excessively stereotyped behavior, and that it is but an example of a widespread phenomenon. We also suggest that our method can be adapted to other species, invertebrate and vertebrate, in the study of orientation, memory, perception, learning and communication.

  15. Beyond ANT

    Jansen, Till

    2016-01-01

    Actor-Network-Theory (ANT) offers an ‘infra-language’ of the social that allows one to trace social relations very dynamically, while at the same time dissolving human agency, thus providing a flat and de-centred way into sociology. However, ANT struggles with its theoretical design that may lead...... us to reduce agency to causation and to conceptualize actor-networks as homogeneous ontologies of force. This article proposes to regard ANT’s inability to conceptualize reflexivity and the interrelatedness of different ontologies as the fundamental problem of the theory. Drawing on Günther, it...... offers an ‘infra-language’ of reflexive relations while maintaining ANT’s de-centred approach. This would enable us to conceptualize actor-networks as non-homogeneous, dynamic and connecting different societal rationales while maintaining the main strengths of ANT....

  16. ALTERNATIVAS DE FORMICIDAS EM PÓ NO CONTROLE DA FORMIGA-VERMELHA-DE-MONTE, Acromyrmex heyeri

    Fábio Moreira Link

    2000-11-01

    Full Text Available Com o objetivo de criar alternativas no controle químico da formiga-vermelha-de-monte, Acromyrmex heyeri (Forel, 1899 (Hymenoptera: Formicidae, Attini foram instalados quatro ensaios com formicidas em pó, em Santa Maria, estado do Rio Grande do Sul, entre 1996 e 1998. Avaliaram-se em formigueiros médios (+/- 45cm de diâmetro ou em formigueiros grandes (diâmetro superior a 60cm, doses de Deltametrina (2g i.a./kg, de Acefato (750g i.a./kg, de Clorpirifós (20g i.a./kg e 50g i.a./kg, de Fentiom (50g i.a./kg e de Diazinom (10g i.a./kg. Deltametrina e Acefato, partindo-se de 5g/ninho e, Clorpirifós (50g i.a./kg e Fentiom, partindo-se de 10g/ninho, foram eficazes no controle de formigueiros médios. Clorpirifós (50 g i.a./kg e Diazinom, com base em 10g/ninho e, Clorpirifós (20g i.a./kg, partindo-se de 30g/ninho controlaram eficientemente os formigueiros grandes dessa espécie.

  17. EFEITO DE DIFERENTES DOSES DO FORMICIDA “CITROMAX” NO CONTROLE DE Acromyrmex lundi (HYMENOPTERA: FORMICIDAE

    Edison Rogério Perrando

    2005-08-01

    Full Text Available Neste trabalho, objetivou-se avaliar o efeito do formicida Citromax a base de timbó (Ateleia glazioviana em diferentes doses no controle de Acromyrmex lundi, em campo nativo, no município de São Sepé, estado do Rio Grande do Sul. Foram analisados quatro tratamentos, constituídos por doses de 5g, 10g e 15g de “Citromax” e 10g de “Mirex-S” (sulfluramida 0,3% por formigueiro. O delineamento experimental foi inteiramente casualizado com dez repetições, considerando cada formigueiro uma repetição. A eficiência foi avaliada no 1º, 5º, 10º, 15º e 20º dia após a aplicação dos tratamentos. Os resultados obtidos permitiram concluir que “Citromax” apresenta ação de choque, pois houve alto percentual de controle nos primeiros cinco dias. O controle de A. lundi mediante a utilização do formicida “Citromax”, foi eficiente em todas as doses avaliadas, obtendo-se um percentual de controle superior a 85%. Não houve influência do tamanho do formigueiro em relação ao percentual de controle.

  18. Laccase gene expression as a possible key adaptation for herbivorous niche expansion in the attine fungus-growing ants

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    of mostly fresh but shed plant material to actively cutting leaves. However, the way in which these ants managed to overcome the chemical defences of leaves has remained poorly understood. Here we document that fungal laccases may have played an important role in allowing the leaf-cutting ants to...... become generalist functional herbivores. Laccases are polyphenol oxidase enzymes (PPOs) that are best known for their ability to degrade lignin in saprophytic and wood-pathogenic fungi. We found that laccase activity was primarily expressed in newly constructed garden sections where secondary leaf...... compounds are most likely to hinder decomposition. A combination of genomic and transcriptional analyses showed that there are at least eight copies of putative laccase coding genes in a draft genome of the fungal symbiont Leucocoprinus gongylophorus, but only a single copy of these multiple laccase genes...

  19. Male adaptations and female sperm use in organismal societies of ants and bees

    Stürup, Marlene

    strong selection to produce high quality ejaculates. In multiply mated queens, ejaculates from different males arrive as discrete units, but genetic diversity among workers has been documented to provide several colony benefits and this diversity can only be maximized if sperm becomes completely mixed......’s sperm stores and compared this with paternity shares in offspring. I also examined whether patriline distributions in worker cohorts remain stable over time, which is expected to yield the highest colony benefits in terms of worker genetic variation. Selection for extreme sperm viability in males is...... likely costly and expected to trade off with investments into other traits. I tested this by measuring sperm viability in honeybee males after exposure to mild external stress factors. Additionally, I infected leaf-cutting ant males with a pathogenic fungus and measured their subsequent immune response...

  20. The Ants Have It!

    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. Does Diatomaceous Earth Control Leaf-Cutter Ants (Hymenoptera: Formicidae) in the Eucalyptus Plantations?

    Ferreira-Filho, Pedro J; Wilcken, Carlos F; Neves, Daniela A; Pogetto, Mario H F A D; Carmo, Janaina B; Guerreiro, Julio C; Serrão, José E; Zanuncio, José C

    2015-06-01

    Genus Atta includes some of the most important Formicidae leaf cutter ants which cause extensive damage to the eucalyptus plantations. Atta sexdens rubropilosa Forel, one of the chief pests in Brazilian reforestation, can restrict and reduce forest productivity by its intense and constant leaf-cutting activities on plants at all stages. Therefore, the demand for new products to control A. sexdens rubropilosa indicates the study of the utilization of the dry powder formulation of diatomaceous earth (DE) against this pest in the eucalyptus cultivars. The study was conducted using 120 colonies of A. sexdens rubropilosa in Eucalyptus grandis Hill ex. Maiden x Eucalyptus urophylla Blake (Myrtaceae) (urograndis) stand. The randomized block experimental design was used with six treatments (1, 10, 25, and 50 g/m2 of DE, 6.0 g/m2 sulfluramid bait per square meter of loose soil, and the control) with five replications, each with four colonies of this ant. Diatomaceous earth was applied to the active A. sexdens rubropilosa ant holes, and the sulfluramid bait was applied in bulk in a localized manner. The control efficacy of A. sexdens rubropilosa with DE was low, showing values similar to that of the control, and, for this reason, it cannot be used to control this ant. The bait with sulfluramid showed higher efficacy than those of the other treatments. PMID:26470237

  2. Fungos Filamentosos Associados às Espécies Atta sexdens (Linnaeus e Atta laevigata (F. Smith (Hymenoptera: Formicidae

    Aline Dornelas

    2016-04-01

    Abstract. Leaf-cutting ants, Atta and Acromyrmex genera, are considered major pests in a neotropical agroforestry system because they cut plant material that will serve as food for the symbiotic fungus cultivated by them. Several fungi naturally occurring in the soil can be found associated with leaf-cutting ants, many of them are demonstrably entomopathogenic. However, these agents have not been used as biological control of leaf-cutting ants. The aim of this study was to isolate and to identify filamentous fungi associated with forage workers of Atta sexdens (Linnaeus and Atta laevigata (F. Smith and to test their pathogenicity against workers from laboratory colonies. To isolate filamentous fungi, it was collected a total of 180 forage workers (30 in each colony in six field colonies, 90 of A. sexdens and 90 workers of A. laevigata. Six fungi species from A. sexdens were isolated and identified: Metarhizium anisopliae (Metchnikoff Sorokin, Aspergillus flavus Link, Acremonium sp. 1, Aspergillus sp. 1, Colletotrichum sp. and Acremonium sp. 2. In A. laevigata, it was found four species: Mucor sp., Aspergillus flavus, Fusarium solani (Martius Saccardo, Aspergillus niger van Tieghem. Three of these fungi were selected for pathogenicity tests against workers of the leaf-cutting ant A. sexdens: A. flavus, A. niger and M. anisopliae. The LT50 (time to cause 50% mortality of workers in tests with A. niger and M. anisopliae were five days and significantly lower than the control group. Therefore, further tests should proceed with those isolates to demonstrate their potential use in the biological control of leaf-cutting ants.

  3. EFFECTS OF DIFFERENT DOSES OF THE FORMICIDE “CITROMAX” ON THE CONTROL OF Acromyrmex lundi (HYMENOPTERA: FORMICIDAE

    Edison Bisognin Cantarelli

    2010-08-01

    Full Text Available The objective of this study was the analysis of the effect of the formicide “Citromax”, formulated with Ateleia glazioviana, in different doses on the control of Acromyrmex lundi, in native field in São Sepé county,  Rio Grande do Sul, Brazil. Four treatments were analyzed, constituted of doses of 5, 10 and 15g of “Citromax” and 10g of “Mirex-S” (sulphluramide 0,3% in each nest. The statistical design was completely randomized with 10 repetitions, considering each nest as one repetition. The effectiveness was evaluated in the 1st, 5th, 10th, 15th and 20th day after treatment application. The obtained results allow to conclude that “Citromax” shows an impact action, because there was a high percentage of control in the first five days. The Acromyrmex lundi control due to “Citromax” formicide was efficient in all the evaluated doses, obtaining a control percentage up to 85%. The influence of net size was not observed in relation to the percentage control.

  4. Screening of Leaf Cutting Flower Varieties Interplanted With Areca Catechu in Hainan Province%海南槟榔林下套种切叶花卉品种筛选

    任军方; 张浪; 姜殿强; 李海文; 云勇

    2015-01-01

    After respectively interplanting Asplenium nidus ,Chrysalidocarpuslutescens and Philodenron selloum Koch in the undergrow th of Areca catechu ,the research conducts a study on the grow th process at different matrixes and canopy densities .The results show that the best effect comes from the mixed matrix of coconut residuum ,farmyard manure and undergrow th original soil .When canopy density is 70% ,the grow th of leaf cutting flowers is the best .While the growing status of Asplenium nidus and Chrysalidocarpuslutes‐cens in undergrowth of Areca catechu is fine and the two can be selected as the preferred varieties .%在槟榔林下分别套种鸟巢蕨、散尾葵、春羽,对不同基质,不同郁闭度,进行了生长过程研究,结果表明:椰糠、农家肥和槟榔林下原土混合基质,效果最好;70%郁闭度时,切叶花卉生长最好;而鸟巢蕨和散尾葵在槟榔林下生长状态良好,为优选品种。

  5. Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

    Aylward, Frank O. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burnum-Johnson, Kristin E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tringe, Susannah G. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Teiling, Clotilde [Roche Diagnostics, Indianapolis, IN (United States); Tremmel, Daniel [Univ. of Wisconsin, Madison, WI (United States); Moeller, Joseph [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scott, Jarrod J. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barry, Kerrie W. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Piehowski, Paul D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nicora, Carrie D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Malfatti, Stephanie [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Monroe, Matthew E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Purvine, Samuel O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Goodwin, Lynne A. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Smith, Richard D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weinstock, George [Washington Univ. School of Medicine, St. Louis, MS (United States); Gerardo, Nicole [Emory Univ., Atlanta, GA (United States); Suen, Garret [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Lipton, Mary S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Currie, Cameron R. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smothsonian Tropical Research Inst., Balboa (Panama)

    2013-06-12

    Plants represent a large reservoir of organic carbon comprised largely of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate fungus gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous symbiont that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and using genomic, metaproteomic, and phylogenetic tools we investigate its role in lignocellulose degradation in the fungus gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in fungus gardens, and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that may be playing an important but previously uncharacterized role in lignocellulose degradation. Our study provides a comprehensive analysis of plant biomass degradation in leaf-cutter ant fungus gardens and provides insight into the molecular dynamics underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.

  6. Fire Ant Bites

    ... Favorite Name: Category: Share: Yes No, Keep Private Fire Ant Bites Share | Fire ants are aggressive, venomous insects that have pinching ... across the United States, even into Puerto Rico. Fire ant stings usually occur on the feet or ...

  7. Are workers of Atta leafcutter ants capable of reproduction?

    Dijkstra, Michiel Bendert; Boomsma, Jacobus Jan

    2006-01-01

    ovaries. Workers of Atta leafcutter ants only lay trophic eggs in queenright colonies. Although Atta colonies are commonly kept at universities, museums, and zoos, no reports of worker sons in orphaned colonies exist, suggesting that Atta workers are infertile. To explicitly test this, we created eleven...... orphaned laboratory nests of Atta cephalotes, A. sexdens, and A. colombica, and maintained them for 3-6 months after queen loss. Eight colonies did not produce any brood, but three nests produced 1-4 worker-derived male larvae and pupae. Microsatellite genotyping indicated that these were worker sons...... fertility is low compared to the sister genus Acromyrmex, where workers routinely produce normally-size males after queen loss in the laboratory. We hypothesize that worker reproduction in orphaned Atta field colonies is almost never successful because the last workers die before their sons can be raised to...

  8. Influências de Atta spp. (Hymenoptera: Formicidae na recuperação da vegetação pós-fogo em floresta de transição amazônica Influences of leafcutter ant Atta spp. (Hymenoptera: Formicidae on vegetation recovery after fire in Amazonian transitional forest

    Karine Santana Carvalho

    2012-03-01

    Full Text Available Este estudo investigou o papel das saúvas na recuperação da vegetação pós-fogo. Foi hipotetizado que a perturbação do fogo aumenta a abundância de ninhos de saúva (1 e as atividades de remoção de sementes (2 e desfolha (3, especialmente no ambiente de borda. Os ninhos de saúva foram inventariados e mapeados e após 17 meses, checados para o registro de sua atividade e de novas colônias emergindo na área. Realizou-se experimentos comparativos de remoção de sementes e desfolha de plântulas em duas parcelas de 50 ha, uma submetida a fogo anual (tratamento e outra sem fogo (controle. A abundância de ninhos de saúva foi maior na parcela tratamento que na parcela controle, especialmente na borda da floresta. As espécies encontradas foram: Atta cephalotes, A. laevigata e A. sexdens , sendo esta última a espécie mais abundante e que mostrou aumento em número de colônias ativas após 17 meses. O aumento na abundância de ninhos na parcela tratamento foi acompanhado por um aumento na atividade dessas formigas. Enquanto mais de duas folhas foram arrancadas por plântula nessa parcela, menos de uma foi registrada na parcela controle. Também a abundância média de galhos desfolhados e de sementes removidas por saúvas foi maior na parcela tratamento que na parcela controle. As saúvas tanto podem diminuir ou retardar o processo de regeneração florestal pós-fogo, quanto acelerá-lo, devido à elevada predação seletiva que favorece as espécies menos palatáveis. Desta forma, suas atividades podem modificador apenas a composição da vegetação recuperando-se do fogo.In this study we investigated the role of leaf-cutting ants in the post-fire vegetation recovery. We hypothesized that a forest plot submitted to annual fire presents: (1 higher abundance of leaf-cutting ant nests; (2 higher removal of seeds; and (3 higher herbivory rates of leaf-cutting ants, when compared to the forest plots without fire (control. The leaf-cutting

  9. MECHANIZED SYSTEMATIC APPLICATION OF GRANULETED ANTS BAITS IN EUCALYPTUS PLANTATIONS IN MAINTENANCE PHASE

    Marcelo de Almeida Reis

    2015-09-01

    Full Text Available Compared to manual control, systematic control WITH ant bait requires less labor, results in lower exposure of workers and increases operating YIELD. This study aimed to evaluate the mortality of leaf-cutting ants nests with a mechanized systematic application of ant bait in three spacings on eucalyptus plantations in maintenance phase, the operational capability of mechanized application and the quality of the distribution of bait throughout the area. The experiment was conducted in the city of Paropeba, Minas Gerais, Brazil, in stands of eucalyptus plantations in maintenance phase. A sulfluramid (0.3% based bait was systematically applied at 1 kg.ha-1 every 6 x 2.5 9 x 2.5 and 12 x 2.5 meters, with an application equipment attached to the hydraulic system of a tractor, comprising three treatments with five repetitions. Nests with a size of up to one square meter of land area were selected and marked and evaluated their inactivity at 60 and 210 days after bait application. The percentage of bait loading, the operational capability of the mechanized process and the quality of the distribution process of the bait were also evaluated, using control charts. It was found that the different spacings applied did not influence the effectiveness of control. The largest spacing used provided greater operational capacity (8.42 ha.h-1. The mechanized systematic application provided good distribution as to the process’ statistical control, being a viable alternative to manual application.

  10. [Composition, abundance and infestation rate of ant species in a children's hospital in the city of Palmas, Tocantins, Brazil].

    Bragança, Marcos A L; Lima, Jefferson D

    2010-01-01

    This first survey of the ant fauna in a children's hospital in the city of Palmas, state of Tocantins, compares species composition, abundance and infestation rate of ants between rainy and dry seasons, day and night periods, and among 15 hospital sectors. Forty-eight collections, being 12 diurnal and 12 nocturnal in each season using five attractive baits distributed per sector, maintained for 3h per sampling. A total of 34,309 ants were collected, distributed in 12 species: Acromyrmex sp., Brachymyrmex sp., Camponotus spp. (four morphospecies), Dorymyrmex sp., Tetramorium sp., Solenopsis globularia (Creighton), Solenopsis saevissima Smith, Tapinoma melanocephalum (Fabricius) and Paratrechina longicornis (Latreille). The hospital presented an average building infestation rate (40.3%), when compared with hospitals from other Brazilian regions. In general, there was no difference in the species composition between seasons and the period of the day, although abundance of ants was higher at night. The dry season and the nocturnal period showed the highest infestation rate, mainly by T.melanocephalum and S.globularia. Gynecologic ward, lactation unit, preconception and pediatric ward access ramp showed higher infestation rate, although these varied between seasons. The significant infestation levels by the three species above, especially in sectors with restricted access such as lactation unit, laboratory, Intensive Care Unit e surgery center, indicate potential risks for contamination of patients by multi resistant pathogens possibly present in ants' bodies, as verified in others studies. PMID:20305908

  11. Ant colony for TSP

    Feng, Yinda

    2010-01-01

    The aim of this work is to investigate Ant Colony Algorithm for the traveling salesman problem (TSP). Ants of the artificial colony are able to generate successively shorter feasible tours by using information accumulated in the form of a pheromone trail deposited on the edges of the TSP graph. This paper is based on the ideas of ant colony algorithm and analysis the main parameters of the ant colony algorithm. Experimental results for solving TSP problems with ant colony algorithm show great...

  12. Velvet Ants: Hymenoptera: Mutillidae

    Dellinger, Theresa A.; Day, Eric R.

    2012-01-01

    Describes Velvet Ants, their life cycle, habitats, and discusses control if necessary, although they are generally not regarded as pests. Caution is noted in handling velvet ants, since their stings are very painful.

  13. ACO - Ant Colony Optimization

    Žumer, Viljem; Brest, Janez; Pešl, Ivan

    2015-01-01

    Ant colony optimization is a relatively new approach to solving NP-Hard problems. It is based on the behavior of real ants, which always find the shortest path between their nest and a food source. Such behavior can be transferred into the discrcte world, were real ants are replaced by simple agents. Such simple agents are placed into the environment where different combinatorial problems can be solved In this paper we describe an artificial ant colony capable of solving the travelling salesm...

  14. Cassava leaf methanolic extract as an alternative to control of fall armyworm and leaf cutter ants

    Mírian Aparecida Isidro Santos

    2013-12-01

    Full Text Available The objective of this study was to characterize phenolic compounds and evaluate the effect, under laboratory conditions, of the cassava leaf powder methanol extract on the development of fall armyworm Spodoptera frugiperda and of leaf-cutting ant Atta sexdens rubropilosa. The extract was incorporated into an artificial diet, to which the armyworm was exposed, at concentrations of 250, 500, 1,000 and 1,500 mg kg-1, in order to evaluate biological characteristics. Soon after the insects emergence, another experiment was conducted to verify the possible sub lethal activity of the extract; therefore, S. frugiperda couples were isolated in cages and eggs were collected and counted. The Manihot esculenta Crantz extract caused a reduction in the percentage of armyworm survival, as well as in the eggs number. Then, the same extract was solubilized in 10% ethanol and applied to ants; mortality was observed, compared to the control. It is possible to conclude that the M. esculenta Crantz leaf powder methanolic extract, containing gallic acid and catechin, is a promising alternative to control S. frugiperda and Atta sexdens rubropilosa.

  15. Ant- and Ant-Colony-Inspired ALife Visual Art.

    Greenfield, Gary; Machado, Penousal

    2015-01-01

    Ant- and ant-colony-inspired ALife art is characterized by the artistic exploration of the emerging collective behavior of computational agents, developed using ants as a metaphor. We present a chronology that documents the emergence and history of such visual art, contextualize ant- and ant-colony-inspired art within generative art practices, and consider how it relates to other ALife art. We survey many of the algorithms that artists have used in this genre, address some of their aims, and explore the relationships between ant- and ant-colony-inspired art and research on ant and ant colony behavior. PMID:26280070

  16. Ant Colony Optimization

    Zahálka, Jaroslav

    2007-01-01

    This diploma thesis deals with Ant Colony algorithms and their usage for solving Travelling Salesman Problems and Vehicle Routing Problems. These algorithms are metaheuristics offering new approach to solving NP-hard problems. Work begins with a description of the forementioned tasks including ways to tackle them. Next chapter analyses Ant Colony metaheuristic and its possible usage and variations. The most important part of the thesis is practical and is represented by application Ant Colony...

  17. Specificity in chemical profiles of workers, brood and mutualistic fungi in Atta, Acromyrmex, and Sericomyrmex fungus-growing ants

    Richard, Freddie-Jeanne; Poulsen, Michael; Drijfhout, Falko; Jones, Graeme; Boomsma, Jacobus Jan

    2007-01-01

    , acetates, acids, and esters. The chemical profiles in all three species are likely to be sufficiently different to allow discrimination at the species and colony level and sufficiently similar within colonies to generate a relatively constant colony-specific chemical gestalt. The relative likelihood of...

  18. Alternativas de formicidas em pó no controle da formiga-vermelha-de-monte, Acromyrmex heyeri.

    Fábio Moreira Link

    2009-10-01

    Full Text Available Normal 0 21 MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} Com o objetivo de criar alternativas no controle químico da formiga-vermelha-de-monte, Acromyrmex heyeri (Forel, 1899 (Hymenoptera: Formicidae, Attini  foram instalados quatro ensaios com formicidas em pó, em Santa Maria, estado do Rio Grande do Sul, entre 1996 e 1998. Avaliaram-se em formigueiros médios (+/- 45cm de diâmetro ou em formigueiros grandes (diâmetro superior a 60cm, doses de Deltametrina (2g i.a./kg, de Acefato (750g i.a./kg, de Clorpirifós (20g i.a./kg e 50g i.a./kg, de Fentiom (50g i.a./kg e de Diazinom (10g i.a./kg. Deltametrina e Acefato, partindo-se de 5g/ninho e, Clorpirifós (50g i.a./kg e Fentiom, partindo-se de 10g/ninho, foram eficazes no controle de formigueiros médios. Clorpirifós (50 g i.a./kg e Diazinom, com base em 10g/ninho e, Clorpirifós (20g i.a./kg, partindo-se de 30g/ninho controlaram eficientemente os formigueiros grandes dessa espécie.

  19. Ant Ballet: Phase I

    Ollie Palmer

    2014-01-01

    The Ant Ballet project aims to create a precisely choreographed movement from a colony of ants through the use of artificial pheromones. This article presents an annotated storyboard of the film that documents the first set of experiments within the project. The full film can be viewed online at href="http://www.antballet.org"www.antballet.org.

  20. Formigas (Hymenoptera: Formicidae como vetores de bactérias em dois hospitais do município de Divinópolis, Estado de Minas Gerais Ants (Hymenoptera: Formicidae as vectors for bacteria in two hospitals in the municipality of Divinópolis, State of Minas Gerais

    Paula Fernandes dos Santos

    2009-10-01

    Full Text Available A presença de formigas (Hymenoptera: Formicidae em ambientes hospitalares pode constituir um problema de saúde pública, especialmente por serem vetores mecânicos de organismos patogênicos. O trabalho teve como objetivo realizar o levantamento de formigas e analisar a presença de bactérias a elas associadas em dois hospitais regionais de médio porte da cidade de Divinópolis, MG. As coletas foram realizadas mensalmente, durante um período de seis meses. Foram coletadas formigas Pheidole sp1 e sp2, Linepithema humile, Wasmannia auropunctata, Camponotus sp1 e sp2, Odontomachus sp, Solenopsis sp, Acromyrmex sp e Tapinoma melenocephalum. Observou-se que estas transportavam mecanicamente Pseudomonas aeruginosa, Enterococcus, Streptococcus, Staphylococcus patogênico e não patogênico e Escherichia coli. Tais resultados evidenciam a propensão à ocorrência de infecções hospitalares nesses locais pela transmissão mecânica de agentes patogênicos por formigas.The presence of ants (Hymenoptera: Formicidae in hospital environments may constitute a public health problem, especially since they are mechanical vectors for pathogenic organisms. This study aimed to survey the ant populations and analyze the presence of bacteria associated with them in two medium-sized regional hospitals in the municipality of Divinópolis, Minas Gerais, Brazil. Specimens were collected every monthly over a six-month period. The following ant species were found: Pheidole sp1 and sp2, Linepithema humile, Wasmannia auropunctata, Camponotus sp1 and sp2, Odontomachus sp, Solenopsis sp, Acromyrmex sp and Tapinoma melenocephalum. It was observed that these ants mechanically transported Pseudomonas aeruginosa, Enterococcus, Streptococcus, Escherichia coli and non-pathogenic and pathogenic Staphylococcus. These results show the propensity for occurrences of hospital infections at these sites caused by mechanical transmission of pathogens by ants.

  1. Sick ants become unsociable

    Bos, Nicky Peter Maria; Lefevre, T.; Jensen, A.B.;

    2012-01-01

    Parasites represent a severe threat to social insects, which form high-density colonies of related individuals, and selection should favour host traits that reduce infection risk. Here, using a carpenter ant (Camponotus aethiops) and a generalist insect pathogenic fungus (Metarhizium brunneum), we...... show that infected ants radically change their behaviour over time to reduce the risk of colony infection. Infected individuals (i) performed less social interactions than their uninfected counterparts, (ii) did not interact with brood anymore and (iii) spent most of their time outside the nest from...... day 3 post-infection until death. Furthermore, infected ants displayed an increased aggressiveness towards non-nestmates. Finally, infected ants did not alter their cuticular chemical profile, suggesting that infected individuals do not signal their physiological status to nestmates. Our results...

  2. The Cocktail ant count

    A better understanding of Cocktail ant populations (Crematogaster) is engendered by the use of 32P labelling to measure the population density of the colonies, once the biology of the species is known

  3. Ant traffic rules.

    Fourcassié, Vincent; Dussutour, Audrey; Deneubourg, Jean-Louis

    2010-07-15

    Many animals take part in flow-like collective movements. In most species, however, the flow is unidirectional. Ants are one of the rare group of organisms in which flow-like movements are predominantly bidirectional. This adds to the difficulty of the task of maintaining a smooth, efficient movement. Yet, ants seem to fare well at this task. Do they really? And if so, how do such simple organisms succeed in maintaining a smooth traffic flow, when even humans experience trouble with this task? How does traffic in ants compare with that in human pedestrians or vehicles? The experimental study of ant traffic is only a few years old but it has already provided interesting insights into traffic organization and regulation in animals, showing in particular that an ant colony as a whole can be considered as a typical self-organized adaptive system. In this review we will show that the study of ant traffic can not only uncover basic principles of behavioral ecology and evolution in social insects but also provide new insights into the study of traffic systems in general. PMID:20581264

  4. It is not all pheromones: No evidence that pheromones affect digging face choice during ant nest excavation.

    Bruce, Andrew I

    2016-01-01

    Ants create nests of a size that is tailored to the number of individuals in a nest via a self-organized process. It is not yet clear how they accomplish this. Deposition and evaporation of pheromones at the digging face has been hypothesised by Deneubourg and Franks (1995) and Buhl et al. (2005) to be part of the nest construction process, with models being presented to support this contention. This hypothesis was tested by allowing groups of 5 Acromyrmex lundi workers to choose between two excavation sites, one that was freshly exposed to digging and one where digging had ceased an hour previously. It was expected that if pheromones played a role in stimulating digging, then ants would show a preference for digging in the "fresh" sites rather than the "aged" sites where the putative digging pheromone had decayed. No significant difference in digging activity between "fresh" and "aged" sites was detected. It is therefore likely that, while digging pheromones may play other roles in other parts of the digging system, they do not play an important role in regulation of soil excavation at the digging face. PMID:26529291

  5. Alate susceptibility in ants.

    Ho, Eddie K H; Frederickson, Megan E

    2014-11-01

    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

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

    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.

