Science.gov

Sample records for muir ant problem

  1. Muir Inlet

    USGS Multimedia Gallery

    Muir Glacier has retreated more than 2 km and ceased to have a tidewater terminus. Note that the retreat of Muir Glacier has left several ice-cored morainal mounds between the shoreline and the terminus. Since 1980, Muir Glacier has thinned by several hundred meters permitting a view of a mountain w...

  2. Muir Inlet

    USGS Multimedia Gallery

    This ship-deck-based photograph of Muir Glacier and Muir Inlet, Glacier Bay National Park and Preserve, St. Elias Mountains, Alaska, is taken towards the north-northwest and shows the nearly 50-m-high retreating tidewater terminus of the glacier with part of its face capped by a few angular sé...

  3. When Ants Attack: Comparing Ant Algorithms for Constraint Problems

    E-print Network

    Bridge, Derek

    When Ants Attack: Comparing Ant Algorithms for Constraint Problems Finbarr Tarrant and Derek Bridge. We describe an ant algorithm for solving constraint problems [Sol02]. We devise a number of variants and the best heuristics for state transitions may differ from current practice. 1 Introduction In ant

  4. Muir Glacier and Muir Inlet 1980

    USGS Multimedia Gallery

    This ship-deck-based August 1980 photograph of Muir Glacier and Muir Inlet, Glacier Bay National Park and Preserve, St. Elias Mountains, Alaska, shows the nearly 200-ft-high retreating tidewater end of Muir Glacier with part of its face capped by a few angular pinnacles of ice, called séracs....

  5. Muir Glacier and Muir Inlet 2003

    USGS Multimedia Gallery

    This photo was taken in September 2003; in the 23 years between photographs, Muir Glacier has retreated more than a mile and ceased to have a tidewater terminus. Since 1980, Muir Glacier has thinned by more than 600 ft, permitting a view of a mountain with a summit elevation of greater than 4000 ft,...

  6. Ant Algorithms Solve Difficult Optimization Problems

    E-print Network

    Libre de Bruxelles, Université

    Ant Algorithms Solve Difficult Optimization Problems Marco Dorigo IRIDIA Universit´e Libre de Bruxelles 50 Avenue F. Roosevelt B-1050 Brussels, Belgium mdorigo@ulb.ac.be Abstract. The ant algorithms research field builds on the idea that the study of the behavior of ant colonies or other social insects

  7. Muir Glacier Retreats

    USGS Multimedia Gallery

    Muir Glacier has retreated out of the field of view and is now nearly 5 miles to the northwest. Riggs Glacier has retreated as much as 2000 ft and thinned by more than 800 feet. Note the dense vegetation that has developed. Also note the correlation between Muir Glacier’s 1941 thickness and th...

  8. Solving the ANTS Problem with Asynchronous Finite State Machines

    E-print Network

    Solving the ANTS Problem with Asynchronous Finite State Machines Yuval Emek, Tobias Langner, Jara + D) #12;Previous Work ANTS problem (Ants Nearby Treasure Search) introduced by Feinerman, Korman, Lotker, Sereni [PODC 2012] = #12;Previous Work ANTS problem (Ants Nearby Treasure Search) introduced

  9. Solving the ANTS Problem with Asynchronous Finite State Machines

    E-print Network

    Solving the ANTS Problem with Asynchronous Finite State Machines Yuval Emek1 , Tobias Langner2 the Ants Nearby Treasure Search (ANTS) problem introduced by Feinerman, Korman, Lotker, and Sereni (PODC-time of any ANTS algorithm. 1 Introduction "They operate without any central control. Their collective

  10. Solving Permutation Constraint Satisfaction Problems with Artificial Ants

    E-print Network

    Wolf, Christian

    Solving Permutation Constraint Satisfaction Problems with Artificial Ants Christine Solnon 1 Abstract. We describe in this paper Ant­P­solver, a generic con­ straint solver based on the Ant Colony Optimization (ACO) meta­ heuristic. The ACO metaheuristic takes inspiration on the observa­ tion of real ants

  11. The John Muir Award.

    ERIC Educational Resources Information Center

    White, Graham

    2002-01-01

    The John Muir Award was established in the United Kingdom to respond to minimal environmental awareness, especially among youth. The Award has three levels of effort; all involve discovering a wild place, exploring its wildness, helping to conserve it, and sharing the experience with a wider audience. There is an effort to establish the award in…

  12. Reply to James Muir

    ERIC Educational Resources Information Center

    White, John

    2004-01-01

    In "EPAT", vol. 36, no. 1, 2004, James Muir takes the author and fellow philosophers of education to task for their ignorance of the history of philosophy of education. "[T]oo many currently influential educationists, Professor White in particular, are literally unaware that educational philosophy has a history more than three hundred years in…

  13. Muir and Riggs Glaciers, Muir Inlet, Alaska - 1950

    USGS Multimedia Gallery

    This, the first of two repeat photographs, documents significant changes that have occurred during the nine years between photographs A and B. Although Muir Glacier has retreated more than 3 kilometers and thinned more than 100 meters, exposing Muir Inlet, it remains connected with tributary Riggs G...

  14. Muir and Riggs Glaciers, Muir Inlet, Alaska - 1941

    USGS Multimedia Gallery

    This northeast-looking photograph, on the southeastern side of White Thunder Ridge ,shows the lower reaches of Muir Glacier, then a large tidewater calving valley glacier, and its tributary Riggs Glacier. The séracs in the lower right-hand corner of the photograph mark Muir Glacier’s te...

  15. JOHNMUIRCOLLEGE Learning and Living at Muir

    E-print Network

    California at San Diego, University of

    #12;#12;JOHNMUIRCOLLEGE Learning and Living at Muir 2014-2015 Guide to John Muir College #12, or with a grade of P. See the UCSD catalog for more information and the Muir website for a comprehensive list of courses. 2. COLLEGE REQUIREMENTS o Muir College Writing Requirement You must complete a two

  16. Ant Colony Optimization for Multiple Knapsack Problem and Heuristic Model

    E-print Network

    Fidanova, Stefka

    solutions. Modern heuristics include simulated annealing [7], genetic algorithms [4], tabu search [5], antAnt Colony Optimization for Multiple Knapsack Problem and Heuristic Model Stefka Fidanova (stefka practical problems from di#11;erent domains, including transport, like cargo loading, cutting stock, bin

  17. JOHN MUIR WILDERNESS, CALIFORNIA.

    USGS Publications Warehouse

    Dellinger, David A.; Johnson, Frederick L.

    1984-01-01

    The mineral survey of the John Muir Wilderness, California revealed eight areas of probable and substantiated potential for the occurrence of mineral resources. Tungsten, with accompanying resources of gold, copper, silver, and molybdenum, is found along contacts between granitic rocks and metamorphosed calcareous sedimentary rocks; it is estimated that more than 1 million tons of demonstrated tungsten resources exist in areas of sustantiated resource potential within the wilderness. Resources of gold, silver, lead, copper, zinc, molydenum, and cobalt, occur in small deposits not associated with tungsten; however, the known deposits of these commodities are small and the possibility of the occurrence of larger ones is unlikely. The geologic setting precludes the presence of fossil fuel resources.

  18. THE UNIVERSITY OF EDINBURGH, John Muir Building,

    E-print Network

    Edinburgh, University of

    THE UNIVERSITY OF EDINBURGH, John Muir Building, King's Buildings, A GUIDE TO ACCESS AND FACILITIES, Address John Muir Building, University of Edinburgh. King's Buildings. Edinburgh, E,H,9,3,J,L, United Kingdom, Telephone. 0,1,3,1,. 6,5,0, 4,8,6,5, Map Link. http://www.ed.ac.uk/maps/buildings/john-muir

  19. Muir and Riggs Glaciers, Muir Inlet, Alaska - 2004

    USGS Multimedia Gallery

    The second repeat photograph documents significant changes that have occurred during the 63 years between photographs A and C, and during the 54 years between photographs B and C. Muir Glacier has retreated out of the field of view and is now more than 7 kilometers northwest. Riggs Glacier has retre...

  20. Registration of ‘Muir’ spring feed barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Muir’ (Reg. No. CV-357, PI 674172) is a two-row, spring, hulled feed barley (Hordeum vulgare L.) cultivar developed and evaluated as 07WA-601.6, and released in 2013 by Washington State University (WSU). Muir was derived from the cross ‘Baronesse’/‘Bob’ and selected through singleseed descent from ...

  1. Ant colony optimization for solving university facility layout problem

    NASA Astrophysics Data System (ADS)

    Mohd Jani, Nurul Hafiza; Mohd Radzi, Nor Haizan; Ngadiman, Mohd Salihin

    2013-04-01

    Quadratic Assignment Problems (QAP) is classified as the NP hard problem. It has been used to model a lot of problem in several areas such as operational research, combinatorial data analysis and also parallel and distributed computing, optimization problem such as graph portioning and Travel Salesman Problem (TSP). In the literature, researcher use exact algorithm, heuristics algorithm and metaheuristic approaches to solve QAP problem. QAP is largely applied in facility layout problem (FLP). In this paper we used QAP to model university facility layout problem. There are 8 facilities that need to be assigned to 8 locations. Hence we have modeled a QAP problem with n ? 10 and developed an Ant Colony Optimization (ACO) algorithm to solve the university facility layout problem. The objective is to assign n facilities to n locations such that the minimum product of flows and distances is obtained. Flow is the movement from one to another facility, whereas distance is the distance between one locations of a facility to other facilities locations. The objective of the QAP is to obtain minimum total walking (flow) of lecturers from one destination to another (distance).

  2. Ant-Q: A Reinforcement Learning approach to the traveling salesman problem

    E-print Network

    Gambardella, Luca Maria

    Ant-Q: A Reinforcement Learning approach to the traveling salesman problem Luca M. Gambardella@ulb.ac.be http://iridia.ulb.ac.be/dorigo/dorigo.html Abstract In this paper we introduce Ant-Q, a family to the solution of symmetric and asym- metric instances of the traveling salesman prob- lem (TSP). Ant

  3. Enhanced ant colony optimization for inventory routing problem

    NASA Astrophysics Data System (ADS)

    Wong, Lily; Moin, Noor Hasnah

    2015-10-01

    The inventory routing problem (IRP) integrates and coordinates two important components of supply chain management which are transportation and inventory management. We consider a one-to-many IRP network for a finite planning horizon. The demand for each product is deterministic and time varying as well as a fleet of capacitated homogeneous vehicles, housed at a depot/warehouse, delivers the products from the warehouse to meet the demand specified by the customers in each period. The inventory holding cost is product specific and is incurred at the customer sites. The objective is to determine the amount of inventory and to construct a delivery routing that minimizes both the total transportation and inventory holding cost while ensuring each customer's demand is met over the planning horizon. The problem is formulated as a mixed integer programming problem and is solved using CPLEX 12.4 to get the lower and upper bound (best integer) for each instance considered. We propose an enhanced ant colony optimization (ACO) to solve the problem and the built route is improved by using local search. The computational experiments demonstrating the effectiveness of our approach is presented.

  4. Muir Glacier in Glacier Bay National Monument 1941

    USGS Multimedia Gallery

    This August 1941 photograph is of Muir Glacier in Glacier Bay National Monument, Alaska. It shows the lower reaches of Muir Glacier, then a large, tidewater calving valley glacier and its tributary, Riggs Glacier. For nearly two centuries before 1941, Muir Glacier had been retreating. In places, a t...

  5. SCOPE OF WORK DIRECTOR, JOHN MUIR INSTITUTE OF THE ENVIRONMENT

    E-print Network

    Ullrich, Paul

    4/28/15 SCOPE OF WORK DIRECTOR, JOHN MUIR INSTITUTE OF THE ENVIRONMENT Dept: Office of Research Position: Director, John Muir Institute of the Environment Term: 5 years on a 50% time basis Reporting to or other administrative unit. The John Muir Institute of the Environment is an Organized Research Unit

  6. Solving Flipping Coin Problem and Penney-Ante Game without Using Generating Function

    E-print Network

    Tang, Pingzhong

    Institute for Theoretical Computer Science, Tsinghua University Beijing, 100084, P. R. China, cscjjkSolving Flipping Coin Problem and Penney-Ante Game without Using Generating Function Kai Jin@gmail.com Abstract. We revisit the Flipping Coins (FCP) Problem and Penny- Ante Game(PAG) and present a new method

  7. Houston, We Have a Problem: Rasberry Crazy Ants 

    E-print Network

    Drees, Bastiaan M.

    2009-03-15

    sound like science fiction, but it?s true. A new exotic insect species, the Rasberry crazy ant, has invaded 11 counties in the Houston area since pest control operator Tom Rasberry discovered the ants in Pasadena in 2002. By 2008 they had spread...

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

    PubMed

    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

  9. Ants on a Doughnut Purpose. In this project you will use calculus to solve a geometry problem. This project

    E-print Network

    Brand, Neal

    Ants on a Doughnut Purpose. In this project you will use calculus to solve a geometry problem. This project serves as an introduction to differential geometry. The Problem. Two ants are exploring a doughnut and grease. The two regions are as far apart on the doughnut as they can be. The ants must leave a path

  10. The California Dream: a dangerous social and environmental myth protested by John Muir and John Steinbeck

    E-print Network

    Winter, Raymond Earl III

    2010-01-01

    and morality as modeled in wild nature, Muir approached theand to alter the nature of wild spaces from a mysteriouswild. The third concept that shaped Muir‘s environmental ethic dealt with the identity of nature

  11. 36 CFR 7.6 - Muir Woods National Monument.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Property 1 2010-07-01 2010-07-01 false Muir Woods National Monument. 7.6 Section 7.6 Parks, Forests...REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.6 Muir Woods National Monument. (a) Fires. Fires are prohibited...

  12. A GP Neutral Function for the Artificial Ant Problem Esteban Ricalde

    E-print Network

    Fernandez, Thomas

    A GP Neutral Function for the Artificial Ant Problem Esteban Ricalde IIMAS-UNAM, Circuito Escolar s introduces a function that increases the amount of neutrality (inactive code in Genetic Programming Algorithms Keywords Evolutionary Computation, Genetic Programming, Neutral- ity 1. INTRODUCTION The Santa Fe

  13. Solving optimum operation of single pump unit problem with ant colony optimization (ACO) algorithm

    NASA Astrophysics Data System (ADS)

    Yuan, Y.; Liu, C.

    2012-11-01

    For pumping stations, the effective scheduling of daily pump operations from solutions to the optimum design operation problem is one of the greatest potential areas for energy cost-savings, there are some difficulties in solving this problem with traditional optimization methods due to the multimodality of the solution region. In this case, an ACO model for optimum operation of pumping unit is proposed and the solution method by ants searching is presented by rationally setting the object function and constrained conditions. A weighted directed graph was constructed and feasible solutions may be found by iteratively searching of artificial ants, and then the optimal solution can be obtained by applying the rule of state transition and the pheromone updating. An example calculation was conducted and the minimum cost was found as 4.9979. The result of ant colony algorithm was compared with the result from dynamic programming or evolutionary solving method in commercial software under the same discrete condition. The result of ACO is better and the computing time is shorter which indicates that ACO algorithm can provide a high application value to the field of optimal operation of pumping stations and related fields.

  14. Page 1 of 3 Muir College Student Affairs Intern Positions 2015-2016 Academic Year

    E-print Network

    California at San Diego, University of

    such as Welcome Week, Inspiring Leaders Conference, Triton Day, Celebrating John Muir Week, Spring Leadership, Celebrating John Muir Week, Triton Day, and the Spring Leadership Retreat. The intern will also advertisePage 1 of 3 Muir College Student Affairs Intern Positions 2015-2016 Academic Year Apply

  15. Coed Trecastell: A Personal Experience of the John Muir Award.

    ERIC Educational Resources Information Center

    Collister, Rob

    1999-01-01

    A John Muir Award participant describes his satisfying experience cleaning up a wooded gorge near his home in Wales. Sidebar explains how the British award achieves its purpose of empowering people to conserve wild places through four challenges: discover a wild place, explore it, conserve it, and share the experience with others. The award has…

  16. EVALUA TION OF PINNING MATERIALS FOR MARBLE REPAIR Christina Muir

    E-print Network

    EVALUA TION OF PINNING MATERIALS FOR MARBLE REPAIR Christina Muir Submitted in partial fulfillment, Planning and Preservation Columbia University (May 2008) #12;Abstract The practice of repairing marble material is best suited for use in marble repair. Marble cores were cut and repaired with pins

  17. Reach Survival Estimates, 2008 Bill Muir, Steve Smith, Doug Marsh,

    E-print Network

    Reach Survival Estimates, 2008 Bill Muir, Steve Smith, Doug Marsh, John Williams, and Jim FaulknerDalles JohnDay Hells Canyon Oxbow Brownlee Priest Rapids Wanapum Rock Island Rocky Reach Wells Chief Joseph. . Date at McNary Number released McNary to John Day Dam John Day to Bonneville Dam McNary to Bonneville

  18. A modified ant colony optimization to solve multi products inventory routing problem

    NASA Astrophysics Data System (ADS)

    Wong, Lily; Moin, Noor Hasnah

    2014-07-01

    This study considers a one-to-many inventory routing problem (IRP) network consisting of a manufacturer that produces multi products to be transported to many geographically dispersed customers. We consider a finite horizon where a fleet of capacitated homogeneous vehicles, housed at a depot/warehouse, transport products from the warehouse to meet the demand specified by the customers in each period. The demand for each product is deterministic and time varying and each customer requests a distinct product. The inventory holding cost is product specific and is incurred at the customer sites. The objective is to determine the amount on inventory and to construct a delivery schedule that minimizes both the total transportation and inventory holding costs while ensuring each customer's demand is met over the planning horizon. The problem is formulated as a mixed integer programming problem and is solved using CPLEX 12.4 to get the lower and upper bound (best integer solution) for each problem considered. We propose a modified ant colony optimization (ACO) to solve the problem and the built route is improved by using local search. ACO performs better on large instances compared to the upper bound.

  19. Fuzzy Random ?-Mean SAD Portfolio Selection Problem: An Ant Colony Optimization Approach

    NASA Astrophysics Data System (ADS)

    Thakur, Gour Sundar Mitra; Bhattacharyya, Rupak; Mitra, Swapan Kumar

    2010-10-01

    To reach the investment goal, one has to select a combination of securities among different portfolios containing large number of securities. Only the past records of each security do not guarantee the future return. As there are many uncertain factors which directly or indirectly influence the stock market and there are also some newer stock markets which do not have enough historical data, experts' expectation and experience must be combined with the past records to generate an effective portfolio selection model. In this paper the return of security is assumed to be Fuzzy Random Variable Set (FRVS), where returns are set of random numbers which are in turn fuzzy numbers. A new ?-Mean Semi Absolute Deviation (?-MSAD) portfolio selection model is developed. The subjective opinions of the investors to the rate of returns of each security are taken into consideration by introducing a pessimistic-optimistic parameter vector ?. ?-Mean Semi Absolute Deviation (?-MSAD) model is preferred as it follows absolute deviation of the rate of returns of a portfolio instead of the variance as the measure of the risk. As this model can be reduced to Linear Programming Problem (LPP) it can be solved much faster than quadratic programming problems. Ant Colony Optimization (ACO) is used for solving the portfolio selection problem. ACO is a paradigm for designing meta-heuristic algorithms for combinatorial optimization problem. Data from BSE is used for illustration.

  20. Ant System Thomas Stutzle

    E-print Network

    Hoos, Holger H.