  7. Morpho-physiological Differences of the Spermatheca of Attini Ants (Hymenoptera: Myrmicinae

    Gabriela Ortiz

    2006-01-01

    Full Text Available The insect's spermatheca store the spermatozoa from the time of copulation until the fertilization of the eggs and consists of a sac, usually associated to glands. The ant species Atta laevigata, Atta sexdens sexdens, Atta sexdens piriventris, Acromyrmex coronatus and Cyphomyrmex muelleri are considered pests, as they cause economics losses to several crops. The spermatheca of these species were examined by scanning electron microscopy, histological and histochemical techniques. Their morphology resembled that of a bilobular pouch partially jointed in the central portion. In A. coronatus and C. muelleri it is flatter in shape than those of other species. The external spermathecal gland, groups of secretory cells, was located at the joining point of the two spermathecal lobes of the reservoir. This was observed in A. laevigata, A. s. sexdens and A. coronatus, like a group of cells, while in C. muelleri, like filaments. An external associated gland was not observed in A. s. piriventris, instead secretory cells were arranged in a simple prismatic epithelium internally lining the spermathecal lumen. This epithelium was also observed in A. s. sexdens, although it was restricted to the joining point of the spermathecal lobes. The presence of an internal secretory epithelium in A. s. piriventris and A. s. sexdens suggests that their physiology for the maintenance of spermatozoa in viable conditions for egg fertilization might differ from A. laevigata, A. coronatus and C. muelleri, in which only an external spermathecal gland was observed.

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

    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...

  9. Ant Colony Optimization for Control

    Van Ast, J.M.

    2010-01-01

    The very basis of this thesis is the collective behavior of ants in colonies. Ants are an excellent example of how rather simple behavior on a local level can lead to complex behavior on a global level that is beneficial for the individuals. The key in the self-organization of ants is communication

  10. ANT i arbejdslivsforskningen

    2012-01-01

    for Tidsskrift for Arbejdsliv at stille skarpt på, hvorledes teknologi kan forstås og udforskes, og her står nyere teoridannelser som STS (Science- and Technology Studies) og ANT (Actor-Network Theory) centralt. Dette temanummer af tidsskriftet har derfor disse teorier og deres anvendelse i studier af...

  11. Tiny, Powerful, Awesome Ants!

    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…

  12. Ant Colony Optimization: A Review and Comparison

    Sundus Shaukat; Riaz Ahmed Bhatti; Khalid Ibrahim Qureshi; Shafqat Ali Shad

    2014-01-01

    Many optmization algorithms are developed over period of time, among these most famous and widely used is Ant Colony systems (ACA). Ant Colony Systems (ACS) are the collection of different ant colony optimization algorithms. Different algorithms are used for solve the Travelling salesmen Problem (TCP) but ant colony algorithm is more preferred to solve the travelling salesmen problem. In ant colony best solution is found with the help of cooperating agents called ants. Ants cooperate with eac...

  13. Antártida

    Ricardo Felicio

    2007-01-01

    No extremo Sul do planeta Terra há a última fronteira ao avanço e controle total do homem. Se já são tantas as dificuldades para a sobrevivência em um ambiente hostil, podemos imaginar o esforço maior para a permanência total e indefinida. Tal território, sempre idealizado pelos antigos gregos, cerca de 300 a.C., mas descoberto há pouco mais de um século é a Antártida. Suas diferenças são marcantes em relação ao seu par, no pólo Norte, em todos os sentidos. O mais importante é o fato de a Ant...

  14. Ante la ley

    Kafka Franz

    1999-12-01

    Full Text Available Ante las puertas de la ley hay un guardian. Un campesino se llega hasta ese guardian y le pide que le permita entra en la ley, pero el guardian le dice que por ahora no se lo puede permitir. El hombre reflexiona y entonces pregunta si podria entrar despues. Es posible -dice el guardian-; pero no ahora. La puerta de entrada a la ley esta abierta como siempre.

  15. Alate susceptibility in ants

    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 investm...

  16. Artificial Ant Species on Solving Optimization Problems

    Pintea, Camelia-M.

    2013-01-01

    During the last years several ant-based techniques were involved to solve hard and complex optimization problems. The current paper is a short study about the influence of artificial ant species in solving optimization problems. There are studied the artificial Pharaoh Ants, Lasius Niger and also artificial ants with no special specificity used commonly in Ant Colony Optimization.

  17. Mechanics of fire ant aggregations

    Tennenbaum, Michael; Liu, Zhongyang; Hu, David; Fernandez-Nieves, Alberto

    2016-01-01

    Fire ants link their bodies to form aggregations; these can adopt a variety of structures, they can drip and spread, or withstand applied loads. Here, by using oscillatory rheology, we show that fire ant aggregations are viscoelastic. We find that, at the lowest ant densities probed and in the linear regime, the elastic and viscous moduli are essentially identical over the spanned frequency range, which highlights the absence of a dominant mode of structural relaxation. As ant density increases, the elastic modulus rises, which we interpret by alluding to ant crowding and subsequent jamming. When deformed beyond the linear regime, the aggregation flows, exhibiting shear-thinning behaviour with a stress load that is comparable to the maximum load the aggregation can withstand before individual ants are torn apart. Our findings illustrate the rich, collective mechanical behaviour that can arise in aggregations of active, interacting building blocks.

  18. Further travels with my ant

    Gale, David; Propp, James; Sutherland, Scott; Troubetzkoy, Serge

    1995-01-01

    We discuss some properties of a class of cellular automata sometimes called a "generalized ant". This system is perhaps most easily understood by thinking of an ant which moves about a lattice in the plane. At each vertex (or "cell"), the ant turns right or left, depending on the the state of the cell, and then changes the state of the cell according to certain prescribed rule strings. (This system has been the subject of several Mathematical Entertainments columns in the Mathematical Intelli...

  19. Extrações de óleos de sementes de citros e suas atividades sobre a formiga cortadeira Atta sexdens e seu fungo simbionte Citrus seed oils extractions and their activity against leaf cutting ant Atta sexdens and its symbiotic fungus

    João B Fernandes; Valmir David; Patrícia H. Facchini; M. Fátima das G. F. da Silva; Edson Rodrigues Filho; Paulo C. Vieira; Mário S. Galhiane; Pagnocca, Fernando C.; Odair C. Bueno; M. José Hebling; Sandra R. Victor; Ana Maria Rodrigues dos Santos

    2002-01-01

    Seeds Citrus oils (C. sinensis, C. limon and C. reticulata) extraction with hexane in a soxhlet apparatus and through supercritical fluid (CO2) were done. Besides triglycerides, the oils obtained with hexane comprised volatile compounds such as terpenes and fatty alcohols, esters, and aldehydes. However, the oils obtained by extraction with supercritical fluid presented only triglycerides. These results indicate that the extraction using supercritical fluid presents better selectivity. The ac...

  20. Chemically armed mercenary ants protect fungus-farming societies

    Adams, R. M. M.; Liberti, J.; Illum, A. A.; Jones, T H; Nash, D R; Boomsma, J.J.

    2013-01-01

    We document the behavioral interactions among three ant species: a fungus-growing host ant, a permanently associated parasitic guest ant, and a raiding agro-predator ant. We show that the presence of guest ants becomes advantageous when host ants are attacked by raider ants, because guest ants use alkaloid venom to defend their host ant colony. Furthermore, detection of the guest ant odors is sufficient to discourage raider scouts from recruiting nestmates to host colonies. Guest ants likely ...

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

    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...

  2. Ex Ante Allusions

    Holt, Jason

    2015-01-01

    We tend to think of allusions as indirect references to objects that already exist. Here I argue against this post facto orthodoxy and for the view that certain cases of allusion count as ex ante allusions (i.e. allusions before the fact). I argue that the standard view conflates the epistemic dependence of allusion (knowledge of the object of allusion) with an existential dependence (the object must already exist). As an adequate account of allusion should explain both the apparent paradoxic...

  3. Army Ants as Research and Collection Tools

    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 meaningfu...

  4. Temperature: Human Regulating, Ants Conforming

    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.

  5. The metapleural gland of ants

    Yek, Sze Huei; Mueller, Ulrich G

    2011-01-01

    The metapleural gland (MG) is a complex glandular structure unique to ants, suggesting a critical role in their origin and ecological success. We synthesize the current understanding of the adaptive function, morphology, evolutionary history, and chemical properties of the MG. Two functions of th...... MG, sanitation and chemical defence, have received the strongest empirical support; two additional possible functions, recognition odour and territorial marking, are less well supported. The design of the MG is unusual for insects; glandular secretions are stored in a rigid, non...... more commonly absent in males than in workers. MG chemistry has been characterized mostly in derived ant lineages with unique biologies (e.g. leafcutter ants, fire ants), currently precluding any inferences about MG chemistry at the origin of the ants. A synthetic approach integrating functional...

  6. AntR-mediated bidirectional activation of antA and antR, anthranilate degradative genes in Pseudomonas aeruginosa.

    Kim, Soo-Kyoung; Im, Su-Jin; Yeom, Doo-Hwan; Lee, Joon-Hee

    2012-08-15

    Bidirectional activation of transcription is a peculiar regulation mode of gene expression. In this study, we show that genes involved in the metabolism of anthranilate, a precursor of biosynthesis of tryptophan and Pseudomonas quinolone signal (PQS) are regulated by this bidirectional activation of transcription. Anthranilate is degraded by anthranilate dioxygenase complex encoded by antABC operon, and AntR, a LysR-type regulator encoded by antR activates the transcription of antABC operon in the presence of anthranilate. In P. aeruginosa, antABC and antR are divergently located and AntR binds to the intergenic region between antA and antR to activate the antABC transcription. In this study, we determined the transcriptional start site of the antA promoter (antA(p)) and AntR-responsive elements (AREs) in P. aeruginosa. The upstream deletion analysis of antA(p) and in vitro gel shift assay with purified AntR showed that there are two AREs at -194 to -148 and -88 to -47 regions. We also found that AntR activates antR promoter (antR(p)) in the opposite direction and both AREs are important in the bidirectional activation of antA(p) and antR(p). Two AREs have different binding affinities to AntR and the strength of transcriptional activation was dramatically asymmetric depending on the direction. We suggest that the different affinities of two AREs may explain the asymmetry of the bidirectional activation by AntR. PMID:22609066

  7. Ants for Document Clustering

    Priya Vaijayanthi

    2012-03-01

    Full Text Available The usage of computers for mass storage has become mandatory nowadays due to World Wide Web (WWW. This has placed many challenges to the Information Retrieval (IR system. Clustering of documents available improves the efficiency of IR system. The problem of clustering has become a combinatorial optimization problem in IR system due to the exponential growth in information over WWW. In this paper, a hybrid algorithm that combines the basic Ant Colony Optimization with Tabu search has been proposed. The feasibility of the proposed algorithm is tested over a few standard benchmark datasets. The experimental results reveal that the proposed algorithm yields promising quality clusters compared to other ones produced by K-means algorithm.

  8. ESTUDIOS SOBRE EL COMPORTAMIENTO DE FORRAJEO DE Acromyrmex lundi Guering (HYMENOPTERA, FORMICIDAE Y SU EFECTO SOBRE EL CRECIMIENTO DE PROCEDENCIAS DE Eucalyptus globulus Labill. (Myrtaceae

    Carmen Lidia Martínez

    2015-02-01

    Full Text Available El ataque de las hormigas cortadoras es una de las principales razones de pérdida de plantas durante la etapa de establecimiento de un monte forestal. Los objetivos de este estudio fueron evaluar la intensidad de forrajeo de Acromyrmex lundi asociado a algunas condiciones ambientales y procedencias de Eucalyptus globulus y estimar el impacto de la herbivoría sobre el crecimiento inicial de estos árboles. Dos ensayos se llevaron a cabo durante dos temporadas estivo-otoñales consecutivas, en el Campo Experimental de la Universidad Nacional de Luján, Argentina. Los materiales de diferentes procedencias fueron dispuestos en bloques equidistantes a 5 m de un nido activo de A. lundi. Durante doce semanas se contabilizó el número de hojas cortadas por las hormigas y se registraron algunas variables meteorológicas. En el segundo año la mitad de las parcelas fue protegida de las hormigas y se midieron variables de crecimiento. Los materiales de todas las procedencias fueron atacadas por A. lundi, aunque el número de hojas cosechada fue significativamente diferente sólo entre los orígenes Flinders Island (52,5 hojas y Nullo Mountain (28,5 hojas. El número de días lluviosos fue el único factor ambiental que se relacionó positivamente con la actividad de las hormigas.Todos los tratamientos redujeron significativamente la altura, el diámetro y el área foliar cuando fueron atacados por las hormigas. Las distintas procedencias compensaron diferencialemnte la herbivoría. Se discuten los resultados en función de los criterios a tener en cuenta para la selección de materiales genéticos como herramienta de manejo y control del ataque de A. lundi.

  9. Runtime analysis of the 1-ANT ant colony optimizer

    Doerr, Benjamin; Neumann, Frank; Sudholt, Dirk;

    2011-01-01

    The runtime analysis of randomized search heuristics is a growing field where, in the last two decades, many rigorous results have been obtained. First runtime analyses of ant colony optimization (ACO) have been conducted only recently. In these studies simple ACO algorithms such as the 1-ANT are...... investigated. The influence of the evaporation factor in the pheromone update mechanism and the robustness of this parameter w.r.t. the runtime behavior have been determined for the example function OneMax.This work puts forward the rigorous runtime analysis of the 1-ANT on the example functions Leading......Ones and BinVal. With respect to Evolutionary Algorithms (EAs), such analyses were essential to develop methods for the analysis on more complicated problems. The proof techniques required for the 1-ANT, unfortunately, differ significantly from those for EAs, which means that a new reservoir of methods has...

  10. Pest repelling properties of ant pheromones

    Offenberg, Joachim

    2014-01-01

    Ants control pests via predation and physical deterrence; however, ant communication is based on chemical cues which may serve as warning signals to potential prey and other intruders. The presence of ant pheromones may, thus, be sufficient to repel pests from ant territories. This mini-review shows that four out of five tested ant species deposit pheromones that repel herbivorous prey from their host plants.

  11. Le cybercommerçant

    Lauboué, Adongon Sylvain

    2015-01-01

    Le cybercommerçant se distingue du commerçant traditionnel à travers ladématérialisation de ses activités due à l’utilisation d’Internet. Ainsi, la dématérialisation desactivités du cybercommerçant, en dépit des avantages, pose deux séries de problèmes dues àl’ubiquité et à la dépersonnalisation. L’ubiquité se manifeste par le fait que le site Internet ducybercommerçant est accessible dans presque tous les États. La dépersonnalisation crée desrisques dus d’une part, au défaut de présence phys...

  12. Termites, hemimetabolous diploid white ants?

    Korb Judith

    2008-01-01

    Abstract Ants and termites are the most abundant animals on earth. Their ecological success is attributed to their social life. They live in colonies consisting of few reproducing individuals, while the large majority of colony members (workers/soldiers) forego reproduction at least temporarilly. Despite their apparent resemblance in social organisation, both groups evolved social life independently. Termites are basically social cockroaches, while ants evolved from predatory wasps. In this r...

  13. Neuroretinitis following bull ant sting

    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 appr...

  14. Identifying potential evolutionary relationships within a facultative lycaenid-ant system: Ant association,oviposition, and butterfly-ant conflict

    NEIL COLLIER

    2007-01-01

    Facultative associations are commonly encountered between ants and lycaenids,although the nature and patterns of associations are typically unclear. This study investigated a facultative symbiosis involving the lycaenid Theclinesthes albocincta (Lycaenidae), its host plant Adriana quadripartita and Australian native ants. Ants in the genera Ochetellus and Iridomyrmex were most frequently found in association with T. albocincta larvae,although Iridomyrmex ants were found in much lower abundance than were ants in Ochetellus. The abundances of Ochetellus and Iridomyrmex were highly correlated with larval abundance, but not egg abundance. Observations and experiments recorded oviposition on male inflorescences on more than 95% of occasions, but oviposition was not greater on inflorescences with ants present. Behavioral assays showed that Iridomyrmex ants were aggressive towards female butterflies on significantly more occasions than were Ochetellus ants. These findings indicate potential evolutionary relationships between T. albocincta and two genera of ants that were abundant within the habitat.

  15. Determinação do fator de conversão em colônias de Atta sexdens rubropilosa (Hymenoptera: Formicidae e sua relação com a qualidade do material vegetal cortado Determination of the conversion factor in colonies of Atta sexdens rubropilosa (Hymenoptera: Formicidae and its relationship with the quality of harvested leaf substrate

    Leandro Sousa-Sou

    2007-02-01

    Full Text Available As formigas cortadeiras (Atta e Acromyrmex são consideradas importantes pragas na agricultura e silvicultura, mas pouco se sabe sobre os reais danos dessas espécies. Uma forma bastante difundida de avaliação do dano é por meio do cálculo da taxa de conversão, dividindo-se o peso do material cortado pelo peso de lixo produzido pelas colônias. Foi levantada a hipótese de que a qualidade do substrato cortado pode influenciar no forrageamento das operárias, alterando a taxa de conversão e dificultando as estimativas de dano. A taxa de conversão de oito colônias de Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae foi calculada com duas espécies vegetais com diferentes concentrações de lignina e celulose, para testar essa hipótese. Colônias mantidas com folhas de baixa qualidade (razão lignina/celulose elevada tiveram maior forrageamento e produziram mais lixo. Entretanto, a taxa de conversão das colônias foi semelhante com essas duas plantas (média = 1,54. Esse valor está dentro da variação encontrada para outras espécies no campo (1,5-1,8, indicando um fator semelhante de conversão entre os gêneros Atta e Acromyrmex. O consumo médio de material vegetal, em termos de pesos seco e fresco, de uma colônia de A. sexdens rubropilosa com 4.500 operárias, foi estimado em 520 e 1.100 g/ano, respectivamente.Leaf-cutting ants (Atta and Acromyrmex are important pests in agriculture and forestry, although few data exist on the actual damage caused by these species. A model used to evaluate damage by leaf-cutting ants are estimates of the conversion factor, which is the ratio between the weight of material cut by the ants and the refuse produced by the colonies. The hypothesis that substrate quality influences foraging by workers, modifying the conversion factor and impairing damage estimates was put forward. To test this hypothesis, the conversion factor was calculated for eight colonies of Atta sexdens rubropilosa Forel

  16. Ant larval demand reduces aphid colony growth rates in an ant-aphid interaction

    Cook, James M.; Leather, Simon R; Oliver, Tom H.

    2012-01-01

    Ants often form mutualistic interactions with aphids, soliciting honeydew in return for protective services. Under certain circumstances, however, ants will prey upon aphids. In addition, in the presence of ants aphids may increase the quantity or quality of honeydew produced, which is costly. Through these mechanisms, ant attendance can reduce aphid colony growth rates. However, it is unknown whether demand from within the ant colony can affect the ant-aphid interaction. In a factorial exper...

  17. Pest repelling properties of ant pheromones

    Offenberg, Joachim

    2014-01-01

    Ants control pests via predation and physical deterrence; however, ant communication is based on chemical cues which may serve as warning signals to potential prey and other intruders. The presence of ant pheromones may, thus, be sufficient to repel pests from ant territories. This mini-review sh......Ants control pests via predation and physical deterrence; however, ant communication is based on chemical cues which may serve as warning signals to potential prey and other intruders. The presence of ant pheromones may, thus, be sufficient to repel pests from ant territories. This mini......-review shows that four out of five tested ant species deposit pheromones that repel herbivorous prey from their host plants....

  18. Using Ants as bioindicators: Multiscale Issues in Ant Community Ecology

    Alan Andersen

    1997-06-01

    Full Text Available Ecological patterns and processes are characteristically scale dependent, and research findings often cannot be translated easily from one scale to another. Conservation biology is challenged by a lack of congruence between the spatial scales of ecological research (typically involving small plots and land management (typically involving whole landscapes. Here, I discuss spatial scaling issues as they relate to an understanding of ant communities and, consequently, their use as bioindicators in land management. Our perceptions of fundamental patterns and processes in ant communities depend on scale: taxa that are behaviorally dominant at one scale are not necessarily so at others, functional groups recognized at one scale are often inappropriate for others, and the role of competition in community structure depends on the scale of analysis. Patterns of species richness and composition, and the ability of total richness to be estimated by surrogates, are all also scale dependent. Ant community ecology has a tradition of detailed studies in small plots, but the use of ants as bioindicators requires a predictive understanding of community structure and dynamics at a range of spatial scales. Such an appreciation of ant communities and their most effective use as bioindicators is best served by studies integrating results from plot-scale research with the broad-scale paradigms of biogeography, systematics, and evolutionary biology.

  19. Monoculture of leafcutter ant gardens.

    Ulrich G Mueller

    Full Text Available 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.

  20. Evaluation of the possible role of ants (Hymenoptera: Formicidae as mechanical vectors of nematodes and protists

    Fabio Villani

    2008-10-01

    Full Text Available Nematodes and protists can be transmitted to humans in many ways and little concern has been given to the mechanical transmission by ants. This study aimed at analysing how the eggs of Ascaris lumbricoides and cysts of Entamoeba coli could be mechanically transmitted to the man by Formicidae. Through the experiments using nests of Tapinoma melanocephalum, Linepithema humile and Monomorium pharaonis reared in the laboratory allied to observations of some 17 ant species in an urban park area in Mogi das Cruzes (SP, it was found that L. humile was capable of carrying eggs of A. lumbricoides both in the field and laboratory conditions (1 worker, as well as was Camponotus rufipes (2, Solenopsis saevissima (1 and Acromyrmex niger (1. The cysts of Escherichia coli were found over three workers of C. rufipes. Although the frequency of the workers found transporting pathogens was low, the capacity of common household species in carrying pathogens like nematodes and protists was demonstrated.Os Nematoda e Protista podem ser transmitidos ao homem de diversas maneiras, mas pouca ênfase é dada para a transmissão mecânica por intermédio de formigas. Assim, esse trabalho procurou investigar a transmissão mecânica de ovos de Ascaris lumbricoides e cistos de Entamoeba coli pelos Formicidae. Através de experimentos com espécies mantidas em ninhos no laboratório (Tapinoma melanocephalum, Linepithema humile e Monomorium pharaonis e com 17 espécies de formigas de uma área antropizada na região de Mogi as Cruzes (SP, foi possível constar que os ovos A. lumbricoides foram transportados por L. humile, tanto no campo (1 operária como no laboratório (1 operária, por Camponotus rufipes (2, por Solenopsis saevissima (1 e por Acromyrmrex niger (1. Em três operárias de C. rufipes foram encontrados cistos de E. coli. Apesar da baixa incidência de transporte, as três primeiras espécies pelo fato de viverem muito próximas ao ser humano, podem levar para

  1. Detrimental effects of highly efficient interference competition: invasive Argentine ants outcompete native ants at toxic baits.

    Buczkowski, Grzegorz; Bennett, Gary W

    2008-06-01

    The Argentine ant (Linepithema humile) is an invasive species that disrupts the balance of natural ecosystems by displacing indigenous ant species throughout its introduced range. Previous studies that examined the mechanisms by which Argentine ants attain ecological dominance showed that superior interference and exploitation competition are key to the successful displacement of native ant species. The objective of this research was to test the hypothesis that effective interference competition by Argentine ants may also be detrimental to the survival of Argentine ant colonies where Argentine ants and native ants compete at toxic baits used to slow the spread of Argentine ants. To study this hypothesis, we examined the competitive interactions between Argentine ants and native odorous house ants, Tapinoma sessile, in the presence and absence of toxic baits. Results showed that Argentine ants aggressively outcompete T. sessile from toxic baits through efficient interference competition and monopolize bait resources. This has severe negative consequences for the survival of Argentine ants as colonies succumb to the toxic effects of the bait. In turn, T. sessile avoid areas occupied by Argentine ants, give up baits, and consequently suffer minimal mortality. Our results provide experimental evidence that highly efficient interference competition may have negative consequences for Argentine ants in areas where toxic baits are used and may provide a basis for designing innovative management programs for Argentine ants. Such programs would have the double benefit of selectively eliminating the invasive species while simultaneously protecting native ants from the toxic effects of baits. PMID:18559180

  2. Ants as flower visitors : floral ant-repellence and the impact of ant scent-marks on pollinator behaviour

    Ballantyne, Gavin

    2011-01-01

    As flower visitors, ants rarely benefit a plant, commonly disrupting pollination by deterring other flower visitors, or stealing nectar. This thesis examines three aspects of ant-flower interactions, focusing on the occurrence of floral traits that prevent disruption of pollination and a novel means by which ants may influence pollinator behaviour. To assess which types of plant species possess ant-repelling floral traits I carried out a survey of 49 Neotropical plant species. ...

  3. Myrmecotrophy: Plants fed by ants.

    Beattie, A

    1989-06-01

    Two plant genera with tubers specialized for occupation by ants absorb nutrients from waste materials accumulated by the resident colonies. The mineral resources of these host plants are augmented by colony foraging which functions as a second root system. This mutualistic interaction has become known as myrmecotrophy. Many other kinds of plant structure are apparent adaptations to accommodate ant colonies; these include pouches on leaves or petioles and hollow twigs, stems or thorns. Sometimes the ant species residing in these structures are aggressive towards enemies of the host plant and are important for plant defence. Recent research provides some evidence that myrmecotrophy may have a wider role in plant nutrition, at least when subsidizing the costs of plant defence. PMID:21227344

  4. Ants as tools in sustainable agriculture

    Offenberg, Joachim

    2015-01-01

    multiple crops. Their efficiency is comparable to chemical pesticides or higher, while at lower costs. They provide a rare example of documented efficient conservation biological control. 3. Weaver ants share beneficial traits with almost 13 000 other ant species and are unlikely to be unique in their....... Being predatory and organized as superorganisms, ants possess traits making them suitable agents in IPM. Recent works on weaver ants Oecophylla spp. showcase ants as highly efficient pest controllers. A synthesis shows that weaver ants can reduce pest numbers and their damage and increase yields in...... properties as control agents. A synthesis of applied work on other ant species illustrates potentials for control of arthropod pests, weeds and plant diseases in orchards, forestry and arable crops. 4. Synthesis and applications. By showing that ant biocontrol can match synthetic pesticides in a wide setting...

  5. A cellular automata model for ant trails

    Sibel Gokce; Ozhan Kayacan

    2013-05-01

    In this study, the unidirectional ant traffic flow with U-turn in an ant trail was investigated using one-dimensional cellular automata model. It is known that ants communicate with each other by dropping a chemical, called pheromone, on the substrate. Apart from the studies in the literature, it was considered in the model that (i) ant colony consists of two kinds of ants, goodand poor-smelling ants, (ii) ants might make U-turn for some special reasons. For some values of densities of good- and poor-smelling ants, the flux and mean velocity of the colony were studied as a function of density and evaporation rate of pheromone.

  6. Hey! A Fire Ant Stung Me!

    ... Snowboarding, Skating Crushes What's a Booger? Hey! A Fire Ant Stung Me! KidsHealth > For Kids > Hey! A ... Me picó una roja o colorada! What's a Fire Ant? There are many different types of fire ...

  7. Ants defend coffee from berry borer colonization

    Gonthier, DJ; Ennis, KK; Philpott, SM; Vandermeer, J; Perfecto, I.

    2013-01-01

    Ants frequently prevent herbivores from damaging plants. In agroecosystems they may provide pest control services, although their contributions are not always appreciated. Here we compared the ability of eight ant species to prevent the coffee berry borer from colonizing coffee berries with a field exclusion experiment. We removed ants from one branch (exclusion) and left ants to forage on a second branch (control) before releasing 20 berry borers on each branch. After 24 h, six of eight spec...

  8. The Biochemical Toxin Arsenal from Ant Venoms

    Axel Touchard; Aili, Samira R.; Eduardo Gonçalves Paterson Fox; Pierre Escoubas; Jérôme Orivel; Nicholson, Graham M; Alain Dejean

    2016-01-01

    Ants (Formicidae) represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralyt...

  9. The biochemical toxin arsenal from ant venoms

    Aili, Samira R.; Fox, Eduardo Goncalves Paterson; Escoubas, Pierre; Orivel, Jérôme; Nicholson, Graham M.; Dejean, Alain

    2016-01-01

    Ants (Formicidae) represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralyt...

  10. Ants as Fluids: Physics-Inspired Biology

    Streiff, Micah; Shinotsuka, Sho; Alexeev, Alex; Hu, David

    2010-01-01

    Fire ants use their claws to grip diverse surfaces, including each other. As a result of their mutual adhesion and large numbers, ant colonies flow like inanimate fluids. In this sequence of films, we demonstrate how ants behave similarly to the spreading of drops, the capillary rise of menisci, and gravity-driven flow down a wall. By emulating the flow of fluids, ant colonies can remain united under stressful conditions.

  11. cAnt-Miner: an ant colony classification algorithm to cope with continuous attributes

    Otero, Fernando E.B.; Freitas, Alex. A.; Johnson, Colin G.

    2008-01-01

    This paper presents an extension to Ant-Miner, named cAnt-Miner (Ant-Miner coping with continuous attributes), which incorporates an entropy-based discretization method in order to cope with continuous attributes during the rule construction process. By having the ability to create discrete intervals for continuous attributes "on-the-fly", cAnt-Miner does not requires a discretization method in a preprocessing step, as Ant-Miner requires. cAnt-Miner has been compared against Ant-Miner in eigh...

  12. Using Ants to Investigate the Environment

    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. FIRE ANT, BIOLOGY, ECOLOGY, AND BIOCONTROL

    The red fire ant Solenopsis invicta was accidentally introduced into the United States from South America sometime in the 1930s. These ants do best in open, disturbed habitats associated with human activities. Fire ants construct large earthen mounds which function as solar collecting devises. Fire...

  14. Ant colony optimization in continuous problem

    YU Ling; LIU Kang; LI Kaishi

    2007-01-01

    Based on the analysis of the basic ant colony optimization and optimum problem in a continuous space,an ant colony optimization (ACO) for continuous problem is constructed and discussed. The algorithm is efficient and beneficial to the study of the ant colony optimization in a continuous space.

  15. Male parentage in army ants

    Kronauer, Daniel J C; Schöning, Caspar; Boomsma, Jacobus J

    2006-01-01

    active research in insect sociobiology. Here we present microsatellite data for 176 males from eight colonies of the African army ant Dorylus (Anomma) molestus. Comparison with worker genotypes and inferred queen genotypes from the same colonies show that workers do not or at best very rarely reproduce...

  16. Microsatellite primers for fungus-growing ants

    Villesen, Palle; Gertsch, P J; Boomsma, JJ

    2002-01-01

    developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants.......We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...

  17. Microsatellite Primers for Fungus-Growing Ants

    Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

    2002-01-01

    developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants.......We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...

  18. Discrimination Behavior in the Supercolonial Pharaoh Ant

    Pontieri, Luigi

    The majority of eusocial insect species live in small, kin structured colonies that are mutually aggressive and rarely interact. By contrast, a restricted group of ant species show a peculiar social organization called unicoloniality, where colonies can grow to vast networks of geographically...... discrimination behavior of the invasive pharaoh ant (Monomorium pharaonis) as a model for other invasive and supercolonial ant species. The pharaoh ant is one of the few ant species that can be reared in the laboratory for many generations. Furthermore, the possibility to do controlled crosses of colonies...... of invasive ants. In the first chapter I focused on the nestmate recognition system of pharaoh ants, investigating whether the cues used for discrimination had a genetic origin and how different level of within-colony genetic diversity and relatedness influenced the discrimination abilities of the...

  19. ANT, tourism and situated globality

    Jóhannesson, Gunnar Thór; Ren, Carina Bregnholm; van der Duim, René

    2015-01-01

    are used to define as the separate spheres of nature and culture. This paper explores and relates the central tenets of ANT in tourism with regard to the concept of the Anthropocene. It presents the ANT approach as a flat and object-oriented ontology and methodology and explores its potentials to...... carve out viable descriptions of the collective condition of humans and more-than-humans in the Anthropocene. Also and moving past a merely descriptive approach, it discusses it as a useful tool to engage with the situated globalities which come into being through the socio-spatial coupling of tourism...... and the Anthropocene through, as we propose improvisation, valuing and caring....

  20. Revolutionizing Remote Exploration with ANTS

    Clark, P. E.; Rilee, M. L.; Curtis, S.; Truszkowski, W.

    2002-05-01

    We are developing the Autonomous Nano-Technology Swarm (ANTS) architecture based on an insect colony analogue for the cost-effective, efficient, systematic survey of remote or inaccessible areas with multiple object targets, including planetary surface, marine, airborne, and space environments. The mission context is the exploration in the 2020s of the most compelling remaining targets in the solar system: main belt asteroids. Main belt asteroids harbor important clues to Solar System origins and evolution which are central to NASA's goals in Space Science. Asteroids are smaller than planets, but their number is far greater, and their combined surface area likely dwarfs the Earth's. An asteroid survey will dramatically increase our understanding of the local resources available for the Human Exploration and Development of Space. During the mission composition, shape, gravity, and orbit parameters could be returned to Earth for perhaps several thousand asteroids. A survey of this area will rival the great explorations that encircled this globe, opened up the New World, and laid the groundwork for the progress and challenges of the last centuries. The ANTS architecture for a main belt survey consists of a swarm of as many as a thousand or more highly specialized pico-spacecraft that form teams to survey as many as one hundred asteroids a month. Multi-level autonomy is critical for ANTS and the objective of the proposed study is to work through the implications and constraints this entails. ANTS couples biologically inspired autonomic control for basic functions to higher level artificial intelligence that together enable individual spacecraft to operate as specialized, cooperative, social agents. This revolutionary approach postulates highly advanced, but familiar, components integrated and operated in a way that uniquely transcends any evolutionary extrapolation of existing trends and enables thousand-spacecraft missions.

  1. Fire ant-detecting canines: a complementary method in detecting red imported fire ants.

    Lin, Hui-Min; Chi, Wei-Lien; Lin, Chung-Chi; Tseng, Yu-Ching; Chen, Wang-Ting; Kung, Yu-Ling; Lien, Yi-Yang; Chen, Yang-Yuan

    2011-02-01

    In this investigation, detection dogs are trained and used in identifying red imported fire ants, Solenopsis invicta Buren, and their nests. The methodology could assist in reducing the frequency and scope of chemical treatments for red imported fire ant management and thus reduce labor costs and chemical use as well as improve control and quarantine efficiency. Three dogs previously trained for customs quarantine were retrained to detect the scents of red imported fire ants. After passing tests involving different numbers of live red imported fire ants and three other ant species--Crematogaster rogenhoferi Mayr, Paratrechina longicornis Latreille, and Pheidole megacephala F.--placed in containers, ajoint field survey for red imported fire ant nests by detection dogs and bait traps was conducted to demonstrate their use as a supplement to conventional detection methods. The most significant findings in this report are (1) with 10 or more red imported fire ants in scent containers, the dogs had >98% chance in tracing the red imported fire ant. Upon the introduction of other ant species, the dogs still achieved on average, a 93% correct red imported fire ant indication rate. Moreover, the dogs demonstrated great competence in pinpointing emerging and smaller red imported fire ant nests in red imported fire ant-infested areas that had been previously confirmed by bait trap stations. (2) Along with the bait trap method, we also discovered that approximately 90% of red imported fire ants foraged within a distance of 14 m away from their nests. The results prove detection dogs to be most effective for red imported fire ant control in areas that have been previously treated with pesticides and therefore containing a low density of remaining red imported fire ant nests. Furthermore, as a complement to other red imported fire ant monitoring methods, this strategy will significantly increase the efficacy of red imported fire ant control in cases of individual mount treatment

  2. Symbiont recruitment versus ant-symbiont co-evolution in the attine ant-microbe symbiosis.

    Mueller, Ulrich G

    2012-06-01

    The symbiosis between fungus-farming ants (Attini, Formicidae), their cultivated fungi, garden-infecting Escovopsis pathogens, and Pseudonocardia bacteria on the ant integument has been popularized as an example of ant-Escovopsis-Pseudonocardia co-evolution. Recent research could not verify earlier conclusions regarding antibiotic-secreting, integumental Pseudonocardia that co-evolve to specifically suppress Escovopsis disease in an ancient co-evolutionary arms-race. Rather than long-term association with a single, co-evolving Pseudonocardia strain, attine ants accumulate complex, dynamic biofilms on their integument and in their gardens. Emerging views are that the integumental biofilms protect the ants primarily against ant diseases, whereas garden biofilms protect primarily against garden diseases; attine ants selectively recruit ('screen in') microbes into their biofilms; and the biofilms of ants and gardens serve diverse functions beyond disease-suppression. PMID:22445196

  3. The agricultural pathology of ant fungus gardens

    Currie, Cameron R; Mueller, Ulrich G.; Malloch, David

    1999-01-01

    Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure “monocultures.” We conducted extensive isolations of “alien” (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites th...

  4. Path integration in desert ants, Cataglyphis fortis

    Müller, Martin; Wehner, Rüdiger

    1988-01-01

    Foraging desert ants, Cataglyphis fortis, continually keep track of their own posotions relative to home— i.e., integrate their tortuous outbound routes and return home along straight (inbound) routes. By experimentally manipulating the ants' outbound trajectories we show that the ants solve this path integration problem not by performing a true vector summation (as a human navigator does) but by employing a computationally simple approximation. This approximation is characterized by small, b...

  5. Towards a multilevel ant colony optimization

    Lian, Thomas Andreé; Llave, Marilex Rea

    2014-01-01

    Ant colony optimization is a metaheuristic approach for solving combinatorial optimization problems which belongs to swarm intelligence techniques. Ant colony optimization algorithms are one of the most successful strands of swarm intelligence which has already shown very good performance in many combinatorial problems and for some real applications. This thesis introduces a new multilevel approach for ant colony optimization to solve the NP-hard problems shortest path and traveling salesman....

  6. GRID SCHEDULING USING ENHANCED ANT COLONY ALGORITHM

    Mr. P.Mathiyalagan; U.R. Dhepthie; S.N. Sivanandam

    2010-01-01

    Grid computing is a high performance computing used to solve larger scale computational demands. Task scheduling is a major issue in grid computing systems. Scheduling of tasks is the NP hard problem. The heuristic approach provides optimal solution for NP hard problems .The ant colony algorithm provides optimal solution. The existing ant colony algorithm takes more time to schedule the tasks. In this paper ant colony algorithm improved by enhancing pheromone updating rule such that it schedu...

  7. Ant cuticular response to phthalate pollution

    Lenoir, Alain; Axel, Touchard; Devers, Séverine; Christidès, Jean-Philippe; Boulay, Raphaël; Cuvillier-Hot, Virginie

    2014-01-01

    Phthalates are common atmospheric contaminantsused in the plastic industry. Ants have been shown to constitutegood bioindicators of phthalate pollution. Hence,phthalates remain trapped on ant cuticles which are mostlycoated with long-chain hydrocarbons. In this study, we artificiallycontaminated Lasius niger ants with four phthalates:dibutyl phthalate (DBP), diisobutyl phthalate (DiBP), di(2-ethylhexyl) phthalate (DEHP), and benzyl butyl phthalate(BBP). The first three have previously been fo...

  8. The fire ant Solenopsis saevissima and habitat disturbance alter ant communities

    Dejean, A; Cereghino, R.; Leponce, M.; Rossi, V; Roux, Olivier; Compin, A.; Delabie, J. H. C.; Corbara, B.

    2015-01-01

    The fire ant Solenopsis saevissima is a major pest frequent in human-disturbed areas of its native range where it forms 'supercolonies'. We determined that its natural habitat in French Guiana is likely the sporadically flooded riparian forest and aimed to evaluate this ant's impact on the abundance and diversity of other ants by comparing different habitats at two sites. We noted a significant decrease in ant species richness between the rainforest and human-disturbed habitats (but not betwe...

  9. Multi-Phase Defense by the Big-Headed Ant, Pheidole obtusospinosa, Against Raiding Army Ants

    Huang, Ming H.

    2010-01-01

    Army ants are well known for their destructive raids of other ant colonies. Some known defensive strategies include nest evacuation, modification of nest architecture, blockade of nest entrances using rocks or debris, and direct combat outside the nest. Since army ants highly prefer Pheidole ants as prey in desert habitats, there may be strong selective pressure on Pheidole to evolve defensive strategies to better survive raids. In the case of P. obtusospinosa Pergande (Hymenoptera: Formicida...

  10. Ant Colony Optimization Algorithm for Continuous Domains Based on Position Distribution Model of Ant Colony Foraging

    Liqiang Liu; Yuntao Dai; Jinyu Gao

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules...

  11. Pest repellent properties of ant pheromones

    Offenberg, Joachim

    2012-01-01

    of ant pheromones may be sufficient to repel pest insects from ant territories. The study of ant semiochemicals is in its infancy, yet, evidence for their potential use in pest management is starting to build up. Pheromones from four of five tested ant species have been shown to deter herbivorous insect...... from the ants’ host plants. (i) Oecophylla smaragdina deposits disrupt chrysomelid (Rhyparida wallacei) feeding on a Thai mangrove, and (ii) deposits from O. longinoda repel ovipositing fruit flies (Bactrosera invadens and Ceratitis cosyra) from mango fruits in Benin. Also, deposits from two New World...

  12. Ilmub suurmeister Evald Okase monograafia / Ants Juske

    Juske, Ants, 1956-

    2009-01-01

    22. aprillil Kumu Kunstimuuseumis esitletavast monograafiast "Evald Okas", mille on kirjutanud Ants Juske, kujundanud Tiit Jürna. Evald Okasest, tema loomingust, elust Jaroslavlis ja rindekunstnikuna

  13. GRID SCHEDULING USING ENHANCED ANT COLONY ALGORITHM

    P. Mathiyalagan

    2010-10-01

    Full Text Available Grid computing is a high performance computing used to solve larger scale computational demands. Task scheduling is a major issue in grid computing systems. Scheduling of tasks is the NP hard problem. The heuristic approach provides optimal solution for NP hard problems .The ant colony algorithm provides optimal solution. The existing ant colony algorithm takes more time to schedule the tasks. In this paper ant colony algorithm improved by enhancing pheromone updating rule such that it schedules the tasks efficiently and better resource utilization. The simulation results prove that proposed method reduces the execution time of tasks compared to existing ant colony algorithm.

  14. Antígona y la muerte

    Pérez Alcolea, Simona Micaela

    2012-01-01

    La ponencia analiza la muerte de Antígona en la obra de Sófocles. Se propone que su suicidio es un acto consciente de voluntad preanunciado a lo largo de toda la obra y no una medida desesperada. Con ese fin se exploran las posibles motivaciones de Antígona para poner fin a su vida. En el análisis se proponen tres respuestas (no necesariamente excluyentes): -Antígona responde a la ética homérica. Está en lucha con Creón, y su suicidio es su golpe de gracia al poder del rey. -Antígona...

  15. Enhanced ants system and its application

    2005-01-01

    NP-hard combinational optimization problem is not solved very well until now. One enhanced ants system based on ants system is advanced after analysis of the deficiencies of existing ants systems. Some improvements are made in state transfer rule and local modification rule. Furthermore, the enhanced ants system can solve NP-hard combinational optimization problem with restraints and condition path. The successful application of TSP problem and transportation net problem indicates that the proposed system has stronger function and higher efficiency than the original system.

  16. Plants in Your Ants: Using Ant Mounds to Test Basic Ecological Principles

    Zettler, Jennifer A.; Collier, Alexander; Leidersdorf, Bil; Sanou, Missa Patrick

    2010-01-01

    Urban students often have limited access to field sites for ecological studies. Ubiquitous ants and their mounds can be used to study and test ecology-based questions. We describe how soil collected from ant mounds can be used to investigate how biotic factors (ants) can affect abiotic factors in the soil that can, in turn, influence plant growth.

  17. The evolution of genome size in ants

    Spagna Joseph C

    2008-02-01

    Full Text Available Abstract Background Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta, and the two published estimates for this species differ by 146.7 Mb (0.15 pg. Results Here, we report the genome size for 40 species of ants distributed across 10 of the 20 currently recognized subfamilies, thus making Formicidae the 4th most surveyed insect family and elevating the Hymenoptera to the 5th most surveyed insect order. Our analysis spans much of the ant phylogeny, from the less derived Amblyoponinae and Ponerinae to the more derived Myrmicinae, Formicinae and Dolichoderinae. We include a number of interesting and important taxa, including the invasive Argentine ant (Linepithema humile, Neotropical army ants (genera Eciton and Labidus, trapjaw ants (Odontomachus, fungus-growing ants (Apterostigma, Atta and Sericomyrmex, harvester ants (Messor, Pheidole and Pogonomyrmex, carpenter ants (Camponotus, a fire ant (Solenopsis, and a bulldog ant (Myrmecia. Our results show that ants possess small genomes relative to most other insects, yet genome size varies three-fold across this insect family. Moreover, our data suggest that two whole-genome duplications may have occurred in the ancestors of the modern Ectatomma and Apterostigma. Although some previous studies of other taxa have revealed a relationship between genome size and body size, our phylogenetically-controlled analysis of this correlation did not reveal a significant relationship. Conclusion This is the first analysis of genome size in ants (Formicidae and the first across multiple species of social insects. We show that genome size is a variable trait that can evolve gradually over long time spans, as well as rapidly, through processes that may

  18. Antthrushes, antpittas, and gnateaters (Aves, Formicariidae) as army ant followers

    Edwin O Willis

    1984-01-01

    Antthrushes (Formicarius, Chamaeza) sometimes walk around swarms of army ants and capture ground prey, but do not follow ants regularly. Among antpittas, only fast-leaping Pittasoma michleri and P. rufopileatum regularly follow ants. Gnateaters (Conopophaga) follow ants little. All these ground-foraging genera are poorly adapted for rapid flying, and failure to follow ants is perhaps due to inability to evade predators or out fly competitors near groups of birds attracted by ants.

  19. Implementasi Algoritma Ant Colony System Dalam Menentukan Optimisasi Network Routing .

    Lubis, Dini Anggraini

    2011-01-01

    Ant Colony System is an algorithm that adapt from ants biologic behavior which the ant colony can hold to find shortest path. Ant Colony System can implement for several optimization problems and one of them is in network routing. Ant colony system that talked in this paper is about optimization cases in network routing called AntNet. The purpose of AntNet is to search shortest path between source node to destination node based the table routing read by AntNet. In this research, it implemente...

  20. The Biochemical Toxin Arsenal from Ant Venoms.

    Touchard, Axel; Aili, Samira R; Fox, Eduardo Gonçalves Paterson; Escoubas, Pierre; Orivel, Jérôme; Nicholson, Graham M; Dejean, Alain

    2016-01-01

    Ants (Formicidae) represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents. PMID:26805882

  1. The Biochemical Toxin Arsenal from Ant Venoms

    Axel Touchard

    2016-01-01

    Full Text Available Ants (Formicidae represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents.

  2. The Complexity of Fire Ant Nestmate Recognition

    Fire ants, Solenopsis invicta and Solenopsis richteri, were inadvertently introduced into the United States in the early 1900s and currently inhabit over 129 million hectares in Puerto Rico and twelve southern states from Texas to Virginia. Imported fire ants have also become established in isolated...

  3. Dynamical Equilibrium of Interacting Ant Societies

    Leok, B T M

    1996-01-01

    The sustainable biodiversity associated with a specific ecological niche as a function of land area is analysed computationally by considering the interaction of ant societies over a collection of islands. A power law relationship between sustainable species and land area is observed. We will further consider the effect a perturbative inflow of ants has upon the model.

  4. AntStar: Enhancing Optimization Problems by Integrating an Ant System and A⁎ Algorithm

    Mohammed Faisal

    2016-01-01

    Full Text Available Recently, nature-inspired techniques have become valuable to many intelligent systems in different fields of technology and science. Among these techniques, Ant Systems (AS have become a valuable technique for intelligent systems in different fields. AS is a computational system inspired by the foraging behavior of ants and intended to solve practical optimization problems. In this paper, we introduce the AntStar algorithm, which is swarm intelligence based. AntStar enhances the optimization and performance of an AS by integrating the AS and A⁎ algorithm. Applying the AntStar algorithm to the single-source shortest-path problem has been done to ensure the efficiency of the proposed AntStar algorithm. The experimental result of the proposed algorithm illustrated the robustness and accuracy of the AntStar algorithm.

  5. Hybrid chaotic ant swarm optimization

    Chaotic ant swarm optimization (CASO) is a powerful chaos search algorithm that is used to find the global optimum solution in search space. However, the CASO algorithm has some disadvantages, such as lower solution precision and longer computational time, when solving complex optimization problems. To resolve these problems, an improved CASO, called hybrid chaotic swarm optimization (HCASO), is proposed in this paper. The new algorithm introduces preselection operator and discrete recombination operator into the CASO; meanwhile it replaces the best position found by own and its neighbors' ants with the best position found by preselection operator and discrete recombination operator in evolution equation. Through testing five benchmark functions with large dimensionality, the experimental results show the new method enhances the solution accuracy and stability greatly, as well as reduces the computational time and computer memory significantly when compared to the CASO. In addition, we observe the results can become better with swarm size increasing from the sensitivity study to swarm size. And we gain some relations between problem dimensions and swam size according to scalability study.

  6. Spectacular Batesian mimicry in ants

    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.

  7. Cryptococcus neoformans carried by Odontomachus bauri ants

    Mariana Santos de Jesus

    2012-06-01

    Full Text Available Cryptococcus neoformans is the most common causative agent of cryptococcosis worldwide. Although this fungus has been isolated from a variety of organic substrates, several studies suggest that hollow trees constitute an important natural niche for C. neoformans. A previously surveyed hollow of a living pink shower tree (Cassia grandis positive for C. neoformans in the city of Rio de Janeiro, Brazil, was chosen for further investigation. Odontomachus bauri ants (trap-jaw ants found inside the hollow were collected for evaluation as possible carriers of Cryptococcus spp. Two out of 10 ants were found to carry phenoloxidase-positive colonies identified as C. neoformans molecular types VNI and VNII. The ants may have acted as a mechanical vector of C. neoformans and possibly contributed to the dispersal of the fungi from one substrate to another. To the best of our knowledge, this is the first report on the association of C. neoformans with ants of the genus Odontomachus.

  8. Urban ants and transportation of nosocomial bacteria.

    Rodovalho, Cynara M; Santos, Ana L; Marcolino, Marcus T; Bonetti, Ana M; Brandeburgo, Malcon A M

    2007-01-01

    Many ant species displaying synanthropic behavior that have successfully dispersed in urban areas can cause problems in hospitals by acting as bacterial vectors. In this study, we encountered bacteria on ants collected at the Universidade Federal de Uberlândia hospital, in the campus and at households nearby. The ants were identified as Tapinoma melanocephalum (Fabricius) and Camponotus vittatus (Forel) (Hymenoptera: Formicidae) and the bacterial strains found here belong to the group of the coagulase-positive staphylococcus, coagulase-negative staphylococcus and gram negative bacilli, including antimicrobial drug-resistant strains. An investigation of the bacteria found in the ants and in the environment revealed that some ants carried non-isolated bacteria from the same environment and with high levels of resistance, evidencing the transmission potential of these insects. PMID:17710329

  9. Ant-Based Cyber Security

    Haack, Jereme N.; Fink, Glenn A.; Maiden, Wendy M.; McKinnon, Archibald D.; Templeton, Steven J.; Fulp, Errin W.

    2011-07-12

    We describe a swarming-agent-based, mixed-initiative approach to infrastructure defense where teams of humans and software agents defend cooperating organizations in tandem by sharing insights and solutions without violating proprietary boundaries. The system places human administrators at the appropriate level where they provide system guidance while lower-level agents carry out tasks humans are unable to perform quickly enough to mitigate today’s security threats. Cooperative Infrastructure Defense (CID) uses our ant-based approach to enable dialogue between humans and agents to foster a collaborative problem-solving environment, increase human situational awareness and influence using visualization and shared control. We discuss theoretical implementation characteristics along with results from recent proof-of-concept implementations.

  10. Individual Recognition in Ant Queens

    D'Ettorre, Patrizia; Heinze, Jürgen

    2005-01-01

    recognize each other's unique facial color patterns [3] . Individual recognition is advantageous when dominance hierarchies control the partitioning of work and reproduction 2 and 4 . Here, we show that unrelated founding queens of the ant Pachycondyla villosa use chemical cues to recognize each other...... individually. Aggression was significantly lower in pairs of queens that had previously interacted than in pairs with similar social history but no experience with one another. Moreover, subordinates discriminated familiar and unfamiliar dominants in choice experiments in which physical contact, but not odor...... perception, was prevented and in tests with anaesthetized queens. The cuticular chemical profiles of queens were neither associated with dominance nor fertility and, therefore, do not represent status badges 5 and 6 , and nestmate queens did not share a common odor. Personal recognition facilitates...

  11. How to be an ant on figs

    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.

  12. Riqueza de formigas de solo na praia da Pedreira, Parque Estadual de Itapuã, Viamão, RS, Brasil Richness of ground-dwelling ants in the Praia da Pedreira, Parque Estadual de Itapuã, Viamão, RS, Brazil

    Elena Diehl

    2005-12-01

    Full Text Available Neste trabalho são listadas as espécies de formigas de solo encontradas em três ambientes (mata nativa, barreira pedregosa e areias da orla na praia da Pedreira, localizada na Zona de Uso Intensivo do Parque Estadual de Itapuã, município de Viamão, RS. No total, foram identificadas 60 espécies representantes de 24 gêneros, 18 tribos e oito subfamílias (Dolichoderinae, Ecitoninae, Ectatomminae, Formicinae, Heteroponerinae, Myrmicinae, Ponerinae e Pseudomyrmecinae. Dos três ambientes amostrados, de acordo com o estimador de riqueza jackknife de primeira ordem, a mata nativa apresentou a maior riqueza (Sest= 37,5, seguindo-se a barreira pedregosa (Sest= 8,9 e as areias da orla (Sest= 5,9. Apenas Acromyrmex laticeps, Crematogaster sp. e Solenopsis invicta foram comuns aos três ambientes. Neste trabalho é feito o primeiro registro de ocorrência de Pachycondyla crenata e Pachycondyla laevigata (Ponerinae para o Rio Grande do Sul.Aiming to improve the knowledge on the Brazilian biodiversity, especially the ant fauna of Rio Grande do Sul State (Southern Brazil, this survey was conducted in the Praia da Pedreira, a site of Intensive Use of the Parque Estadual de Itapuã. Ground-dwelling ant species were surveyed for three environments in the beach (native forest, rock bar and sand bar, during 12 months (April/2000 - March/2001. Collections resulted in 60 species belonging to 24 genera, 18 tribes and eight subfamilies (Dolichoderinae, Ecitoninae, Ectatomminae, Formicinae, Heteroponerinae, Myrmicinae, Ponerinae and Pseudomyrmecinae. According to the first order jackknife estimator, the native forest area presented the greatest richness (Sest= 37.5, followed by rock bar (Sest= 8.9 and sand bar (Sest= 5.9. Only Acromyrmex laticeps, Crematogaster sp. and Solenopsis invicta were common to all three environments. This paper presents the first record of Pachycondyla crenata and Pachycondyla laevigata (Ponerinae occurrence in the Rio Grande do Sul

  13. Pheromone disruption of Argentine ant trail integrity.

    Suckling, D M; Peck, R W; Manning, L M; Stringer, L D; Cappadonna, J; El-Sayed, A M

    2008-12-01

    Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m(2)) to 1- and 4-m(2) plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. PMID:19034574

  14. Calibration of vector navigation in desert ants.

    Collett, M; Collett, T. S.; Wehner, R

    1999-01-01

    Desert ants (Cataglyphis sp.) monitor their position relative to the nest using a form of dead reckoning [1] [2] [3] known as path integration (PI) [4]. They do this with a sun compass and an odometer to update an accumulator that records their current position [1]. Ants can use PI to return to the nest [2] [3]. Here, we report that desert ants, like honeybees [5] and hamsters [6], can also use PI to approach a previously visited food source. To navigate to a goal using only PI information, a...

  15. Data classification by Fuzzy Ant-Miner

    Mohamed Hamlich

    2012-03-01

    Full Text Available In this paper we propose an extension of classification algorithm based on ant colony algorithms to handle continuous valued attributes using the concepts of fuzzy logic. The ant colony algorithms transform continuous attributes into nominal attributes by creating clenched discrete intervals. This may lead to false predictions of the target attribute, especially if the attribute value history is close to the borders of discretization. Continuous attributes are discretized on the fly into fuzzy partitions that will be used to develop an algorithm called Fuzzy Ant-Miner. Fuzzy rules are generated by using the concept of fuzzy entropy and fuzzy fitness of a rule.

  16. Faster-is-slower effect in escaping ants revisited: Ants do not behave like humans

    Parisi, Daniel R; Josens, Roxana

    2014-01-01

    In this work we studied the trajectories, velocities and densities of ants when egressing under controlled levels of stress produced by a chemical repellent at different concentrations. We found that, unlike other animals escaping under life-and-death conditions and pedestrian simulations, ants do not produce a higher density zone near the exit door. Instead, ants are uniformly distributed over the available space allowing for efficient evacuations. Consequently, the faster-is-slower effect observed in ants (Soria et al., 2012) is clearly of a different nature to that predicted by de social force model. In the case of ants, the minimum evacuation time is correlated with the lower probability of taking backward steps. Thus, as biological model ants have important differences that make their use inadvisable for the design of human facilities.