    ¡£¢ ­ ¤¦¥ Ant System Thomas St¨utzle § Universit´e Libre de Bruxelles IRIDIA Brussels, Belgium Ant System, the first Ant Colony Optimization algorithm, showed to be a viable method for attacking Problem. To show that Ant Colony Opti- mization algorithms could be good alternatives to existing

  1. Osaka-UCSD Workshop 2011 John Muir Room, Price Center East, UC San Diego

    E-print Network

    de Sa, Virginia

    Osaka-UCSD Workshop 2011 John Muir Room, Price Center East, UC San Diego March 15-16, 2011 Center-UCSD Workshop 2011 John Muir Room, Price Center East, UC San Diego March 15-16, 2011 Tuesday, March 15 09

  2. Muir–Torre-like syndrome in Fhit-deficient mice

    PubMed Central

    Fong, Louise Y. Y.; Fidanza, Vincenzo; Zanesi, Nicola; Lock, Leslie F.; Siracusa, Linda D.; Mancini, Rita; Siprashvili, Zurab; Ottey, Michelle; Martin, S. Eric; Druck, Teresa; McCue, Peter A.; Croce, Carlo M.; Huebner, Kay

    2000-01-01

    To investigate the role of the Fhit gene in carcinogen induction of neoplasia, we have inactivated one Fhit allele in mouse embryonic stem cells and produced (129/SvJ × C57BL/6J) F1 mice with a Fhit allele inactivated (+/?). Fhit +/+ and +/? mice were treated intragastrically with nitrosomethylbenzylamine and observed for 10 wk posttreatment. A total of 25% of the +/+ mice developed adenoma or papilloma of the forestomach, whereas 100% of the +/? mice developed multiple tumors that were a mixture of adenomas, squamous papillomas, invasive carcinomas of the forestomach, as well as tumors of sebaceous glands. The visceral and sebaceous tumors, which lacked Fhit protein, were similar to those characteristic of Muir–Torre familial cancer syndrome. PMID:10758156

  3. Muir-Torre-like syndrome in Fhit-deficient mice.

    PubMed

    Fong, L Y; Fidanza, V; Zanesi, N; Lock, L F; Siracusa, L D; Mancini, R; Siprashvili, Z; Ottey, M; Martin, S E; Druck, T; McCue, P A; Croce, C M; Huebner, K

    2000-04-25

    To investigate the role of the Fhit gene in carcinogen induction of neoplasia, we have inactivated one Fhit allele in mouse embryonic stem cells and produced (129/SvJ x C57BL/6J) F(1) mice with a Fhit allele inactivated (+/-). Fhit +/+ and +/- mice were treated intragastrically with nitrosomethylbenzylamine and observed for 10 wk posttreatment. A total of 25% of the +/+ mice developed adenoma or papilloma of the forestomach, whereas 100% of the +/- mice developed multiple tumors that were a mixture of adenomas, squamous papillomas, invasive carcinomas of the forestomach, as well as tumors of sebaceous glands. The visceral and sebaceous tumors, which lacked Fhit protein, were similar to those characteristic of Muir-Torre familial cancer syndrome. PMID:10758156

  4. John Muir, Yosemite, and the Sublime Response: A Study in the Rhetoric of Preservationism.

    ERIC Educational Resources Information Center

    Oravec, Christine

    1981-01-01

    Shows how Muir's writing succeeded in transforming his readers' imaginative experience of scenic grandeur into an obligation to support preservationist legislation. Demonstrates how he influenced the establishment of Yosemite National Park and the preservation of wilderness reserves. (PD)

  5. Towards More Realistic ANTS Tobias Langner

    E-print Network

    Towards More Realistic ANTS Tobias Langner ETH Zurich ­ Distributed Computing Group ­ www.disco.ethz.ch #12;#12;#12; D + D2 /n #12;Previous Work ANTS problem (Ants Nearby Treasure Search) introduced by Feinerman, Korman, Lotker, Sereni [PODC 2012] #12;Previous Work ANTS problem (Ants Nearby Treasure Search

  6. Odorant binding proteins of the red imported fire ant, Solenopsis invicta: an example of the problems facing the analysis of widely divergent proteins.

    PubMed

    Gotzek, Dietrich; Robertson, Hugh M; Wurm, Yannick; Shoemaker, DeWayne

    2011-01-01

    We describe the odorant binding proteins (OBPs) of the red imported fire ant, Solenopsis invicta, obtained from analyses of an EST library and separate 454 sequencing runs of two normalized cDNA libraries. We identified a total of 18 putative functional OBPs in this ant. A third of the fire ant OBPs are orthologs to honey bee OBPs. Another third of the OBPs belong to a lineage-specific expansion, which is a common feature of insect OBP evolution. Like other OBPs, the different fire ant OBPs share little sequence similarity (? 20%), rendering evolutionary analyses difficult. We discuss the resulting problems with sequence alignment, phylogenetic analysis, and tests of selection. As previously suggested, our results underscore the importance for careful exploration of the sensitivity to the effects of alignment methods for data comprising widely divergent sequences. PMID:21305009

  7. AN ANT COLONY SYSTEM APPROACH FOR SOLVING THE AT-LEAST VERSION OF THE GENERALIZED MINIMUM SPANNING TREE PROBLEM

    E-print Network

    Arabshahi, Payman

    AN ANT COLONY SYSTEM APPROACH FOR SOLVING THE AT-LEAST VERSION OF THE GENERALIZED MINIMUM SPANNING-hard. In this paper, we pro- pose an ant colony system based solution approach for the L-GMST. A key feature of our algorithm is its use of ants of different behavioral characteristics, which are adapted over time

  8. Honey Ants.

    ERIC Educational Resources Information Center

    Conway, John R.

    1984-01-01

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

  9. At-Least Version of the Generalized Minimum Spanning Tree Problem: Optimization Through Ant Colony System and Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Janich, Karl W.

    2005-01-01

    The At-Least version of the Generalized Minimum Spanning Tree Problem (L-GMST) is a problem in which the optimal solution connects all defined clusters of nodes in a given network at a minimum cost. The L-GMST is NPHard; therefore, metaheuristic algorithms have been used to find reasonable solutions to the problem as opposed to computationally feasible exact algorithms, which many believe do not exist for such a problem. One such metaheuristic uses a swarm-intelligent Ant Colony System (ACS) algorithm, in which agents converge on a solution through the weighing of local heuristics, such as the shortest available path and the number of agents that recently used a given path. However, in a network using a solution derived from the ACS algorithm, some nodes may move around to different clusters and cause small changes in the network makeup. Rerunning the algorithm from the start would be somewhat inefficient due to the significance of the changes, so a genetic algorithm based on the top few solutions found in the ACS algorithm is proposed to quickly and efficiently adapt the network to these small changes.

  10. An ant colony optimisation algorithm for the 2D and 3D hydrophobic polar protein folding problem

    PubMed Central

    Shmygelska, Alena; Hoos, Holger H

    2005-01-01

    Background The protein folding problem is a fundamental problems in computational molecular biology and biochemical physics. Various optimisation methods have been applied to formulations of the ab-initio folding problem that are based on reduced models of protein structure, including Monte Carlo methods, Evolutionary Algorithms, Tabu Search and hybrid approaches. In our work, we have introduced an ant colony optimisation (ACO) algorithm to address the non-deterministic polynomial-time hard (NP-hard) combinatorial problem of predicting a protein's conformation from its amino acid sequence under a widely studied, conceptually simple model – the 2-dimensional (2D) and 3-dimensional (3D) hydrophobic-polar (HP) model. Results We present an improvement of our previous ACO algorithm for the 2D HP model and its extension to the 3D HP model. We show that this new algorithm, dubbed ACO-HPPFP-3, performs better than previous state-of-the-art algorithms on sequences whose native conformations do not contain structural nuclei (parts of the native fold that predominantly consist of local interactions) at the ends, but rather in the middle of the sequence, and that it generally finds a more diverse set of native conformations. Conclusions The application of ACO to this bioinformatics problem compares favourably with specialised, state-of-the-art methods for the 2D and 3D HP protein folding problem; our empirical results indicate that our rather simple ACO algorithm scales worse with sequence length but usually finds a more diverse ensemble of native states. Therefore the development of ACO algorithms for more complex and realistic models of protein structure holds significant promise. PMID:15710037

  11. Tuesday, October 20, 2015 9:00 a.m. Breakfast (Price Center Ballroom East, Muir room)

    E-print Network

    Simunic, Tajana

    meeting (Price Center Ballroom East) 9:00 a.m. Breakfast (Price Center Ballroom East, John Muir room) 9Tuesday, October 20, 2015 9:00 a.m. Breakfast (Price Center Ballroom East, Muir room) 9:30 a Scuba Diving John McCullough Google CC DCA SER Climbing Mountains Kurt Thomas Google Frank Uyeda Google

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Towards More Realistic ANTS Tobias Langner

    E-print Network

    Towards More Realistic ANTS Yuval Emek Tobias Langner§ David Stolz § Jara Uitto§ Roger Wattenhofer of the Ants Nearby Treasure Search (ANTS) problem, where n mobile agents, controlled by asynchronous to solve the ANTS problem depends crucially on the computational capabilities of the agents as well

  15. Ant Colony Optimization From Scholarpedia

    E-print Network

    Libre de Bruxelles, Université

    Ant Colony Optimization From Scholarpedia From Scholarpedia, the free peer-reviewed encyclopedia p.18620 Curator: Marco Dorigo, IRIDIA, Université Libre de Bruxelles, Brussels, Belgium Ant colony to difficult optimization problems. In ACO, a set of software agents called artificial ants search for good

  16. Carpenter Ants 

    E-print Network

    Gold, Roger E.; Glenn, Grady J.; Brown, Elizabeth

    2006-08-07

    This publication shows how homeowners can minimize damage from carpenter ants. It explains how to identify the ants, recognize their nest site preferences, and take proper preventive and control measures....

  17. Ant colony algorithm Ant colony algorithm mimics the behavior of insect colonies completing

    E-print Network

    Ferland, Jacques A.

    Ant colony algorithm · Ant colony algorithm mimics the behavior of insect colonies completing their activities Ant colony looking for food Solving a problem N Individual ants N Solutions Each time the colony goes to Population of N solutions look for food and returns to the nest #12;Ant

  18. Framing a Philosophy of Environmental Action: Aldo Leopold, John Muir, and the Importance of Community

    ERIC Educational Resources Information Center

    Goralnik, Lissy; Nelson, Michael P.

    2011-01-01

    A philosophy of action consists of a theory about how and why we do things and what motivates us to act. By juxtaposing the theory of environmental action implied by the works and life of John Muir with the philosophy of action suggested by Aldo Leopold's Land Ethic, we will illuminate the importance of a philosophy of action in determining one's…

  19. MANAGING IMPORTED FIRE ANTS IN URBAN AREAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The two species of imported fire ants (red imported fire ant, Solenopsis invicta, and black imported fire ant, Solenopsis richteri) and their sexually reproducing hybrid are invasive insects whose stings can cause serious medical problems. Imported fire ants interfere with outdoor activities and ha...

  20. Ants Nearby Treasure Search

    E-print Network

    Linial, Nathan "Nati"

    1 Ants Nearby Treasure Search Biological Distributed Algorithms - ANTS MOSHE SULAMY © #12;Plan ANTS to study biological scenarios 4MOSHE SULAMY © #12;ANTS 5MOSHE SULAMY © #12;ANTS 6MOSHE SULAMY © #12;ANTS 7 The Power of Pheromones in Ant Foraging Not clear whether ants have notion of their number Double loops

  1. A temporal ant colony optimization approach to the shortest path problem in dynamic scale-free networks

    NASA Astrophysics Data System (ADS)

    Yu, Feng; Li, Yanjun; Wu, Tie-Jun

    2010-02-01

    A large number of networks in the real world have a scale-free structure, and the parameters of the networks change stochastically with time. Searching for the shortest paths in a scale-free dynamic and stochastic network is not only necessary for the estimation of the statistical characteristics such as the average shortest path length of the network, but also challenges the traditional concepts related to the “shortest path” of a network and the design of path searching strategies. In this paper, the concept of shortest path is defined on the basis of a scale-free dynamic and stochastic network model, and a temporal ant colony optimization (TACO) algorithm is proposed for searching for the shortest paths in the network. The convergence and the setup for some important parameters of the TACO algorithm are discussed through theoretical analysis and computer simulations, validating the effectiveness of the proposed algorithm.

  2. Pulse Detection in Initial Value ODEs Amy Marie Hynick 1 Patrick Keast a,1 Paul H. Muir b,1

    E-print Network

    Keast, Patrick

    software and a process of defect sampling to attempt to detect, and handle e#ciently, any pulses whichPulse Detection in Initial Value ODEs Amy Marie Hynick 1 Patrick Keast a,1 Paul H. Muir b,1 and that significant computational savings are obtained. Key words: pulse detection, initial value ordinary di

  3. Ant nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

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

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

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

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

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

    The Space Telescope Science Institute, Baltimore, Md., manages space operations for the Hubble Space Telescope for NASA's Office of Space Science, Washington, D.C. The Institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA under contract with NASA's Goddard Space Flight Center, Greenbelt, Md. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. JPL is a division of the California Institute of Technology in Pasadena.

    Additional information about the Hubble Space Telescope is available at http://www.stsci.edu . More information about the Wide Field and Planetary Camera 2 is available at http://wfpc2.jpl.nasa.gov.

  4. Understanding and Managing Experiential Aspects of Soundscapes at Muir Woods National Monument

    NASA Astrophysics Data System (ADS)

    Pilcher, Ericka J.; Newman, Peter; Manning, Robert E.

    2009-03-01

    Research has found that human-caused noise can detract from the quality of the visitor experience in national parks and related areas. Moreover, impacts to the visitor experience can be managed by formulating indicators and standards of quality as suggested in park and outdoor recreation management frameworks, such as Visitor Experience and Resource Protection (VERP), as developed by the U.S. National Park Service. The research reported in this article supports the formulation of indicators and standards of quality for human-caused noise at Muir Woods National Monument, California. Phase I identified potential indicators of quality for the soundscape of Muir Woods. A visitor “listening exercise” was conducted, where respondents identified natural and human-caused sounds heard in the park and rated the degree to which each sound was “pleasing” or “annoying.” Certain visitor-caused sounds such as groups talking were heard by most respondents and were rated as annoying, suggesting that these sounds may be a good indicator of quality. Loud groups were heard by few people but were rated as highly annoying, whereas wind and water were heard by most visitors and were rated as highly pleasing. Phase II measured standards of quality for visitor-caused noise. Visitors were presented with a series of 30-second audio clips representing increasing amounts of visitor-caused sound in the park. Respondents were asked to rate the acceptability of each audio clip on a survey. Findings suggest a threshold at which visitor-caused sound is judged to be unacceptable, and is therefore considered as noise. A parallel program of sound monitoring in the park found that current levels of visitor-caused sound sometimes violate this threshold. Study findings provide an empirical basis to help formulate noise-related indicators and standards of quality in parks and related areas.

  5. The Ants Have It!

    ERIC Educational Resources Information Center

    Daugherty, Belinda

    2001-01-01

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

  6. Red Harvester Ants 

    E-print Network

    Drees, Bastiaan M.

    2006-04-24

    Red harvester ants are one of the more noticeable and larger ants in open areas in Texas. However, their populations are declining and this has affected an animal that preys upon the ants--the threatened Texas horned lizard....

  7. Anting” in Blue Jays

    PubMed Central

    Eisner, Thomas; Aneshansley, Daniel

    2008-01-01

    Summary Anting, the plumage-dipping behavior to which ants (mostly formicines) are commonly subjected by birds (mostly passerines), is shown in tests with hand-raised Blue Jays (Cyanocitta cristata) and the ant Formica exsectoides to be instinctive: the birds displayed typical renditions of the behavior on the first occasion that they encountered ants. Evidence is presented supportive of the view that anting is a strategy by which birds render ants fit for ingestion. Formicine ants are ordinarily protected by their formic acid-containing spray. Being wiped into the bird’s plumage causes them to discharge that spray, without harm to the bird, to the point of almost total emptying of the glandular sac in which the secretion is stored. The ants are therefore essentially secretion-free by the time they are swallowed. Further evidence indicates that it is the ant’s possession of the acid sac that triggers the anting behavior in the bird. If F. exsectoides are surgically deprived of their acid sac, they are eaten by the birds without first being subjected to anting. Data are also presented indicating that the ant’s crop, which is especially capacious in formicines (its contents may amount to over 30% of the formicine’s mass), and which appears to survive the anting procedure intact, constitutes, at least when laden, a valuable component of the trophic package that the bird accesses by anting. PMID:19169379

  8. Mineral resource potential map of the John Muir Wilderness, Fresno, Inyo, Madera, and Mono counties, California

    USGS Publications Warehouse

    Du Bray, E.A.; Dellinger, D.A.; Diggles, M.F.; Oliver, H.W.; Johnson, F.L.; Thurber, H.K.; Morris, R.W.; Perers, T.J.; Lindsey, D.S.

    1982-01-01

    Under the provisions of the Wilderness Act (Public Law 88-577, September 3, 1964) and the Joint Conference Report on Senate Bill 4, 88th Congress, the U.S. Geological Survey and the U.S. Bureau of Mines have been conducting mineral surveys of wilderness and primitive areas. Areas officially designated as "wilderness," "wild," or "canoe" when the act was passed were incorporated into the National Wilderness Preservation System, and some of them are presently being studied. The act provided that areas under consideration for wilderness designation should be studied for suitability for incorporation into the Wilderness System. The mineral surveys constitute one aspect of the suitability studies. The act directs that the results of such surveys are to be made available to the public and be submitted to the President and the Congress. This report discusses the results of a mineral survey of the John Muir Wilderness, Inyo and Sierra National Forests, Fresno, lnyo, Madera, and Mono Counties, California. The area was established as a wilderness by Public Law 88-577, September 3, 1964.

  9. Marine benthic habitat mapping of Muir Inlet, Glacier Bay National Park and Preserve, Alaska, with an evaluation of the Coastal and Marine Ecological Classification Standard III

    USGS Publications Warehouse

    Trusel, Luke D.; Cochrane, Guy R.; Etherington, Lisa L.; Powell, Ross D.; Mayer, Larry A.

    2010-01-01

    Seafloor geology and potential benthic habitats were mapped in Muir Inlet, Glacier Bay National Park and Preserve, Alaska, using multibeam sonar, ground-truth information, and geological interpretations. Muir Inlet is a recently deglaciated fjord that is under the influence of glacial and paraglacial marine processes. High glacially derived sediment and meltwater fluxes, slope instabilities, and variable bathymetry result in a highly dynamic estuarine environment and benthic ecosystem. We characterize the fjord seafloor and potential benthic habitats using the Coastal and Marine Ecological Classification Standard (CMECS) recently developed by the National Oceanic and Atmospheric Administration (NOAA) and NatureServe. Substrates within Muir Inlet are dominated by mud, derived from the high glacial debris flux. Water-column characteristics are derived from a combination of conductivity temperature depth (CTD) measurements and circulation-model results. We also present modern glaciomarine sediment accumulation data from quantitative differential bathymetry. These data show Muir Inlet is divided into two contrasting environments: a dynamic upper fjord and a relatively static lower fjord. The accompanying maps represent the first publicly available high-resolution bathymetric surveys of Muir Inlet. The results of these analyses serve as a test of the CMECS and as a baseline for continued mapping and correlations among seafloor substrate, benthic habitats, and glaciomarine processes.