  17. Faster-is-slower effect in escaping ants revisited: Ants do not behave like humans

    Parisi, Daniel R.; Soria, Sabrina A; Josens, Roxana

    2014-01-01

    In this work we studied the trajectories, velocities and densities of ants when egressing under controlled levels of stress produced by a chemical repellent at different concentrations. We found that, unlike other animals escaping under life-and-death conditions and pedestrian simulations, ants do not produce a higher density zone near the exit door. Instead, ants are uniformly distributed over the available space allowing for efficient evacuations. Consequently, the faster-is-slower effect o...

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

    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. PMID:25571873

  19. Are ant feces nutrients for plants? A metabolomics approach to elucidate the nutritional effects on plants hosting weaver ants

    Vidkjær, Nanna Hjort; Wollenweber, Bernd; Gislum, René;

    2015-01-01

    Weaver ants (genus Oecophylla) are tropical carnivorous ant species living in high numbers in the canopies of trees. The ants excrete copious amounts of fecal matter on leaf surfaces, and these feces may provide nutrients to host trees. This hypothesis is supported by studies of ant-plant interac...

  20. Egocentric information helps desert ants to navigate around familiar obstacles.

    Bisch-Knaden, S.; Wehner, R.

    2001-01-01

    Homing ants have been shown to associate directional information with familiar landmarks. The sight of these local cues might either directly guide the path of the ant or it might activate a landmark-based vector that points towards the goal position. In either case, the ants define their courses within allocentric systems of reference. Here, we show that desert ants, Cataglyphis fortis, forced to run along a devious path can use egocentric information as well. The ants were trained to deviat...

  1. Rose Atoll - Eradication of Invasive Ants

    US Fish and Wildlife Service, Department of the Interior — There are at least 9 species of ants introduced to Rose Atoll, including species that tend to scale insects that are devastating the Pisonia grandis trees on the 15...

  2. Thomas Stearns Elioti neoklassitsistlik luuleteooria / Ants Oras

    Oras, Ants

    2003-01-01

    Varem ilmunud: rmt.: "Looming" 1932, nr. 2, lk. 196-208 ; rmt.: Ants Oras, "Laiemasse ringi : kirjanduslikke perspektiive ja profiile". Stockholm : Vaba Eesti, 1961, lk. 29-48, pealkirjaga "T. S. Elioti neoklassiline luuleteooria"

  3. An Improved Heuristic Ant-Clustering Algorithm

    Yunfei Chen; Yushu Liu; Jihai Zhao

    2004-01-01

    An improved heuristic ant-clustering algorithm(HAC)is presented in this paper. A device of 'memory bank' is proposed,which can bring forth heuristic knowledge guiding ant to move in the bi-dimension grid space.The device experiments on real data sets and synthetic data sets.The results demonstrate that HAC has superiority in misclassification error rate and runtime over the classical algorithm.

  4. Structure and formation of ant transportation networks

    Latty, Tanya; Ramsch, Kai; Ito, Kentaro; Nakagaki, Toshiyuki; Sumpter, David J. T.; Middendorf, Martin; Beekman, Madeleine

    2011-01-01

    Many biological systems use extensive networks for the transport of resources and information. Ants are no exception. How do biological systems achieve efficient transportation networks in the absence of centralized control and without global knowledge of the environment? Here, we address this question by studying the formation and properties of inter-nest transportation networks in the Argentine ant (Linepithema humile). We find that the formation of inter-nest networks depends on the number...

  5. Statistical Approach for Selecting Elite Ants

    S., Raghavendra G

    2012-01-01

    Applications of ACO algorithms to obtain better solutions for combinatorial optimization problems have become very popular in recent years. In ACO algorithms, group of agents repeatedly perform well defined actions and collaborate with other ants in order to accomplish the defined task. In this paper, we introduce new mechanisms for selecting the Elite ants dynamically based on simple statistical tools. We also investigate the performance of newly proposed mechanisms.

  6. On Ants, Bacteria and Dynamic Environments

    Ramos, Vitorino; Fernandes, Carlos; Rosa, Agostinho C

    2005-01-01

    Wasps, bees, ants and termites all make effective use of their environment and resources by displaying collective swarm intelligence. Termite colonies - for instance - build nests with a complexity far beyond the comprehension of the individual termite, while ant colonies dynamically allocate labor to various vital tasks such as foraging or defense without any central decision-making ability. Recent research suggests that microbial life can be even richer: highly social, intricately networked...

  7. Clustering outdoor soundscapes using fuzzy ants

    De Coensel, Bert; Botteldooren, Dick; Debacq, K.; Nilsson, M.E.; Berglund, B

    2008-01-01

    A classification algorithm for environmental sound recordings or "soundscapes" is outlined. An ant clustering approach is proposed, in which the behavior of the ants is governed by fuzzy rules. These rules are optimized by a genetic algorithm specially designed in order to achieve the optimal set of homogeneous clusters. Soundscape similarity is expressed as fuzzy resemblance of the shape of the sound pressure level histogram, the frequency spectrum and the spectrum of temporal fluctuations. ...

  8. Covenant idea in ante-Nicene theology

    Duncan, Jennings Ligon

    1995-01-01

    This thesis argues that the covenant idea was more significant in the writings of particular ante-Nicene theologians than has generally been admitted in patristic research or general surveys of the history of the covenant idea in the Christian tradition. Indeed, this survey of the covenant idea in the ante-Nicene period demonstrates a significant usage, development, and modification of the covenant concept as it is found in the OT and NT writings and in early Judaism. This investigation revea...

  9. Worker Longevity in Harvester Ants (Pogonomyrmex)

    Gordon, D M; Hölldobler, B.

    1987-01-01

    Most studies of worker longevity in ants have been made in the laboratory (Haskins and Haskins 1980; Porter and Tschinkel 1982). In the field, increased energy expenditures, predation, and environmental fluctuations may all contribute to shorten the life of a worker ant. In the few existing studies of worker longevity conducted in the field, the lifespan of exterior workers was found to be extremely short. For example, Schmid-Hempel and Schmid- Hempel (1984) found that the half-life of Catagl...

  10. Data classification by Fuzzy Ant-Miner

    Mohamed Hamlich; Mohammed Ramdani

    2012-01-01

    In this paper we propose an extension of classification algorithm based on ant colony algorithms to handle continuous valued attributes using the concepts of fuzzy logic. The ant colony algorithms transform continuous attributes into nominal attributes by creating clenched discrete intervals. This may lead to false predictions of the target attribute, especially if the attribute value history is close to the borders of discretization. Continuous attributes are discretized on the fly into fuzz...

  11. Optic disc detection using ant colony optimization

    Dias, Marcy; Monteiro, Fernando C.

    2012-01-01

    The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detectio...

  12. Automatic Programming with Ant Colony Optimization

    Green, Jennifer; Jacqueline L. Whalley; Johnson, Colin G.

    2004-01-01

    Automatic programming is the use of search techniques to find programs that solve a problem. The most commonly explored automatic programming technique is genetic programming, which uses genetic algorithms to carry out the search. In this paper we introduce a new technique called Ant Colony Programming (ACP) which uses an ant colony based search in place of genetic algorithms. This algorithm is described and compared with other approaches in the literature.

  13. HERBAL PLANTS AS AN ANT REPELLENT

    Chaudhari PS*, Jangam SS Chaudhari SV, Baheti KG, Patil SU and Jadhav GB

    2013-01-01

    The present study focused on developing effective ant repellent from herbal plant extracts. The extracts of mentioned plants were prepared by grinding with water. The aqueous extracts were treated individually as well as in different combination against 15 ants at dose levels of 1%, 5%, 10%. Observations were made at 5 min of time intervals for total period of 15 min. Highest % repellency was recorded in cucumber-mint (100%) , lemon-garlic (100%), garlic-mint (100%) & all plant mixture (1...

  14. Entangled active matter: From cells to ants

    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.

  15. Toxic industrial deposit remediation by ant activity

    Jilkova, Veronika; Frouz, Jan

    2016-04-01

    Toxic industrial deposits are often contaminated by heavy metals and the substrates have low pH values. In such systems, soil development is thus slowed down by high toxicity and acidic conditions which are unfavourable to soil fauna. Ants (Hymenoptera, Formicidae) are considered tolerant to heavy metal pollution and are known to increase organic matter content and microbial activity in their nests. Here, we focused on soil remediation caused by three ant species (Formica sanguinea, Lasius niger, and Tetramorium sp.) in an ore-washery sedimentation basin near Chvaletice (Czech Republic). Soil samples were taken from the centre of ant nests and from the nest surroundings (>3 m from nests). Samples were then analyzed for microbial activity and biomass and contents of organic matter and nutrients. As a result, ant species that most influenced soil properties was F. sanguinea as there were higher microbial activity and total nitrogen and ammonia contents in ant nests than in the surrounding soil. We expected such a result because F. sanguinea builds conspicuous large nests and is a carnivorous species that brings substantial amounts of nitrogen in insect prey to their nests. Effects of the other two ant species might be lower because of smaller nests and different feeding habits as they rely mainly on honeydew from aphids or on plant seeds that do not contain much nutrients.

  16. Exploration adjustment by ant colonies.

    Doran, Carolina; Stumpe, Martin C; Sendova-Franks, Ana; Franks, Nigel R

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  17. Preference of food particle size among several urban ant species.

    Hooper-Bùi, Linda M; Appel, Arthur G; Rust, Michael K

    2002-12-01

    Appropriate particle size may be a critical characteristic for effective granular ant baits. We examined the particle size preference of six species of pest ants to an anchovy-based bait. We also examined head capsule widths of Argentine ants, Linepithema humile (Mayr) (mean = 0.54 mm), California harvester ants, Pogonomyrmex californicus (Buckley) (mean = 1.63 mm), red imported fire ants, Solenopsis invicta Buren (mean = 0.9 mm), and southern fire ants, Solenopsis xyloni McCook (mean = 0.76 mm) and compared them with the first and second most preferred particle size. There were differences between particle size of which the most mass was removed and of which there were more particles removed by ants. California Argentine ants, southern fire ants, and Alabama Argentine ants removed more 840 to 1,000-microm particle mass of the anchovy diet but had more visits to dishes containing 420 to 590 microm particles. California harvester ants and Allegheny mound ants, Formica spp., removed more >2,000 microm particle mass but visited dishes containing 1,000 to 2,000 microm particles more often. Red imported fire ants also removed more >2,000 microm particle mass but visited dishes with 590 to 840-microm particles most often. Pharaoh ants, Monomorium pharaonis (L.), removed and visited 420 to 590-microm particles more than any other size. A linear regression model determined that particle size preferred by each ant species relates to forager head width. The majority of particles of commercial ant bait, including Amdro, Ascend, Award, Bushwhacker, Max Force with fipronil, and old and new formulations of Max Force with hydramethylnon, were 1,000 to 2,000 microm, but the majority of Niban particles were ant baits to fit the particle size preference of each pest ant species may increase the efficacy of ant baits. PMID:12539835

  18. No detection of Vairimorpha invictae in fire ant decapitating flies reared from V. invictae- infected ants

    Vairimorpha invictae is a microsporidian entomopathogen that is under evaluation as a biological control agent for red imported fire ants, Solenopsis invicta. Infections of V. invictae alone and in combination with another pathogen of fire ants, Thelohania solenopsae, have resulted in declines of 5...

  19. Solution to the problem of ant being stuck by ant colony routing algorithm

    ZHAO Jing; TONG Wei-ming

    2009-01-01

    Many ant colony routing (ACR) algorithms have been presented in recent years, but few have studied the problem that ants will get stuck with probability in any terminal host when they are searching paths to route packets around a network. The problem has to be faced when designing and implementing the ACR algorithm. This article analyzes in detail the differences between the ACR and the ant colony optimization (ACO). Besides, particular restrictions on the ACR are pointed out and the three causes of ant being-stuck problem are obtained. Furthermore, this article proposes a new ant searching mechanism through dual path-checking and online routing loop removing by every intermediate node an ant visited and the destination host respectively, to solve the problem of ant being stuck and routing loop simultaneously. The result of numerical simulation is abstracted from one real network. Compared with existing two typical ACR algorithms, it shows that the proposed algorithm can settle the problem of ant being stuck and achieve more effective searching outcome for optimization path.

  20. Oecophylla smaragdina food conversion efficiency: prospects for ant farming

    Offenberg, Hans Joachim

    2011-01-01

    can be combined with the use of the ants in biological control programmes in tropical plantations where pest insects are converted into ant biomass. To assess the cost-benefits of ant farming based on artificial feeding, food consumption and food conversion efficiency (ECI) of Oecophylla smaragdina......Oecophylla ants are sold at high prices on several commercial markets as a human delicacy, as pet food or as traditional medicine. Currently markets are supplied by ants collected from the wild; however, an increasing interest in ant farming exists as all harvest is easily sold and as ant farming...... (Fabricius) was tested under laboratory conditions. Of the two types of food offered, the ants ingested 76% pure sucrose and 24% insect prey (dry weights) leading to ECI’s of 29% and 39% including brood only or brood plus imago gain, respectively. Based on Thai sugar and protein food costs and ant brood...

  1. Impacts of residual insecticide barriers on perimeter-invading ants, with particular reference to the odorous house ant, Tapinoma sessile.

    Scharf, Michael E; Ratliff, Catina R; Bennett, Gary W

    2004-04-01

    Three liquid insecticide formulations were evaluated as barrier treatments against perimeter-invading ants at a multifamily housing complex in West Lafayette, IN. Several ant species were present at the study site, including (in order of abundance) pavement ant, Tetramorium caespitum (L.); honey ant, Prenolepis imparis (Say); odorous house ant, Tapinoma sessile (Say); thief ant, Solenopsis molesta (Say); acrobat ant, Crematogaster ashmeadi (Mayr); crazy ant, Paratrechina longicornis (Latrielle), field ants, Formica spp.; and carpenter ant Camponotus pennsylvanicus (DeGeer). Studies began in May 2001 and concluded 8 wk later in July. Individual replicate treatments were placed 0.61 in (2 feet) up and 0.92 m (3 feet) out from the ends of 46.1 by 10.1-m (151 by 33-foot) apartment buildings. Ant sampling was performed with 10 placements of moist cat food for 1 h within treatment zones, followed by capture and removal of recruited ants for later counting. All treatments led to substantial reductions in ant numbers relative to untreated controls. The most effective treatment was fipronil, where 2% of before-treatment ant numbers were present at 8 wk after treatment. Both imidacloprid and cyfluthrin barrier treatments had efficacy comparative with fipronil, but to 4 and 2 wk, respectively. Odorous house ants were not sampled before treatment. Comparisons of ant species composition between treatments and controls revealed an increase in odorous house ant frequencies at 1-8 wk after treatment in treated locations only. These results demonstrate efficacy for both nonrepellent and repellent liquid insecticides as perimeter treatments for pest ants. In addition, our findings with odorous house ant highlight an apparent invasive-like characteristic of this species that may contribute to its dramatic increase in structural infestation rates in many areas of the United States. PMID:15154488

  2. The distribution of weaver ant pheromones on host trees

    Offenberg, Joachim

    2007-01-01

    The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested for ...... leaves. Also there was a positive correlation between spot density and the likelihood of being detected by ants. Anal spots may thus function as reliable cues to interacting species and be an important factor in shaping the community around Oecophylla colonies.......The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested for...... correlations between spot density, ant activity and the likelihood of being detected by an ant. Spots were only found on trees with ants. On ant-trees, spots were distributed throughout the trees but with higher densities in areas with high ant activity and pheromone densities were higher on twigs compared to...

  3. Ecology of a fig ant-plant

    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.

  4. The descent of ant: field-measured performance of gliding ants.

    Munk, Yonatan; Yanoviak, Stephen P; Koehl, M A R; Dudley, Robert

    2015-05-01

    Gliding ants avoid predatory attacks and potentially mortal consequences of dislodgement from rainforest canopy substrates by directing their aerial descent towards nearby tree trunks. The ecologically relevant measure of performance for gliding ants is the ratio of net horizontal to vertical distance traveled over the course of a gliding trajectory, or glide index. To study variation in glide index, we measured three-dimensional trajectories of Cephalotes atratus ants gliding in natural rainforest habitats. We determined that righting phase duration, glide angle, and path directness all significantly influence variation in glide index. Unsuccessful landing attempts result in the ant bouncing off its target and being forced to make a second landing attempt. Our results indicate that ants are not passive gliders and that they exert active control over the aerodynamic forces they experience during their descent, despite their apparent lack of specialized control surfaces. PMID:25788722

  5. Ant colony optimization algorithm for continuous domains based on position distribution model of ant colony foraging.

    Liu, Liqiang; Dai, Yuntao; Gao, Jinyu

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm. PMID:24955402

  6. Improving the cAnt-MinerPB Classification Algorithm

    Medland, Matthew; Otero, Fernando E. B.; Freitas, Alex A

    2012-01-01

    Ant Colony Optimisation (ACO) has been successfully applied to the classification task of data mining in the form of Ant-Miner. A new extension of Ant-Miner, called cAnt-MinerPB, uses the ACO procedure in a different fashion. The main difference is that the search in cAnt-MinerPB is optimised to find the best list of rules, whereas in Ant-Miner the search is optimised to find the best individual rule at each step of the sequential covering, producing a list of best rules. We aim to improve cA...

  7. Fossil evidence for the early ant evolution

    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.

  8. Statistical Mechanics of Collective Transport by Ants

    Pinkoviezky, Itai; Gelblum, Aviram; Fonio, Ehud; Ghosh, Abhijit; Gov, Nir; Feinerman, Ofer

    Collective decisions and cooperation within groups are essential for the survival of many species. Conflicts within the group must be suppressed but conformism may render the system unresponsive to new information. Collective transport by ants is therefore an ideal model system to study how animal groups optimize these opposing requirements. We combine experiments and theory to characterize the collective transport. The ants are modeled as binary Ising spins, representing the two roles ants can perform during transport. It turns out that the ants poise themselves collectively near a critical point where the response to a newly attached ant is maximized. We identify the size as being proportional to an inverse effective temperature and thus the system can exhibit a mesoscopic transition between order and disorder by manipulating the size. Constraining the cargo with a string makes the system behave as a strongly non-linear pendulum. Theoretically we predict that a Hopf bifurcation occurs at a critical size followed by a global bifurcation where full swings emerge. Remarkably, these theoretical predictions were verified experimentally.

  9. Early ant trajectories: spatial behaviour before behaviourism.

    Wehner, Rüdiger

    2016-04-01

    In the beginning of the twentieth century, when Jacques Loeb's and John Watson's mechanistic view of life started to dominate animal physiology and behavioural biology, several scientists with different academic backgrounds got engaged in studying the wayfinding behaviour of ants. Largely unaffected by the scientific spirit of the time, they worked independently of each other in different countries: in Algeria, Tunisia, Spain, Switzerland and the United States of America. In the current literature on spatial cognition these early ant researchers-Victor Cornetz, Felix Santschi, Charles Turner and Rudolf Brun-are barely mentioned. Moreover, it is virtually unknown that the great neuroanatomist Santiago Ramón y Cajal had also worked on spatial orientation in ants. This general neglect is certainly due to the fact that nearly all these ant researchers were scientific loners, who did their idiosyncratic investigations outside the realm of comparative physiology, neurobiology and the behavioural sciences of the time, and published their results in French, German, and Spanish at rather inaccessible places. Even though one might argue that much of their work resulted in mainly anecdotal evidence, the conceptual approaches of these early ant researchers preempt much of the present-day discussions on spatial representation in animals. PMID:26898725

  10. Ecosystem services delivered by weaver ants

    Offenberg, Joachim

    other species are more likely to form trophobioses with hompteran species that act as disease vectors. Lastly, weaver ants are edible and easy to harvest. They can be utilized for protein production and harvested in significant amounts at the same time as they are managing insect pests. In other words...... they convert pest insects into accessible and edible protein. In short, this review show that weaver ants in agriculture can increase crop yields, improve fruit quality, chemically deter pests, fertilize crops, reduce diseases, and produce protein for human and livestock consumption.......Weaver ants (Oecopgylla spp.) are increasingly being utilized as efficient biocontrol agents in a number of tropical tree crops, as they prey on pest insects and increase yields. However, recent studies and a review of the literature reveal that a number of other services may derive from the...

  11. Swarm controlled emergence for ant clustering

    Scheidler, Alexander; Merkle, Daniel; Middendorf, Martin

    2013-01-01

    .g. moving robots, and clustering algorithms. Design/methodology/approach: Different types of control agents for that ant clustering model are designed by introducing slight changes to the behavioural rules of the normal agents. The clustering behaviour of the resulting swarms is investigated by extensive......Purpose: Swarm controlled emergence is proposed as an approach to control emergent effects in (artificial) swarms. The method involves the introduction of specific control agents into the swarm systems. Control agents behave similar to the normal agents and do not directly influence the behavior...... of the normal agents. The specific design of the control agents depends on the particular swarm system considered. The aim of this paper is to apply the method to ant clustering. Ant clustering, as an emergent effect, can be observed in nature and has inspired the design of several technical systems, e...

  12. Desert ants learn vibration and magnetic landmarks.

    Cornelia Buehlmann

    Full Text Available The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context.

  13. Recognition of social identity in ants

    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...

  14. Moribund Ants Do Not Call for Help.

    Miler, Krzysztof

    2016-01-01

    When an antlion captures a foraging ant, the victim's nestmates may display rescue behaviour. This study tested the hypothesis that the expression of rescue behaviour depends on the life expectancy of the captured ant. This hypothesis predicts that the expression of rescue behaviour will be less frequent when the captured ant has a lower life expectancy than when it has a higher life expectancy because such a response would be adaptive at the colony level. Indeed, significant differences were found in the frequency of rescue behaviours in response to antlion victims with differing life expectancies. In agreement with prediction, victims with lower life expectancies were rescued less frequently, and those rescues had a longer latency and shorter duration. There was also a qualitative difference in the behaviour of rescuers to victims from the low and high life expectancy groups. Several explanations for these findings are proposed. PMID:26986741

  15. Hopfield neural network based on ant system

    洪炳镕; 金飞虎; 郭琦

    2004-01-01

    Hopfield neural network is a single layer feedforward neural network. Hopfield network requires some control parameters to be carefully selected, else the network is apt to converge to local minimum. An ant system is a nature inspired meta heuristic algorithm. It has been applied to several combinatorial optimization problems such as Traveling Salesman Problem, Scheduling Problems, etc. This paper will show an ant system may be used in tuning the network control parameters by a group of cooperated ants. The major advantage of this network is to adjust the network parameters automatically, avoiding a blind search for the set of control parameters.This network was tested on two TSP problems, 5 cities and 10 cities. The results have shown an obvious improvement.

  16. An ant's-eye view of an ant-plant protection mutualism.

    Lanan, M C; Bronstein, J L

    2013-07-01

    Ant protection of extrafloral nectar (EFN)-secreting plants is a common form of mutualism found in most habitats around the world. However, very few studies have considered these mutualisms from the ant, rather than the plant, perspective. In particular, a whole-colony perspective that takes into account the spatial structure and nest arrangement of the ant colonies that visit these plants has been lacking, obscuring when and how colony-level foraging decisions might affect tending rates on individual plants. Here, we experimentally demonstrate that recruitment of Crematogaster opuntiae (Buren) ant workers to the EFN-secreting cactus Ferocactus wislizeni (Englem) is not independent between plants up to 5 m apart. Colony territories of C. opuntiae are large, covering areas of up to 5,000 m(2), and workers visit between five and 34 EFN-secreting barrel cacti within the territories. These ants are highly polydomous, with up to 20 nest entrances dispersed throughout the territory and interconnected by trail networks. Our study demonstrates that worker recruitment is not independent within large polydomous ant colonies, highlighting the importance of considering colonies rather than individual workers as the relevant study unit within ant/plant protection mutualisms. PMID:23515612

  17. Recruitment strategies and colony size in ants.

    Robert Planqué

    Full Text Available Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method. Very small colonies tend to use solitary foraging; small to medium sized colonies use tandem running or group recruitment whereas larger colonies use pheromone recruitment trails. Until now, explanations for this correlation have focused on the ants' ecology, such as food resource distribution. However, many species have colonies with a single queen and workforces that grow over several orders of magnitude, and little is known about how a colony's organization, including recruitment methods, may change during its growth. After all, recruitment involves interactions between ants, and hence the size of the colony itself may influence which recruitment method is used--even if the ants' behavioural repertoire remains unchanged. Here we show using mathematical models that the observed correlation can also be explained by recognizing that failure rates in recruitment depend differently on colony size in various recruitment strategies. Our models focus on the build up of recruiter numbers inside colonies and are not based on optimality arguments, such as maximizing food yield. We predict that ant colonies of a certain size should use only one recruitment method (and always the same one rather than a mix of two or more. These results highlight the importance of the organization of recruitment and how it is affected by colony size. Hence these results should also expand our understanding of ant ecology.

  18. Ant-gardens of tropical Asian rainforests

    Kaufmann, Eva; Maschwitz, Ulrich

    2006-05-01

    Ant-garden (AG) associations are systems of epiphytic plants and arboricolous (i.e., tree-living) ants, in which the ants build fragile carton nests containing organic material. They collect and incorporate seeds or fruits of epiphytes that then germinate and grow on the nest [sensu Corbara et al. (1999) 38:73-89]. The plant roots stabilize the nest carton. AGs have been well-known in the neotropics for more than 100 years. In contrast, reports on similar associations in the paleotropics are scarce so far. After discovering a first common AG system on giant bamboo [Kaufmann et al. (2001) 48:125-133], we started a large-scale survey for AGs in Peninsular Malaysia, Borneo, Java, and southern Thailand. A great variety of AG systems (altogether including 18 ant species and 51 plant species) was discovered and is described in the present paper. The high number of species participating in AG associations was reflected by a great variability in the specific appearances of the nest gardens. Frequently, further groups of organisms (e.g., hemipteran trophobionts, fungi) were also involved. Preference patterns of particular ant and epiphyte species for each other and for particular phorophytes (carrier trees) were detected. We integrate domatia-producing, so-called ant-house epiphytes in our study and compare their phases of establishment, as well as other characteristics, to “classical” AGs, coming to the conclusion that they should be regarded only as a special type of AG epiphyte and not as a separate ecological category.

  19. Fuzzy system identification via chaotic ant swarm

    In this paper, we introduce a chaotic optimization method, called CAS (chaotic ant swarm), to solve the problem of designing a fuzzy system to identify dynamical systems. The position vector of each ant in the CAS algorithm corresponds to the parameter vector of the selected fuzzy system. At each learning time step, the CAS algorithm is iterated to give the optimal parameters of fuzzy systems based on the fitness theory. Then the corresponding CAS-designed fuzzy system is built and applied to the identification of the unknown nonlinear dynamical systems. Numerical simulation results are provided to show the effectiveness and feasibility of the developed CAS-designed fuzzy system.

  20. Bus Network Modeling Using Ant Algorithms

    Sepideh Eshragh

    2010-02-01

    Full Text Available Bus transit network modeling is a complex and combinatorial problem. The main purpose of this paper is to apply a contemporary method for designing a bus transit network with the objective of achieving optimum results. The method is called Ant Algorithms, a Meta Heuristic method, which has been applied to optimization problems in transportation with noticeable success. The description of the algorithm, as well as the main methodology and computations, is presented in this paper. Furthermore, a case study using Ant Algorithms applied to the city of Ghazvin, one of the most important suburbs of Tehran, Iran, is presented.

  1. Antes del analizante (Freud 1877-1888)

    Pierre Bruno

    2011-01-01

    Freud antes del analizante, es decir, antes de encontrarse con Fliess. Durante ese periodo, de 1877 a 1888 (entre los 21 y los 32 años de edad), Freud mantiene una relación con cinco “campos del saber”: la histología, la cocaína, la histeria, la hipnosis y la afasia. La lectura de esos textos nos permite hacer el seguimiento de cómo Freud se separa de la neurología sin afiliarse a la psicología. Palabras clave: afasia, Freud, hipnosis, histeria, neurolog...

  2. Sobre: Julio Ortega Bobadilla, Foucault ante Freud

    Zavaleta Betancourt, José Alfredo; IIH-S, Universidad Veracruzana, Xalapa, Ver.

    2014-01-01

    Desde el título, Foucault ante Freud es un texto elíptico. Quizá debería titularse Foucault contra Freud o bien Freud ante Foucault o, mejor, Freud a pesar de Foucault. Ortega describe el contexto de las relaciones discursivas de Foucault con mÚltiples autores que lo influyeron: modelos ejempla- res, mentores o aliados, y es vasta la información que utiliza para reconstruir el contexto de esta lucha discursiva. 

  3. Lithiase géante sur enterocystoplastie

    Elmortaji, Khalid; Elomri, Ghassane; Bennani, Saad; Rabii, Redouane; Aboutaib, Rachid; Meziane, Fethi

    2014-01-01

    La formation des lithiases est une complication fréquente des entérocystoplasties après cystectomie radicale pour tumeur de vessie infiltrante. Le délai d'apparition dépend des facteurs de risque favorisants notamment les infections urinaires. Néanmoins la survenue de lithiase géante sur néovessie reste exceptionnelle, seulement 5 cas ont été rapportés dans la littérature. Nous rapportons dans ce travail, le cas d'une lithiase géante compliquant une entérocystoplastie chez un malade suivi pou...

  4. The ejaculatory biology of leafcutter ants

    den Boer, Susanne; Stürup, Marlene; Boomsma, Jacobus Jan;

    2015-01-01

    The eusocial ants are unique in that females (queens) acquire and store sperm on a single mating flight early in adult life. This event largely determines the size (possibly millions of workers), longevity (possibly decades) and genetic variation of the colonies that queens found, but our...... understanding of the fundamental biology of ejaculate production, transfer and physiological function remains extremely limited. We studied the ejaculation process in the leafcutter ant Atta colombica and found that it starts with the appearance of a clear pre-ejaculatory fluid (PEF) at the tip of the...

  5. GrAnt: Inferring Best Forwarders from Complex Networks' Dynamics through a Greedy Ant Colony Optimization

    Kochem Vendramin, Ana Cristina; Munaretto, Anelise; Regattieri Delgado, Myriam; Carneiro Viana, Aline

    2011-01-01

    This paper presents a new prediction-based forwarding protocol for the complex and dynamic Delay Tolerant Networks (DTN). The proposed protocol is called GrAnt (Greedy Ant) as it uses a greedy transition rule for the Ant Colony Optimization (ACO) metaheuristic to select the most promising forwarder nodes or to provide the exploitation of good paths previously found. The main motivation for the use of ACO is to take advantage of its population-based search and of the rapid adaptation of its le...

  6. Predation by ants on arthropods and other animals

    Cerdá, Xim; Dejean, A

    2011-01-01

    Ants are the most widely distributed and most numerically abundant group of social insects. First, they were ground- or litter-dwelling predators or scavengers, and certain taxa evolved to adopt an arboreal way of life. Most ant species are generalist feeders, and only some ground-nesting and ground- foraging species are strictly predators. Ants are central-place foragers (with the exception of army ants during the nomadic phase) that may use different foraging strategies. Solitary hunting is...

  7. Trait-Mediated Indirect Effects of Phorid Flies on Ants

    Hsun-Yi Hsieh; Ivette Perfecto

    2012-01-01

    This paper provides a synthesis of the ecological impact of phorid fly parasitoids on ants. We find the most important impact of phorids on ants to be trait-mediated effects. Phorids diminish the foraging activity of ants, frequently reducing the number and average size of foragers and reducing the amount of food retrieved by a colony. However, ants' coping mechanisms include changing foraging site and time. Phorids can also affect competition, especially through changes in the ability of the...

  8. Liquid baits control Argentine ants sustainably in coastal vineyards

    Cooper, Monica L; Daane, Kent M.; Nelson, Erik H; Varela, Lucia G; Battany, Mark; Tsutsui, Neil D.; Rust, M K

    2008-01-01

    Liquid ant baits are an alternative to broad-spectrum insecticide sprays conventionally used to control Argentine ants. We review the development of liquid ant baits, which capitalize on the ants’ sugar-feeding requirements and social structure to deliver small doses of toxicant throughout the colony. The ant bait program described here, developed for commercial vineyards, also has the potential to facilitate the use of biological controls for mealybug and scale pests. The implementation of a...

  9. Millipede defense: use of detachable bristles to entangle ants.

    Eisner, T.; Eisner, M; Deyrup, M.

    1996-01-01

    The millipede Polyxenus fasciculatus (Diplopoda; Polyxenida) defends itself against ants by use of a pair of bristle tufts at its rear. When attacked, it wipes the tufts against the ants, thereby causing these to become encumbered by bristles that detach from the tufts. Ants contaminated with bristles desist from their assault. The bristles have grappling hooks at the tip by which they lock onto setae of the ants and barbs along their length by which they interlink. In attempting to rid thems...

  10. Tracing the Rise of Ants - Out of the Ground

    Lucky, Andrea; Trautwein, Michelle D.; Guénard, Benoit S.; Weiser, Michael D.; Dunn, Robert R.

    2013-01-01

    The evolution of ants (Hymenoptera: Formicidae) is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions ...

  11. Extended phenotype: nematodes turn ants into bird-dispersed fruits

    Hughes, D P; Kronauer, D J C; Boomsma, J J

    2008-01-01

    A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs.......A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs....

  12. Ant-Crypto, a Cryptographer for Data Encryption Standard

    Salabat Khan; Armughan Ali; Mehr Yahya Durrani

    2013-01-01

    Swarm Intelligence and Evolutionary Techniques are attracting the cryptanalysts in the field of cryptography. This paper presents a novel swarm based attack called Ant-Crypto (Ant-Cryptographer) for the cryptanalysis of Data Encryption Standard (DES). Ant-Crypto is based on Binary Ant Colony Optimization (BACO) i.e. a binary search space based directed graph is modeled for efficiently searching the optimum result (an original encryption key, in our case). The reason that why evolutionary tech...

  13. Optimized Ant Colony Algorithm by Local Pheromone Update

    Hui Yu

    2013-01-01

    Ant colony algorithm, a heuristic simulated algorithm, provides better solutions for non-convex, non-linear and discontinuous optimization problems. For ant colony algorithm, it is frequently to be trapped into local optimum, which might lead to stagnation. This article presents the  city-select strategy, local pheromone update strategy, optimum solution prediction strategy and local optimization strategy to optimize ant colony algorithm, provides ant colony algorithm based on local pheromone...

  14. The ant colony metaphor in continuous spaces using boundary search

    Leguizamón, Guillermo

    2003-01-01

    This paper presents an application of the ant colony metaphor for continuous space optimization problems. The ant algortihm proposed works following the principle of the ant colony approach, i.e., a population of agents iteratively, cooperatively, and independently search for a solution. Each ant in the distributed algorithm applies a local search operator which explores the neighborhood region of a particular point in the search space (individual search level). The local search operator i...

  15. Comparative study of nest architecture and colony structure of the fungus-growing ants, Mycocepurus goeldii and M. smithii.

    Rabeling, C; Verhaagh, M; Engels, W

    2007-01-01

    Nest architecture and demography of the non leaf-cutting fungus-growing ant species Mycocepurus goeldii and M. smithii (Attini: Formicidae) were studied in an agroforest habitat near Manaus, Brazil during the excavation of 13 nests. Both species built their nests in two different ways. The first type possessed a "tree-like" architecture, in which a vertical tunnel led downwards and lateral tunnels branched off at 90 degrees angles from the main tunnel, with a chamber at the end of each side branch. Alternatively, other nests displayed a "necklace-like" architecture, where the main tunnel also led down vertically, but entered each chamber from the top and exited it at the bottom, resulting in an architecture where chambers appeared like pearls on a necklace. The nest systems of M. goeldii and M. smithii consisted of 1-21 or 1-15 chambers, respectively. Of 199 excavated chambers, 57 % contained fungus-gardens. Chambers not containing fungus gardens were filled with organic matter from decaying fungus gardens or earthworm feces. Only M. smithii workers deposited loose soil in abandoned chambers during the construction of new nest chambers. Workers of M. smithii constructed significantly smaller chambers than those of M. goeldii. In both species, fungus garden-containing chambers were larger than non-garden chambers and were homogenously distributed in the soil between 17 cm and 105 cm depth. Neither fungus gardens nor abandoned chambers were encountered more frequently in deeper or shallower soil strata indicating that ants of both species did not abandon shallower versus deeper chambers, or move the colony to deeper soil layers with increasing colony age. Fungus gardens were suspended from the ceiling of the subterranean chambers and originated as small mycelial tufts. Through continual addition of organic debris, the tufts first grew vertically to strands before they expanded laterally until most of the chamber volume was filled with fungus garden curtains. New

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

    Stuble, Katharine L.; Kirkman, L. Katherine; Carroll, C. Ronald;

    2011-01-01

    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...... 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...

  17. Dynamics of an ant-plant-pollinator model

    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.

  18. Fire ant control with Entomopathogens in the USA

    Fire ants, Solenopsis richteri and Solenopsis invicta, are stinging invasive ants from South America that infest over 129.5 million hectares in the southern United States. In the southern U.S., eradication is no longer considered possible and toxicant-based fire ant baiting is currently the primary...

  19. Ants Orasest ja Anne Lange monograafiast / Jüri Talvet

    Talvet, Jüri, 1945-

    2005-01-01

    Arvustus: Oras, Ants. Luulekool. I, Apoloogia / koostajad Hando Runnel ja Jaak Rähesoo. Tartu : Ilmamaa, 2003 ; Oras, Ants. Luulekool II, Meistriklass. Tartu : Ilmamaa, 2004 ; Lange, Anne. Ants Oras : [kirjandusteadlane, -kriitik ja tõlkija (1900-1982)]. Tartu : Ilmamaa, 2004

  20. Mutualistic ants as an indirect defence against leaf pathogens.

    González-Teuber, Marcia; Kaltenpoth, Martin; Boland, Wilhelm

    2014-04-01

    Mutualistic ants are commonly considered as an efficient indirect defence against herbivores. Nevertheless, their indirect protective role against plant pathogens has been scarcely investigated. We compared the protective role against pathogens of two different ant partners, a mutualistic and a parasitic ant, on the host plant Acacia hindsii (Fabaceae). The epiphytic bacterial community on leaves was evaluated in the presence and absence of both ant partners by cultivation and by 454 pyrosequencing of the 16S rRNA gene. Pathogen-inflicted leaf damage, epiphytic bacterial abundance (colony-forming units) and number of operational taxonomic units (OTUs) were significantly higher in plants inhabited by parasitic ants than in plants inhabited by mutualistic ants. Unifrac unweighted and weighted principal component analyses showed that the bacterial community composition on leaves changed significantly when mutualistic ants were removed from plants or when plants were inhabited by parasitic ants. Direct mechanisms provided by ant-associated bacteria would contribute to the protective role against pathogens. The results suggest that the indirect defence of mutualistic ants also covers the protection from bacterial plant pathogens. Our findings highlight the importance of considering bacterial partners in ant-plant defensive mutualisms, which can contribute significantly to ant-mediated protection from plant pathogens. PMID:24392817

  1. Extreme Morphogenesis and Ecological Specialization among Cretaceous Basal Ants.

    Perrichot, Vincent; Wang, Bo; Engel, Michael S

    2016-06-01

    Ants comprise one lineage of the triumvirate of eusocial insects and experienced their early diversification within the Cretaceous [1-9]. Their ecological success is generally attributed to their remarkable social behavior. Not all ants cooperate in social hunting, however, and some of the most effective predatory ants are solitary hunters with powerful trap jaws [10]. Recent evolutionary studies predict that the early branching lineages of extant ants formed small colonies of ground-dwelling, solitary specialist predators [2, 5, 7, 11, 12], while some Cretaceous fossils suggest group recruitment and socially advanced behavior among stem-group ants [9]. We describe a trap-jaw ant from 99 million-year-old Burmese amber with head structures that presumably functioned as a highly specialized trap for large-bodied prey. These are a cephalic horn resulting from an extreme modification of the clypeus hitherto unseen among living and extinct ants and scythe-like mandibles that extend high above the head, both demonstrating the presence of exaggerated morphogenesis early among stem-group ants. The new ant belongs to the Haidomyrmecini, possibly the earliest ant lineage [9], and together these trap-jaw ants suggest that at least some of the earliest Formicidae were solitary specialist predators. With their peculiar adaptations, haidomyrmecines had a refined ecology shortly following the advent of ants. PMID:27238278

  2. Tomb evaders: house-hunting hygiene in ants

    Franks, Nigel R; Hooper, James; Webb, Catherine; Dornhaus, Anna

    2005-01-01

    House-hunting ants avoid otherwise excellent potential nest sites that contain dead ants which may pose risks from poor hygiene. This discovery adds another category to the exceptionally long list of nest site attributes that ants evaluate. It further indicates the importance of disease as a selection pressure on social insects.

  3. 7 CFR Appendix to Subpart - Imported Fire Ant

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Imported Fire Ant Appendix to Subpart Agriculture..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations Costs and charges. Pt. 301, Subpt., App. Appendix to Subpart—Imported Fire Ant III. Regulatory Procedures...

  4. Nematode Parasites and Associates of Ants: Past and Present

    George Poinar

    2012-01-01

    Ants can serve as developmental, definitive, intermediate, or carrier hosts of a variety of nematodes. Parasitic ant nematodes include members of the families Mermithidae, Tetradonematidae, Allantonematidae, Seuratidae, Physalopteridae, Steinernematidae, and Heterorhabditidae. Those nematodes that are phoretically associated with ants, internally or externally, are represented by the Rhabditidae, Diplogastridae, and Panagrolaimidae. Fossils of mermithids, tetradonematids, allantonematids, and...

  5. The use of weaver ants (Oecophylla spp.) in tropical agriculture

    Offenberg, Hans Joachim

    2011-01-01

    Canopy dwelling weaver ants are widely distributed throughout the Old World Tropics where they build up high densities on their host trees. If managed properly the high number of ants will control a range of pest insects and benefit crop production. Simultaneously the ant larvae production, fuelled...

  6. Model Specification Searches Using Ant Colony Optimization Algorithms

    Marcoulides, George A.; Drezner, Zvi

    2003-01-01

    Ant colony optimization is a recently proposed heuristic procedure inspired by the behavior of real ants. This article applies the procedure to model specification searches in structural equation modeling and reports the results. The results demonstrate the capabilities of ant colony optimization algorithms for conducting automated searches.

  7. New results of ant algorithms for the Linear Ordering Problem

    Pintea, Camelia-M.; Chira, Camelia; Dumitrescu, D.

    2012-01-01

    Ant-based algorithms are successful tools for solving complex problems. One of these problems is the Linear Ordering Problem (LOP). The paper shows new results on some LOP instances, using Ant Colony System (ACS) and the Step-Back Sensitive Ant Model (SB-SAM).

  8. A Novel delivery Method for Ant (Hymenoptera: Formicidae) toxicants

    Described here is a new delivery method for ant toxicants consisting of an inert carrier, an attractant, and a toxicant. Unlike baits, this system does not contain a food source, but uses ant to ant contact rather than trophallaxis as the mechanism for horizontal dispersal of the toxicant through th...

  9. Dealing with water deficit in Atta ant colonies: large ants scout for water while small ants transport it

    Antonio Carlos Da-Silva

    2012-07-01

    Leafcutter ants (Atta sexdens rubropilosa (Forel 1908 have an elaborate social organization, complete with caste divisions. Activities carried out by specialist groups contribute to the overall success and survival of the colony when it is confronted with environmental challenges such as dehydration. Ants detect variations in humidity inside the nest and react by activating several types of behavior that enhance water uptake and decrease water loss, but it is not clear whether or not a single caste collects water regardless of the cost of bringing this resource back to the colony. Accordingly, we investigated water collection activities in three colonies of Atta sexdens rubropilosa experimentally exposed to water stress. Specifically, we analyzed whether or not the same ant caste foraged for water, regardless of the absolute energetic cost (distance of transporting this resource back to the colony. Our experimental design offered water sources at 0 m, 1 m and 10 m from the nest. We studied the body size of ants near the water sources from the initial offer of water (time  =  0 to 120 min, and tested for specialization. We observed a reduction in the average size and variance of ants that corroborated the specialization hypothesis. Although the temporal course of specialization changed with distance, the final outcome was similar among distances. Thus, we conclude that, for this species, a specialist (our use of the word “specialist” does not mean exclusive task force is responsible for collecting water, regardless of the cost of transporting water back to the colony.

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

    Ballantyne, Gavin Andrew; Willmer, Patricia Gillian

    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 positi...

  11. Nõunik Ants Laansalu - rohkem talupoeg kui sulane / Ants Laansalu ; interv. Heiki Raudla

    Laansalu, Ants, 1938-2011

    2008-01-01

    Intervjuu põllumajandusministeeriumi nõunikuga, kes vastab küsimustele, mis puudutavad Eesti põllumajandusministreid, põllumehe mainet, põllumajanduse tulevikku Eestis ja maailmas. Vt. samas: Ants Laansalu: CV

  12. Ants ja Jaak / Ants Juske, Jaak Juske ; intervjueerinud Margit Tõnson, Maris Sander

    Juske, Ants, 1956-

    2011-01-01

    Kunstiteadlane Ants Juske ja tema poliitikust poeg Jaak Juske räägivad põlvkondade erinevustest ja konfliktidest, oma poliitilisest identiteedist, haridusest, eeskujudest, huvidest, eluviisidest. Nende eluloolisi andmeid

  13. Ants Veetõusme ja tema valikud / Ants Veetõusme ; interv. Imbi E. Kaljuste

    Veetõusme, Ants, 1949-

    2002-01-01

    Eesti Maksumaksjate Liidu juhatuse esimehe Ants Veetõusme varasemast elust ning praegusest tegevusest EML-i juhi, spordijuhi ja FIE-na. Kommenteerivad Tõnu Anton ja Tiit Nuudi. Tartu linnapea 1991-1993

  14. Vestlus päevapoliitikast Ants Vahtrasega / Ants Vahtras ; interv. Hillar Padu

    Vahtras, Ants, 1953-

    2001-01-01

    Keskerakonna Hiiumaa osakonna esimees Ants Vahtras keskendub vestluses Keskerakonna kandidaatidele presidendi valimistele, arutleb presidendile vajalike isikuomaduste, haldusreformi, Hiiumaa Suurkogu, erastamiselt laekuva raha kasutamise üle ning annab hinnangu kultuuripoliitikale. Autor: Keskerakond

  15. The worldwide expansion of the Argentine ant

    Vogel, Valerie; Pedersen, Jes Søe; Giraud, Tatiana;

    2010-01-01

    the native range) and secondary introductions (from sites with established invasive supercolonies) were important in the global expansion of the Argentine ant. In combination with the similar social organization of colonies in the native and introduced range, this indicates that invasiveness did not...

  16. Water surface locomotion in tropical canopy ants.

    Yanoviak, S P; Frederick, D N

    2014-06-15

    Upon falling onto the water surface, most terrestrial arthropods helplessly struggle and are quickly eaten by aquatic predators. Exceptions to this outcome mostly occur among riparian taxa that escape by walking or swimming at the water surface. Here we document sustained, directional, neustonic locomotion (i.e. surface swimming) in tropical arboreal ants. We dropped 35 species of ants into natural and artificial aquatic settings in Peru and Panama to assess their swimming ability. Ten species showed directed surface swimming at speeds >3 body lengths s(-1), with some swimming at absolute speeds >10 cm s(-1). Ten other species exhibited partial swimming ability characterized by relatively slow but directed movement. The remaining species showed no locomotory control at the surface. The phylogenetic distribution of swimming among ant genera indicates parallel evolution and a trend toward negative association with directed aerial descent behavior. Experiments with workers of Odontomachus bauri showed that they escape from the water by directing their swimming toward dark emergent objects (i.e. skototaxis). Analyses of high-speed video images indicate that Pachycondyla spp. and O. bauri use a modified alternating tripod gait when swimming; they generate thrust at the water surface via synchronized treading and rowing motions of the contralateral fore and mid legs, respectively, while the hind legs provide roll stability. These results expand the list of facultatively neustonic terrestrial taxa to include various species of tropical arboreal ants. PMID:24920838

  17. Ant System Algorithm Research and Its Applications

    2002-01-01

    In this paper, systematic review on Ant System (AS) algorithm research and application is made, and the authors works of introducing As algorithm into continuous space application are summarized. Then the applicability characters of AS in continuous space optimization problems are also discussed.

  18. Histrionicotoxin alkaloids finally detected in an ant

    Jones, Tappey H.; Adams, Rachelle Martha Marie; Spande, Thomas F.; Garraffo, H. Martin; Kaneko, Tetsuo; Schultz, Ted R.

    2012-01-01

    Workers of the ant Carebarella bicolor collected in Panama were found to have two major poison-frog alkaloids, cis- and trans-fused decahydroquinolines (DHQs) of the 269AB type, four minor 269AB isomers, two minor 269B isomers, and three isomers of DHQ 271D. For the first time in an ant, however......, the DHQs were accompanied by six histrionicotoxins (HTXs), viz., 283A, 285A, 285B, 285C, 287A, and 287D. This co-occurrence of the HTX and DHQ alkaloids is the usual pattern seen in dendrobatid frogs. This finding contrasts with our earlier study, where workers of a Brazilian ant, Solenopsis...... (Diplorhoptrum) sp., were found to have a very similar DHQ complex but failed to show HTXs. Several new DHQ alkaloids of MW 271 (named in the frog as 271G) are reported from the above ants that have both m/z 202 and 204 as major fragment ions, unlike the spectrum seen for the poison-frog alkaloid 271D, which has...

  19. The Kanizsa triangle illusion in foraging ants.

    Sakiyama, Tomoko; Gunji, Yukio-Pegio

    2016-01-01

    The Kanizsa triangle, wherein three Pac-Man configurations symmetrically face inwards, is a well-known illusion. By exposing foraging ants (Lasius niger) to Kanizsa-shaped honeydew solutions, we studied the origin of this illusion. More specifically, we examined whether foraging ants showed different movement reactions to local honeydew patterns formed by nestmates. This novel phenomenon could serve as an abstract model of the Kanizsa triangle illusion under the assumption that such an illusion could arise through the sum of each agent's limited global cognitions, because each agent could not perceive the entire subjective contours. Even a subjective consciousness consists of some parts which have no identical perception and could be an illusion. We succeeded in inducing foragers to move along the sides of a Kanizsa triangle when Pac-Man-shaped inducers were introduced. Furthermore, foragers appeared to form Y-shaped trajectories when dot-shaped or inverse Kanizsa inducers were used. Based on our findings, we propose an agent-based ant model that compares modelled behaviour with experimental phenomena. Our abstract model could be used to explain such cognitive phenomena for bottom-up processes, because ants cannot perceive the given subjective contours, instead simply move along the edges. PMID:26930477

  20. The evolution of invasiveness in garden ants

    Cremer, Sylvia; Ugelvig, Line Vej; Drijfhout, Falko P;

    2008-01-01

    It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its ra...

  1. Fungal enzymes in the attine ant symbiosis

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    build huge nests displacing several cubic meters of soil, whereas lower attine genera such as Cyphomyrmex and Mycocepurus have small nests with a fungus garden the size of a table-tennis ball. Only the leaf-cutter ants are specialized on using fresh leaves as substrate for their fungus gardens, whereas...

  2. Ants mediate the structure of phytotelm communities in an ant-garden bromeliad

    Céréghino, Régis; Leroy, Céline; Dejean, Alain; Corbara, Bruno

    2010-01-01

    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...

  3. TestAnt: an ant colony system approach to sequential testing under precedence constraints

    Çatay, Bülent; Catay, Bulent; Özlük, Özgür; Ozluk, Ozgur; Ünlüyurt, Tonguç; Unluyurt, Tonguc

    2011-01-01

    We consider the problem of minimum cost sequential testing (diagnosis) of a series (or parallel) system under precedence constraints. We model the problem as a nonlinear integer program. We develop and implement an ant colony algorithm for the problem. We demonstrate the performance of this algorithm for special type of instances for which the optimal solutions can be found in polynomial time. In addition, we compare the performance of the ant colony algorithm with a branch and bound algorith...

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

    Mathis, Kaitlyn A; Tsutsui, Neil D

    2016-08-17

    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

  5. Insects associated with tropical foliage produced in the coffee growing region of Colombia

    Luis F. Aristizábal

    2013-09-01

    Full Text Available We conducted a survey of insects and pest management practices on 34 farms growing ornamental tropical foliage plants in the central coffee region of Colombia over two years. Tropical foliage provided habitat for a diverse range of insects. In total, phytophagous or detritivorous insects from six orders, 40 families and 62 genera were collected. The most common were Hemiptera (29 genera from 16 families, followed by Coleoptera (17 genera from 4 families, Diptera (5 genera from 5 families, Lepidoptera (5 genera from 4 families, Hymenoptera (3 genera from 2 families and Orthoptera (2 genera from 2 families. The most common phytophagous species were leaf cutting ants (Atta and Acromyrmex spp., leaf beetles (Chrysomelidae, leafhoppers (Cicadellidae, stinkbugs (Pentatomidae, squash bugs (Coreidae, tree hoppers (Membracidae and plant hoppers (Fulgoridae. Beneficial insects identified from tropical foliage included predators and parasitoids amongst 5 orders, 12 families and 22 genera. The most abundant were predators among the Coccinellidae, Chrysopidae, Reduviidae, Lycidae and Formicidae but only low numbers of parasitoids (Ichneumonidae, Braconidae and Tachinidae were collected. A pest management questionnaire given to growers revealed a preponderance of reliance on broad spectrum insecticides with a smaller number of growers (approximately one third also using some biological control methods. Our survey contributes basic information regarding diversity of Neotropical insects associated with ornamental foliage plants.

  6. Parameters of ante-mortem delirium

    Deksnyte, Aušra

    2014-02-01

    Full Text Available Objectives. The aim of this study was to investigate the parameters of ante-mortem delirium of the patients in a closed psychiatric institution and to compare them with the ante-mortem psychopathology of the medical patients. Methods. There were 139 medical records of the patients analyzed, who died during the period of 1997-2003 at the in-patient psychiatric institution. The diagnoses were recorded according to the International Classification of Diseases, 10th Revision (ICD-10 criteria. Patients’ data included age, gender, previous psychiatric disorders, current somatic and psychiatric morbidity, and comorbidity. Results. The incidence of delirium was 83,7%. The delirium group included more elder, male persons who were more likely to have dementia and less inclined to depression. Surprisingly the incidence of delirium among non-dementia men was quite high – 76,9%, as compared to non-dementia women – 23,1% (P=0,008. The duration of delirium differed from 1 to 1335 days. Longer delirium was observed among elder than 75 years (87,7, SD 183,9 vs52,6, SD 121,4 days; P=0,019 and dementia (83,6, SD 173,6 vs 13,5, SD 11,6 days; P<0,001 patients, but did not differ in gender groups. Conclusions. Ante-mortem delirium occurred more commonly in more elder and demented patients The duration of ante-mortem delirium was shorter in younger and non-dementia patients. Patients of the psychiatric institution tend to have longer deliriums than medical patients. The patients with depression and the history of alcohol abuse were not likely to get ante-mortem delirium. Before death in many persons hyperactive and mixed delirium transformed into hypoactive.

  7. Host ant independent oviposition in the parasitic butterfly Maculinea alcon

    Fürst, Matthias A; Nash, David Richard

    2010-01-01

    Parasitic Maculinea alcon butterflies can only develop in nests of a subset of available Myrmica ant species, so female butterflies have been hypothesized to preferentially lay eggs on plants close to colonies of the correct host ants. Previous correlational investigations of host-ant-dependent o......Parasitic Maculinea alcon butterflies can only develop in nests of a subset of available Myrmica ant species, so female butterflies have been hypothesized to preferentially lay eggs on plants close to colonies of the correct host ants. Previous correlational investigations of host...

  8. The Pied Piper: A Parasitic Beetle's Melodies Modulate Ant Behaviours.

    Andrea Di Giulio

    Full Text Available 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.

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

    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.

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

    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

  11. Various Chemical Strategies to Deceive Ants in Three Arhopala Species (Lepidoptera: Lycaenidae) Exploiting Macaranga Myrmecophytes

    Inui, Yoko; Shimizu-kaya, Usun; Okubo, Tadahiro; Yamsaki, Eri; Itioka, Takao

    2015-01-01

    Macaranga myrmecophytes (ant-plants) are generally well protected from herbivore attacks by their symbiotic ants (plant-ants). However, larvae of Arhopala (Lepidoptera: Lycaenidae) species survive and develop on specific Macaranga ant-plant species without being attacked by the plant-ants of their host species. We hypothesized that Arhopala larvae chemically mimic or camouflage themselves with the ants on their host plant so that the larvae are accepted by the plant-ant species of their host....

  12. Low-toxicity baits control ants in citrus orchards and grape vineyards

    Tollerup, Kris E.; Rust, Michael K.; Dorschner, Keith W.; Phillips, Phil A.; Klotz, John H.

    2004-01-01

    Effective ant control is critical for controlling honeydew-secreting homopteran agricultural pests such as whitefly and mealybug. Low-toxicity ant baits may more effectively control ants than the broad-spectrum insecticides currently used in California vineyards and citrus orchards. This study focused on developing effective ant baits for use in bait stations to control field ant and Argentine ant, which aggressively tend homopteran pests. In the Coachella Valley, field ant is associated with...

  13. Lithiase géante sur enterocystoplastie

    Elmortaji, Khalid; Elomri, Ghassane; Bennani, Saad; Rabii, Redouane; Aboutaib, Rachid; Meziane, Fethi

    2014-01-01

    La formation des lithiases est une complication fréquente des entérocystoplasties après cystectomie radicale pour tumeur de vessie infiltrante. Le délai d'apparition dépend des facteurs de risque favorisants notamment les infections urinaires. Néanmoins la survenue de lithiase géante sur néovessie reste exceptionnelle, seulement 5 cas ont été rapportés dans la littérature. Nous rapportons dans ce travail, le cas d'une lithiase géante compliquant une entérocystoplastie chez un malade suivi pour tumeur de vessie infiltrante. PMID:25932070

  14. Optic disc detection using ant colony optimization

    Dias, Marcy A.; Monteiro, Fernando C.