  10. Fire Ants and Their Control. 

    E-print Network

    Hamman, Philip J.; Drees, Bastiaan M.; Vinson, S. Bradleigh

    1986-01-01

    stream_source_info Bull1536a.pdf.txt stream_content_type text/plain stream_size 17111 Content-Encoding ISO-8859-1 stream_name Bull1536a.pdf.txt Content-Type text/plain; charset=ISO-8859-1 fire ant control usually... results. The Non-Control Option - Why Consider it? In areas where fire ants are not causing a problem, it may be best not to attempt any control measures. The reason is that a unit area, sue as an acre ofland, ill support only a limited numbe of fire...

  11. How Many Ants Does It Take To Find the Food? Yuval Emek1

    E-print Network

    How Many Ants Does It Take To Find the Food? Yuval Emek1 , Tobias Langner2 , David Stolz2 , Jara the Ants Nearby Treasure Search (ANTS) problem, where n mobile agents, initially placed at the origin constant-size mes- sages. We show that the minimum number of agents required to solve the ANTS problem

  12. The ANT Architecture { An Architecture For CS1

    E-print Network

    The ANT Architecture { An Architecture For CS1 Dan Ellard, Penelope Ellard, James Megquier, J this problem, we have developed a sim- ple virtual machine called ANT for use in our intro- ductory computer science (CS1) curriculum. ANT is designed to be simple enough that a CS1 student can quickly understand it

  13. Sebaceous hyperplasia of the vulva: a series of cases reporting no association with the Muir-Torre syndrome.

    PubMed

    Roma, Andres A; Barry, Jessica; Pai, Rish K; Billings, Steven D

    2014-07-01

    Sebaceous gland hyperplasia is a common skin condition, very rarely reported in the female genital region. We present 13 cases from 12 patients, the first case series of sebaceous gland hyperplasia of the vulva. Differences in age at presentation and clinical presentation compared with classic sebaceous gland hyperplasia from the head and neck region were noted. Also, it was rarely included in the clinical differential diagnosis. Immunohistochemical studies to determine any possible association with the Muir-Torre syndrome were performed and mismatch repair protein loss was not identified. PMID:24901406

  14. Rasberry Crazy Ant 

    E-print Network

    Drees, Bastiaan M.

    2009-05-04

    The rasberry crazy ant is an exotic species recently introduced in Texas. It was originally discovered in Harris County, but has the potential to spread to other areas. The ants may literally cover the ground and trees, ...

  15. Fire Ants Photos

    MedlinePLUS

    ... Membership About the AAAAI Share | Photos & Graphics: Fire Ants Please attribute all images as follows: Source: The ... Plant and Pollen Photo Gallery . Solenopsis invicta worker ants and queen. Arranged in a circle are majors ( ...

  16. Managing Household Ant Pests 

    E-print Network

    Drees, Bastiaan M.

    2005-12-02

    , and mating may occur within the nest without swarming. These ants form new colo- nies when one or more of the queen ants, along with some workers and brood, leave the nest and move to a new location. Ant colonies do not nest in permanent locations. Often...

  17. ETH Zurich Distributed Computing www.disco.ethz.ch Fault-Tolerant ANTS

    E-print Network

    § ETH Zurich ­ Distributed Computing ­ www.disco.ethz.ch Jara Uitto Fault-Tolerant ANTS #12;#12;Model #12;Model #12;Model #12;Model #12;· ANTS (Ants Nearby Treasure Search) problem by Feinerman, Korman, Lotker, and Sereni [PODC 2012] · ants, controlled by Turing machines. · Communication restricted

  18. Two new phragmotic ant species from Africa: morphology and next-generation sequencing solve a caste association problem in the genus Carebara Westwood

    PubMed Central

    Fischer, Georg; Azorsa, Frank; Garcia, Francisco Hita; Mikheyev, Alexander S.; Economo, Evan P.

    2015-01-01

    Abstract Phragmotic or “door head” ants have evolved independently in several ant genera across the world, but in Africa only one case has been documented until now. Carebara elmenteitae (Patrizi) is known from only a single phragmotic major worker collected from sifted leaf-litter near Lake Elmenteita in Kenya, but here the worker castes of two species collected from Kakamega Forest, a small rainforest in Western Kenya, are studied. Phragmotic major workers were previously identified as Carebara elmenteitae and non-phragmotic major and minor workers were assigned to Carebara thoracica (Weber). Using evidence of both morphological and next-generation sequencing analysis, it is shown that phragmotic and non-phragmotic workers of the two different species are actually the same and that neither name – Carebara elmenteitae or Carebara thoracica – correctly applies to them. Instead, this and another closey related species from Ivory Coast are both morphologically different from Carebara elmenteitae, and thus they are described as the new species Carebara phragmotica sp. n. and Carebara lilith sp. n. PMID:26487817

  19. Caribbean Crazy Ants and their look-alikes in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Caribbean crazy ant (Nylanderia pubens) continues to grow as a nuisance pest problem in Florida. Homeowners and pest management professionals alike have difficulty in controlling the huge populations that can occur on infested properties. Key to dealing with any pest ant problem is to identify...

  20. Potential hazards from floodflows within the John Muir House National Historic Site, Franklin Creek drainage basin, California

    USGS Publications Warehouse

    Meyer, R.W.

    1994-01-01

    The drainage-area-ratio method, adjusted by multiple regression coefficients, was used to determine flood magnitudes of specific recurrence intervals in the Franklin Creek drainage basin, John Muir House National Historic Site in California. Water-surface elevations and inundation areas were determined using hydraulic equations that assume uniform flow and stable channel geometry as surveyed in the 1984 water year. Franklin Creek is expected to overflow its banks during all floods greater than the 25-year flood. Maximum flood discharges within the historic site boundaries are limited by the large culvert that conveys floodwaters into the site. The historically significant structures were constructed above the flood elevation of the 100-year flood; therefore, with the exception of the carriage house, there is little or no danger to the irreplaceable structures at the site. The carriage house could be inundated several feet during the 100-year flood.

  1. Multi-Goal Feasible Path Planning Using Ant Colony Optimization

    E-print Network

    Englot, Brendan J.

    A new algorithm for solving multi-goal planning problems in the presence of obstacles is introduced. We extend ant colony optimization (ACO) from its well-known application, the traveling salesman problem (TSP), to that ...

  2. Flooding and Fire Ants 

    E-print Network

    Nester, Paul

    2008-08-05

    until they build new mounds in the soil. During flooding Avoid contact with floating mats of fire ants. If you are in a row boat, do not touch the ants with the oars. If you must work in flood water, try to dress appropriately in rubber boots, rain... the soil, form a loose ball or ribbon, and float or flow with the water until they reach a dry area or object that the ants can crawl up on. As the flood water recedes, these colonies can be found on piles of debris or in homes and other build- ings...

  3. A CONCISE OVERVIEW OF APPLICATIONS OF ANT COLONY

    E-print Network

    Libre de Bruxelles, Université

    optimization (ACO) [1­3] is a metaheuristic for solving hard combinatorial optimization problems inspired by the indirect communication of real ants. In ACO algorithms, (artificial) ants construct candi- date solutions construction mechanism can be conceived. Most applications of ACO deal with NP-hard combinatorial optimization

  4. Ant Colony Optimization with Immigrants Schemes in Dynamic Environments

    E-print Network

    Yang, Shengxiang

    Ant Colony Optimization with Immigrants Schemes in Dynamic Environments Michalis Mavrovouniotis1 of the pop- ulation and enhance the performance of the algorithm for DOPs. Among these approaches, immigrants immigrants schemes are applied to ant colony optimization (ACO) for the dynamic travelling salesman problem

  5. Distributed House-Hunting in Ant Colonies Mohsen Ghaffari

    E-print Network

    Lynch, Nancy

    Distributed House-Hunting in Ant Colonies Mohsen Ghaffari MIT Cambridge, MA, USA ghaffari house-hunting problem from a distributed computing perspective. When an ant colony's nest becomes tools and techniques from distributed computing theory in order to gain insight into the house-hunting

  6. [The tip of the iceberg: multiple cutaneous sebaceous tumor in colon cancer. Muir-Torre syndrome--case report].

    PubMed

    Herr, Gyula; Szenes, Mária; Hohl, Györgyi; Vinkler, Márta Erzsébet; Tüske, György; Horváth, János; Nagy, Gyöngyi; Tihanyi, Mariann; Széll, Márta; Nagy, Nikoletta; Gasztonyi, Beáta

    2015-06-14

    Muir-Torre syndrome is a rare genodermatosis with autosomal dominant inheritance. The syndrome is considered to be a subtype of the hereditary nonpolyposis colorectal cancer (or Lynch-syndrome). In two-third of the cases, it develops as the consequence of germline mutations in mismatch-repair genes--most commonly MutS Homolog-2 and MutL Homolog-1. Its diagnosis can be established if at least one sebaceous tumor (sebaceoma, sebaceous adenoma, epithelioma, carcinoma or basal-cell carcinoma with sebaceous differentiation) and/or keratoacanthoma and at least one internal neoplasm are present. Here the authors present the history of a 52-year-old man with multiple sebaceous carcinomas on his back. Immunohistochemical analysis showed the lack of MutL Homolog-1 protein expression in the tumor cells. Detailed clinical workup in order to identify internal malignancy found malignant coecum tumor. Histopathological evaluation of the sample from the right hemicolectomy revealed mid-grade adenocarcinoma with MutL Homolog-1 and postmeiotic segregation increased-2 deficiency. The detection of the cutaneous sebaceous carcinoma and the application of the modern diagnostic methods resulted in identification of the associated colorectal cancer in an early stage; hence, definitive treatment was available for the patient. PMID:26051134

  7. Record Dynamics in Ants

    PubMed Central

    Richardson, Thomas O.; Robinson, Elva J. H.; Christensen, Kim; Jensen, Henrik J.; Franks, Nigel R.; Sendova-Franks, Ana B.

    2010-01-01

    The success of social animals (including ourselves) can be attributed to efficiencies that arise from a division of labour. Many animal societies have a communal nest which certain individuals must leave to perform external tasks, for example foraging or patrolling. Staying at home to care for young or leaving to find food is one of the most fundamental divisions of labour. It is also often a choice between safety and danger. Here we explore the regulation of departures from ant nests. We consider the extreme situation in which no one returns and show experimentally that exiting decisions seem to be governed by fluctuating record signals and ant-ant interactions. A record signal is a new ‘high water mark’ in the history of a system. An ant exiting the nest only when the record signal reaches a level it has never perceived before could be a very effective mechanism to postpone, until the last possible moment, a potentially fatal decision. We also show that record dynamics may be involved in first exits by individually tagged ants even when their nest mates are allowed to re-enter the nest. So record dynamics may play a role in allocating individuals to tasks, both in emergencies and in everyday life. The dynamics of several complex but purely physical systems are also based on record signals but this is the first time they have been experimentally shown in a biological system. PMID:20300174

  8. Alate susceptibility in ants

    PubMed Central

    Ho, Eddie K H; Frederickson, Megan E

    2014-01-01

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

  9. FDTD-ANT User Manual

    NASA Technical Reports Server (NTRS)

    Zimmerman, Martin L.

    1995-01-01

    This manual explains the theory and operation of the finite-difference time domain code FDTD-ANT developed by Analex Corporation at the NASA Lewis Research Center in Cleveland, Ohio. This code can be used for solving electromagnetic problems that are electrically small or medium (on the order of 1 to 50 cubic wavelengths). Calculated parameters include transmission line impedance, relative effective permittivity, antenna input impedance, and far-field patterns in both the time and frequency domains. The maximum problem size may be adjusted according to the computer used. This code has been run on the DEC VAX and 486 PC's and on workstations such as the Sun Sparc and the IBM RS/6000.

  10. Routing Vehicles with Ants

    NASA Astrophysics Data System (ADS)

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

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

  11. Pheromone Biosynthesis Activating Neuropeptide (PBAN)/Pyrokinin Family of Peptides and Fire Ants, Solenopsis spp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fire ant, Solenopsis invicta, is an economically important invasive pest ant, causing over 6 billion dollars in control and repair costs each year in the United States. The fire ant is becoming a global problem increasing its importance and the need for the development of biologically-based con...

  12. Abundance of -1,6-piperideine alkaloids in imported fire ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Workers of imported fire ants, including red imported fire ants, Solenopsis invicta Buren, black imported fire ants, S. richteri Forel, and their hybrid (S. invicta × S. richteri), are vicious stingers. Since the venomous sting is a significant medical problem to humans, the chemistry of imported f...

  13. How Many Ants Does It Take To Find the Food? Yuval Emeka

    E-print Network

    How Many Ants Does It Take To Find the Food? Yuval Emeka , Tobias Langnerb , David Stolzb, , Jara Uittob , Roger Wattenhoferb aTechnion, Israel bETH Z¨urich, Switzerland Abstract Consider the Ants Nearby Treasure Search (ANTS) problem, where n mobile agents, initially placed at the origin of an infinite grid

  14. Ant Colony Optimization Start Strategies: Two Case Stefka Fidanova and Pencho Marinov

    E-print Network

    Fidanova, Stefka

    Ant Colony Optimization Start Strategies: Two Case Studies Stefka Fidanova and Pencho Marinov 1 Introduction The ability of ant colonies to form paths for carrying food is rather fascinating. The problem is solved collectively by the whole colony. This ability is explained by the fact that ants communicate

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Ant Hill in Pantanal

    USGS Multimedia Gallery

    Ant hill with flowers in Copernicia alba palm savannah near the Rio Negro river. Yellow flowers are 2 species of Asteraceae, blue flowers are a Commelina spp. Located near RAMSAR site and Rio Negro National Park in the Pantanal ecoregion, near the border between Paraguay and Bolivia. This region, si...

  17. Tiny, Powerful, Awesome Ants!

    ERIC Educational Resources Information Center

    Tate, Kathleen

    2007-01-01

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

  18. Solving the Mixed Vrp with Backhauling Using Ants

    NASA Astrophysics Data System (ADS)

    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.

  19. Simulation of an Ant Colony Optimization Technique in Continuous Space-Time

    NASA Astrophysics Data System (ADS)

    Vlachos, D. S.

    2008-11-01

    The ant colony optimization system is an algorithm inspired by the ants' foraging behavior. The good results obtained by this system on academic problems has made it appealing for applications in industrial settings, one of the current hot topics of the method is the application in continuous problems. In this work, a modified model is presented which is based on autonomous agents, the ants, which behave like the ants in the ant colony system. These agents communicate by the biological inspired pheromone mechanism in order to find sources of food which located near their nest (optimal solutions).

  20. Ants: the supreme soil manipulators

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  1. Ant Algorithms for Discrete Optimization

    E-print Network

    Gambardella, Luca Maria

    Ant Algorithms for Discrete Optimization Marco Dorigo and Gianni Di Caro IRIDIA, Universit´e Libre, Switzerland luca@idsia.ch Abstract This paper overviews recent work on ant algorithms, that is, algorithms for discrete optimization which took inspiration from the observation of ant colonies foraging behavior

  2. Ant Algorithms for Discrete Optimization

    E-print Network

    Libre de Bruxelles, Université

    Ant Algorithms for Discrete Optimization Marco Dorigo Gianni Di Caro IRIDIA CP 194/6 Universit@iridia.ulb.ac.be Luca M. Gambardella IDSIA Corso Elvezia 36 CH-6900 Lugano Switzerland luca@idsia.ch Keywords ant algorithms, ant colony optimiza- tion, swarm intelligence, metaheuris- tics, natural computation Abstract

  3. Ice-proximal sediment dynamics and their effect on the stability of Muir Glacier, Alaska: A case study of non-climatic glacier response

    SciTech Connect

    Hunter, L.E.; Powell, R.D. . Dept. of Geology)

    1992-01-01

    Recent studies have shown that water depth at tidewater termini affect calving rates and, therefore, glacier mass balance and terminus stability. Grounding-line water depths are themselves governed by glacial and marine processes that interact during the formation of morainal bank depocenters. These morainal banks can fluctuate 10s of meters in height within an interval of a few weeks. Recent investigations in Glacier Bay have focused on quantitatively assessing sediment budgets in the ice-proximal environment. The monitoring of morainal banks in upper Muir Inlet has included repeated bathymetric mapping, sediment trap studies, bottom grab sampling, glacier and iceberg sampling, and submersible ROV investigations within 1 km of the terminus. Such relationships are important in interpreting recent changes in the dynamics of Muir Glacier where a century of retreat has been succeeded by quasi stability. The new glacier regime has accompanied basin infilling from approximately 100 m depth to a maximum of 52 m at the grounding line. Two large grounding-line fans have aggraded to deltas and reduced the length of the calving margin from 900 m to 290 m wide. These effects have reduced the ice flow velocities by 45%. Annual morainal bank growth ranged from 10[sup 6] to 10[sup 7] m[sup 3] and is the result of glacifluvial dumping, suspension settling from turbid overflow plumes, debris dumping from ice-cliff and iceberg melting, glacier squeezing and pushing of morainal bank sediment, and sediment gravity flow processes. Each of these processes are an integral facet of the morainal bank dynamics and glacier response. These studies of Muir Glacier indicate that glacier response to sediment dynamics need to be addresses before climatic implications are made.

  4. An improved ant colony algorithm with diversified solutions based on the immune strategy

    PubMed Central

    Qin, Ling; Pan, Yi; Chen, Ling; Chen, Yixin

    2006-01-01

    Background Ant colony algorithm has emerged recently as a new meta-heuristic method, which is inspired from the behaviours of real ants for solving NP-hard problems. However, the classical ant colony algorithm also has its defects of stagnation and premature. This paper aims at remedying these problems. Results In this paper, we propose an adaptive ant colony algorithm that simulates the behaviour of biological immune system. The solutions of the problem are much more diversified than traditional ant colony algorithms. Conclusion The proposed method for improving the performance of traditional ant colony algorithm takes into account the polarization of the colonies, and adaptively adjusts the distribution of the solutions obtained by the ants. This makes the solutions more diverse so as to avoid the stagnation and premature phenomena. PMID:17217521

  5. Ant-Based Cyber Security

    SciTech Connect

    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.

  6. The Dynamics of Foraging Ants

    NASA Astrophysics Data System (ADS)

    Baxter, G. William

    2009-03-01

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

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

    PubMed Central

    Mehdiabadi, Natasha J; Gilbert, Lawrence E

    2002-01-01

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

  8. Chaos-order transition in foraging behavior of ants.

    PubMed

    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

  9. Distributed nestmate recognition in ants

    PubMed Central

    Esponda, Fernando; Gordon, Deborah M.

    2015-01-01

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

  10. Mechanics of fire ant aggregations.

    PubMed

    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. PMID:26501413

  11. Application of ant colony optimization to optimal foragaing theory: comparison of simulation and field results

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ant Colony Optimization (ACO) refers to the family of algorithms inspired by the behavior of real ants and used to solve combinatorial problems such as the Traveling Salesman Problem (TSP).Optimal Foraging Theory (OFT) is an evolutionary principle wherein foraging organisms or insect parasites seek ...

  12. USING ANT COMMUNITIES FOR RAPID ASSESSMENT OF TERRESTRIAL ECOSYSTEM HEALTH

    SciTech Connect

    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.

  13. Muir-Torre Syndrome

    MedlinePLUS

    ... is a medical procedure done in conjunction with in-vitro fertilization (IVF). It allows people who carry a specific known genetic mutation to have children who do not carry the mutation. A woman’s eggs are removed and fertilized in a laboratory. When the embryos reach a certain ...