    2012-09-01

    The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detection. Recently, the ACO was used in fundus images to detect edges, and therefore, to segment the OD and other anatomical retinal structures. We present an algorithm for the detection of OD in the retina which takes advantage of the Gabor wavelet transform, entropy and ACO algorithm. Forty images of the retina from DRIVE database were used to evaluate the performance of our method.

  15. Ant Colony Optimization and Hypergraph Covering Problems

    Pat, Ankit

    2011-01-01

    Ant Colony Optimization (ACO) is a very popular metaheuristic for solving computationally hard combinatorial optimization problems. Runtime analysis of ACO with respect to various pseudo-boolean functions and different graph based combinatorial optimization problems has been taken up in recent years. In this paper, we investigate the runtime behavior of an MMAS*(Max-Min Ant System) ACO algorithm on some well known hypergraph covering problems that are NP-Hard. In particular, we have addressed the Minimum Edge Cover problem, the Minimum Vertex Cover problem and the Maximum Weak- Independent Set problem. The influence of pheromone values and heuristic information on the running time is analysed. The results indicate that the heuristic information has greater impact towards improving the expected optimization time as compared to pheromone values. For certain instances of hypergraphs, we show that the MMAS* algorithm gives a constant order expected optimization time when the dominance of heuristic information is ...

  16. Some 'ant'swers: Application of a layered barcode approach to problems in ant taxonomy.

    Paknia, Omid; Bergmann, Tjard; Hadrys, Heike

    2015-11-01

    DNA barcoding has emerged as a routine tool in modern taxonomy. Although straightforward, this approach faces new challenges, when applied to difficult situation such as defining cryptic biodiversity. Ants are prime examples for high degrees of cryptic biodiversity due to complex population differentiation, hybridization and speciation processes. Here, we test the DNA barcoding region, cytochrome c oxidase 1 and two supplementary markers, 28S ribosomal DNA and long-wavelength rhodopsin, commonly used in ant taxonomy, for their potential in a layered, character-based barcoding approach across different taxonomic levels. Furthermore, we assess performance of the character-based barcoding approach to determine cryptic species diversity in ants. We found (i) that the barcode potential of a specific genetic marker varied widely among taxonomic levels in ants; (ii) that application of a layered, character-based barcode for identification of specimens can be a solution to taxonomical challenging groups; (iii) that the character-based barcoding approach allows us to differentiate specimens even within locations based on pure characters. In summary, (layered) character-based barcoding offers a reliable alternative for problematic species identification in ants and can be used as a fast and cost-efficient approach to estimate presence, absence or frequency of cryptic species. PMID:25712507

  17. Polyethism in a colony of artificial ants

    Marriott, Chris

    2011-01-01

    We explore self-organizing strategies for role assignment in a foraging task carried out by a colony of artificial agents. Our strategies are inspired by various mechanisms of division of labor (polyethism) observed in eusocial insects like ants, termites, or bees. Specifically we instantiate models of caste polyethism and age or temporal polyethism to evaluated the benefits to foraging in a dynamic environment. Our experiment is directly related to the exploration/exploitation trade of in machine learning.

  18. Ants and sustainable agriculture. A review

    Benckiser, Gero

    2010-01-01

    International audience 60% of the world's ecosystems are not used in a sustainable way. Modern agriculture is blamed for declining soil carbon and biodiversity. Climate change, habitat fragmentation and other obstacles impede the movement of many animal species, and distribution changes are projected to continue. Therefore, we need alternative management strategies. The colony organisation of social insects, especially of ants, is seen as a model to design an improved agricultural manageme...

  19. Recruitment Strategies and Colony Size in Ants

    Planqué, Robert; van den Berg, Jan Bouwe; Franks, Nigel R

    2010-01-01

    Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method. Very small colonies tend to use solitary foraging; small to medium sized colonies use tandem running or group recruitment whereas larger colonies use pheromone recruitment trails. Until now, explana...

  20. Associations Between Australian Pseudoscorpions and Ants

    Harvey, Mark S.; Mark A. Elgar; Cole, Deborah C.

    1994-01-01

    The distribution of three species of pseudoscorpions, found under the bark of blue gum Eucalyptus globulus, is closely correlated with the presence of three species of ants. Marachernes bellus is never found on trees without Anonychomyrma sp. near foetens, and Protochelifer victorianus and Paraustrochernes victorianus are more commonly found on trees with Technomyrmex jocosus and/or Tapinoma minutum. The distribution of another pseudoscorpion, Conicochernes sp., is not influenced by the prese...

  1. Bus Network Modeling Using Ant Algorithms

    Sepideh Eshragh; Shahriar Afandizadeh Zargari; Ardeshir Faghri; Earl Rusty Lee

    2010-01-01

    Bus transit network modeling is a complex and combinatorial problem. The main purpose of this paper is to apply a contemporary method for designing a bus transit network with the objective of achieving optimum results. The method is called Ant Algorithms, a Meta Heuristic method, which has been applied to optimization problems in transportation with noticeable success. The description of the algorithm, as well as the main methodology and computations, is presented in this paper. Furthermore, ...

  2. Road Traffic System: Optimization Using Ant Systems

    Yeong, Kim Ming

    2003-01-01

    Let us look at these social insects, which are relatively simple however, they can perform effective strategy following the simple, adaptive to local rules, which allows them to change according to the environment for survival. This uniqueness of the insect world helps us to understand that complex situation does have solution. The study of ant colonies behavior is an interesting issue that provides good modeling solution for difficult optimization and distributed control problems. Transporta...

  3. Ant-Man and the quantum realm

    Michalakis, Spiros

    2015-11-01

    I was in Los Angeles airport, stuffing French fries into my mouth and waiting for a flight to Charlotte, North Carolina, when my phone buzzed. The e-mail was from the Science and Entertainment Exchange, a non-profit organization working to elevate the level of science in the movies, and it told me to report to Atlanta to consult on a new superhero movie: Ant-Man.

  4. Ant colony optimization and constraint programming

    Solnon, Christine

    2013-01-01

    Ant colony optimization is a metaheuristic which has been successfully applied to a wide range of combinatorial optimization problems. The author describes this metaheuristic and studies its efficiency for solving some hard combinatorial problems, with a specific focus on constraint programming. The text is organized into three parts. The first part introduces constraint programming, which provides high level features to declaratively model problems by means of constraints. It describes the main existing approaches for solving constraint satisfaction problems, including complete tree search

  5. Polydomy in the ant Ectatomma opaciventre.

    Tofolo, Viviane C; Giannotti, Edilberto; Neves, Erika F; Andrade, Luis H C; Lima, Sandro M; Súarez, Yzel R; Antonialli-Junior, William F

    2014-01-01

    Tropical ants commonly exhibit a hyper-dispersed pattern of spatial distribution of nests. In polydomous species, nests may be satellites, that is, secondary structures of the main nest, where the queen is found. In order to evaluate whether the ant Ectatomma opaciventre Roger (Formicidae: Ectatomminae) uses the strategy of building polydomous nests, the spatial distribution pattern of 33 nests in a 1,800 m(2) degraded area located in Rio Claro, SP, Brazil, were investigated using the nearest neighbor method. To complement the results of this investigation, the cuticular chemical profile of eight colonies was analyzed using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). The nests of E. opaciventre presented a hyper-dispersed or regular distribution, which is the most common in ants. The analysis of the cuticular hydrocarbons apparently con-firmed the hypothesis that this species is polydomous, since the chemical profiles of all studied colonies with nests at different sites were very similar to the chemical signature of the single found queen and were also different from those of colonies used as control. PMID:25373168

  6. Polygyny and polyandry in small ant societies.

    Kellner, K; Trindl, A; Heinze, J; D'Ettorre, P

    2007-06-01

    Social insects, ants in particular, show considerable variation in queen number and mating frequency resulting in a wide range of social structures. The dynamics of reproductive conflicts in insect societies are directly connected to the colony kin structure, thus, the study of relatedness patterns is essential in order to understand the evolutionary resolution of these conflicts. We studied colony kin structure and mating frequencies in two closely related Neotropical ant species Pachycondyla inversa and Pachycondyla villosa. These represent interesting model systems because queens found new colonies cooperatively but, unlike many other ant species, they may still co-exist when the colony becomes mature (primary polygyny). By using five specific and highly variable microsatellite markers, we show that in both species queens usually mate with two or more males and that cofounding queens are always unrelated. Polygynous and polyandrous colonies are characterized by a high genetic diversity, with a mean relatedness coefficient among worker nestmates of 0.27 (+/- 0.03 SE) for P. inversa and 0.31 (+/- 0.05 SE) for P. villosa. However, relatedness among workers of the same matriline is high (0.60 +/- 0.03 in P. inversa, 0.62 +/- 0.08 in P. villosa) since males that mated with the same queen are on average closely related. Hence, we have found a new taxon in social Hymenoptera with high queen-mating frequencies and with intriguing mating and dispersal patterns of the sexuals. PMID:17561897

  7. Recognition of social identity in ants

    Nick Bos

    2012-03-01

    Full Text Available 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.

  8. Reduced Chitinase Activities in Ant Plants of the Genus Macaranga

    Heil, Martin; Fiala, Brigitte; Linsenmair, K. Eduard; Boller, Thomas

    Many plant species have evolved mutualistic associations with ants, protecting their host against detrimental influences such as herbivorous insects. Letourneau (1998) reported in the case of Piper that ants defend their plants principally against stem-boring insects and also reduce fungal infections on inflorescences. Macaranga plants that were experimentally deprived of their symbiotic Crematogaster ants suffered heavily from shoot borers and pathogenic fungi (Heil 1998). Here we report that ants seem to reduce fungal infections actively in the obligate myrmecophyte Macarangatriloba (Euphorbiaceae), while ant-free plants can be easily infected. We also found extremely low chitinase activity in Macaranga plants. The plants' own biochemical defense seems to be reduced, and low chitinase activity perhaps may represent a predisposition for the evolution of myrmecophytism. These plants are therefore highly dependent on their ants, which obviously function not only as an antiherbivore defense but also as an effective agent against fungal pathogens.

  9. Image feature extraction based multiple ant colonies cooperation

    Zhang, Zhilong; Yang, Weiping; Li, Jicheng

    2015-05-01

    This paper presents a novel image feature extraction algorithm based on multiple ant colonies cooperation. Firstly, a low resolution version of the input image is created using Gaussian pyramid algorithm, and two ant colonies are spread on the source image and low resolution image respectively. The ant colony on the low resolution image uses phase congruency as its inspiration information, while the ant colony on the source image uses gradient magnitude as its inspiration information. These two ant colonies cooperate to extract salient image features through sharing a same pheromone matrix. After the optimization process, image features are detected based on thresholding the pheromone matrix. Since gradient magnitude and phase congruency of the input image are used as inspiration information of the ant colonies, our algorithm shows higher intelligence and is capable of acquiring more complete and meaningful image features than other simpler edge detectors.

  10. Patterns of diversity and abundance of fungus-growing ants (Formicidae: Attini in areas of the Brazilian Cerrado Padrões de diversidade e abundância de formigas cultivadoras de fungo (Formicidade: Attini em áreas do Cerrado Brasileiro

    Heraldo L. Vasconcelos

    2008-09-01

    Full Text Available Fungus-growing ants (tribe Attini are characteristic elements of the New World fauna. However, there is little information on the patterns of diversity, abundance, and distribution of attine species in their native ecosystems, especially for the so-called "lower" genera of the tribe. A survey of attine ant nests (excluding Atta Fabricus, 1804 and Acromyrmex Mayr, 1865 was conducted in a variety of savanna and forest habitats of the Cerrado biome near Uberlândia, Brazil. In total, 314 nests from 21 species of nine genera were found. Trachymyrmex Forel, 1893 was the most diverse genus with 10 species. Eighteen species were found in the savannas, including Mycetagroicus cerradensis Brandão & Mayhé-Nunes, 2001, a species from a recently-described genus of Attini, whereas in the forests only 12 species were found. Forest and savannas support relatively distinct faunas, each with a number of unique species; the species present in the forest habitats did not represent a nested subset of the species found in the savannas. Furthermore, although many species were common to both types of vegetation, their abundances were quite different. The density of attine nests is relatively high at some sites, exceeding an estimated 4,000 nests per hectare. In this sense, attine ants can be regarded as prevalent invertebrate taxa in the Brazilian Cerrado.As formigas cultivadoras de fungos (tribo Attini são exclusivas da fauna do Novo Mundo. Entretanto, existem poucas informações sobre os padrões de diversidade, abundância e distribuição das espécies de Attini em seus ecossistemas nativos, em especial para os gêneros menos derivados desta tribo. Um levantamento de ninhos de Attini (excluindo Atta Fabricius, 1804 e Acromyrmex Mayr, 1865 foi realizado em diversos ambientes savânicos e de floresta do bioma Cerrado próximos à Uberlândia, Brasil. Encontramos 314 ninhos de 21 espécies pertencentes a nove gêneros da tribo. Trachymyrmex Forel, 1893 foi o g

  11. The evolution of social traits and biodiversity in the ants.

    Ferguson-Gow, Henry

    2014-01-01

    Cooperation has shaped the evolution of life on Earth. The ants are the most numerically diverse of the eusocial Hymenoptera, and display wide variation in social complexity. This positions the ants as an ideal taxon in which to study social evolution in a comparative framework. Social evolution theory has generated many hypotheses that are testable in ants, however the lack of comprehensive or complete phylogenies, and the decentralised and scattered nature of trait data, has been an obstacl...

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

    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 th...

  13. Entomopathogens Isolated from Invasive Ants and Tests of Their Pathogenicity

    Maria Fernanda Miori de Zarzuela; Luis Garrigós Leite; José Eduardo Marcondes; Ana Eugênia de Carvalho Campos

    2012-01-01

    Some ant species cause severe ecological and health impact in urban areas. Many attempts have been tested to control such species, although they do not always succeed. Biological control is an alternative to chemical control and has gained great prominence in research, and fungi and nematodes are among the successful organisms controlling insects. This study aimed to clarify some questions regarding the biological control of ants. Invasive ant species in Brazil had their nests evaluated for t...

  14. Newly discovered sister lineage sheds light on early ant evolution

    Rabeling, Christian; Brown, Jeremy M.; Verhaagh, Manfred

    2008-01-01

    Ants are the world's most conspicuous and important eusocial insects and their diversity, abundance, and extreme behavioral specializations make them a model system for several disciplines within the biological sciences. Here, we report the discovery of a new ant that appears to represent the sister lineage to all extant ants (Hymenoptera: Formicidae). The phylogenetic position of this cryptic predator from the soils of the Amazon rainforest was inferred from several nuclear genes, sequenced ...

  15. The Molecular Clockwork of the Fire Ant Solenopsis invicta

    Ingram, Krista K.; Alexander Kutowoi; Yannick Wurm; Dewayne Shoemaker; Rudolf Meier; Guy Bloch

    2012-01-01

    The circadian clock is a core molecular mechanism that allows organisms to anticipate daily environmental changes and adapt the timing of behaviors to maximize efficiency. In social insects, the ability to maintain the appropriate temporal order is thought to improve colony efficiency and fitness. We used the newly sequenced fire ant (Solenopsis invicta) genome to characterize the first ant circadian clock. Our results reveal that the fire ant clock is similar to the clock of the honeybee, a ...

  16. Consuming fire ants reduces northern bobwhite survival and weight gain

    Myers, P.E.; Allen, Craig R.; Birge, Hannah E.

    2014-01-01

    Northern bobwhite quail, Colinus virginianus (L.) (Galliformes: Odontophoridae), population declines are well documented, but pinpointing the reasons for these decreases has proven elusive. Bobwhite population declines are attributed primarily to loss of habitat and land use changes. This, however, does not entirely explain population declines in areas intensively managed for bobwhites. Although previous research demonstrates the negative impact of red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae) on northern bobwhites, the mechanisms underlying this effect are largely unknown. To meet the protein demands of early growth and development, bobwhite chicks predominantly consume small insects, of which ants are a substantial proportion. Fire ants alter ant community dynamics by often reducing native ant diversity and abundance while concurrently increasing the abundance of individuals. Fire ants have negative effects on chicks, but they are also a large potential protein source, making it difficult to disentangle their net effect on bobwhite chicks. To help investigate these effects, we conducted a laboratory experiment to understand (1) whether or not bobwhites consume fire ants, and (2) how the benefits of this consumption compare to the deleterious impacts of bobwhite chick exposure to fire ants. Sixty bobwhite chicks were separated into two groups of 30; one group was provided with starter feed only and the second group was provided with feed and fire ants. Bobwhite chicks were observed feeding on fire ants. Chicks that fed on fire ants had reduced survival and weight gain. Our results show that, while fire ants increase potential food sources for northern bobwhite, their net effect on bobwhite chicks is deleterious. This information will help inform land managers and commercial bobwhite rearing operations.

  17. Surface structure helps desert ants return to known feeding sites

    Merkle, Tobias

    2009-01-01

    Desert ants, Cataglyphis fortis, return to their nest when they are disturbed during their foraging trips. Training them to a landmark corridor enabled us to induce ants that were captured immediately after leaving the nest and transferred to an unknown area to start their foraging trips.1 However, most of the ants never traveled the entire foraging distance to the feeder, but aborted their runs after the landmark corridor was no longer visible. Therefore, apart from landmark information and ...

  18. Chaos–order transition in foraging behavior of ants

    Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

    2014-01-01

    We have studied the foraging behavior of group animals that live in fixed colonies (especially ants) as an important problem in ecology. Building on former findings on deterministic chaotic activities of single ants, we uncovered that the transition from chaotic to periodic regimes results from an optimization scheme of the self-organization of such an animal colony. We found that an effective foraging of ants mainly depends on their nest as well as their physical abilities and knowledge due ...

  19. Protein structure optimization with a "Lamarckian" ant colony algorithm.

    Oakley, Mark T; Richardson, E Grace; Carr, Harriet; Johnston, Roy L

    2013-01-01

    We describe the LamarckiAnt algorithm: a search algorithm that combines the features of a "Lamarckian" genetic algorithm and ant colony optimization. We have implemented this algorithm for the optimization of BLN model proteins, which have frustrated energy landscapes and represent a challenge for global optimization algorithms. We demonstrate that LamarckiAnt performs competitively with other state-of-the-art optimization algorithms. PMID:24407312

  20. A Theoretic Basis for IS? The Contribution of ANT

    Jim Underwood

    2002-11-01

    Full Text Available Representation is a key issue of IS design and operation that is often ignored. Actor-network theory (ANT, a semiotic theory of stakeholders, provides a way of dealing with representation. Combining aspects of ANT and Foucault's discourse theory allows us to include concepts as actors and promises a flexible and durable foundation for IS practice, but ANT itself indicates that the search for a purely theoretical foundation for IS is misguided.

  1. Nutritional composition of Polyrhachis vicina Roger (Edible Chinese black ant)

    Yucui Ren; Lirong Shen; Fengqin Feng; Duo Li

    2006-01-01

    Edible black ant (Polyrhachis vicina Roger) is a traditional edible insect species in China. It has been used as a functional ingredient in various tonics or health foods. This study determined the nutritional composition of the black ant, which included minerals, amino acids, superoxide dismutase (SOD), Vitamin E, and total acid. Supercritical CO2 fluid extraction was used to extract the organic compounds. The compounds were identified and quantified by GC-MS. Results showed that the ant pow...

  2. Tuning PID Controller Using Multiobjective Ant Colony Optimization

    Pierre Borne; Noureddine Liouane; Ibtissem Chiha

    2012-01-01

    This paper treats a tuning of PID controllers method using multiobjective ant colony optimization. The design objective was to apply the ant colony algorithm in the aim of tuning the optimum solution of the PID controllers (Kp, Ki, and Kd) by minimizing the multiobjective function. The potential of using multiobjective ant algorithms is to identify the Pareto optimal solution. The other methods are applied to make comparisons between a classic approach based on the “Ziegler-Nichols” method an...

  3. Optimization Planning based on Improved Ant Colony Algorithm for Robot

    Xin Zhang; Zhanwen Wu

    2014-01-01

    As the ant colony algorithm has the defects in robot optimization path planning such as that low convergence cause local optimum, an improved ant colony algorithm is proposed to apply to the planning of path finding for robot. This algorithm uses the search way of exhumation ant to realize the complementation of advantages and accelerate the convergence of algorithm. The experimental result shows that the algorithm of this paper make the optimization planning of robot more reasonable

  4. Improved Ant Colony Clustering Algorithm and Its Performance Study

    Wei Gao

    2015-01-01

    Clustering analysis is used in many disciplines and applications; it is an important tool that descriptively identifies homogeneous groups of objects based on attribute values. The ant colony clustering algorithm is a swarm-intelligent method used for clustering problems that is inspired by the behavior of ant colonies that cluster their corpses and sort their larvae. A new abstraction ant colony clustering algorithm using a data combination mechanism is proposed to improve the computational ...

  5. An Improved Ant Colony Routing Algorithm for WSNs

    Tan Zhi; Zhang Hui

    2015-01-01

    Ant colony algorithm is a classical routing algorithm. And it are used in a variety of application because it is economic and self-organized. However, the routing algorithm will expend huge amounts of energy at the beginning. In the paper, based on the idea of Dijkstra algorithm, the improved ant colony algorithm was proposed to balance the energy consumption of networks. Through simulation and comparison with basic ant colony algorithms, it is obvious that improved algorithm can effectively...

  6. Improvement and Implementation of Best-worst Ant Colony Algorithm

    Xianmin Wei

    2013-01-01

    In this study, we introduced the ant colony algorithm of best-worst ant system based on the pheromone update. By update improvements of local pheromone and global pheromone, as well as the optimal solution enhancement to a greater extent and the weakening of the worst solution, the algorithm further increased the difference of pheromone amount between the edge of the optimal path and the edge of the worst path and allowed the ant colony search behavior more focused near the optimal solution. ...

  7. Cercomacra and related antbirds (Aves, Formicariidae as army ant followers

    Edwin O. Willis

    1984-01-01

    Full Text Available Cercomacra and Schistocichla antbirds (Formicariidae favor dense foliage and seldom follow army ants for flushed prey, since the ants move through open forest understory as well as through dense zones. Two other lineages, the Drymophila-Hypocnemis lineage (of dense woodland understory and the Formicivora lineage (of dense bushes in dry or semiopen zones, also cannot follow ants regularly through open forest understory.

  8. Adventitious shoot formation on leaf cuttings in vivo, a tool in horticulture.

    Custers, J.B.M.

    1986-01-01

    Adventitious shoot formation implies the regeneration or development of shoots from fully differentiated tissue. Its application has, after the rise of in vitro culture, assumed large proportions. Then the question arose whether in vivo adventitious shoot formation could not be applied more widely i

  9. Ant plant herbivore interactions in the neotropical cerrado savanna

    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.

  10. Chimpanzees prey on army ants with specialized tool set.

    Sanz, Crickette M; Schöning, Caspar; Morgan, David B

    2010-01-01

    Several populations of chimpanzees have been reported to prey upon Dorylus army ants. The most common tool-using technique to gather these ants is with "dipping" probes, which vary in length with regard to aggressiveness and lifestyle of the prey species. We report the use of a tool set in army ant predation by chimpanzees in the Goualougo Triangle, Republic of Congo. We recovered 1,060 tools used in this context and collected 25 video recordings of chimpanzee tool-using behavior at ant nests. Two different types of tools were distinguished based on their form and function. The chimpanzees use a woody sapling to perforate the ant nest, and then a herb stem as a dipping tool to harvest the ants. All of the species of ants preyed upon in Goualougo are present and consumed by chimpanzees at other sites, but there are no other reports of such a regular or widespread use of more than one type of tool to prey upon Dorylus ants. Furthermore, this tool set differs from other types of tool combinations used by chimpanzees at this site for preying upon termites or gathering honey. Therefore, we conclude that these chimpanzees have developed a specialized method for preying upon army ants, which involves the use of an additional tool for opening nests. Further research is needed to determine which specific ecological and social factors may have shaped the emergence and maintenance of this technology. PMID:19731231

  11. Five new records of ants (Hymenoptera: Formicidae) for Nebraska

    Nemec, Kristine T.; Trager, James C.; Manley, Elizabeth; Allen, Craig R.

    2012-01-01

    Ants are ubiquitous and influential organisms in terrestrial ecosystems. About 1,000 ant species occur in North America, where they are found in nearly every habitat (Fisher and Cover 2007). Ants are critical to ecological processes and structure. Ants affect soils via tunneling activity (Baxter and Hole 1967), disperse plant seeds (Lengyel et al. 2009), prey upon a variety of insects and other invertebrates (Way and Khoo 1992, Folgarait 1998), are often effective primary consumers through their prodigious consumption of floral and especially extrafloral nectar, and honeydew (Tobin 1994), and serve as prey for invertebrates (Gotelli 1996, Gastreich 1999) and vertebrates (Reiss 2001).

  12. Ant-Crypto, a Cryptographer for Data Encryption Standard

    Salabat Khan

    2013-01-01

    Full Text Available Swarm Intelligence and Evolutionary Techniques are attracting the cryptanalysts in the field of cryptography. This paper presents a novel swarm based attack called Ant-Crypto (Ant-Cryptographer for the cryptanalysis of Data Encryption Standard (DES. Ant-Crypto is based on Binary Ant Colony Optimization (BACO i.e. a binary search space based directed graph is modeled for efficiently searching the optimum result (an original encryption key, in our case. The reason that why evolutionary techniques are becoming attractive is because of the inapplicability of traditional techniques and brute force attacks against feistel ciphers due to their inherent structure based on high nonlinearity and low autocorrelation. Ant-Crypto uses a known-plaintext attack to recover the secret key of DES which is required to break/ decipher the secret messages. Ant-Crypto iteratively searches for the secret key while generating several candidate optimum keys that are guessed across different runs on the basis of routes completed by ants. These optimum keys are then used to find each individual bit of the 56 bit secret key used during encryption by DES. Ant-Crypto is compared with some other state of the art evolutionary based attacks i.e. Genetic Algorithm and Comprehensive Binary Particle Swarm Optimization. The experimental results show that Ant-Crypto is an effective evolutionary attack against DES and can deduce large number of valuable bits as compared to other evolutionary algorithms; both in terms of time and space complexity.

  13. Insecticide transfer efficiency and lethal load in Argentine ants

    Hooper-Bui, L. M.; Kwok, E. S. C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-10-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  14. Improved Ant Colony Clustering Algorithm and Its Performance Study.

    Gao, Wei

    2016-01-01

    Clustering analysis is used in many disciplines and applications; it is an important tool that descriptively identifies homogeneous groups of objects based on attribute values. The ant colony clustering algorithm is a swarm-intelligent method used for clustering problems that is inspired by the behavior of ant colonies that cluster their corpses and sort their larvae. A new abstraction ant colony clustering algorithm using a data combination mechanism is proposed to improve the computational efficiency and accuracy of the ant colony clustering algorithm. The abstraction ant colony clustering algorithm is used to cluster benchmark problems, and its performance is compared with the ant colony clustering algorithm and other methods used in existing literature. Based on similar computational difficulties and complexities, the results show that the abstraction ant colony clustering algorithm produces results that are not only more accurate but also more efficiently determined than the ant colony clustering algorithm and the other methods. Thus, the abstraction ant colony clustering algorithm can be used for efficient multivariate data clustering. PMID:26839533

  15. Nectar theft and floral ant-repellence: a link between nectar volume and ant-repellent traits?

    Gavin Ballantyne

    Full Text Available 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.

  16. Ants Laaneots : palgaarmeele üleminek pole praegu aktuaalne / Ants Laaneots ; interv. Peeter Kuimet

    Laaneots, Ants, 1948-

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke 6. dets. lk. 2. Kaitseväe uus juhataja kindralmajor Ants Laaneots vastab küsimustele kaitseväe ja ajateenistuse probleemide kohta. Lisa: Eesti kaitseväe juhatajad 1993-2006. Vt. samas: Laaneotsalt oodatakse sisetülide lahendamist

  17. Ants Laaneots : Peame venelaste provokatsiooniks valmis olema / Ants Laaneots ; interv. Urmo Soonvald

    Laaneots, Ants, 1948-

    2002-01-01

    Ilmunud ka: Den za Dnjom 13. september lk. 9. Kindralmajor Ants Laaneots vastab küsimustele, kui reaalne on tulevikus Eesti pinnal sõja puhkemise oht, 11. septembri sündmuste kohta USA-s, Eesti NATO liikmeks kutsumise, provokatsioonide vastu valmisoleku, võõrriigi oletatava Eestisse sissetungi kohta

  18. The evolution of invasiveness in garden ants.

    Sylvia Cremer

    Full Text Available It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects.