  14. Evolution of Fire Ant Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The imported fire ants that entered the United States over 70 years ago have spread within the country to over 129.5 million ha. Efforts to stop the expansion and suppress fire ant populations have resulted in changing methods of control. Initial efforts focused on treating individual nests with h...

  15. Temperature: Human Regulating, Ants Conforming

    ERIC Educational Resources Information Center

    Clopton, Joe R.

    2007-01-01

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

  16. Hey! A Fire Ant Stung Me!

    MedlinePLUS

    ... the Body Works Main Page Hey! A Fire Ant Stung Me! KidsHealth > Kids > Illnesses & Injuries > Bug Bites ... How to Avoid Getting Bitten What's a Fire Ant? There are many different types of fire ants, ...

  17. Summary. The architecture of underground ant nests was studied in the ant Formica pallidefulva. These ants build

    E-print Network

    Ronquist, Fredrik

    Summary. The architecture of underground ant nests was studied in the ant Formica pallidefulva. These ants build shallow (30­45 cm deep) nests, which consist of more or less vertical shafts that bear of an ant's life passes inside the nest, whose relative security conceals the queen, piles of brood and

  18. INVASIVE ANTS Invasive species, those species that demonstrate

    E-print Network

    Suarez, Andrew V.

    PART IV INVASIVE ANTS Invasive species, those species that demonstrate ecological, environmental own right. Though invasive ants currently comprise ant species, the contribution of these species to understanding ant ecology is dis- proportional to their number. Invasive ants represent

  19. Ant Colony Optimization and Stochastic Gradient Descent

    E-print Network

    Libre de Bruxelles, Université

    Ant Colony Optimization and Stochastic Gradient Descent Nicolas Meuleau Marco Dorigo IRIDIA@iridia.ulb.ac.be mdorigo@ulb.ac.be Keywords heuristic, ant system, ant colony optimization, combinatorial optimi- zation between the two techniques known as ant colony optimization (ACO) and stochastic gradient descent. More

  20. Dripping faucet with ants Eric Bonabeau,1,

    E-print Network

    Theraulaz, Guy

    Dripping faucet with ants Eric Bonabeau,1, * Guy Theraulaz,2 Jean-Louis Deneubourg,3 Arnaud Lioni,2 Brussels, Belgium Received 21 November 1997 The formation of droplets of ants is observed under certain, and a droplet containing up to 40 ants eventually falls down. When the flux of incoming ants is sufficient

  1. SRO-NERP-14 r: THE ANTS....,~

    E-print Network

    Georgia, University of

    SRO-NERP-14 r: THE ANTS....,~ (Hymenoptera: Formicidae) OF THE SAVANNAH RIVER PLANT; SOUTH CAROLINA MARCH,I985 Copies may be obtained from Savannah River Ecology Laboratory #12;r». The Ants (Hymenoptera. Distribution and Nesting Information for Ants of the Savannah River Plant Table 2. Frequencies of Foraging Ants

  2. Ant Foraging Revisited Liviu Alexandru Panait1

    E-print Network

    Luke, Sean

    Ant Foraging Revisited Liviu Alexandru Panait1 and Sean Luke1 1. Department of Computer Science: lpanait@cs.gmu.edu Abstract Previous artificial (non-biological) ant foraging models have to date relied ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  3. Ants in Parking Lots Arnold L. Rosenberg

    E-print Network

    Massachusetts at Amherst, University of

    Ants in Parking Lots Arnold L. Rosenberg Electrical & Computer Engineering Colorado State University Fort Collins, CO 80523, USA rsnbrg@colostate.edu Abstract Ants provide an attractive metaphor of ant-based computation models. We study the ability of ant-robots that are essentially mobile finite

  4. TECHNICAL NOTE Polymorphic microsatellite loci for the ant-garden ant,

    E-print Network

    TECHNICAL NOTE Polymorphic microsatellite loci for the ant-garden ant, Crematogaster levior (Forel Throughout Amazonia, the ant Crematogaster levior is known for its participation in a complex ant-garden Ants in the genus Crematogaster are common and domi- nant members of Neotropical forest fauna (Longino

  5. COMMUNITY ECOLOGY -ORIGINAL RESEARCH Introduced fire ants can exclude native ants from critical

    E-print Network

    Suarez, Andrew V.

    COMMUNITY ECOLOGY - ORIGINAL RESEARCH Introduced fire ants can exclude native ants from critical. For ants, one resource that may be particularly valuable for both introduced and native species is high imported fire ants (Solenopsis invicta) competed with native ants for access to mutualisms with aphids

  6. vol. 176, no. 3 the american naturalist september 2010 Interaction between Mutualisms: Ant-Tended Butterflies

    E-print Network

    Oliveira, Paulo S.

    - occurrence of ant-tended insects on a plant have never been ex- amined for survival effects on either butterflies. Keywords: ant-plant-herbivore interactions, cerrado savanna, insect trophobionts, natural enemies. 2003). Thus, insect herbivores face a major problem in order to feed on plant tissue: they need to find

  7. Monoculture of Leafcutter Ant Gardens

    PubMed Central

    Mueller, Ulrich G.; Scott, Jarrod J.; Ishak, Heather D.; Cooper, Michael; Rodrigues, Andre

    2010-01-01

    Background Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. Methodology/Principal Findings Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens) and extended lifespans (10–20 years). In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells), and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. Conclusions/Significance Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants), an analog of artificial selection. PMID:20844760

  8. How ants drop out: ant abundance on tropical mountains.

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  10. COMBINATIONAL LOGIC CIRCUITS DESIGN THROUGH ANT COLONY OPTIMIZATION ALGORITHM

    E-print Network

    Al-Saiari, Uthman

    based on a modified Ant Colony (ACO) algorithm is presented. The re- sults obtained using the proposed. The first work in evolutionary design of digital circuits, Designer Genetic Algorithms (DGA), was proposed problems. Unlike Genetic Algorithms (GAs), which is a blind search heuristic, ACO is an optimization of co

  11. ORIGINAL PAPER Worldwide ant invasions under climate change

    E-print Network

    Courchamp, Franck

    and with predicted climate change (in 2080), globally, regionally and within the world's 34 biodiversity hotspots correspond with biodiversity hotspots. Contrary to general expectations, cli- mate change and invasive ant global problem, especially where invasion hotspots coincide with biodiversity hotspots. Keywords

  12. Selective broadcast of fenoxycarb bait on fire ant infested prairie: effect on native ant community 

    E-print Network

    Morris, John Robert

    1994-01-01

    This research describes the effect of a fire ant (Solenopsis invicta Buren) infestation on the ant community of two north Texas blackland prairies, and the effect on the ant community when a bait formulation of the insect growth regulator...

  13. Macroevolutionary assembly of ant/plant symbioses: Pseudomyrmex ants and their ant-housing plants in the Neotropics.

    PubMed

    Chomicki, Guillaume; Ward, Philip S; Renner, Susanne S

    2015-11-22

    Symbioses include some of the clearest cases of coevolution, but their origin, loss or reassembly with different partners can rarely be inferred. Here we use ant/plant symbioses involving three plant clades to investigate the evolution of symbioses. We generated phylogenies for the big-eyed arboreal ants (Pseudomyrmecinae), including 72% of their 286 species, as well as for five of their plant host groups, in each case sampling more than 61% of the species. We show that the ant-housing Vachellia (Mimosoideae) clade and its ants co-diversified for the past 5 Ma, with some species additionally colonized by younger plant-nesting ant species, some parasitic. An apparent co-radiation of ants and Tachigali (Caesalpinioideae) was followed by waves of colonization by the same ant clade, and subsequent occupation by a younger ant group. Wide crown and stem age differences between the ant-housing genus Triplaris (Polygonaceae) and its obligate ant inhabitants, and stochastic trait mapping, indicate that its domatium evolved earlier than the ants now occupying it, suggesting previous symbioses that dissolved. Parasitic ant species evolved from generalists, not from mutualists, and are younger than the mutualistic systems they parasitize. Our study illuminates the macroevolutionary assembly of ant/plant symbioses, which has been highly dynamic, even in very specialized systems. PMID:26582029

  14. Natural selection drives the evolution of ant life cycles

    PubMed Central

    Wilson, Edward O.; Nowak, Martin A.

    2014-01-01

    The genetic origin of advanced social organization has long been one of the outstanding problems of evolutionary biology. Here we present an analysis of the major steps in ant evolution, based for the first time, to our knowledge, on combined recent advances in paleontology, phylogeny, and the study of contemporary life histories. We provide evidence of the causal forces of natural selection shaping several key phenomena: (i) the relative lateness and rarity in geological time of the emergence of eusociality in ants and other animal phylads; (ii) the prevalence of monogamy at the time of evolutionary origin; and (iii) the female-biased sex allocation observed in many ant species. We argue that a clear understanding of the evolution of social insects can emerge if, in addition to relatedness-based arguments, we take into account key factors of natural history and study how natural selection acts on alleles that modify social behavior. PMID:25114217

  15. Ant Ecdysteroid Extraction and Radioimmunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecdysteroids are a group of steroid compounds present in many plant and invertebrate species. In arthropods, they function primarily as hormones involved in the regulation of molting. This protocol describes how to extract ecdysteroid hormones from ant specimens and subsequently quantify circulating...

  16. Ant Hill Near Tebicuary River

    USGS Multimedia Gallery

    Ant hill near grassland-forest ecotone near Tebicuary river. This former pasture has not been grazed since an endangered bird species was discovered here half a dozen years ago. The Ñeembucú Region is typified by extensive grasslands and wetlands. Near 26°34’52’’S...

  17. Optimal cue integration in ants.

    PubMed

    Wystrach, Antoine; Mangan, Michael; Webb, Barbara

    2015-10-01

    In situations with redundant or competing sensory information, humans have been shown to perform cue integration, weighting different cues according to their certainty in a quantifiably optimal manner. Ants have been shown to merge the directional information available from their path integration (PI) and visual memory, but as yet it is not clear that they do so in a way that reflects the relative certainty of the cues. In this study, we manipulate the variance of the PI home vector by allowing ants (Cataglyphis velox) to run different distances and testing their directional choice when the PI vector direction is put in competition with visual memory. Ants show progressively stronger weighting of their PI direction as PI length increases. The weighting is quantitatively predicted by modelling the expected directional variance of home vectors of different lengths and assuming optimal cue integration. However, a subsequent experiment suggests ants may not actually compute an internal estimate of the PI certainty, but are using the PI home vector length as a proxy. PMID:26400741

  18. Exploitation of Fallen Diaspores by Ants: Are there AntPlant Partner Choices? Alexander V. Christianini1,4

    E-print Network

    Oliveira, Paulo S.

    of fallen diaspores was common among several ant genera, and included carnivorous, omnivorous and omnivorous ants, probably influenced by the chemical composition of the plant diaspores. Omnivorous ants

  19. WORKER LONGEVITY IN HARVESTER ANTS (POGONOMYRMEX)

    E-print Network

    Gordon, Deborah

    WORKER LONGEVITY IN HARVESTER ANTS (POGONOMYRMEX) BY D. M. GORDON* AND B. HOLLDOBLER Museum of Comparative Zoology, Harvard University, Cambridge, Mass. 02138, USA Most studies of worker longevity in ants the life of a worker ant. In the few existing studies of worker longevity con- ducted in the field

  20. Biological control of red imported fire ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two species of Imported Fire Ants (IFA), the Red Imported Fire Ant, Solenopsis invicta Buren, and the Black Imported Fire Ant, S. richteri Forel, were introduced into the United States in the early 1900s and currently inhabit over 320 million acres in the southern United States and Puerto Rico. Red ...

  1. FIRE ANT, BIOLOGY, ECOLOGY, AND BIOCONTROL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Using Ants to Investigate the Environment

    ERIC Educational Resources Information Center

    Hagevik, Rita A.

    2005-01-01

    The best place for students to begin to understand complex environmental relationships is in their own back yards. Doing investigations of ants allows students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenance, and increase their understanding of the environment and their…

  3. Using Ants To Investigate the Environment.

    ERIC Educational Resources Information Center

    Hagevik, Rita A.

    2003-01-01

    Describes three inquiry-based activities designed for students to begin to understand complex environmental relationships in their own backyard. Includes investigations of ants, which allow students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenances, and increase student…

  4. Ant Colony Optimization for Constraint Satisfaction

    E-print Network

    Wolf, Christian

    Ant Colony Optimization for Constraint Satisfaction Christine Solnon LIRIS, UMR 5205 CNRS / University of Lyon Tutorial at CP'2007 #12;Ant Colony Optimization Application to car sequencing Application to CSPs Conclusion Table of contents 1 Basic principles of Ant Colony Optimization 2 Application

  5. RESEARCH ARTICLE The descent of ant: field-measured performance of gliding ants

    E-print Network

    Koehl, Mimi

    RESEARCH ARTICLE The descent of ant: field-measured performance of gliding ants Yonatan Munk1,2, *, Stephen P. Yanoviak3 , M. A. R. Koehl2 and Robert Dudley2,4 ABSTRACT Gliding ants avoid predatory attacks descent towards nearby tree trunks. The ecologically relevant measure of performance for gliding ants

  6. Koptur et al.: Ants and Plants on Andros, Bahamas 89 ANTS AND PLANTS WITH EXTRAFLORAL NECTARIES

    E-print Network

    Koptur, Suzanne

    : extrafloral nectaries, ant-plant interactions, ants, Bahamas, Caribbean, fire, mutualism, rocklands RESUMEN Se with these and other beneficial insects (Rogers 1985; Nuessley et al. 2004; Koptur 2005). Plants with extrafloralKoptur et al.: Ants and Plants on Andros, Bahamas 89 ANTS AND PLANTS WITH EXTRAFLORAL NECTARIES

  7. High rates of army ant raids in the Neotropics and implications for ant colony and

    E-print Network

    O'Donnell, Sean

    High rates of army ant raids in the Neotropics and implications for ant colony and community ABSTRACT Army ants form nomadic insect colonies whose chief food is other social insects. Here we compare the rate of army ant raids with the average density of their potential prey from 28 New World subtropical

  8. Memory Analysis and Significance Test for Agent University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom

    E-print Network

    Fernandez, Thomas

    : Artificial ant trails (a) John Muir trail (b) Santa Fe trail (*: ant agent, : food) The artificial ant the food on the trails. The first work, by Jef- ferson et al. [7], used the John Muir trail, and another in the John Muir trail with two different con- troller schemes, finite state machines and recurrent neural

  9. Methods for Casting Subterranean Ant Nests

    PubMed Central

    Tschinkel, Walter R.

    2010-01-01

    The study of subterranean ant nests has been impeded by the difficulty of rendering their structures in visible form. Here, several different casting materials are shown to make perfect casts of the underground nests of ants. Each material (dental plaster, paraffin wax, aluminum, zinc) has advantages and limitations, which are discussed. Some of the materials allow the recovery of the ants entombed in the casts, allowing a census of the ants to be connected with features of their nest architecture. The necessary equipment and procedures are described in the hope that more researchers will study this very important aspect of ant natural history. PMID:20673073

  10. Mineralogy, petrology and chemistry of ANT-suite rocks from the lunar highlands

    NASA Technical Reports Server (NTRS)

    Prinz, M.; Keil, K.

    1977-01-01

    Anorthositic-noritic-troctolitic (ANT) rocks are the oldest and most abundant rocks of the lunar surface, and comprise about 90% of the suite of the lunar highlands. Consideration is given to the mineralogy, petrology, bulk chemistry, and origin of ANT-suite rocks. Problems associated in classifying and labeling lunar highland rocks because of textural complexities occurring from impact modifications are discussed. The mineralogy of ANT-suite rocks, dominated by plagioclase, olivine and pyrozene, and containing various minor minerals, is outlined. The petrology of ANT-suite rocks is reviewed along with the major element bulk composition of these rocks, noting that they are extremely depleted in K2O and P2O5. Various models describing the origin of ANT-suite rocks are summarized, and it is suggested that this origin involves a parental liquid of high-alumina basalt with low Fe/Fe+Mg.

  11. Ant ecdysteroid extraction and radioimmunoassay.

    PubMed

    Brent, Colin; Dolezal, Adam

    2009-07-01

    Ecdysteroids are a group of steroid compounds present in many plant and invertebrate species. In arthropods, they function primarily as hormones involved in the regulation of molting. This protocol describes how to extract ecdysteroid hormones from ant specimens and subsequently quantify circulating levels of the hormone. The hormone can be extracted from hemolymph or from whole-body homogenates of insects and quantified by radioimmunoassay. PMID:20147212

  12. Ants Can Learn to Forage on One-Way Trails

    PubMed Central

    Ribeiro, Pedro Leite; Helene, André Frazão; Xavier, Gilberto; Navas, Carlos; Ribeiro, Fernando Leite

    2009-01-01

    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. PMID:19337369

  13. Improved Clonal Selection Algorithm Combined with Ant Colony Optimization

    NASA Astrophysics Data System (ADS)

    Gao, Shangce; Wang, Wei; Dai, Hongwei; Li, Fangjia; Tang, Zheng

    Both the clonal selection algorithm (CSA) and the ant colony optimization (ACO) are inspired by natural phenomena and are effective tools for solving complex problems. CSA can exploit and explore the solution space parallely and effectively. However, it can not use enough environment feedback information and thus has to do a large redundancy repeat during search. On the other hand, ACO is based on the concept of indirect cooperative foraging process via secreting pheromones. Its positive feedback ability is nice but its convergence speed is slow because of the little initial pheromones. In this paper, we propose a pheromone-linker to combine these two algorithms. The proposed hybrid clonal selection and ant colony optimization (CSA-ACO) reasonably utilizes the superiorities of both algorithms and also overcomes their inherent disadvantages. Simulation results based on the traveling salesman problems have demonstrated the merit of the proposed algorithm over some traditional techniques.

  14. Metatranscriptomics and pyrosequencing facilitate discovery of potential viral natural enemies of the invasive Caribbean crazy ant, Nylanderia pubens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Nylanderia pubens (Forel) is an invasive ant species that in recent years has developed into a serious nuisance problem in the Caribbean and United States. A rapidly expanding range, explosive localized population growth, and control difficulties have elevated this ant to pest status. ...

  15. Mimetic host shifts in an endangered social parasite of ants

    PubMed Central

    Thomas, Jeremy A.; Elmes, Graham W.; Sielezniew, Marcin; Stankiewicz-Fiedurek, Anna; Simcox, David J.; Settele, Josef; Schönrogge, Karsten

    2013-01-01

    An emerging problem in conservation is whether listed morpho-species with broad distributions, yet specialized lifestyles, consist of more than one cryptic species or functionally distinct forms that have different ecological requirements. We describe extreme regional divergence within an iconic endangered butterfly, whose socially parasitic young stages use non-visual, non-tactile cues to infiltrate and supplant the brood in ant societies. Although indistinguishable morphologically or when using current mitochondrial and nuclear sequence-, or microsatellite data, Maculinea rebeli from Spain and southeast Poland exploit different Myrmica ant species and experience 100 per cent mortality with each other's hosts. This reflects major differences in the hydrocarbons synthesized from each region by the larvae, which so closely mimic the recognition profiles of their respective hosts that nurse ants afford each parasite a social status above that of their own kin larvae. The two host ants occupy separate niches within grassland; thus, conservation management must differ in each region. Similar cryptic differentiation may be common, yet equally hard to detect, among the approximately 10 000 unstudied morpho-species of social parasite that are estimated to exist, many of which are Red Data Book listed. PMID:23193127

  16. Ant Larval Demand Reduces Aphid Colony Growth Rates in an Ant-Aphid Interactio

    PubMed Central

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

    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 experiment, we tested whether the presence of larvae in Lasius niger ant colonies affected the growth rate of Aphis fabae colonies. Other explanatory variables tested were the origin of ant colonies (two separate colonies were used) and previous diet (sugar only or sugar and protein). We found that the presence of larvae in the ant colony significantly reduced the growth rate of aphid colonies. Previous diet and colony origin did not affect aphid colony growth rates. Our results suggest that ant colonies balance the flow of two separate resources from aphid colonies- renewable sugars or a protein-rich meal, depending on demand from ant larvae within the nest. Aphid payoffs from the ant-aphid interaction may change on a seasonal basis, as the demand from larvae within the ant colony waxes and wanes. PMID:26467951

  17. Blind and myopic ants in heterogeneous networks

    NASA Astrophysics Data System (ADS)

    Hwang, S.; Lee, D.-S.; Kahng, B.

    2014-11-01

    The diffusion processes on complex networks may be described by different Laplacian matrices due to heterogeneous connectivity. Here we investigate the random walks of blind ants and myopic ants on heterogeneous networks: While a myopic ant hops to a neighbor node every step, a blind ant may stay or hop with probabilities that depend on node connectivity. By analyzing the trajectories of blind ants, we show that the asymptotic behaviors of both random walks are related by rescaling time and probability with node connectivity. Using this result, we show how the small eigenvalues of the Laplacian matrices generating the two random walks are related. As an application, we show how the return-to-origin probability of a myopic ant can be used to compute the scaling behaviors of the Edwards-Wilkinson model, a representative model of load balancing on networks.

  18. Broadcast Baits for Fire Ant Control 

    E-print Network

    Barr, Charles L.

    2005-10-17

    - tion offers little or no additional benefi t in eliminating ants; it just costs more money. Baits do require special conditions and handling for best results: The ants must be actively foraging for bait. Fire ants search for food (forage) at a wide... or rabbits) tested when administered either orally or dermally. Higher values indicate less-toxic pesticides. Do not wear the clothes again before washing them separately from other laundry. Application safety The spinning rotor of an electric spreader can...

  19. Major evolutionary transitions in ant agriculture

    PubMed Central

    Schultz, Ted R.; Brady, Seán G.

    2008-01-01

    Agriculture is a specialized form of symbiosis that is known to have evolved in only four animal groups: humans, bark beetles, termites, and ants. Here, we reconstruct the major evolutionary transitions that produced the five distinct agricultural systems of the fungus-growing ants, the most well studied of the nonhuman agriculturalists. We do so with reference to the first fossil-calibrated, multiple-gene, molecular phylogeny that incorporates the full range of taxonomic diversity within the fungus-growing ant tribe Attini. Our analyses indicate that the original form of ant agriculture, the cultivation of a diverse subset of fungal species in the tribe Leucocoprineae, evolved ?50 million years ago in the Neotropics, coincident with the early Eocene climatic optimum. During the past 30 million years, three known ant agricultural systems, each involving a phylogenetically distinct set of derived fungal cultivars, have separately arisen from the original agricultural system. One of these derived systems subsequently gave rise to the fifth known system of agriculture, in which a single fungal species is cultivated by leaf-cutter ants. Leaf-cutter ants evolved remarkably recently (?8–12 million years ago) to become the dominant herbivores of the New World tropics. Our analyses identify relict, extant attine ant species that occupy phylogenetic positions that are transitional between the agricultural systems. Intensive study of those species holds particular promise for clarifying the sequential accretion of ecological and behavioral characters that produced each of the major ant agricultural systems. PMID:18362345

  20. Spectacular Batesian mimicry in ants

    NASA Astrophysics Data System (ADS)

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

    2004-10-01

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

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

    ERIC Educational Resources Information Center

    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.

  2. ACOustic: A Nature-Inspired Exploration Indicator for Ant Colony Optimization

    PubMed Central

    Sagban, Rafid; Ku-Mahamud, Ku Ruhana; Abu Bakar, Muhamad Shahbani

    2015-01-01

    A statistical machine learning indicator, ACOustic, is proposed to evaluate the exploration behavior in the iterations of ant colony optimization algorithms. This idea is inspired by the behavior of some parasites in their mimicry to the queens' acoustics of their ant hosts. The parasites' reaction results from their ability to indicate the state of penetration. The proposed indicator solves the problem of robustness that results from the difference of magnitudes in the distance's matrix, especially when combinatorial optimization problems with rugged fitness landscape are applied. The performance of the proposed indicator is evaluated against the existing indicators in six variants of ant colony optimization algorithms. Instances for travelling salesman problem and quadratic assignment problem are used in the experimental evaluation. The analytical results showed that the proposed indicator is more informative and more robust. PMID:25954768

  3. A Hybrid Ant Colony Algorithm for Loading Pattern Optimization

    NASA Astrophysics Data System (ADS)

    Hoareau, F.

    2014-06-01

    Electricité de France (EDF) operates 58 nuclear power plant (NPP), of the Pressurized Water Reactor (PWR) type. The loading pattern (LP) optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF R&D has developed automatic optimization tools that assist the experts. The latter can resort, for instance, to a loading pattern optimization software based on ant colony algorithm. This paper presents an analysis of the search space of a few realistic loading pattern optimization problems. This analysis leads us to introduce a hybrid algorithm based on ant colony and a local search method. We then show that this new algorithm is able to generate loading patterns of good quality.

  4. The beauty of ant antics DeborahM.Gordon enjoys a photographic paean to individual ants and their rarely glimpsed

    E-print Network

    Gordon, Deborah

    The beauty of ant antics DeborahM.Gordon enjoys a photographic paean to individual ants and their rarely glimpsed exploits on behalf of the collective. Ant expert and photographer Mark Moffett likes to explore. In Adventures Among Ants, he describes his tropical encounters with his favourite kind of ant

  5. The Complexity of Fire Ant Nestmate Recognition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Extrafloral nectar fuels ant life in deserts

    PubMed Central

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

    2014-01-01

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

  7. Ants cushion applied stress by active rearrangements

    NASA Astrophysics Data System (ADS)

    Liu, Zhongyang; Hyatt, John; Mlot, Nathan; Gerov, Michael; Fernandez-Nieves, Alberto; Hu, David

    2013-11-01

    Fire ants, Solenopsis invicta, link their bodies together to form waterproof rafts, which in turn drip, spread, and coagulate, demonstrating properties of an active material that can change state from a liquid to a solid. This soft-matter phase transition is important when the raft interacts with environmental forces such as raindrops and crashing waves. We study this active behavior through plate-on-plate rheology on the ants, extracting the active components by comparison with the rheological behavior of a collection of dead ants. In controlled shear tests, both and live and dead ants show properties of a non-Newtonian fluid, specifically, shear-thinning behavior. In oscillatory tests, live ants exhibit a rare behavior in which their storage modulus (G') and loss modulus (G'') have approximately the same value over three orders magnitudes of frequency and two orders of magnitude of strain, indicating the ants are neither fluid nor solid. In comparison, dead ants are more solid-like, with a storage modulus twice as large as their loss modulus. This striking active behavior arises from rearrangement of their bodies and storage and dissipation of energy with the ants' muscles.

  8. TERRITORIAL BEHAVIOR OF THE IMPORTED FIRE ANT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The imported fire ant (IFA), Solenopsis invicta Buren, is an exotic species introduced to the United States from parts of South America. It has spread throughout much of the southeastern United States despite the presence of indigenous ant species. The IFA uses tunnels that afford access to foragi...

  9. Urban Pest Management of Ants in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keeping pace with the dynamic and evolving landscape of invasive ants in California presents a formidable challenge to the pest management industry. Pest management professionals (PMPs) are on the frontlines when it comes to battling these exotic ant pests, and are often the first ones to intercept ...

  10. Community ecology Ants defend aphids against

    E-print Network

    Agrawal, Anurag

    Community ecology Ants defend aphids against lethal disease Charlotte Nielsen1,, Anurag A. Agrawal1 colonies and some species also protect their mutualist partners. In mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural

  11. CONTROL FIRE ANTS BY USING DECAPITATING FLIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers with the USDA, ARS Biological Control of Pests Research Unit are rearing Pseudacteon curvatus, a tiny fly in the family Phoridae that parasitizes and kills imported fire ants. The flies only attack fire ants, and are not attracted to vegetables (12 kinds), fruit (13 kinds), raw meat (7 ...

  12. A Study of Greedy, Local Search, and Ant Colony Optimization Approaches for Car

    E-print Network

    Wolf, Christian

    A Study of Greedy, Local Search, and Ant Colony Optimization Approaches for Car Sequencing Problems and compares several heuristic approa- ches for the car sequencing problem. We first study greedy heuristics, for which it was formerly unknown whether it is satisfiable or not. 1 Introduction The car sequencing

  13. Particle Swarm and Ant Colony Approaches in Multiobjective Optimization

    NASA Astrophysics Data System (ADS)

    Rao, S. S.

    2010-10-01

    The social behavior of groups of birds, ants, insects and fish has been used to develop evolutionary algorithms known as swarm intelligence techniques for solving optimization problems. This work presents the development of strategies for the application of two of the popular swarm intelligence techniques, namely the particle swarm and ant colony methods, for the solution of multiobjective optimization problems. In a multiobjective optimization problem, the objectives exhibit a conflicting nature and hence no design vector can minimize all the objectives simultaneously. The concept of Pareto-optimal solution is used in finding a compromise solution. A modified cooperative game theory approach, in which each objective is associated with a different player, is used in this work. The applicability and computational efficiencies of the proposed techniques are demonstrated through several illustrative examples involving unconstrained and constrained problems with single and multiple objectives and continuous and mixed design variables. The present methodologies are expected to be useful for the solution of a variety of practical continuous and mixed optimization problems involving single or multiple objectives with or without constraints.

  14. Spatiotemporal chemotactic model for ant foraging

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Subramanian; Laurent, Thomas; Kumar, Manish; Bertozzi, Andrea L.

    2014-12-01

    In this paper, we present a generic theoretical chemotactic model that accounts for certain emergent behaviors observed in ant foraging. The model does not have many of the constraints and limitations of existing models for ants colony dynamics and takes into account the distinctly different behaviors exhibited in nature by ant foragers in search of food and food ferrying ants. Numerical simulations based on the model show trail formation in foraging ant colonies to be an emergent phenomenon and, in particular, replicate behavior observed in experiments involving the species P. megacephala. The results have broader implications for the study of randomness in chemotactic models. Potential applications include the developments of novel algorithms for stochastic search in engineered complex systems such as robotic swarms.

  15. Ants defend aphids against lethal disease.

    PubMed

    Nielsen, Charlotte; Agrawal, Anurag A; Hajek, Ann E

    2010-04-23

    Social insects defend their own colonies and some species also protect their mutualist partners. In mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural enemies. Here we report that Formica podzolica ants tending milkweed aphids, Aphis asclepiadis, protect aphid colonies from lethal fungal infections caused by an obligate aphid pathogen, Pandora neoaphidis. In field experiments, bodies of fungal-killed aphids were quickly removed from ant-tended aphid colonies. Ant workers were also able to detect infective conidia on the cuticle of living aphids and responded by either removing or grooming these aphids. Our results extend the long-standing view of ants as mutualists and protectors of aphids by demonstrating focused sanitizing and quarantining behaviour that may lead to reduced disease transmission in aphid colonies. PMID:19923138

  16. Ant-seed mutualisms: Can red imported fire ants sour the relationship?

    USGS Publications Warehouse

    Zettler, J.A.; Spira, T.P.; Allen, C.R.

    2001-01-01

    Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant species and assessed the amount of scarification or damage that results from handling by fire ants. Fire ants removed nearly 100% of seeds of the ant-dispersed plants Trillium undulatum, T. discolor, T. catesbaei, Viola rotundifolia, and Sanguinaria canadensis. In recovered seeds fed to ant colonies, fire ants scarified 80% of S. canadensis seeds and destroyed 86% of V. rotundifolia seeds. Our study is the first to document that red imported fire ants are attracted to and remove seeds of species adapted for ant dispersal. Moreover, fire ants might damage these seeds and discard them in sites unfavorable for germination and seedling establishment. ?? 2001 Elsevier Science Ltd. All rights reserved.

  17. Thermal physiology. Keeping cool: Enhanced optical reflection and radiative heat dissipation in Saharan silver ants.

    PubMed

    Shi, Norman Nan; Tsai, Cheng-Chia; Camino, Fernando; Bernard, Gary D; Yu, Nanfang; Wehner, Rüdiger

    2015-07-17

    Saharan silver ants, Cataglyphis bombycina, forage under extreme temperature conditions in the African desert. We show that the ants' conspicuous silvery appearance is created by a dense array of triangular hairs with two thermoregulatory effects. They enhance not only the reflectivity of the ant's body surface in the visible and near-infrared range of the spectrum, where solar radiation culminates, but also the emissivity of the ant in the mid-infrared. The latter effect enables the animals to efficiently dissipate heat back to the surroundings via blackbody radiation under full daylight conditions. This biological solution for a thermoregulatory problem may lead to the development of biomimetic coatings for passive radiative cooling of objects. PMID:26089358

  18. Development of virtual bait stations to control Argentine ants (Hymenoptera: Formicidae) in environmentally sensitive habitats.

    PubMed

    Choe, Dong-Hwan; Vetter, Richard S; Rust, Michael K

    2010-10-01

    A novel bait station referred to as a virtual bait station was developed and tested against field populations of the invasive Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), at White Beach, Camp Pendleton, in Oceanside, CA. White Beach is a nesting habitat for an endangered seabird, the California least tern (Sterna antillarum browni Mearns). The beach is heavily infested with Argentine ants, one of the threats for the California least tern chicks. Conventional pest control strategies are prohibited because of the existence of the protected bird species and the site's proximity to the ocean. The bait station consisted of a polyvinyl chloride pipe that was treated on the inside with fipronil insecticide at low concentrations to obtain delayed toxicity against ants. The pipe was provisioned with an inverted bottle of 25% sucrose solution, then capped, and buried in the sand. Foraging ants crossed the treated surface to consume the sucrose solution. The delayed toxicity of fipronil deposits allowed the ants to continue foraging on the sucrose solution and to interact with their nestmates, killing them within 3-5 d after exposure. Further modification of the bait station design minimized the accumulation of dead ants in the sucrose solution, significantly improving the longevity and efficacy of the bait station. The virtual bait station exploits the foraging behavior of the ants and provides a low impact approach to control ants in environmentally sensitive habitats. It excluded all insects except ants, required only milligram quantities of toxicant, and eliminated the problem of formulating toxicants into aqueous sugar baits. PMID:21061977

  19. A Biomechanical Study of Hyoid Bone and Laryngeal Movements During Swallowing Comparing the Blom Low Profile Voice Inner Cannula and Passy-Muir One Way Tracheotomy Tube Speaking Valves.

    PubMed

    Srinet, Prateek; Van Daele, Douglas J; Adam, Stewart I; Burrell, Morton I; Aronberg, Ryan; Leder, Steven B

    2015-12-01

    The aim of this prospective, consecutive, cohort study was to investigate the biomechanical effects, if any, of the Blom low profile voice inner cannula and Passy-Muir one-way tracheotomy tube speaking valves on movement of the hyoid bone and larynx during swallowing. Ten adult patients (8 male, 2 female) with an age range of 61-89 years (mean 71 years) participated. Criteria for inclusion were ?18 years of age, English speaking, and ability to tolerate both changing to a Blom tracheotomy tube and placement of a one-way tracheotomy tube speaking valve with a fully deflated tracheotomy tube cuff. Digitized videofluoroscopic swallow studies were performed at 30 frames/s and with each patient seated upright in the lateral plane. A total of 18 swallows (three each with 5 cc bolus volumes of single contrast barium and puree + barium × 3 conditions) were analyzed for each participant. Variables evaluated included larynx-to-hyoid bone excursion (mm), maximum hyoid bone displacement (mm), and aspiration status under three randomized conditions: 1. Tracheotomy tube open with no inner cannula; 2. Tracheotomy tube with Blom valve; and 3. Tracheotomy tube with Passy-Muir valve. Blinded reliability testing with a Pearson product moment correlation was performed on 20 % of the data. Intra- and inter-rater reliability for combined measurements of larynx-to-hyoid bone excursion and maximum hyoid bone displacement was r = 0.98. Intra- and inter-rater reliability for aspiration status was 100 %. No significant differences (p > 0.05) were found for larynx-to-hyoid bone excursion and maximum hyoid bone displacement during swallowing based upon an open tracheotomy tube, Blom valve, or Passy-Muir valve. Aspiration status was identical for all three randomized conditions. The presence of a one-way tracheotomy tube speaking valve did not significantly alter two important components of normal pharyngeal swallow biomechanics, i.e., hyoid bone and laryngeal movements. Aspiration status was similarly unaffected by valve use. Clinicians should be aware that the data do not support placement of a one-way tracheotomy tube speaking valve to reduce prandial aspiration. PMID:26376918

  20. How to be an ant on figs

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  1. Fuzzy Rules from Ant-Inspired Computation 

    E-print Network

    Galea, Michelle

    This research identifies and investigates major issues in inducing accurate and comprehensible fuzzy rules from datasets.... of fuzzy rulebases, that of iterative rule learning where the rules are generated one by one and independently of each other, may not be an optimal one....FRANTIC, a system that provides a framework for exploring the claims above is developed. At the core lies a mechanism for creating individual fuzzy rules. This is based on a significantly modified social insect-inspired heuristic for combinatorial optimisation -- Ant Colony Optimisation. The rule discovery mechanism is utilised in two very different strategies for the induction of a complete fuzzy rulebase: 1. The first follows the common iterative rule learning approach for the induction of crisp and fuzzy rules; 2. The second has been designed during this research explicitly for the induction of a fuzzy rulebase, and generates all rules in parallel....Both strategies have been tested on a number of classification problems, including medical diagnosis and industrial plant fault detection, and compared against other crisp or fuzzy induction algorithms that use more well-established approaches. The results challenge statement A above, by presenting evidence to show that one criterion need not be met at the expense of the other. This research also uncovers the cost that is paid -- that of computational expenditure -- and makes concrete suggestions on how this may be resolved....With regards to statement B, until now little or no evidence has been put forward to support or disprove the claim. The results of this research indicate that definite advantages are offered by the second simultaneous strategy, that are not offered by the iterative one. These benefits include improved accuracy over a wide range of values for several key system parameters. However, both approaches also fare well when compared to other learning algorithms. This latter fact is due to the rule discovery mechanism itself -- the adapted Ant Colony Optimisation algorithm -- which affords several additional advantages. These include a simple mechanism within the rule construction process that enables it to cope with datasets that have an imbalanced distribution between the classes, and another for controlling the amount of fit to the training data....In addition, several system parameters have been designed to be semi-autonomous so as to avoid unnecessary user intervention, and in future work the social insect metaphor may be exploited and extended further to enable it to deal with industrial...

  2. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.

    PubMed

    Pringle, Elizabeth G

    2014-06-22

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output. PMID:24807259

  3. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant–plant mutualism

    PubMed Central

    Pringle, Elizabeth G.

    2014-01-01

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant–plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output. PMID:24807259

  4. Pheromone disruption of Argentine ant trail integrity

    USGS Publications Warehouse

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

    2008-01-01

    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/m2) to 1- and 4-m2 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. ?? 2008 Springer Science+Business Media, LLC.

  5. How to Control Ants at Home 

    E-print Network

    Merchant, Michael E.