  19. Enhanced ant colony optimization for multiscale problems

    Hu, Nan; Fish, Jacob

    2016-03-01

    The present manuscript addresses the issue of computational complexity of optimizing nonlinear composite materials and structures at multiple scales. Several solutions are detailed to meet the enormous computational challenge of optimizing nonlinear structures at multiple scales including: (i) enhanced sampling procedure that provides superior performance of the well-known ant colony optimization algorithm, (ii) a mapping-based meshing of a representative volume element that unlike unstructured meshing permits sensitivity analysis on coarse meshes, and (iii) a multilevel optimization procedure that takes advantage of possible weak coupling of certain scales. We demonstrate the proposed optimization procedure on elastic and inelastic laminated plates involving three scales.

  20. Sexual selection in the ant Leptothorax gredleri

    Oppelt, Angelika

    2010-01-01

    L. gredleri is an ant species that is mating by female calling. Virgin queens attract males with a droplet of a sexual pheromone in the vicinity of their maternal nest. Both sexes are expected to be choosy because females store the semen in their spermatheca throughout their whole lives and do not remate after this initial mating period. Males are short-lived and survive only as sperm in the spermathecae of queens. Furthermore, males possess only a fixed amount of sperm, since their testes de...

  1. Review and Phylogenetic Evaluation of Associations between Microdontinae (Diptera: Syrphidae) and Ants (Hymenoptera: Formicidae)

    Menno Reemer

    2013-01-01

    The immature stages of hoverflies of the subfamily Microdontinae (Diptera: Syrphidae) develop in ant nests, as predators of the ant brood. The present paper reviews published and unpublished records of associations of Microdontinae with ants, in order to discuss the following questions. (1) Are all Microdontinae associated with ants? (2) Are Microdontinae associated with all ants? (3) Are particular clades of Microdontinae associated with particular clades of ants? (4) Are Microdontinae assoc...

  2. What is important for ant assemblages in temperate forest soils?

    Tae-Sung Kwon

    2016-06-01

    Full Text Available Ant assemblages in the soil have been studied at eight forest sites (4 oak forest sites, and 4 pine forest sites in four study areas (1 seminatural area, and 3 industrialized areas in South Korea for 6 years from 2002 to 2010. Soil cores and Tullgren funnel were used for the ant survey. Ant surveys were carried out once per year in autumn (from late September to mid-October. The soil pH was lower in the industrialized than in the seminatural area, showing the acidified soils in the industrialized areas. However, the soil acidification did not influence the ant assemblages. The results from the nonmetric multidimensional scaling ordination and from the community temperature index values indicate that temperature is a key determinant for structures of the soil ant assemblages. The ant assemblages were not different according to the forest types (oak forests vs. pine forests. Occurrence of ant species varied greatly among years, indicating that more replicates and advanced sampling method are needed for the monitoring of the soil ant assemblages.

  3. Diversity of peptide toxins from stinging ant venoms.

    Aili, Samira R; Touchard, Axel; Escoubas, Pierre; Padula, Matthew P; Orivel, Jérôme; Dejean, Alain; Nicholson, Graham M

    2014-12-15

    Ants (Hymenoptera: Formicidae) represent a taxonomically diverse group of arthropods comprising nearly 13,000 extant species. Sixteen ant subfamilies have individuals that possess a stinger and use their venom for purposes such as a defence against predators, competitors and microbial pathogens, for predation, as well as for social communication. They exhibit a range of activities including antimicrobial, haemolytic, cytolytic, paralytic, insecticidal and pain-producing pharmacologies. While ant venoms are known to be rich in alkaloids and hydrocarbons, ant venoms rich in peptides are becoming more common, yet remain understudied. Recent advances in mass spectrometry techniques have begun to reveal the true complexity of ant venom peptide composition. In the few venoms explored thus far, most peptide toxins appear to occur as small polycationic linear toxins, with antibacterial properties and insecticidal activity. Unlike other venomous animals, a number of ant venoms also contain a range of homodimeric and heterodimeric peptides with one or two interchain disulfide bonds possessing pore-forming, allergenic and paralytic actions. However, ant venoms seem to have only a small number of monomeric disulfide-linked peptides. The present review details the structure and pharmacology of known ant venom peptide toxins and their potential as a source of novel bioinsecticides and therapeutic agents. PMID:25448389

  4. Disease dynamics in a specialized parasite of ant societies

    Andersen, Sandra Breum; Ferrari, Matthew; Evans, Harry C.; Elliot, Simon L.; Boomsma, Jacobus Jan; Hughes, David P.

    2012-01-01

    Coevolution between ant colonies and their rare specialized parasites are intriguing, because lethal infections of workers may correspond to tolerable chronic diseases of colonies, but the parasite adaptations that allow stable coexistence with ants are virtually unknown. We explore the trade...

  5. Tracing the rise of ants - out of the ground.

    Andrea Lucky

    Full Text Available The evolution of ants (Hymenoptera: Formicidae is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions of crown-group ants through time, focusing on where they nest and forage (in the canopy, litter, or soil. Based on ancestral character reconstructions, we show that in contrast to the current consensus based on verbal arguments that ants evolved in tropical leaf litter, the soil is supported as the ancestral stratum of all ants. We also find subsequent movements up into the litter and, in some cases, into the canopy. Given the global importance of ants, because of their diversity, ecological influence and status as the most successful eusocial lineage on Earth, understanding the early evolution of this lineage provides insight into the factors that made this group so successful today.

  6. Pre-adaptive cadmium tolerance in the black garden ant.

    Grześ, Irena M; Okrutniak, Mateusz

    2016-04-01

    The black garden ant Lasius niger is a common component of habitats subjected to anthropological stress. The species can develop very abundant populations in metal-polluted areas. In this study, we raised the question of its tolerance to Cd pollution. Workers of L. niger were collected from 54 colonies, originating from 19 sites located along an increasing gradient of Cd pollution in Poland. Ants were exposed to a range of dietary Cd concentrations in a controlled 14-day laboratory experiment in order to test Cd-sensitivity in the investigated ants. The level of ant mortality was recorded as the endpoint of the experiment. We used much higher concentrations of dietary Cd than those the ants are most likely exposed to in field conditions. The investigated ants were highly Cd-tolerant; even a very high dietary Cd concentration of approx. 1300 mg/kg did not affect mortality of workers when compared to the control. Mortality was unrelated to Cd-pollution along the pollution gradient, meaning that high Cd-tolerance can be found even in ants from unpolluted areas. The results stress the importance of pre-adaptive mechanisms in the development of metal tolerance in ants. PMID:26820778

  7. Chaos-order transition in foraging behavior of ants.

    Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

    2014-06-10

    The study of the foraging behavior of group animals (especially ants) is of practical ecological importance, but it also contributes to the development of widely applicable optimization problem-solving techniques. Biologists have discovered that single ants exhibit low-dimensional deterministic-chaotic activities. However, the influences of the nest, ants' physical abilities, and ants' knowledge (or experience) on foraging behavior have received relatively little attention in studies of the collective behavior of ants. This paper provides new insights into basic mechanisms of effective foraging for social insects or group animals that have a home. We propose that the whole foraging process of ants is controlled by three successive strategies: hunting, homing, and path building. A mathematical model is developed to study this complex scheme. We show that the transition from chaotic to periodic regimes observed in our model results from an optimization scheme for group animals with a home. According to our investigation, the behavior of such insects is not represented by random but rather deterministic walks (as generated by deterministic dynamical systems, e.g., by maps) in a random environment: the animals use their intelligence and experience to guide them. The more knowledge an ant has, the higher its foraging efficiency is. When young insects join the collective to forage with old and middle-aged ants, it benefits the whole colony in the long run. The resulting strategy can even be optimal. PMID:24912159

  8. Commercial agrochemical applications in vineyards do not influence ant communities.

    Chong, Chee Seng; Hoffmann, Ary A; Thomson, Linda J

    2007-12-01

    Ants have been widely used as bioindicators for various terrestrial monitoring and assessment programs but are seldom considered in evaluation of nontarget pesticide effect. Much chemical assessment has been biased toward laboratory and bioassay testing for control of specific pest ant species. Several field studies that did explore the nontarget impacts of pesticides on ants have reported contradictory findings. To address the impact of chemical applications on ants, we tested the response of epigeal ant assemblages and community structure to three pesticide gradients (cumulative International Organization for Biological and Integrated Control toxicity rating, chlorpyrifos use rate, and sulfur use rate) in 19 vineyards. Ordination analyses using nonmetric multidimensional scaling detected community structures at species and genus levels, but the structures were not explained by any pesticide variables. There was no consistent pattern in species and genus percentage complementarities and ant assemblages along pesticide gradients. In contrast, ant community structure was influenced by the presence of shelterbelts near the sampling area. Reasons for the resilience of ants to pesticides are given and assessment at the colony level instead of workers abundance is suggested. The presence of Linepithema humile (Mayr) is emphasized. PMID:18284765

  9. The infrabuccal pellet piles of fungus-growing ants.

    Little, Ainslie E F; Murakami, Takahiro; Mueller, Ulrich G; Currie, Cameron R

    2003-12-01

    Fungus-growing ants (Attini) live in an obligate mutualism with the fungi they cultivate for food. Because of the obligate nature of this relationship, the success of the ants is directly dependent on their ability to grow healthy fungus gardens. Attine ants have evolved complex disease management strategies to reduce their garden's exposure to potential parasitic microbes, to prevent the establishment of infection in their gardens, and to remove infected garden sections. The infrabuccal pocket, a filtering device located in the oral cavity of all ants, is an integral part of the mechanisms that leaf-cutter ants use to prevent the invasion and spread of general microbial parasites and the specific fungal-garden parasite Escovopsis. Fungus-growing ants carefully groom their garden, collecting general debris and pathogenic spores of Escovopsis in their infrabuccal pocket, the contents of which are later expelled in dump chambers inside the nest or externally. In this study we examined how a phylogenetically diverse collection of attine ants treat their infrabuccal pellets. Unlike leaf-cutters that deposit their infrabuccal pellets directly in refuse piles, ants of the more basal attine lineages stack their infrabuccal pellets in piles located close to their gardens, and a separate caste of workers is devoted to the construction, management, and eventual disposal of these piles. PMID:14676952

  10. The genome of the fire ant Solenopsis invicta

    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 ...

  11. Life-Histories of Sub-Arctic Ants

    Heinze, Jürgen

    1993-01-01

    Ant species belonging to seven genera occur in habitats near the tree line in the Northern Hemisphere. An analysis of colony founding strategies suggests that in addition to physiological cold resistance, behavioral and sociometric adaptations might be important for survival and propagation of ants in subarctic biomes.

  12. ANT tuner retrofit for LEB cavity

    This report describes a ferrite tuner design for the LEB cavity that utilizes techniques for bonding ferrite to metallic cooling plates that is utilized in the high-power rf and microwave industry. A test tuner was designed to fit into the existing LEB-built magnet and onto the Grimm LEB Cavity. It will require a new vacuum window in order to attain maximal tuning range and high voltage capability and a new center conductor of longer length and a different vacuum window connection than the Grimm center conductor. However, the new center conductor will be essentially identical to the Grimm center conductor in its basic construction and in the way it connects to the stand for support. The tuner is mechanically very similar to high-power stacked circulators built by ANT of Germany and was designed according to ANT's established engineering and design criteria and SSC LEB tuning and power requirements. The tuner design incorporates thin tiles of ferrite glued using a high-radiation-resistance epoxy to copper-plated stainless steel cooling plates of thickness 6.5 mm with water cooling channels inside the plates. The cooling plates constitute 16 pie-shaped segments arranged in a disk. They are electrically isolated from each other to suppress eddy currents. Five of these disks are arranged in parallel with high-pressure rf contacts between the plates at the outer radius. The end walls are slotted copper-plated stainless steel of thickness 3 mm

  13. Loading pattern optimization using ant colony algorithm

    Hoareau, Fabrice [EDF R and D, Clamart (France)

    2008-07-01

    Electricite de France (EDF) operates 58 nuclear power plants (NPP), of the Pressurized Water Reactor type. The loading pattern optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF R and D has developed automatic optimization tools that assist the experts. LOOP is an industrial tool, developed by EDF R and D and based on a simulated annealing algorithm. In order to improve the results of such automatic tools, new optimization methods have to be tested. Ant Colony Optimization (ACO) algorithms are recent methods that have given very good results on combinatorial optimization problems. In order to evaluate the performance of such methods on loading pattern optimization, direct comparisons between LOOP and a mock-up based on the Max-Min Ant System algorithm (a particular variant of ACO algorithms) were made on realistic test-cases. It is shown that the results obtained by the ACO mock-up are very similar to those of LOOP. Future research will consist in improving these encouraging results by using parallelization and by hybridizing the ACO algorithm with local search procedures. (author)

  14. Loading pattern optimization using ant colony algorithm

    Electricite de France (EDF) operates 58 nuclear power plants (NPP), of the Pressurized Water Reactor type. The loading pattern optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF R and D has developed automatic optimization tools that assist the experts. LOOP is an industrial tool, developed by EDF R and D and based on a simulated annealing algorithm. In order to improve the results of such automatic tools, new optimization methods have to be tested. Ant Colony Optimization (ACO) algorithms are recent methods that have given very good results on combinatorial optimization problems. In order to evaluate the performance of such methods on loading pattern optimization, direct comparisons between LOOP and a mock-up based on the Max-Min Ant System algorithm (a particular variant of ACO algorithms) were made on realistic test-cases. It is shown that the results obtained by the ACO mock-up are very similar to those of LOOP. Future research will consist in improving these encouraging results by using parallelization and by hybridizing the ACO algorithm with local search procedures. (author)

  15. Remote Sensing Image Feature Extracting Based Multiple Ant Colonies Cooperation

    Zhang Zhi-long

    2014-02-01

    Full Text Available This paper presents a novel feature extraction method for remote sensing imagery based on the cooperation of multiple ant colonies. First, multiresolution expression of the input remote sensing imagery is created, and two different ant colonies are spread on different resolution images. The ant colony in the low-resolution image uses phase congruency as the inspiration information, whereas that in the high-resolution image uses gradient magnitude. The two ant colonies cooperate to detect features in the image by sharing the same pheromone matrix. Finally, the image features are extracted on the basis of the pheromone matrix threshold. Because a substantial amount of information in the input image is used as inspiration information of the ant colonies, the proposed method shows higher intelligence and acquires more complete and meaningful image features than those of other simple edge detectors.

  16. An ant colony algorithm on continuous searching space

    Xie, Jing; Cai, Chao

    2015-12-01

    Ant colony algorithm is heuristic, bionic and parallel. Because of it is property of positive feedback, parallelism and simplicity to cooperate with other method, it is widely adopted in planning on discrete space. But it is still not good at planning on continuous space. After a basic introduction to the basic ant colony algorithm, we will propose an ant colony algorithm on continuous space. Our method makes use of the following three tricks. We search for the next nodes of the route according to fixed-step to guarantee the continuity of solution. When storing pheromone, it discretizes field of pheromone, clusters states and sums up the values of pheromone of these states. When updating pheromone, it makes good resolutions measured in relative score functions leave more pheromone, so that ant colony algorithm can find a sub-optimal solution in shorter time. The simulated experiment shows that our ant colony algorithm can find sub-optimal solution in relatively shorter time.

  17. Behind every great ant, there is a great gut

    Poulsen, Michael; Sapountzis, Panagiotis

    2012-01-01

    potential contribution of the ants’ gut symbionts. This issue of Molecular Ecology contains a study by Anderson et al. (2012), who take a comparative approach to explore the link between trophic levels and ant microbiomes, specifically, to address three main questions: (i) Do closely related herbivorous...... conserved gut microbiomes, suggesting symbiont functions that directly relate to dietary preference of the ant host. These findings suggest an ecological role of gut symbionts in ants, for example, in metabolism and/or protection, and the comparative approach taken supports a model of co-evolution between...... ant species and specific core symbiont microbiomes. This study, thereby, highlights the omnipresence and importance of gut symbioses—also in the Hymenoptera—and suggests that these hitherto overlooked microbes likely have contributed to the ecological success of the ants....

  18. SECURING MOBILE ANT AGENT USING CHINESE REMAINDER THEOREM

    Srinath Doss

    2013-01-01

    Full Text Available Recent days, research in wireless network becomes major area for the past few decades. In wireless routing many routing methods such as table driven, source driven; many characteristics such as reactive routing, proactive routing; many routing algorithms such as dijikstra’s shortest path, distributed bell-man ford algorithm are proposed in the literature. For effective wireless routing, the recent ant colony optimization proves better result than the existing methodologies. The ant colony optimization is a swarm intelligence technique which widely used for combinatorial optimization problems such as travelling salesman, network routing, clustering. The ant colony optimization is a real time routing protocol which offers highly reliable and optimal routing for both single path and multi path routing. As the ant is a small tiny mobile agent, providing security is critical issue. In this study, a secured ant colony optimization using Chinese remainder theorem is proposed.

  19. A Novel Parser Design Algorithm Based on Artificial Ants

    Maiti, Deepyaman; Konar, Amit; Ramadoss, Janarthanan

    2008-01-01

    This article presents a unique design for a parser using the Ant Colony Optimization algorithm. The paper implements the intuitive thought process of human mind through the activities of artificial ants. The scheme presented here uses a bottom-up approach and the parsing program can directly use ambiguous or redundant grammars. We allocate a node corresponding to each production rule present in the given grammar. Each node is connected to all other nodes (representing other production rules), thereby establishing a completely connected graph susceptible to the movement of artificial ants. Each ant tries to modify this sentential form by the production rule present in the node and upgrades its position until the sentential form reduces to the start symbol S. Successful ants deposit pheromone on the links that they have traversed through. Eventually, the optimum path is discovered by the links carrying maximum amount of pheromone concentration. The design is simple, versatile, robust and effective and obviates ...

  20. Improved ant algorithms for software testing cases generation.

    Yang, Shunkun; Man, Tianlong; Xu, Jiaqi

    2014-01-01

    Existing ant colony optimization (ACO) for software testing cases generation is a very popular domain in software testing engineering. However, the traditional ACO has flaws, as early search pheromone is relatively scarce, search efficiency is low, search model is too simple, positive feedback mechanism is easy to produce the phenomenon of stagnation and precocity. This paper introduces improved ACO for software testing cases generation: improved local pheromone update strategy for ant colony optimization, improved pheromone volatilization coefficient for ant colony optimization (IPVACO), and improved the global path pheromone update strategy for ant colony optimization (IGPACO). At last, we put forward a comprehensive improved ant colony optimization (ACIACO), which is based on all the above three methods. The proposed technique will be compared with random algorithm (RND) and genetic algorithm (GA) in terms of both efficiency and coverage. The results indicate that the improved method can effectively improve the search efficiency, restrain precocity, promote case coverage, and reduce the number of iterations. PMID:24883391

  1. Dynamic Task Scheduling Algorithm based on Ant Colony Scheme

    Kamolov Nizomiddin Baxodirjonovich

    2015-08-01

    Full Text Available Many scientific applications running in Cloud Computing system are workflow applications that contains large number of tasks and in which tasks are connected by precedence relations. Efficient scheduling the workflow tasks become a challenging issue in Cloud Computing environments because the scheduling decides performance of the applications. Unfortunately, finding the optimal scheduling is known as NP-hard. Ant Colony Optimization algorithm can be applied to design efficient scheduling algorithms. Previous scheduling algorithms that use Ant Colony mechanism lack rapid adaptivity. This paper proposes a task scheduling algorithm that uses a modified Ant Colony Optimization. The modified version uses probability in order for ants to decide target machine. The proposed task scheduling algorithm is implemented in WorkflowSim in order to measure performance. The experimental results show that the proposed scheduling algorithm reduce average makespan to about 6.4% compared to a scheduling algorithm that uses basic Ant Colony Optimization scheme.

  2. A stochastic model of ant trail following with two pheromones

    Malíčková, Miriam; Boďová, Katarína

    2015-01-01

    Colonies of ants are systems of interacting living organisms in which interactions between individuals and their environment can produce a reliable performance of a complex tasks without the need for centralised control. Particularly remarkable is the process of formation of refined paths between the nest and food sources that is essential for successful foraging. We have designed a simple stochastic off-lattice model of ant foraging in the absence of direct communication. The motion of ants is governed by two components - a random change in direction of motion that improves ability to explore the environment (facilitating food discovery), and a non-random global indirect interaction component based on pheromone signalling. Using numerical simulations we have studied the model behaviour in different parameter regimes and tested the ability of our model ants to adapt to changes in the external environment. The simulated behaviour of ants in the model recapitulated the experimentally observed behaviours of real...

  3. Ecological consequences of traffic organisation in ant societies

    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.

  4. AntNet: Distributed Stigmergetic Control for Communications Networks

    Di Caro, G

    2011-01-01

    This paper introduces AntNet, a novel approach to the adaptive learning of routing tables in communications networks. AntNet is a distributed, mobile agents based Monte Carlo system that was inspired by recent work on the ant colony metaphor for solving optimization problems. AntNet's agents concurrently explore the network and exchange collected information. The communication among the agents is indirect and asynchronous, mediated by the network itself. This form of communication is typical of social insects and is called stigmergy. We compare our algorithm with six state-of-the-art routing algorithms coming from the telecommunications and machine learning fields. The algorithms' performance is evaluated over a set of realistic testbeds. We run many experiments over real and artificial IP datagram networks with increasing number of nodes and under several paradigmatic spatial and temporal traffic distributions. Results are very encouraging. AntNet showed superior performance under all the experimental condit...

  5. Testing baits to control Argentine ants (Hymenoptera: Formicidae) in vineyards.

    Daane, Kent M; Cooper, Monica L; Sime, Karen R; Nelson, Erik H; Battany, Mark C; Rust, Michael K

    2008-06-01

    Liquid baits were evaluated for control of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), and associated mealybug and soft scale pests in California vineyards. In 2003, liquid baits with small doses ofimidacloprid, boric acid, or thiamethoxam dissolved in 25% sucrose water resulted in lower ant and mealybug densities and fruit damage, compared with an untreated control. Similar treatments in a soft scale-infested vineyard showed only a reduction of ant density and fruit infestation in only the boric acid and thiamethoxam treatments. In 2004, commercial and noncommercial formulations of liquid baits reduced ant densities in three separate trials, but they had inconsistent effects on mealybug densities and fruit infestation; granular protein bait had no effect. Using large plots and commercial application methodologies, liquid bait deployed in June resulted in lower ant density and fruit infestation, but it had no effect on mealybug density. Across all trials, liquid bait treatments resulted in lower ant density (12 of 14 trials) and fruit damage (11 of 14 sites), presenting the first report of liquid baits applied using commercial methodologies that resulted in a reduction of ants and their associated hemipteran crop damage. For commercialization of liquid baits, we showed that any of the tested insecticides can suppress Argentine ants when properly delivered in the crop system. For imidacloprid, bait dispensers must be protected from sunlight to reduce photodegradation. Results suggest that incomplete ant suppression can suppress mealybug densities. However, after ant populations are suppressed, there may be a longer period before hemipteran populations are effectively suppressed. Therefore, liquid baits should be considered part of a multiseason program rather than a direct, in-season control of hemipteran pest populations. PMID:18613568

  6. Using pleometrosis (multiple queens) and pupae transplantation to boost weaver ant (Oecophylla smaragdina) colony growth in ant nurseries

    Offenberg, Hans Joachim; Nielsen, Mogens Gissel; Peng, Renkang

    2011-01-01

    Weaver ants (Oecophylla spp.) are increasingly being used for biocontrol and are targeted for future production of insect protein in ant farms. An efficient production of live ant colonies may facilitate the utilization of these ants but the production of mature colonies is hampered by the long...... and no transplantation. Thus, in ant nurseries the use of multiple queens during nest founding as well as transplantation of pupae from foreign colonies may be utilised to decrease the time it takes to produce a colony ready for implementation....... time it takes for newly established colonies to grow to a suitable size. In this study we followed the growth of newly founded O. smaragdina colonies with 2, 3 or 4 founding queens during 12 days of development, following the transplantation of 0, 30 or 60 pupae from a mature donor colony. Colony...

  7. ANT International chemistry update and best practices

    There is an increasing number of Nuclear Power Plants (NPP) in various countries. Their chemistry practices are different due to the variety of designs and experiences while in the past the view was more monolithic. This is allowing a very rich experience that is extremely difficult to fully be aware of. ANT International is now collecting and evaluating these data as well as related R and D Information. This allows interested parties to have an easier access to the various sources of information. The chemistry experts associated to ANT International have been gathering a comprehensive detailed view of: The numerous laboratory data gained all over the world during the past decades; The extensive plant operating experiences with various types of chemistry strategies, crosschecked for various types of reactors designs and materials; An experienced international knowledge able to give the comprehensive overview that young engineers now in charge of many other activities are unable to fully cover. This paper gives the core conclusions of the detailed ANT International reports and results that have recently been gathered in the area of chemistry. It particularly covers: The primary water chemistry and its relation with radionuclides, dose rates and fuel behaviour; The secondary water chemistry focusing on its rationale selection depending on materials, design and other constraints; The start up and shutdown chemistry with it large variety of practices hardly understandable even for some experts; and, The maintenance remedies such as decontamination, steam generator cleaning and its alternate options. Various types of Reactor designs (PWR, VVER, BWR, CANDU®) are considered. The different materials, for example the impact of steam generator tubing and its evolution on the secondary water chemistry rationale or on the radioactivity built-up in the primary coolant, are described. The ways to improve the plant operation with a long term reliability as well as the most

  8. Chimpanzees detect ant-inhabited dead branches and stems: a study of the utilization of plant-ant relationships in the Mahale Mountains, Tanzania.

    Fuse, Mieko

    2013-10-01

    Chimpanzees in the Mahale Mountains of Tanzania consume several species of stem- and branch-inhabiting ants throughout the year, without tools. Those ants are cryptic species, and it was unknown how to find them constantly. There has been little research on how the chimpanzees locate these ants. In this study, I use behavioral observations of the chimpanzee predators and surveys of the ant fauna and plants across different habitats to test the hypothesis that chimpanzees use plant species as a cue to efficiently locate ant colonies in litter units (dead parts of the plant). Ants were found to be associated with live plants and with spaces within litter units which provide nesting places. Such ant-plant litter relationships were not necessarily as strong as the mutualism often observed between live plants and ants. The proportion of available litter units inhabited by ants was 20 %, and litter units of three plant species (Vernonia subligera, Dracaena usambarensis, and Senna spectabilis) were well occupied by ants in the home range of the chimpanzees. The ant-inhabited ratio in chimpanzee-foraged litter units was higher than that in the available units in the home range. Chimpanzees fed more often on Crematogaster spp. than on other resident ants and at a higher rate than expected from their occurrence in the litter units. Above three plant species were well occupied by Crematogaster sp. 3 or C. sp. 18. It is concluded that chimpanzees locate ants by selecting litter units of plant species inhabited by ants. PMID:23842594

  9. Ant Colony Optimization for Capacity Problems

    Tad Gonsalves

    2015-01-01

    Full Text Available This paper deals with the optimization of the capac ity of a terminal railway station using the Ant Colony Optimization algorithm. The capacity of the terminal station is defined as the number of trains that depart from the station in un it interval of time. The railway capacity optimization problem is framed as a typical symmetr ical Travelling Salesman Problem (TSP, with the TSP nodes representing the train arrival / departure events and the TSP total cost representing the total time-interval of the schedul e. The application problem is then optimized using the ACO algorithm. The simulation experiments validate the formulation of the railway capacity problem as a TSP and the ACO algorithm pro duces optimal solutions superior to those produced by the domain experts.

  10. Antes del Diseño

    Javier González Solas

    2014-01-01

    La práctica profesional del diseño está sometida a una dispersión que dificulta la reflexión sobre ella misma. Y la enseñanza universitaria se ha convertido en gran parte en una práctica más. De este modo la ausencia de una reflexión radical, anterior en el tiempo (revisión de la historia) y anterior en el método (pensar antes de hacer), puede convertirse en un colaboracionismo amoral con todo tipo de catástrofe intelectual y sociopolítica. La perspectiva aquí adoptada proviene de una toma de...

  11. Ants mediate the structure of phytotelm communities in an ant-garden bromeliad.

    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. PMID:20503886

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

    Evlyn Pless

    Full Text Available 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.

  13. Entomopathogens Isolated from Invasive Ants and Tests of Their Pathogenicity

    Maria Fernanda Miori de Zarzuela

    2012-01-01

    Full Text Available Some ant species cause severe ecological and health impact in urban areas. Many attempts have been tested to control such species, although they do not always succeed. Biological control is an alternative to chemical control and has gained great prominence in research, and fungi and nematodes are among the successful organisms controlling insects. This study aimed to clarify some questions regarding the biological control of ants. Invasive ant species in Brazil had their nests evaluated for the presence of entomopathogens. Isolated entomopathogens were later applied in colonies of Monomorium floricola under laboratory conditions to evaluate their effectiveness and the behavior of the ant colonies after treatment. The entomopathogenic nematodes Heterorhabditis sp. and Steinernema sp. and the fungi Beauveria bassiana, Metarhizium anisopliae, and Paecilomyces sp. were isolated from the invasive ant nests. M. floricola colonies treated with Steinernema sp. and Heterorhabditis sp. showed a higher mortality of workers than control. The fungus Beauveria bassiana caused higher mortality of M. floricola workers. However, no colony reduction or elimination was observed in any treatment. The defensive behaviors of ants, such as grooming behavior and colony budding, must be considered when using fungi and nematodes for biological control of ants.