    2002-08-23

    on the ground. If you cannot easily find a nest, place bottle caps or pieces of foil with a small amount of peanut butter and jelly in several locations. Watch for ant trails coming to the food and follow them back to their nest. Once you have found the nest..., treat it with an approved insecticide spray. Do not use gasoline or other flammable liquids to kill ant nests. These products are very dangerous and pollute the soil. If you can?t find a nest ? Use a commercial bait designed for ants, or make your own...

  6. Evolution of supercolonies: The Argentine ants of southern Europe

    PubMed Central

    Giraud, Tatiana; Pedersen, Jes S.; Keller, Laurent

    2002-01-01

    Some ants have an extraordinary social organization, called unicoloniality, whereby individuals mix freely among physically separated nests. This type of social organization is not only a key attribute responsible for the ecological domination of these ants, but also an evolutionary paradox and a potential problem for kin selection theory because relatedness between nest mates is effectively zero. The introduction of the Argentine ant in Europe was apparently accompanied by a dramatic loss of inter-nest aggression and the formation of two immense supercolonies (which effectively are two unicolonial populations). Introduced populations experienced only limited loss of genetic diversity at neutral markers, indicating that the breakdown of recognition ability is unlikely to be merely due to a genetic bottleneck. Rather, we suggest that a “genetic cleansing” of recognition cues occurred after introduction. Indeed workers of the same supercolony are never aggressive to each other despite the large geographical distance and considerable genetic differentiation between sampling sites. By contrast, aggression is invariably extremely high between the two supercolonies, indicating that they have become fixed for different recognition alleles. The main supercolony, which ranges over 6,000 km from Italy to the Spanish Atlantic coast, effectively forms the largest cooperative unit ever recorded. PMID:11959924

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

    PubMed

    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

  8. Structure and formation of ant transportation networks

    PubMed Central

    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 of ants involved in the construction process. When the number of ants is sufficient and networks do form, they tend to have short total length but a low level of robustness. These networks are topologically similar to either minimum spanning trees or Steiner networks. The process of network formation involves an initial construction of multiple links followed by a pruning process that reduces the number of trails. Our study thus illuminates the conditions under and the process by which minimal biological transport networks can be constructed. PMID:21288958

  9. Dynamics and elasticity of fire ant aggregations

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    Fire ants, Solenopsis invicta, form aggregations that are able to drip and spread like simple liquids, but that can also store energy and maintain a shape like elastic solids. They are an active material where the constituent particles constantly transform chemical energy into work. We find that fire ant aggregations shear thin and exhibit a stress cutoff below which they are able to oppose the applied stress. In the linear regime, the dynamics is fractal-like with both storage and shear moduli that overlap for over three orders of magnitude and that are power law with frequency. This dynamic behavior, characteristic of polymer gels and the gelation point, gives way to a predominantly elastic regime at higher ant densities. In comparison, dead ants are always solid-like.

  10. Ants, Crickets and Frogs in Cyclic Pursuit

    E-print Network

    Efrat, Alon

    Ants, Crickets and Frogs in Cyclic Pursuit A.M. Bruckstein1 , N. Cohen2 , A. Efrat1 Abstract. We and with preassigned, varying speeds. We also consider two discrete analogs, in which crickets or frogs are engaged

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

    PubMed

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

    2015-06-01

    Plant associations with protective ants are widespread among angiosperms, but carry the risk that ants will deter pollinators as well as herbivores. Such conflict, and adaptations to ameliorate or prevent the conflict, have been documented in African and neotropical acacias. Ant-acacia associations occur in Australia, but little is known of their ecology. Moreover, recent phylogenetic evidence indicates that Australian acacias are only distantly related to African and American acacias, providing an intercontinental natural experiment in the management of ant-pollinator conflict. We examined four populations of Acacia myrtifolia over a 400-km environmental gradient in southeastern Australia using ant and pollinator exclusion as well as direct observation of ants and pollinators to assess the potential for ant-pollinator conflict to affect seed set. Native bees were the only group of floral visitors whose visitation rates were a significant predictor of fruiting success, although beetles and wasps may play an important role as "insurance" pollinators. We found no increase in pollinator visitation or fruiting success following ant exclusion, even with large sample sizes and effective exclusion. Because ants are facultative visitors to A. myrtifolia plants, their presence may be insufficient to interfere greatly with floral visitors. It is also likely that the morphological location of extrafloral nectaries tends to draw ants away from reproductive parts, although we commonly observed ants on inflorescences, so the spatial separation is not strict. A. myrtifolia appears to maintain a generalized mutualism over a wide geographic range without the need for elaborate adaptations to resolve ant-pollinator conflict. PMID:25571873

  12. Ant functional responses along environmental gradients.

    PubMed

    Arnan, Xavier; Cerdá, Xim; Retana, Javier

    2014-11-01

    Understanding species distributions and diversity gradients is a central challenge in ecology and requires prior knowledge of the functional traits mediating species' survival under particular environmental conditions. While the functional ecology of plants has been reasonably well explored, much less is known about that of animals. Ants are among the most diverse, abundant and ecologically significant organisms on earth, and they perform a great variety of ecological functions. In this study, we analyse how the functional species traits present in ant communities vary along broad gradients in climate, productivity and vegetation type in the south-western Mediterranean. To this end, we compiled one of the largest animal databases to date: it contains information on 211 local ant communities (including eight climate variables, productivity, and vegetation type) and 124 ant species, for which 10 functional traits are described. We used traits that characterize different dimensions of the ant functional niche with respect to morphology, life history and behaviour at both individual and colony level. We calculated two complementary functional trait community indices ('trait average' and 'trait dissimilarity') for each trait, and we analysed how they varied along the three different gradients using generalized least squares models that accounted for spatial autocorrelation. Our results show that productivity, vegetation type and, to a lesser extent, each climate variable per se might play an important role in shaping the occurrence of functional species traits in ant communities. Among the climate variables, temperature and precipitation seasonality had a much higher influence on functional responses than their mean values, whose effects were almost lacking. Our results suggest that strong relationships might exist between the abiotic environment and the distribution of functional traits among south-western Mediterranean ant communities. This finding indicates that functional traits may modulate the responses of ant species to the environment. Since these traits act as the link between species distributions and the environment, they could potentially be used to predict community changes under future global change scenarios. PMID:24720700

  13. Visualization of Ant Pheromone Based Path Following 

    E-print Network

    Sutherland, Benjamin T.

    2010-07-14

    OF ANT PHEROMONE BASED PATH FOLOWING A Thesis by Benjamin Sutherland Submited to the O?ce of Graduate Studies of Texas A&M University in partial fulfilment of the requirements for the degre of MASTER OF SCIENCE December... 2009 Major Subject: Visualization Sciences VISUALIZATION OF ANT PHEROMONE BASED PATH FOLOWING A Thesis by Benjamin Sutherland Submited to the O?ce of Graduate Studies of Texas A&M University in partial fulfilment...

  14. Microfungal "weeds" in the leafcutter ant symbiosis.

    PubMed

    Rodrigues, A; Bacci, M; Mueller, U G; Ortiz, A; Pagnocca, F C

    2008-11-01

    Leafcutter ants (Formicidae: tribe Attini) are well-known insects that cultivate basidiomycete fungi (Agaricales: Lepiotaceae) as their principal food. Fungus gardens are monocultures of a single cultivar strain, but they also harbor a diverse assemblage of additional microbes with largely unknown roles in the symbiosis. Cultivar-attacking microfungi in the genus Escovopsis are specialized parasites found only in association with attine gardens. Evolutionary theory predicts that the low genetic diversity in monocultures should render ant gardens susceptible to a wide range of diseases, and additional parasites with roles similar to that of Escovopsis are expected to exist. We profiled the diversity of cultivable microfungi found in 37 nests from ten Acromyrmex species from Southern Brazil and compared this diversity to published surveys. Our study revealed a total of 85 microfungal strains. Fusarium oxysporum and Escovopsis were the predominant species in the surveyed gardens, infecting 40.5% and 27% of the nests, respectively. No specific relationship existed regarding microfungal species and ant-host species, ant substrate preference (dicot versus grass) or nesting habit. Molecular data indicated high genetic diversity among Escovopsis isolates. In contrast to the garden parasite, F. oxysporum strains are not specific parasites of the cultivated fungus because strains isolated from attine gardens have similar counterparts found in the environment. Overall, the survey indicates that saprophytic microfungi are prevalent in South American leafcutter ants. We discuss the antagonistic potential of these microorganisms as "weeds" in the ant-fungus symbiosis. PMID:18369523

  15. Congestion and communication in confined ant traffic

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  16. GLYCEROL IN NEST MATERIAL OF RED IMPORTED FIRE ANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red imported fire ant is a nest-building ant species. Workers build the nest by excavating soils. It was reported that red imported fire ants incorporated ant-derived compounds in their nest soil, such as cuticular hydrocarbons (Vander Meer R. K. unpublished data) and venom alkaloids (Blum, M. S. ...

  17. SCHOOLS INTEGRATED PEST MANAGEMENT (IPM) FOR ANTS *Important Note*

    E-print Network

    Liskiewicz, Maciej

    and help control other pests, including fly larvae, crickets, and termites. Some species of ants colonies. Males die soon after mating. Winged ants are often confused with termites (see Figure 2). However, ants are distinguished from termites by three distinct features. First, ants have elbowed antennae

  18. Leaf litter ant diversity in Guyana JOHN S. LAPOLLA1,

    E-print Network

    Miller, Scott

    -1 Leaf litter ant diversity in Guyana JOHN S. LAPOLLA1, *, TED SUMAN1 , JEFFREY SOSA-CALVO1 Shield, Leaf litter ants Abstract. Leaf litter ants are an important group of organisms for informing conservation plan- ning. This study presents the beginning of a leaf litter ant dataset for Guyana. Following

  19. ORIGINAL ARTICLE Collective decisions in ants when foraging

    E-print Network

    Nicolis, Stamatios C.

    ORIGINAL ARTICLE Collective decisions in ants when foraging under crowded conditions Audrey-recruiting ant Lasius niger. In our experiment, ants had to go from their nest to a food source by crossing underlying the choice of route in ants. A mathematical model was developed to evaluate the impor- tance

  20. Ant Colony Optimisation1 12.1 Introduction

    E-print Network

    Grant, P. W.

    Chapter 12 Ant Colony Optimisation1 12.1 Introduction Real ants can find a shortest path from the old one is no longer feasible due to a new obstacle. In Figure (12.1 A) ants are moving on a straight line that connects a food source to their nest. An ant: · deposits pheromone while walking

  1. Chemically armed mercenary ants protect fungus-farming societies

    E-print Network

    Adams, Rachelle M. M.

    Chemically armed mercenary ants protect fungus-farming societies Rachelle M. M. Adamsa,b,1 June 20, 2013) The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we

  2. ORIGINAL PAPER Invasive Argentine ants reduce fitness of red maple

    E-print Network

    Buckel, Jeffrey A.

    ORIGINAL PAPER Invasive Argentine ants reduce fitness of red maple via a mutualism with an endemic / Published online: 16 October 2009 Ó Springer Science+Business Media B.V. 2009 Abstract Many invasive ant the natural enemies of the Hemiptera. Invasive ant species like the Argentine ant have often been associated

  3. Ant Foraging Revisited Liviu A. Panait and Sean Luke

    E-print Network

    Turk, Greg

    Ant Foraging Revisited Liviu A. Panait and Sean Luke George Mason University, Fairfax, VA 22030 lpanait@cs.gmu.edu, sean@cs.gmu.edu Abstract Most previous artificial ant foraging algorithms have to date the artificial ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  4. Ant-Inspired Navigation In Unknown Environments Stergios I. Roumeliotis

    E-print Network

    Roumeliotis, Stergios I.

    Ant-Inspired Navigation In Unknown Environments Stergios I. Roumeliotis Computer Science Dpt-0781 maja@robotics.usc.edu In contrast to mostother ant species, desert ants (Cataglyphis fortis) do not use) information. Indeed desert ants and honeybees use such information in addition to path integration. On a fa

  5. When Fire Ants Move In, Others Leave Elizabeth Pennisi

    E-print Network

    Gotelli, Nicholas J.

    ECOLOGY: When Fire Ants Move In, Others Leave Elizabeth Pennisi For Amy Arnett, getting a Ph, collecting ants at 33 sites along the way. They had set out to look at how the food resources for ant lions, insects that prey on ants, changed from north to south along the East Coast. But in the process

  6. Morphological phylogeny of army ants and other dorylomorphs (Hymenoptera: Formicidae)

    E-print Network

    Brady, Seán

    Morphological phylogeny of army ants and other dorylomorphs (Hymenoptera: Formicidae) S E A´ N G of ants comprises the three subfamilies of army ants (Aenictinae, Dorylinae, Ecitoninae) together the newly discovered male caste of Lepta- nilloidinae. We used ant taxa from Leptanillinae, Myrmeciinae

  7. Ant Foraging Revisited Liviu A. Panait and Sean Luke

    E-print Network

    Luke, Sean

    Ant Foraging Revisited Liviu A. Panait and Sean Luke George Mason University, Fairfax, VA 22030 lpanait@cs.gmu.edu, sean@cs.gmu.edu Abstract Most previous artificial ant foraging models have to date re the artificial ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  8. TECHNICAL NOTE Nine novel microsatellite markers for the army ant

    E-print Network

    Pierce, Naomi E.

    TECHNICAL NOTE Nine novel microsatellite markers for the army ant Simopelta pergandei (subfamily Simopelta (subfamily Ponerinae) army ants are specialized predators of other ants in New World tropical forests. Although they show a striking convergence in overall life-history with the well known army ants

  9. Higher Education Expansion in China and the "Ant Tribe" Problem

    ERIC Educational Resources Information Center

    He, Yu; Mai, Yinhua

    2015-01-01

    College Enrolment Expansion policies have been implemented in China since 1999. Unfortunately, numbers of qualified teachers and the amount of educational funds input have not caught up with the pace of student intake. Even the curricula taught in colleges are outdated and work practice programmes are inefficient. As a result, new college…

  10. Ant Colony Optimization for the Total Weighted Tardiness Problem

    E-print Network

    Libre de Bruxelles, Université

    -1098 SJ Amsterdam, The Netherlands ^ Universite Libre de Bruxelles, IRIDIA, Avenue Franklin Roosevelt] and for which instances with more than 50jobs can often not be solved to optimality with state-of-the-art branch & bound algorithms [1, 5]. In the SMTWTP n jobs have to be sequentially processed on a single machine

  11. Evolution of ant-cultivar specialization and cultivar switching in Apterostigma fungus-growing ants.

    PubMed

    Villesen, Palle; Mueller, Ulrich G; Schultz, Ted R; Adams, Rachelle M M; Bouck, Amy C

    2004-10-01

    Almost all of the more than 200 species of fungus-growing ants (Formicidae: Attini) cultivate litter-decomposing fungi in the family Lepiotaceae (Basidiomycota: Agaricales). The single exception to this rule is a subgroup of ant species within the lower attine genus Apterostigma, which cultivate pterulaceous fungi distantly related to the Lepiotaceae. Comparison of cultivar and ant phylogenies suggests that a switch from lepiotaceous to pterulaceous fungiculture occurred only once in the history of the fungus-growing ants. This unique switch occurred after the origin of the genus Apterostigma, such that the basal Apterostigma lineages retained the ancestral attine condition of lepiotaceous fungiculture, and none of the Apterostigma lineages in the monophyletic group of pterulaceous fungiculturists are known to have reverted back to lepiotaceous fungiculture. The origin of pterulaceous fungiculture in attine ants may have involved a unique transition from the ancestral cultivation of litter-decomposing lepiotaceous fungi to the cultivation of wood-decomposing pterulaceous fungi. Phylogenetic analyses further indicate that distantly related Apterostigma ant species sometimes cultivate the same cultivar lineage, indicating evolutionarily frequent, and possibly ongoing, exchanges of fungal cultivars between Apterostigma ant species. The pterulaceous cultivars form two sister clades, and different Apterostigma ant lineages are invariably associated with, and thus specialized on, only one of the two cultivar clades. However, within clades Apterostigma ant species are able to switch between fungi. This pattern of broad specialization by attine ants on defined cultivar clades, coupled with flexible switching between fungi within cultivar clades, is also found in other attine lineages and appears to be a general phenomenon of fungicultural evolution in all fungus-growing ants. PMID:15562688

  12. Summary. The Argentine ant, Linepithema humile, has invaded many areas of the world, displacing native ants. Its

    E-print Network

    Gordon, Deborah

    Summary. The Argentine ant, Linepithema humile, has invaded many areas of the world, displacing native ants. Its behavior may contribute to its competitive success. Staged and natural encounters were observed at food resources in the field, between Argentine ants and eight ant species native to northern

  13. Dracula ant phylogeny as inferred by nuclear 28S rDNA sequences and implications for ant systematics

    E-print Network

    Spicer, Greg S.

    Dracula ant phylogeny as inferred by nuclear 28S rDNA sequences and implications for ant Received 12 February 2004; revised 21 June 2004 Available online 3 August 2004 Abstract Ants are one of this group, yet we know little about the evolution of the major lineages of ants and have been unable

  14. Ecology of a fig ant-plant

    NASA Astrophysics Data System (ADS)

    Harrison, Rhett D.

    2014-05-01

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

  15. Applied Ecology and Control of Imported Fire Ants and Argentine Ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red imported fire ant, Solenopsis invicta Buren, and Argentine ant, Linepithema humile (Mayr), are invasive species that are major pests in urban, natural, and agricultural habitats. The goal of this dissertation was to study aspects the chemical sensitivity, behavior, and ecology of each specie...

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

    PubMed

    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

  17. Ant interactions with soil organisms and associated semiochemicals.

    PubMed

    Vander Meer, Robert

    2012-06-01

    This review focuses on the semiochemical interactions between ants and their soil environment. Ants occupy virtually every ecological niche and have evolved mechanisms to not just cope with, but also manipulate soil organisms. The metapleural gland, specific to ants was thought to be the major source of semiochemical antimicrobial compounds targeting general or specific deleterious microbes. The extremely diverse variety of semiochemicals and their sources with antimicrobial activity or potential activity is highlighted. The leaf-cutting ants and fire ant provide the most researched species, in part because they cause significant economic damage. The leaf-cutting ant is particularly interesting because researchers have uncovered unexpected interactions between leaf-cutting ant fungal farm, parasitic fungi, bacteria, yeasts, and ant defensive semiochemicals. These complex relationships highlight the multidimensional aspects of ants and the soil environment in which they live. PMID:22653568

  18. On the Morphology of the Digestive System of Two Monomorium Ant Species

    PubMed Central

    Solis, Daniel Russ; Rossi, Mônica Lanzoni; Fox, Eduardo Gonçalves Paterson; Nogueira, Neusa de Lima; Tanaka, Francisco André Ossamu; Bueno, Odair Correa

    2013-01-01

    The digestive system of adults and mature larvae of two ant species of Monomorium Mayr (Hymoneptera: Formicidae) were described with the aid of light and scanning electron microscopy, as there is a lack of studies in this area. These two ant species are recurrently found in urban habitats and are known as ‘tramp species,’ as they cause problems in households, businesses, and hospitals. The most interesting finds of the present study include the existence of spinules in the crop of adults, and the number of Malpighian tubules and rectal pads was constant among different castes, ages, and species. PMID:24224520

  19. On the morphology of the digestive system of two Monomorium ant species.

    PubMed

    Solis, Daniel Russ; Rossi, Mônica Lanzoni; Fox, Eduardo Gonçalves Paterson; Nogueira, Neusa de Lima; Tanaka, Francisco André Ossamu; Bueno, Odair Correa

    2013-01-01

    The digestive system of adults and mature larvae of two ant species of Monomorium Mayr (Hymoneptera: Formicidae) were described with the aid of light and scanning electron microscopy, as there is a lack of studies in this area. These two ant species are recurrently found in urban habitats and are known as 'tramp species,' as they cause problems in households, businesses, and hospitals. The most interesting finds of the present study include the existence of spinules in the crop of adults, and the number of Malpighian tubules and rectal pads was constant among different castes, ages, and species. PMID:24224520

  20. Recruitment Strategies and Colony Size in Ants

    PubMed Central

    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, 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. PMID:20694195

  1. The Ants of the Arabuko Sokoke Forest

    NASA Astrophysics Data System (ADS)

    Brandau, E.

    2014-12-01

    The core location of my research project was the Arabuko Sokoke Forest. The forest is located along the east coast of Kenya and belongs to the coastal forest zone of eastern Africa. The forest is considered a biodiversity hotspot, having many species being endemic to this habitat. The Arabuko Sokoke Forest is not a rainforest, like the Kakamega Forest in western Kenya, but a tropical dry forest. The objective of my research was to create a general checklist of the ant species collected in teh Arabuko Sokoke Forest in 2009. The general checklist of ant species will be used to document the differences between the three different forest habitat types (Cynometra, Brachystegia and mixed forest) and ant communities found within the forest, as well as the fauna found in those locations. The ants were collected using the leaf litter extraction method and were then mounted and idenified. The results from my research were that out of 73 specimens, there were 13 genera and 24 different species. Four of the 24 species have not been recorded for this forest before and one of the Tetramorium is likely to be a new species. The results also showed that the species diversity on the two transects are almost the same. There was very low overlap between the two transects as well: there were two shared species between the two different forest habitat types. For future work, there are still many undiscovered ant species in the Arabuko Sokoke Forest. In order to get a more complete faunal overview, more samples have to be collected from different parts of the forest. To do this, the canopy ant fauna might offer additional species that were not collected in the leaf litter samples.

  2. An ants-eye view of an ant-plant protection mutualism

    PubMed Central

    Lanan, M. C.; Bronstein, J. L.

    2013-01-01

    Ant protection of extrafloral nectar-secreting plants (EFN 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 extrafloral nectar-secreting cactus Ferocactus wislizeni (Englem) is not independent between plants up to 5m apart. Colony territories of C. opuntiae are large, covering areas of up to 5000m2, and workers visit between five and thirty-four extrafloral nectar-secreting barrel cacti within the territories. These ants are highly polydomous, with up to twenty 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

  3. Detection of mitochondrial COII DNA sequences in ant guts as a method for assessing termite predation by ants.

    PubMed

    Fayle, Tom M; Scholtz, Olivia; Dumbrell, Alex J; Russell, Stephen; Segar, Simon T; Eggleton, Paul

    2015-01-01

    Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest. We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII) from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2 % of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1 % of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63 % (5/7; Camponotus sp. 1) to 0 % (0/7; Ponera sp. 1), there was no evidence (with small sample sizes) for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that ant-termite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs. PMID:25853549

  4. Detection of Mitochondrial COII DNA Sequences in Ant Guts as a Method for Assessing Termite Predation by Ants

    PubMed Central

    Fayle, Tom M.; Scholtz, Olivia; Dumbrell, Alex J.; Russell, Stephen; Segar, Simon T.; Eggleton, Paul

    2015-01-01

    Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest. We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII) from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2 % of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1 % of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63 % (5/7; Camponotus sp. 1) to 0 % (0/7; Ponera sp. 1), there was no evidence (with small sample sizes) for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that ant-termite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs. PMID:25853549

  5. Dual response to nest flooding during monsoon in an Indian ant.

    PubMed

    Kolay, Swetashree; Annagiri, Sumana

    2015-01-01

    Flooding causes destruction of shelter and disruption of activity in animals occupying subterranean nests. To ensure their survival organisms have evolved various responses to combat this problem. In this study we examine the response of an Indian ant, Diacamma indicum, to nest flooding during the monsoon season. Based on characterization of nest location, architecture and the response of these ants to different levels of flooding in their natural habitat as well as in the laboratory, we infer that they exhibit a dual response. On the one hand, the challenges presented by monsoon are dealt with by occupying shallow nests and modifying the entrance with decorations and soil mounds. On the other hand, inundated nests are evacuated and the ants occupy shelters at higher elevations. We conclude that focused studies of the monsoon biology of species that dwell in such climatic conditions may help us appreciate how organisms deal with, and adapt to, extreme seasonal changes. PMID:26349015

  6. Dual response to nest flooding during monsoon in an Indian ant

    PubMed Central

    Kolay, Swetashree; Annagiri, Sumana

    2015-01-01

    Flooding causes destruction of shelter and disruption of activity in animals occupying subterranean nests. To ensure their survival organisms have evolved various responses to combat this problem. In this study we examine the response of an Indian ant, Diacamma indicum, to nest flooding during the monsoon season. Based on characterization of nest location, architecture and the response of these ants to different levels of flooding in their natural habitat as well as in the laboratory, we infer that they exhibit a dual response. On the one hand, the challenges presented by monsoon are dealt with by occupying shallow nests and modifying the entrance with decorations and soil mounds. On the other hand, inundated nests are evacuated and the ants occupy shelters at higher elevations. We conclude that focused studies of the monsoon biology of species that dwell in such climatic conditions may help us appreciate how organisms deal with, and adapt to, extreme seasonal changes. PMID:26349015

  7. Multiple gains and losses of Wolbachia symbionts across a tribe of fungus-growing ants.

    PubMed

    Frost, C L; Fernández-Marín, H; Smith, J E; Hughes, W O H

    2010-09-01

    Although the intracellular bacterium Wolbachia is ubiquitous in insects, it has a unique relationship with New World ants on which particular bacterial strains have specialized. However, data are from distantly related hosts and detailed phylogenetic information which could reveal transmission dynamics are lacking. Here, we investigate host-Wolbachia relationships in the monophyletic fungus-growing ant tribe Attini, screening 23 species and using multilocus sequence typing to reliably identify Wolbachia strains. This technique reduces the significant problem of recombination seen using traditional single gene techniques. The relationship between Wolbachia and the fungus-growing ants appears complex and dynamic. There is evidence of co-cladogenesis, supporting vertical transmission; however, this is incomplete, demonstrating that horizontal transmission has also occurred. Importantly, the infection prevalence is frequently different between closely related taxa, with the Acromyrmex leaf-cutting ants appearing particularly prone to infection and there being no consistent relationship with any of the major life history transitions. We suggest that infection loss and horizontal transmission have driven epidemics or selective sweeps of Wolbachia, resulting in multiple gains and losses of infection across the fungus-growing ants. PMID:20738784

  8. AntEater: Challenging your Automatic Negative

    E-print Network

    Chen, Lei

    alerts and reminders #12;Big Data Analytics Module · Analyze collectively the records of patients and enthusiasm · This project aims users at helping combat their ANTs · Using a backend cloudbased big data Services Domain Expert Services Backend ServerBackend Server Data Analytics Engine Data Analytics Engine

  9. Water surface locomotion in tropical canopy ants.

    PubMed

    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

  10. Modelling the Landmark Navigation Behavior of the Desert Ant Cataglyphis

    E-print Network

    Moeller, Ralf

    Modelling the Landmark Navigation Behavior of the Desert Ant Cataglyphis Technical Report Ralf M of the desert ant Cataglyphis in asymmetrical landmark configurations. Whereas according to the snapshot model

  11. QUEEN REPLACEMENT IN DEQUEENED COLONIES OF THE ARGENTINE ANT

    E-print Network

    Keller, Laurent

    QUEEN REPLACEMENT IN DEQUEENED COLONIES OF THE ARGENTINE ANT IRIDOMYRMEX HUMILIS (MAYR) BY Luc of Iridomyrmex humilis. MATERIAL AND METHODS Large societies of the Argentine ant were collected in December 1985

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Mutualism Between Fire Ants and Mealybugs Reduces Lady Beetle Predation.

    PubMed

    Cheng, Shoujie; Zeng, Ling; Xu, Yijuan

    2015-08-01

    Solenopsis invicta Buren is an important invasive pest that has a negative impact on biodiversity. However, current knowledge regarding the ecological effects of its interaction with honeydew-producing hemipteran insects is inadequate. To partially address this problem, we assessed whether the interaction between the two invasive species S. invicta and Phenacoccus solenopsis Tinsley mediated predation of P. solenopsis by Propylaea japonica Thunbery lady beetles using field investigations and indoor experiments. S. invicta tending significantly reduced predation by the Pr. japonica lady beetle, and this response was more pronounced for lady beetle larvae than for adults. A field investigation showed that the species richness and quantity of lady beetle species in plots with fire ants were much lower than in those without fire ants. In an olfaction bioassay, lady beetles preferred to move toward untended rather than tended mealybugs. Overall, these results suggest that mutualism between S. invicta and P. solenopsis may have a serious impact on predation of P. solenopsis by lady beetles, which could promote growth of P. solenopsis populations. PMID:26470296

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Gómez, Crisanto; Oliveras, Jordi

    2003-04-01

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

  16. Microbiomes of ant castes implicate new microbial roles in the fungus-growing ant Trachymyrmex septentrionalis

    PubMed Central

    Ishak, Heather D.; Miller, Jessica L.; Sen, Ruchira; Dowd, Scot E.; Meyer, Eli; Mueller, Ulrich G.

    2011-01-01

    Fungus-growing ants employ several defenses against diseases, including disease-suppressing microbial biofilms on their integument and in fungal gardens. Here, we compare the phenology of microbiomes in natural nests of the temperate fungus-growing ant Trachymyrmex septentrionalis using culture-dependent isolations and culture-independent 16S-amplicon 454-sequencing. 454-sequencing revealed diverse actinobacteria associated with ants, including most prominently Solirubrobacter (12.2–30.9% of sequence reads), Pseudonocardia (3.5–42.0%), and Microlunatus (0.4–10.8%). Bacterial abundances remained relatively constant in monthly surveys throughout the annual active period (late winter to late summer), except Pseudonocardia abundance declined in females during the reproductive phase. Pseudonocardia species found on ants are phylogenetically different from those in gardens and soil, indicating ecological separation of these Pseudonocardia types. Because the pathogen Escovopsis is not known to infect gardens of T. septentrionalis, the ant-associated microbes do not seem to function in Escovopsis suppression, but could protect against ant diseases, help in nest sanitation, or serve unknown functions. PMID:22355719

  17. Do Desert Ants Use Partial Image Matching for Landmark Navigation?

    E-print Network

    Moeller, Ralf

    Do Desert Ants Use Partial Image Matching for Landmark Navigation? Ralf Moller1;2 , Dimitrios University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland Desert ants (genus Cataglyphis) have of Experimental Biology, 199:129{140, 1996. 3] R. Wehner and F. Raber. Visual spatial memory in desert ants

  18. Fire ant control with Entomopathogens in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Trail pheromone disruption of red imported fire ant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world but toxic bait systems affect non-target ant species and can not be used in sensitive ecosystems. The fire ant uses recruitment pheromones to organize the retrieval of food resources back to the colony....

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. Learning Ant Foraging Behaviors Liviu A. Panait and Sean Luke

    E-print Network

    George Mason University

    . The interest stems from the capacity of such simple organisms to collaboratively work together to solve in (White et al., 1998). AntFarm (Collins and Jefferson, 1992) is another sys- tem that combines presented in this paper. AntFarm uses multi- ple colonies of homogeneous ants, with each colony

  2. Model Specification Searches Using Ant Colony Optimization Algorithms

    ERIC Educational Resources Information Center

    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.

  3. Dynamics of an ant-plant-pollinator model

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  4. Ant Algorithms and Generalized Finite Urns Christopher Leith

    E-print Network

    Wehlau, David

    Ant Algorithms and Generalized Finite Urns by Christopher Leith A thesis submitted behaviour of pheromone trail laying biological agents. These ant algorithms, as they are commonly called system. Our interest lies mainly with the latter application. Analyzing the effectiveness of ant

  5. Collaboration in Distributed Systems: Robots, Ants, and Matchings

    E-print Network

    Collaboration in Distributed Systems: Robots, Ants, and Matchings A thesis submitted to attain soccer together, through ants ensuring the survival of their colony, to nodes in a peer-to-peer network of ants sufficient to locate the treasure for various modifications of the aforementioned model

  6. INTRODUCTION Individual foraging ants show remarkable navigational abilities.

    E-print Network

    Cheng, Ken

    44 INTRODUCTION Individual foraging ants show remarkable navigational abilities. Our current of the strategies underpinning the use of visual information can be observed in the field by capturing homing ants just before they reach their nest (i.e. zero-vector ants) and displacing them to different locations

  7. HOUSEHOLD AND STRUCTURAL INSECTS Trap-Mulching Argentine Ants

    E-print Network

    Buckel, Jeffrey A.

    HOUSEHOLD AND STRUCTURAL INSECTS Trap-Mulching Argentine Ants JULES SILVERMAN,1 CLYDE E. SORENSON. Econ. Entomol. 99(5): 1757Ð1760 (2006) ABSTRACT Argentine ant, Linepithema humile (Mayr), management ants are repelled from a broad domain of nest sites to smaller deÞned areas, which are subsequently

  8. HOW DO ANTS AND SOCIAL CATERPILLARS COLLECTIVELY MAKE DECISIONS?

    E-print Network

    Nicolis, Stamatios C.

    HOW DO ANTS AND SOCIAL CATERPILLARS COLLECTIVELY MAKE DECISIONS? 1 Introduction In social insects detailed descriptions of collective decisions by insect colonies (for example see, ants: Davidson 1978 hand, and equally detailed descriptions of individual decisions on the other (for example see, ants

  9. Pattern Formation and Optimization in Army Ant Raids

    E-print Network

    Delgado, Jordi

    Pattern Formation and Optimization in Army Ant Raids Ricard V. Sol´e , Eric Bonabeau Jordi Delgado, Pau Fern´andez Jesus Mar´in Keywords self-organization, army ants, pattern formation, optimization Abstract Army ant colonies display complex foraging raid patterns involving thousands of individuals

  10. A Graph-Based Ant Colony Optimization Approach for Process Planning

    PubMed Central

    Wang, JinFeng; Fan, XiaoLiang; Wan, Shuting

    2014-01-01

    The complex process planning problem is modeled as a combinatorial optimization problem with constraints in this paper. An ant colony optimization (ACO) approach has been developed to deal with process planning problem by simultaneously considering activities such as sequencing operations, selecting manufacturing resources, and determining setup plans to achieve the optimal process plan. A weighted directed graph is conducted to describe the operations, precedence constraints between operations, and the possible visited path between operation nodes. A representation of process plan is described based on the weighted directed graph. Ant colony goes through the necessary nodes on the graph to achieve the optimal solution with the objective of minimizing total production costs (TPC). Two cases have been carried out to study the influence of various parameters of ACO on the system performance. Extensive comparative experiments have been conducted to demonstrate the feasibility and efficiency of the proposed approach. PMID:24995355

  11. The chemistry, recognition behaviors, and population genetics of Neotropical parabiotic ants

    E-print Network

    Emery, Virginia Jayne

    2013-01-01

    chemical  profiles  of  ants  found  in  ant-­?garden  ant-­?gardens  is  the  first  to   examine  the  chemical  chemical  cues  in  the  parabiotic  nests  of   Crematogaster  levior  and   Camponotus  femoratus,  which  are  found  throughout  ant-­? gardens  

  12. A new routing method based on ant colony algorithm for LEO satellite communication networks

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Hu, Xiulin

    2007-11-01

    LEO(Low Earth Orbit) satellite network is more suitable for multimedia communication than GEO(Geosynchronous Earth Orbit) and MEO(Medium Earth Orbit) satellite network because of short propagation delay. Routing computation in communication network with several constraint factors has been proved to be a NP-C problem. Ant colony algorithm as a bionics algorithm has good performances on solving NP-C problem. Existing research about ant colony algorithm mainly concentrates on Ad hoc network, and application in satellite network is not completely developed. According to the characteristics of LEO satellite network, this paper presents a new routing method based on ant colony algorithm with forecast strategy and elitist strategy. Generally each satellite establishes two intra-ISLs with forward and backward neighbors in the same orbit, and two inter-ISLs with left and right neighbors in the adjacent orbits. Thus the topology of satellite network consists of many grids. According to the specific topology, forecast strategy is introduced to reduce redundant information. On the other hand, pheromone is updated continuously to ensure elitist path chosen. Assuming a reference satellite network model is given, the simulation results show that the improved algorithm converges more quickly than basic ant colony algorithm.

  13. THE FORMIS ANT BIBLIOGRAPHY: A WINDOW ON THE WORLD'S ANT LITERATURE AND A DOOR INTO MYRMECOLOGY'S FUTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    FORMIS 2001 is a composite of several ant literature databases. It contains citations for a large fraction of the world's ant literature (over 30,000 references). It can be downloaded or searched online: http://cmave.usda.ufl.edu/~formis/. General contributions include: UCD Ant Literature Databas...

  14. The distribution and interaction of red imported fire ants and native ants across ecotones in a Post Oak Savanna 

    E-print Network

    Meegan, Rebecca Pharr

    2000-01-01

    types. Wood-Grass was the most diverse ecotone; all 17 ant genera were found. The other ecotones contained from 9 to 5 ant genera. The most abundant native ant genera were Forelius, Hypoponera, Monomorium, and Pheidole. Solenopsis invicta was found...

  15. Multiple ant colony algorithm method for selecting tag SNPs.

    PubMed

    Liao, Bo; Li, Xiong; Zhu, Wen; Li, Renfa; Wang, Shulin

    2012-10-01

    The search for the association between complex disease and single nucleotide polymorphisms (SNPs) or haplotypes has recently received great attention. Finding a set of tag SNPs for haplotyping in a great number of samples is an important step to reduce cost for association study. Therefore, it is essential to select tag SNPs with more efficient algorithms. In this paper, we model problem of selection tag SNPs by MINIMUM TEST SET and use multiple ant colony algorithm (MACA) to search a smaller set of tag SNPs for haplotyping. The various experimental results on various datasets show that the running time of our method is less than GTagger and MLR. And MACA can find the most representative SNPs for haplotyping, so that MACA is more stable and the number of tag SNPs is also smaller than other evolutionary methods (like GTagger and NSGA-II). Our software is available upon request to the corresponding author. PMID:22480582

  16. Optic disc detection using ant colony optimization

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    Fürst, Matthias A.; Nash, David R.

    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 oviposition in this and other Maculinea species have, however, shown equivocal results, leading to a long-term controversy over support for this hypothesis. We therefore conducted a controlled field experiment to study the egg-laying behaviour of M. alcon. Matched potted Gentiana plants were set out close to host-ant nests and non-host-ant nests, and the number and position of eggs attached were assessed. Our results show no evidence for host-ant-based oviposition in M. alcon, but support an oviposition strategy based on plant characteristics. This suggests that careful management of host-ant distribution is necessary for conservation of this endangered butterfly. PMID:19864269

  18. Fast and Flexible: Argentine Ants Recruit from Nearby Trails

    PubMed Central

    Flanagan, Tatiana P.; Pinter-Wollman, Noa M.; Moses, Melanie E.; Gordon, Deborah M.

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources. PMID:23967129

  19. Harvester ant bioassay for assessing hazardous chemical waste sites

    SciTech Connect

    Gano, K.A.; Carlile, D.W.; Rogers, L.E.