  14. Trait-Mediated Indirect Effects of Phorid Flies on Ants

    Hsun-Yi Hsieh

    2012-01-01

    Full Text Available This paper provides a synthesis of the ecological impact of phorid fly parasitoids on ants. We find the most important impact of phorids on ants to be trait-mediated effects. Phorids diminish the foraging activity of ants, frequently reducing the number and average size of foragers and reducing the amount of food retrieved by a colony. However, ants' coping mechanisms include changing foraging site and time. Phorids can also affect competition, especially through changes in the ability of the host to win in exploitative competition. Factors such as microclimate, resource size, and habitat complexity interact with phorids to change their effect on competition. By being highly specific and attacking ants high in the competitive hierarchy, phorids can alter the linear nature of the competitive transitivity, and by reducing the number of foragers, they can change the discovery-dominance tradeoff that is observed in some ant communities. Trait-mediated effects of phorids also cascade to other trophic levels. As an example, we discuss the trait-mediated cascade of phorids on the Azteca instabilis system in coffee. In this system, by reducing the foraging activity of A. instabilis, phorids reduce the direct and indirect biological control impact of the ant in the coffee agroecosystem.

  15. A model for collective dynamics in ant raids.

    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. PMID:26304617

  16. Artificial ants deposit pheromone to search for regulatory DNA elements

    Liu Yunlong

    2006-08-01

    Full Text Available Abstract Background Identification of transcription-factor binding motifs (DNA sequences can be formulated as a combinatorial problem, where an efficient algorithm is indispensable to predict the role of multiple binding motifs. An ant algorithm is a biology-inspired computational technique, through which a combinatorial problem is solved by mimicking the behavior of social insects such as ants. We developed a unique version of ant algorithms to select a set of binding motifs by considering a potential contribution of each of all random DNA sequences of 4- to 7-bp in length. Results Human chondrogenesis was used as a model system. The results revealed that the ant algorithm was able to identify biologically known binding motifs in chondrogenesis such as AP-1, NFκB, and sox9. Some of the predicted motifs were identical to those previously derived with the genetic algorithm. Unlike the genetic algorithm, however, the ant algorithm was able to evaluate a contribution of individual binding motifs as a spectrum of distributed information and predict core consensus motifs from a wider DNA pool. Conclusion The ant algorithm offers an efficient, reproducible procedure to predict a role of individual transcription-factor binding motifs using a unique definition of artificial ants.

  17. Ant diversity and distribution in Acadia National Park, Maine.

    Ouellette, Gary D; Drummond, Francis A; Choate, Beth; Groden, Eleanor

    2010-10-01

    Exotic ant species are a primary threat to ant biological diversity, posing a negative impact to native ant communities. In this study, we examine species richness of ants (family Formicidae) in Acadia National Park, ME, as a fundamental step toward understanding the present impact of the exotic species Myrmica rubra on native ant species. Twelve habitat types were sampled, along six transects, with pitfall traps, visual searching, bait traps, and leaf litter extraction, and the aid of 34 volunteers. We report 42 species of ants in Acadia National Park, comprising five subfamilies (Amblyoponinae, Dolichoderinae, Formicinae, Myrmicinae, and Ponerinae) and 15 genera; the cataloged species represents 75% of the species originally recorded in the area by Procter (1946). Our findings suggest M. rubra is currently not a dominant species throughout the entire island. However, where this species has invaded locally, few competing native species coexist. The species Lasius alienus, Formica subsericea, Myrmica detritinodis, Camponotus herculeanus, Formica argentea, Formica aserva, and Tapinoma sessile occurred most often in our survey. We report the ant species Amblyopone pallipes and Dolichoderus mariae as two new records for the state of Maine. PMID:22546439

  18. USING ANT COMMUNITIES FOR RAPID ASSESSMENT OF TERRESTRIAL ECOSYSTEM HEALTH

    Wike, L; Doug Martin, D; Michael Paller, M; Eric Nelson, E

    2007-01-12

    Ecosystem health with its near infinite number of variables is difficult to measure, and there are many opinions as to which variables are most important, most easily measured, and most robust, Bioassessment avoids the controversy of choosing which physical and chemical parameters to measure because it uses responses of a community of organisms that integrate all aspects of the system in question. A variety of bioassessment methods have been successfully applied to aquatic ecosystems using fish and macroinvertebrate communities. Terrestrial biotic index methods are less developed than those for aquatic systems and we are seeking to address this problem here. This study had as its objective to examine the baseline differences in ant communities at different seral stages from clear cut back to mature pine plantation as a precursor to developing a bioassessment protocol. Comparative sampling was conducted at four seral stages; clearcut, 5 year, 15 year and mature pine plantation stands. Soil and vegetation data were collected at each site. All ants collected were preserved in 70% ethyl alcohol and identified to genus. Analysis of the ant data indicates that ants respond strongly to the habitat changes that accompany ecological succession in managed pine forests and that individual genera as well as ant community structure can be used as an indicator of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in the mature seral stages was likely related to conditions on the forest floor which favored litter dwelling and cool climate specialists.

  19. Species richness, equitability, and abundance of ants in disturbed landscapes

    Graham, J.H.; Krzysik, A.J.; Kovacic, D.A.; Duda, J.J.; Freeman, D.C.; Emlen, J.M.; Zak, J.C.; Long, W.R.; Wallace, M.P.; Chamberlin-Graham, C.; Nutter, J.P.; Balbach, H.E.

    2009-01-01

    Ants are used as indicators of environmental change in disturbed landscapes, often without adequate understanding of their response to disturbance. Ant communities in the southeastern United States displayed a hump-backed species richness curve against an index of landscape disturbance. Forty sites at Fort Benning, in west-central Georgia, covered a spectrum of habitat disturbance (military training and fire) in upland forest. Sites disturbed by military training had fewer trees, less canopy cover, more bare ground, and warmer, more compact soils with shallower A-horizons. We sampled ground-dwelling ants with pitfall traps, and measured 15 habitat variables related to vegetation and soil. Ant species richness was greatest with a relative disturbance of 43%, but equitability was greatest with no disturbance. Ant abundance was greatest with a relative disturbance of 85%. High species richness at intermediate disturbance was associated with greater within-site spatial heterogeneity. Species richness was also associated with intermediate values of the normalized difference vegetation index (NDVI), a correlate of net primary productivity (NPP). Available NPP (the product of NDVI and the fraction of days that soil temperature exceeded 25 ??C), however, was positively correlated with species richness, though not with ant abundance. Species richness was unrelated to soil texture, total ground cover, and fire frequency. Ant species richness and equitability are potential state indicators of the soil arthropod community. Moreover, equitability can be used to monitor ecosystem change. ?? 2008 Elsevier Ltd.

  20. Trail pheromone disruption of red imported fire ant.

    Suckling, David M; Stringer, Lloyd D; Bunn, Barry; El-Sayed, Ashraf M; Vander Meer, Robert K

    2010-07-01

    The fire ant, Solenopsis invicta (Hymenoptera: Formicidae), is considered one of the most aggressive and invasive species in the world. Toxic bait systems are used widely for control, but they also affect non-target ant species and cannot be used in sensitive ecosystems such as organic farms and national parks. The fire ant uses recruitment pheromones to organize the retrieval of large food resources back to the colony, with Z,E-alpha-farnesene responsible for the orientation of workers along trails. We prepared Z,E-alpha-farnesene, (91% purity) from extracted E,E-alpha-farnesene and demonstrated disruption of worker trail orientation after presentation of an oversupply of this compound from filter paper point sources (30 microg). Trails were established between queen-right colony cells and food sources in plastic tubs. Trail-following behavior was recorded by overhead webcam, and ants were digitized before and after presentation of the treatment, using two software approaches. The linear regression statistic, r(2) was calculated. Ants initially showed high linear trail integrity (r(2) = 0.75). Within seconds of presentation of the Z,E-alpha-farnesene treatment, the trailing ants showed little or no further evidence of trail following behavior in the vicinity of the pheromone source. These results show that trailing fire ants become disorientated in the presence of large amounts of Z,E-alpha-farnesene. Disrupting fire ant recruitment to resources may have a negative effect on colony size or other effects yet to be determined. This phenomenon was demonstrated recently for the Argentine ant, where trails were disrupted for two weeks by using their formulated trail pheromone, Z-9-hexadecenal. Further research is needed to establish the long term effects and control potential for trail disruption in S. invicta. PMID:20549330

  1. The molecular clockwork of the fire ant Solenopsis invicta.

    Krista K Ingram

    Full Text Available The circadian clock is a core molecular mechanism that allows organisms to anticipate daily environmental changes and adapt the timing of behaviors to maximize efficiency. In social insects, the ability to maintain the appropriate temporal order is thought to improve colony efficiency and fitness. We used the newly sequenced fire ant (Solenopsis invicta genome to characterize the first ant circadian clock. Our results reveal that the fire ant clock is similar to the clock of the honeybee, a social insect with an independent evolutionary origin of sociality. Gene trees for the eight core clock genes, period, cycle, clock, cryptochrome-m, timeout, vrille, par domain protein 1 & clockwork orange, show ant species grouping closely with honeybees and Nasonia wasps as an outgroup to the social Hymenoptera. Expression patterns for these genes suggest that the ant clock functions similar to the honeybee clock, with period and cry-m mRNA levels increasing during the night and cycle and clockwork orange mRNAs cycling approximately anti-phase to period. Gene models for five of these genes also parallel honeybee models. In particular, the single ant cryptochrome is an ortholog of the mammalian-type (cry-m, rather than Drosophila-like protein (cry-d. Additionally, we find a conserved VPIFAL C-tail region in clockwork orange shared by insects but absent in vertebrates. Overall, our characterization of the ant clock demonstrates that two social insect lineages, ants and bees, share a similar, mammalian-like circadian clock. This study represents the first characterization of clock genes in an ant and is a key step towards understanding socially-regulated plasticity in circadian rhythms by facilitating comparative studies on the organization of circadian clockwork.

  2. The molecular clockwork of the fire ant Solenopsis invicta.

    Ingram, Krista K; Kutowoi, Alexander; Wurm, Yannick; Shoemaker, Dewayne; Meier, Rudolf; Bloch, Guy

    2012-01-01

    The circadian clock is a core molecular mechanism that allows organisms to anticipate daily environmental changes and adapt the timing of behaviors to maximize efficiency. In social insects, the ability to maintain the appropriate temporal order is thought to improve colony efficiency and fitness. We used the newly sequenced fire ant (Solenopsis invicta) genome to characterize the first ant circadian clock. Our results reveal that the fire ant clock is similar to the clock of the honeybee, a social insect with an independent evolutionary origin of sociality. Gene trees for the eight core clock genes, period, cycle, clock, cryptochrome-m, timeout, vrille, par domain protein 1 & clockwork orange, show ant species grouping closely with honeybees and Nasonia wasps as an outgroup to the social Hymenoptera. Expression patterns for these genes suggest that the ant clock functions similar to the honeybee clock, with period and cry-m mRNA levels increasing during the night and cycle and clockwork orange mRNAs cycling approximately anti-phase to period. Gene models for five of these genes also parallel honeybee models. In particular, the single ant cryptochrome is an ortholog of the mammalian-type (cry-m), rather than Drosophila-like protein (cry-d). Additionally, we find a conserved VPIFAL C-tail region in clockwork orange shared by insects but absent in vertebrates. Overall, our characterization of the ant clock demonstrates that two social insect lineages, ants and bees, share a similar, mammalian-like circadian clock. This study represents the first characterization of clock genes in an ant and is a key step towards understanding socially-regulated plasticity in circadian rhythms by facilitating comparative studies on the organization of circadian clockwork. PMID:23152747

  3. Ants of the national park of American Samoa

    Banko, Paul C.; Peck, Robert W.

    2015-01-01

    American Samoa makes up the eastern end of the Samoan Archipelago. On the islands of Tutuila, Taʽū and Ofu, the National Park of American Samoa (NPSA) protects about 4,000 ha of coastal, mid-slope and ridge-top forest. While the ant fauna of the Samoan Archipelago is considered relatively well documented, much of NPSA has never been surveyed for ants, leaving the fauna and its distribution poorly known. To address this shortfall, we systematically surveyed ants within the Tutuila and Taʽū units of NPSA using standard methods (hand collecting, litter sifting, and baits) at 39 sites within six vegetation types ranging from 8 to 945 m elevation. Forty-four ant species were identified, 19 of which are exotic to the Samoan Archipelago. Two notoriously aggressive species, Anoplolepis gracilipes and Pheidole megacephala were detected at two and seven sites, respectively. Both of these species largely excluded all other ants from bait, although their impact on ant community composition is unclear. A suite of habitat variables measured at each site was assessed to explain park-wide ant distributions. Of eight variables evaluated, only elevation was associated with ant community structure, as the ratio of native to exotic ant species increased significantly with elevation on Tutuila. Our survey documented two species not previously reported from American Samoa. Strumigenys eggersi, detected at 12 sites, appears to be a new immigrant to the Pacific Basin. A species of Pheidole was collected that likely represents an undescribed species. Solenopsis geminata, an aggressive species first reported on Tutuila in 2002, was not detected during our survey.

  4. How Random Is Spatiotemporal Chaos of Langton's Ant?1

    Luptáková I. I. Dirgová

    2015-12-01

    Full Text Available In recent years there have been numerous attempts to control chaotic behavior by evolutionary optimization. Most of these attempts were aimed at a study of chaotic systems defined by differential equations, but a few attempts were made also at evolutionary design of initial conditions or rules of cellular automata aimed at performing a specified task. We shall use a simple cellular automaton called Langton's ant after its designer, Christopher Langton. Generally, the ant acts on a 2D grid, where each it’s square can be either black or white. The ant is facing in one of four directions, and its behavior is described by 3 rules: (1 If ant is on a black square, it makes a left turn. (2 If ant is on a white square, it makes a right turn. (3 When ant moves to the next square, the one it was on reverses color. Despite simplicity of these rules, the ant produces extremely complex behavior, but after around 10000 steps the ant begins to construct a diagonal „highway“. This stable attractor has been always achieved regardless of the initial setting of black and white squares, but there is no proof, that it is always so. This behavior can be related to the undecidability of the halting problem. Our goal in this paper is to optimize initial conditions for the ant on a grid, so that it will be maximally “slowed down” in the sense that it should arrive at the preset boundary of the grid as late as possible. By a comparison of greedy stochastic optimization with an optimization by blind search are able to estimate, that is this chaotic system is not reasonably controllable and appears to have no regularity in the “optimal” initial conditions.

  5. Optimal Power Flow Solution Using Ant Manners for Electrical Network

    ALLAOUA, B.

    2009-02-01

    Full Text Available This paper presents ant manners and the collective intelligence for electrical network. Solutions for Optimal Power Flow (OPF problem of a power system deliberate via an ant colony optimization metaheuristic method. The objective is to minimize the total fuel cost of thermal generating units and also conserve an acceptable system performance in terms of limits on generator real and reactive power outputs, bus voltages, shunt capacitors/reactors, transformers tap-setting and power flow of transmission lines. Simulation results on the IEEE 30-bus electrical network show that the ant colony optimization method converges quickly to the global optimum.

  6. Army ants (Formicidae: Ecitoninae) in productive systems of Caqueta (Colombia)

    Five species of army ants (Labidus coecus, Labidus coecus, Neivamyrmex punctaticeps, Cheliomyrmex andicola y Eciton dulcium) are recorded from land under seven different use regimes in Caqueta Department. The ants were captured in agricultural areas of the Amazonian foothills using four sampling methods (TSBF, screening of litter, formalin soil wash, and direct search). We provide information about distribution and habits for each species and report the presence of C. andicola and E. dulcium in Caqueta for the first time. These records contribute to a better knowledge of the ant fauna in Colombia.

  7. What is important for ant assemblages in temperate forest soils?

    Tae-Sung Kwon

    2016-01-01

    Ant assemblages in the soil have been studied at eight forest sites (4 oak forest sites, and 4 pine forest sites) in four study areas (1 seminatural area, and 3 industrialized areas) in South Korea for 6 years from 2002 to 2010. Soil cores and Tullgren funnel were used for the ant survey. Ant surveys were carried out once per year in autumn (from late September to mid-October). The soil pH was lower in the industrialized than in the seminatural area, showing the acidified soils in the industr...

  8. Solving the Mixed Vrp with Backhauling Using Ants

    Wassan, N. A.; Salhi, S.; Nagy, G.

    2009-08-01

    The mixed vehicle routing problem with backhauls is investigated using an ant system heuristic. This distribution problem seems to suffer from a lack of published work even though it has immense practical applicability especially within logistic systems. Some enhancements to the basic ant system algorithm are embedded into the search. In particular a focus is on the choice in the placement of ants, the use of a site-dependent candidate list, the introduction of a look ahead-based visibility, and appropriate strategies for updating local and global trails. Encouraging computational results are reported when tested on benchmark data sets.

  9. A Modified Ant-based Clustering for Medical Data

    C. Immaculate Mary

    2010-10-01

    Full Text Available Ant-based techniques, in the computer sciences, are designed for those who take biological inspirations on the behavior of the social insects. Data-clustering techniques are classification algorithms that have a wide range of applications, from Biology to Image processing and Data presentation. The ant-based clustering technique has been proven a promising technique for the data clustering problems. In this paper a modified ant-based clustering is proposed for medical data processing. The performance of the proposed method is compared with k-means clustering.

  10. Ocelli: A Celestial Compass in the Desert Ant Cataglyphis

    Fent, Karl; Wehner, Rudiger

    1985-04-01

    In addition to multifaceted lateral compound eyes, most insects possess three frontal eyes called ocelli. Each ocellus has a single lens, as does the vertebrate eye. The ocelli of some flying insects, locusts and dragonflies, have been shown to function as horizon detectors involved in the visual stabilization of course. In a walking insect, the desert ant Cataglyphis, it is now shown that the ocelli can read compass information from the blue sky. When the ant's compound eyes are occluded and both sun and landmarks are obscured, the ocelli, using the pattern of polarized light in the sky as a compass cue, help in guiding the ant back home.

  11. Automating ActionScript Projects with Eclipse and Ant

    Koning, Sidney

    2011-01-01

    Automating repetitive programming tasks is easier than many Flash/AS3 developers think. With the Ant build tool, the Eclipse IDE, and this concise guide, you can set up your own "ultimate development machine" to code, compile, debug, and deploy projects faster. You'll also get started with versioning systems, such as Subversion and Git. Create a consistent workflow for multiple machines, or even complete departments, with the help of extensive Ant code samples. If you want to work smarter and take your skills to a new level, this book will get you on the road to automation-with Ant. Set up y

  12. The cavity-nest ant Temnothorax crassispinus prefers larger nests

    Mitrus, S.

    2014-01-01

    Colonies of the ant Temnothorax crassispinus inhabit mostly cavities in wood and hollow acorns. Typically in the field, nest sites that can be used by the ant are a limited resource. In a field experiment, it was investigated whether the ants prefer a specific size of nest, when different ones are available. In July 2011, a total of 160 artificial nests were placed in a beech-pine forest. Four artificial nests (pieces of wood with volume cavities, ca 415, 605, 730, and 980 mm3, respectively) ...

  13. Ant Colony Algorithm for Solving QoS Routing Problem

    SUN Li-juan; WANG Liang-jun; WANG Ru-chuan

    2004-01-01

    Based on the state transition rule, the local updating rule and the global updating rule of ant colony algorithm, we propose an improved ant colony algorithm of the least-cost quality of service (QoS) unicast routing. The algorithm is used for solving the routing problem with delay, delay jitter, bandwidth, and packet loss-constrained. In the simulation, about 52.33% ants find the successful QoS routing , and converge to the best. It is proved that the algorithm is efficient and effective.

  14. An Improved Ant Colony Routing Algorithm for WSNs

    Tan Zhi

    2015-01-01

    Full Text Available Ant colony algorithm is a classical routing algorithm. And it are used in a variety of application because it is economic and self-organized. However, the routing algorithm will expend huge amounts of energy at the beginning. In the paper, based on the idea of Dijkstra algorithm, the improved ant colony algorithm was proposed to balance the energy consumption of networks. Through simulation and comparison with basic ant colony algorithms, it is obvious that improved algorithm can effectively balance energy consumption and extend the lifetime of WSNs.

  15. Disruption of a protective ant-plant mutualism by an invasive ant increases elephant damage to savanna trees.

    Riginos, Corinna; Karande, Megan A; Rubenstein, Daniel I; Palmer, Todd M

    2015-03-01

    Invasive species can indirectly affect ecosystem processes via the disruption of mutualisms. The mutualism between the whistling thorn acacia (Acacia drepanolobium) and four species of symbiotic ants is an ecologically important one; ants strongly defend trees against elephants, which can otherwise have dramatic impacts on tree cover. In Laikipia, Kenya, the invasive big-headed ant (Pheidole megacephala) has established itself at numerous locations within the last 10-15 years. In invaded areas on five properties, we found that three species of symbiotic Crematogaster ants were virtually extirpated, whereas Tetraponera penzigi co-occurred with P. megacephala. T. penzigi appears to persist because of its nonaggressive behavior; in a whole-tree translocation experiment, Crematogaster defended host trees against P. megacephala, but were extirpated from trees within hours. In contrast, T. penzigi retreated into domatia and withstood invading ants for >30 days. In the field, the loss of defensive Crematogaster ants in invaded areas led to a five- to sevenfold increase in the number of trees catastrophically damaged by elephants compared to uninvaded areas. In savannas, tree cover drives many ecosystem processes and provides essential forage for many large mammal species; thus, the invasion of big-headed ants may strongly alter the dynamics and diversity of East Africa's whistling thorn savannas by disrupting this system's keystone acaciaant mutualism. PMID:26236862

  16. Evolution of specialized spermatheca morphology in ant queens: insight from comparative developmental biology between ants and polistine wasps.

    Gotoh, Ayako; Billen, Johan; Hashim, Rosli; Ito, Fuminori

    2009-11-01

    In many ant species, the queens can keep spermatozoa alive in their spermatheca for several years, which goes along with unique morphological characteristics of the queen's spermatheca. The relative spermatheca size in ant queens is prominently larger than that in social wasps. Furthermore, the epithelium lining the spermatheca reservoir of ants consists of columnar cells in the hilar region and squamous cells in the distal region, whereas it is formed by columnar cells only in social wasps. To study the evolution of the unique spermatheca morphology in ant queens, we compared the various processes during spermatheca development between two ponerine ant species of the genus Pachycondyla (=Brachyponera) and three polistine wasp species of the genus Polistes. From histological observations, we can define four developmental events in the ant queens: (1) invagination of the spermatheca primordium, (2) the reservoir wall thickness becomes unequal, (3) the reservoir diameter doubles as the lining epithelial cells become flattened except for the hilar region, and (4) the increase in thickness of the reservoir epithelium is limited to the hilar region which doubles in thickness. In polistine wasps, the second and the third developmental events are absent and the entire epithelium of the spermatheca wall becomes thick in the final step. We therefore conclude that for ant queens the second and third steps are crucial for the enlargement of the spermatheca size, and that the second to the fourth steps are crucial for the specialization of the reservoir wall structure. PMID:19720157

  17. Emergence of altruism behavior in army ant-based social evolutionary system

    Ichimura, Takumi; Uemoto, Takuya; Hara, Akira; Kenneth J. Mackin

    2014-01-01

    Army ants perform the altruism behavior that an ant sacrifices its own well-being for the benefit of another ants. They build bridges using their own bodies along the path from a food to the nest. We developed the army ant inspired social evolutionary system by using Swarm library. The system has 2 kinds of ant agents, ‘Major ant’ and ‘Minor ant’. They communicate with each other via pheromones. Army ant can recognize them as the signals from the other ants. The pheromones evaporate with the ...

  18. Selenium exposure results in reduced reproduction in an invasive ant species and altered competitive behavior for a native ant species.

    De La Riva, Deborah G; Trumble, John T

    2016-06-01

    Competitive ability and numerical dominance are important factors contributing to the ability of invasive ant species to establish and expand their ranges in new habitats. However, few studies have investigated the impact of environmental contamination on competitive behavior in ants as a potential factor influencing dynamics between invasive and native ant species. Here we investigated the widespread contaminant selenium to investigate its potential influence on invasion by the exotic Argentine ant, Linepithema humile, through effects on reproduction and competitive behavior. For the fecundity experiment, treatments were provided to Argentine ant colonies via to sugar water solutions containing one of three concentrations of selenium (0, 5 and 10 μg Se mL(-1)) that fall within the range found in soil and plants growing in contaminated areas. Competition experiments included both the Argentine ant and the native Dorymyrmex bicolor to determine the impact of selenium exposure (0 or 15 μg Se mL(-1)) on exploitation- and interference-competition between ant species. The results of the fecundity experiment revealed that selenium negatively impacted queen survival and brood production of Argentine ants. Viability of the developing brood was also affected in that offspring reached adulthood only in colonies that were not given selenium, whereas those in treated colonies died in their larval stages. Selenium exposure did not alter direct competitive behaviors for either species, but selenium exposure contributed to an increased bait discovery time for D. bicolor. Our results suggest that environmental toxins may not only pose problems for native ant species, but may also serve as a potential obstacle for establishment among exotic species. PMID:27038576

  19. Symbiotic mutualism with a community of opportunistic ants: protection, competition, and ant occupancy of the myrmecophyte Barteria nigritana (Passifloraceae)

    Djiéto-Lordon, Champlain; Dejean, Alain; Gibernau, Marc; Hossaert-McKey, Martine; McKey, Doyle

    2004-10-01

    Barteria nigritana is a myrmecophyte tree of Lower Guinea coastal vegetation. Unlike the more specialised B. fistulosa, which harbours a single host-specific mutualistic ant, B. nigritana is associated with several opportunistic ants. Such symbiotic, yet opportunistic, ant-plant associations have been little studied. On 113 clumps of B. nigritana, we censused ant associates and herbivores and compared herbivory on plants occupied by different ants. In addition to these correlative data, protection conferred by different ant species was compared by herbivore-placement experiments. Identity of ant associate changed predictably over plant ontogeny. Pheidole megacephala was restricted to very small plants; saplings were occupied by either Oecophylla longinoda or Crematogaster sp., and the latter species was the sole occupant of larger trees. Damage by caterpillars of the nymphalid butterfly Acraea zetes accounted for much of the herbivory to leaves. Ant species differed in the protection provided to hosts. While P. megacephala provided no significant protection, plants occupied by O. longinoda and Crematogaster sp. suffered less damage than did unoccupied plants or those occupied by P. megacephala. Furthermore, O. longinoda provided more effective protection than did Crematogaster sp. Herbivore-placement experiments confirmed these results. Workers of O. longinoda killed or removed all larval instars of A. zetes. Crematogaster preyed on only the two first larval instars, and P. megacephala preyed mainly on eggs, only rarely attacking the two first larval instars. Opportunistic ants provided significant protection to this relatively unspecialised myrmecophyte. The usual associate of mature trees was not the species that provided most protection.

  20. Area-wide suppression of invasive fire ant populations

    Full text: The fire ants, Solenopsis invicta and Solenopsis richteri, were inadvertently introduced into the United States in the early 1900s and currently inhabit over 150 million ha in Puerto Rico and twelve southern states from Texas to Virginia. Imported fire ants have also become established in isolated sites in California, Arizona, New Mexico, and Maryland. They have also widened their invasive character by accidental importation and establishment in Australia and Taiwan. Fire ant colonies (single queen) can contain up to 250,000 workers and reach infestation rates of over 130 mounds per hectare. More recently, multiple-queen colonies have proliferated in the southern states with even greater population densities. The fire ant's large numbers, resource requirements, aggressive behavior, and potent sting have resulted in many negative interactions with man and the ecosystem. Many ground inhabiting arthropods and other small animals are destroyed, yields of several agricultural crops are reduced, and ca. 1% of the population is at risk from hypersensitivity to fire ant venom. The population densities in the US are 5-10 times higher than in South America, most likely due to their escape from natural enemies. Chemical Control: Several commercial insecticide baits have been developed for fire ant control; however, they are costly, many are not registered for large acreage, and most have adverse environmental impact when used in environmentally sensitive locations. Biological Control: At least 22 species of parasitic Pseudacteon flies have been found attacking fire ants in South America. These flies have been shown to stop fire ant foraging and shift the local competitive balance to other ant species, thus limiting resources to the fire ant. There are also two Protozoan pathogens, Thelohania solenopsae, and Vairimorpha invictae that naturally infect S. invicta in South America. Both have been shown to cause reductions of field populations, and T. solenopsae