    1984-12-01

    A technique was developed for using harvester ants, Pogonomyrmex owhyeei, in terrestrial bioassays. Procedures were developed for maintaining stock populations, handling ants, and exposing ants to toxic materials. Relative toxicities were determined by exposing ants to 10 different materials. These materials included three insecticides, Endrin, Aldrin, and Dieldrin; one herbicide, 2,4-D; three oil-like compounds, wood preservative, drilling fluid, and slop oil; and three heavy metals, copper, zinc, and cadmium. Ants were exposed in petri dishes containing soil amended with a particular toxicant. Under these test conditions, ants showed no sensitivity to the metals or 2,4-D. Ants were sensitive to the insecticides and oils in repeated tests, and relative toxicity remained consistent throughout. Aldrin was the most toxic material, followed by Dieldrin, Endrin, wood preservative, drilling fluid, and slop oil. 10 refs., 2 figs., 2 tabs.

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  1. Ant antennae: are they sites for magnetoreception?

    PubMed Central

    de Oliveira, Jandira Ferreira; Wajnberg, Eliane; de Souza Esquivel, Darci Motta; Weinkauf, Sevil; Winklhofer, Michael; Hanzlik, Marianne

    2010-01-01

    Migration of the Pachycondyla marginata ant is significantly oriented at 13° with respect to the geomagnetic north–south axis. On the basis of previous magnetic measurements of individual parts of the body (antennae, head, thorax and abdomen), the antennae were suggested to host a magnetoreceptor. In order to identify Fe3+/Fe2+ sites in antennae tissue, we used light microscopy on Prussian/Turnbull's blue-stained tissue. Further analysis using transmission electron microscopy imaging and diffraction, combined with elemental analysis, revealed the presence of ultra-fine-grained crystals (20–100 nm) of magnetite/maghaemite (Fe3O4/?-Fe2O3), haematite (?-Fe2O3), goethite (?-FeOOH) besides (alumo)silicates and Fe/Ti/O compounds in different parts of the antennae, that is, in the joints between the third segment/pedicel, pedicel/scape and scape/head, respectively. The presence of (alumo)silicates and Fe/Ti/O compounds suggests that most, if not all, of the minerals in the tissue are incorporated soil particles rather than biomineralized by the ants. However, as the particles were observed within the tissue, they do not represent contamination. The amount of magnetic material associated with Johnston's organ and other joints appears to be sufficient to produce a magnetic-field-modulated mechanosensory output, which may therefore underlie the magnetic sense of the migratory ant. PMID:19474081

  2. Kin-informative recognition cues in ants.

    PubMed

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

    2011-07-01

    Although social groups are characterized by cooperation, they are also often the scene of conflict. In non-clonal systems, the reproductive interests of group members will differ and individuals may benefit by exploiting the cooperative efforts of other group members. However, such selfish behaviour is thought to be rare in one of the classic examples of cooperation--social insect colonies--because the colony-level costs of individual selfishness select against cues that would allow workers to recognize their closest relatives. In accord with this, previous studies of wasps and ants have found little or no kin information in recognition cues. Here, we test the hypothesis that social insects do not have kin-informative recognition cues by investigating the recognition cues and relatedness of workers from four colonies of the ant Acromyrmex octospinosus. Contrary to the theoretical prediction, we show that the cuticular hydrocarbons of ant workers in all four colonies are informative enough to allow full-sisters to be distinguished from half-sisters with a high accuracy. These results contradict the hypothesis of non-heritable recognition cues and suggest that there is more potential for within-colony conflicts in genetically diverse societies than previously thought. PMID:21123270

  3. Polydomy in the ant Ectatomma opaciventre

    PubMed Central

    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 m2 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 confirmed 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

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

    PubMed Central

    Jiménez-Soto, Estelí; Philpott, Stacy M

    2015-01-01

    Understanding the drivers of ant diversity and co-occurrence in agroecosystems is fundamental because ants participate in interactions that influence agroecosystem processes. Multiple local and regional factors influence ant community assembly. We examined local factors that influence the structure of a twig-nesting ant community in a coffee system in Mexico using an experimental approach. We investigated whether twig characteristics (nest entrance size and diversity of nest entrance sizes) and nest strata (canopy shade tree or coffee shrub) affected occupation, species richness, and community composition of twig-nesting ants and whether frequency of occupation of ant species varied with particular nest entrance sizes or strata. We conducted our study in a shaded coffee farm in Chiapas, Mexico, between March and June 2012. We studied ant nest colonization by placing artificial nests (bamboo twigs) on coffee shrubs and shade trees either in diverse or uniform treatments. We also examined whether differences in vegetation (no. of trees, canopy cover and coffee density) influenced nest colonization. We found 33 ant species occupying 73% of nests placed. Nest colonization did not differ with nest strata or size. Mean species richness of colonizing ants was significantly higher in the diverse nest size entrance treatment, but did not differ with nest strata. Community composition differed between strata and also between the diverse and uniform size treatments on coffee shrubs, but not on shade trees. Some individual ant species were more frequently found in certain nest strata and in nests with certain entrance sizes. Our results indicate that twig-nesting ants are nest-site limited, quickly occupy artificial nests of many sizes, and that trees or shrubs with twigs of a diversity of entrance sizes likely support higher ant species richness. Further, individual ant species more frequently occupy nests with different sized entrances promoting ant richness on individual coffee plants and trees. PMID:26380664

  5. An adaptive grid algorithm for 3-D GIS landform optimization based on improved ant algorithm

    NASA Astrophysics Data System (ADS)

    Wu, Chenhan; Meng, Lingkui; Deng, Shijun

    2005-07-01

    The key technique of 3-D GIS is to realize quick and high-quality 3-D visualization, in which 3-D roaming system based on landform plays an important role. However how to increase efficiency of 3-D roaming engine and process a large amount of landform data is a key problem in 3-D landform roaming system and improper process of the problem would result in tremendous consumption of system resources. Therefore it has become the key of 3-D roaming system design that how to realize high-speed process of distributed data for landform DEM (Digital Elevation Model) and high-speed distributed modulation of various 3-D landform data resources. In the paper we improved the basic ant algorithm and designed the modulation strategy of 3-D GIS landform resources based on the improved ant algorithm. By initially hypothetic road weights ?i , the change of the information factors in the original algorithm would transform from ˜?j to ??j+?i and the weights was decided by 3-D computative capacity of various nodes in network environment. So during the course of initial phase of task assignment, increasing the resource information factors of high task-accomplishing rate and decreasing ones of low accomplishing rate would make load accomplishing rate approach the same value as quickly as possible, then in the later process of task assignment, the load balanced ability of the system was further improved. Experimental results show by improving ant algorithm, our system not only decreases many disadvantage of the traditional ant algorithm, but also like ants looking for food effectively distributes the complicated landform algorithm to many computers to process cooperatively and gains a satisfying search result.

  6. Autonomous NanoTechnology Swarm (ANTS) Prospecting Asteroid Mission (PAM), Asteroid Proximity Operations

    NASA Technical Reports Server (NTRS)

    Marr, Greg; Cooley, Steve; Roithmayr, Carlos; Kay-Bunnell, Linda; Williams, Trevor

    2004-01-01

    The Autonomous NanoTechnology Swarm (ANTS) is a generic mission architecture based on spatially distributed spacecraft, autonomous and redundant components, and hierarchical organization. The ANTS Prospecting Asteroid Mission (PAM) is an ANTS application which will nominally use a swarm of 1000 spacecraft. There would be 10 types of "specialists" with common spacecraft buses. There would be 10 subswarms of approximately 100 spacecraft each or approximately 10 of each specialist in each swarm. The ANTS PAM primary objective is the exploration of the asteroid belt in search of resources and material with astrobiologically relevant origins and signatures. The ANTS PAM spacecraft will nominally be released from a station in an Earth-Moon L1 libration point orbit, and they will use Solar sails for propulsion. The sail structure would be highly flexible, capable of changing morphology to change cross-section for capture of sunlight or to form effective "tip vanes" for attitude control. ANTS PAM sails would be capable of full to partial deployment, to change effective sail area and center of pressure, and thus allow attitude control. Results of analysis of a transfer trajectory from Earth to a sample target asteroid will be presented. ANTS PAM will require continuous coverage of different asteroid locations as close as one to two asteroid "diameters" from the surface of the asteroid for periods of science data collection during asteroid proximity operations. Hovering spacecraft could meet the science data collection objectives. The results of hovering analysis will be presented. There are locations for which hovering is not possible, for example on the illuminated side of the asteroid. For cases where hovering is not possible, the results of utilizing asteroid formations to orbit the asteroid and achieve the desired asteroid viewing will be presented for sample asteroids. The ability of ANTS PAM to reduce the area of the solar sail during asteroid proximity operations is critical to the maintenance of orbiting formations for a period of time. Results of analysis of potential "traffic" problems during asteroid proximity operations will be presented.

  7. How Load-Carrying Ants Avoid Falling Over: Mechanical Stability during Foraging in Atta vollenweideri Grass-Cutting Ants

    PubMed Central

    Moll, Karin; Roces, Flavio; Federle, Walter

    2013-01-01

    Background Foraging workers of grass-cutting ants (Atta vollenweideri) regularly carry grass fragments larger than their own body. Fragment length has been shown to influence the ants’ running speed and thereby the colony’s food intake rate. We investigated whether and how grass-cutting ants maintain stability when carrying fragments of two different lengths but identical mass. Principal Findings Ants carried all fragments in an upright, backwards-tilted position, but held long fragments more vertically than short ones. All carrying ants used an alternating tripod gait, where mechanical stability was increased by overlapping stance phases of consecutive steps. The overlap was greatest for ants carrying long fragments, resulting in more legs contacting the ground simultaneously. For all ants, the projection of the total centre of mass (ant and fragment) was often outside the supporting tripod, i.e. the three feet that would be in stance for a non-overlapping tripod gait. Stability was only achieved through additional legs in ground contact. Tripod stability (quantified as the minimum distance of the centre of mass to the edge of the supporting tripod) was significantly smaller for ants with long fragments. Here, tripod stability was lowest at the beginning of each step, when the center of mass was near the posterior margin of the supporting tripod. By contrast, tripod stability was lowest at the end of each step for ants carrying short fragments. Consistently, ants with long fragments mainly fell backwards, whereas ants carrying short fragments mainly fell forwards or to the side. Assuming that transporting ants adjust neither the fragment angle nor the gait, they would be less stable and more likely to fall over. Conclusions In grass-cutting ants, the need to maintain static stability when carrying long grass fragments has led to multiple kinematic adjustments at the expense of a reduced material transport rate. PMID:23300994

  8. Homing abilities of the Australian intertidal ant Polyrhachis sokolova.

    PubMed

    Narendra, Ajay; Raderschall, Chloé A; Robson, Simon K A

    2013-10-01

    The pressure of returning to and locating the nest after a successful foraging trip is immense in ants. To find their way back home, ants use a number of different strategies (e.g. path integration, trail following) and rely on a range of cues (e.g. pattern of polarised skylight, landmark panorama) available in their environment. How ants weigh different cues has been a question of great interest and has primarily been addressed in the desert ants from Africa and Australia. We here identify the navigational abilities of an intertidal ant, Polyrhachis sokolova, that lives on mudflats where nests and foraging areas are frequently inundated with tidal water. We find that these solitary foraging ants rely heavily on visual landmark information for navigation, but they are also capable of path integration. By displacing ants with and without vector information at different locations within the local familiar territory, we created conflicts between information from the landmarks and information from the path integrator. The homing success of full-vector ants, compared with the zero-vector ants, when displaced 5 m behind the feeder, indicate that vector information had to be coupled with landmark information for successful homing. To explain the differences in the homing abilities of ants from different locations we determined the navigational information content at each release station and compared it with that available at the feeder location. We report here the interaction of multiple navigation strategies in the context of the information content in the environment. PMID:23788703

  9. Scope of Various Random Number Generators in Ant System Approach for TSP

    NASA Technical Reports Server (NTRS)

    Sen, S. K.; Shaykhian, Gholam Ali

    2007-01-01

    Experimented on heuristic, based on an ant system approach for traveling Salesman problem, are several quasi and pseudo-random number generators. This experiment is to explore if any particular generator is most desirable. Such an experiment on large samples has the potential to rank the performance of the generators for the foregoing heuristic. This is just to seek an answer to the controversial performance ranking of the generators in probabilistic/statically sense.

  10. Ant Colony Optimization Analysis on Overall Stability of High Arch Dam Basis of Field Monitoring

    PubMed Central

    Liu, Xiaoli; Chen, Hong-Xin; Kim, Jinxie

    2014-01-01

    A dam ant colony optimization (D-ACO) analysis of the overall stability of high arch dams on complicated foundations is presented in this paper. A modified ant colony optimization (ACO) model is proposed for obtaining dam concrete and rock mechanical parameters. A typical dam parameter feedback problem is proposed for nonlinear back-analysis numerical model based on field monitoring deformation and ACO. The basic principle of the proposed model is the establishment of the objective function of optimizing real concrete and rock mechanical parameter. The feedback analysis is then implemented with a modified ant colony algorithm. The algorithm performance is satisfactory, and the accuracy is verified. The m groups of feedback parameters, used to run a nonlinear FEM code, and the displacement and stress distribution are discussed. A feedback analysis of the deformation of the Lijiaxia arch dam and based on the modified ant colony optimization method is also conducted. By considering various material parameters obtained using different analysis methods, comparative analyses were conducted on dam displacements, stress distribution characteristics, and overall dam stability. The comparison results show that the proposal model can effectively solve for feedback multiple parameters of dam concrete and rock material and basically satisfy assessment requirements for geotechnical structural engineering discipline. PMID:25025089

  11. Isolating antifungals from fungus-growing ant symbionts using a genome-guided chemistry approach.

    PubMed

    Seipke, Ryan F; Grüschow, Sabine; Goss, Rebecca J M; Hutchings, Matthew I

    2012-01-01

    We describe methods used to isolate and identify antifungal compounds from actinomycete strains associated with the leaf-cutter ant Acromyrmex octospinosus. These ants use antibiotics produced by symbiotic actinomycete bacteria to protect themselves and their fungal cultivar against bacterial and fungal infections. The fungal cultivar serves as the sole food source for the ant colony, which can number up to tens of thousands of individuals. We describe how we isolate bacteria from leaf-cutter ants collected in Trinidad and analyze the antifungal compounds made by two of these strains (Pseudonocardia and Streptomyces spp.), using a combination of genome analysis, mutagenesis, and chemical isolation. These methods should be generalizable to a wide variety of insect-symbiont situations. Although more time consuming than traditional activity-guided fractionation methods, this approach provides a powerful technique for unlocking the complete biosynthetic potential of individual strains and for avoiding the problems of rediscovery of known compounds. We describe the discovery of a novel nystatin compound, named nystatin P1, and identification of the biosynthetic pathway for antimycins, compounds that were first described more than 60 years ago. We also report that disruption of two known antifungal pathways in a single Streptomyces strain has revealed a third, and likely novel, antifungal plus four more pathways with unknown products. This validates our approach, which clearly has the potential to identify numerous new compounds, even from well-characterized actinomycete strains. PMID:23084933

  12. Improved multi-objective ant colony optimization algorithm and its application in complex reasoning

    NASA Astrophysics Data System (ADS)

    Wang, Xinqing; Zhao, Yang; Wang, Dong; Zhu, Huijie; Zhang, Qing

    2013-09-01

    The problem of fault reasoning has aroused great concern in scientific and engineering fields. However, fault investigation and reasoning of complex system is not a simple reasoning decision-making problem. It has become a typical multi-constraint and multi-objective reticulate optimization decision-making problem under many influencing factors and constraints. So far, little research has been carried out in this field. This paper transforms the fault reasoning problem of complex system into a paths-searching problem starting from known symptoms to fault causes. Three optimization objectives are considered simultaneously: maximum probability of average fault, maximum average importance, and minimum average complexity of test. Under the constraints of both known symptoms and the causal relationship among different components, a multi-objective optimization mathematical model is set up, taking minimizing cost of fault reasoning as the target function. Since the problem is non-deterministic polynomial-hard(NP-hard), a modified multi-objective ant colony algorithm is proposed, in which a reachability matrix is set up to constrain the feasible search nodes of the ants and a new pseudo-random-proportional rule and a pheromone adjustment mechinism are constructed to balance conflicts between the optimization objectives. At last, a Pareto optimal set is acquired. Evaluation functions based on validity and tendency of reasoning paths are defined to optimize noninferior set, through which the final fault causes can be identified according to decision-making demands, thus realize fault reasoning of the multi-constraint and multi-objective complex system. Reasoning results demonstrate that the improved multi-objective ant colony optimization(IMACO) can realize reasoning and locating fault positions precisely by solving the multi-objective fault diagnosis model, which provides a new method to solve the problem of multi-constraint and multi-objective fault diagnosis and reasoning of complex system.

  13. Behavior of Ants Escaping from a Single-Exit Room

    PubMed Central

    Wang, Shujie; Lv, Wei; Song, Weiguo

    2015-01-01

    To study the rules of ant behavior and group-formation phenomena, we examined the behaviors of Camponotus japonicus, a species of large ant, in a range of situations. For these experiments, ants were placed inside a rectangular chamber with a single exit that also contained a filter paper soaked in citronella oil, a powerful repellent. The ants formed several groups as they moved toward the exit to escape. We measured the time intervals between individual escapes in six versions of the experiment, each containing an exit of a different width, to quantify the movement of the groups. As the ants exited the chamber, the time intervals between individual escapes changed and the frequency distribution of the time intervals exhibited exponential decay. We also investigated the relationship between the number of ants in a group and the group flow rate. PMID:26125191

  14. Image feature extraction based multiple ant colonies cooperation

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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 themselves of bristles, ants may succeed only in further entangling themselves by causing the bristles to become enmeshed. Ants heavily contaminated may remain entangled and die. Most millipedes have chemical defenses; polyxenids, instead, have a mechanical weapon. Images Fig. 2 PMID:8855269

  16. Habitat complexity facilitates coexistence in a tropical ant community.

    PubMed

    Sarty, M; Abbott, K L; Lester, P J

    2006-09-01

    The role of habitat complexity in the coexistence of ant species is poorly understood. Here, we examine the influence of habitat complexity on coexistence patterns in ant communities of the remote Pacific atoll of Tokelau. The invasive yellow crazy ant, Anoplolepis gracilipes (Smith), exists in high densities on Tokelau, but still coexists with up to seven other epigeic ant species. The size-grain hypothesis (SGH) proposes that as the size of terrestrial walking organisms decreases, the perceived complexity of the environment increases and predicts that: (1) leg length increases allometrically with body size in ants, and (2) coexistence between ant species is facilitated by differential habitat use according to body size. Analysis of morphological variables revealed variation inconsistent with the morphological prediction of the SGH, as leg length increased allometrically with head length only. We also experimentally tested the ability of epigeic ants in the field to discover and dominate food resources in treatments of differing rugosity. A. gracilipes was consistently the first to discover food baits in low rugosity treatments, while smaller ant species were consistently the first to discover food baits in high rugosity treatments. In addition, A. gracilipes dominated food baits in planar treatments, while smaller ant species dominated baits in rugose treatments. We found that the normally predictable outcomes of exploitative competition between A. gracilipes and other ant species were reversed in the high rugosity treatments. Our results support the hypothesis that differential habitat use according to body size provides a mechanism for coexistence with the yellow crazy ant in Tokelau. The SGH may provide a mechanism for coexistence in other ant communities but also in communities of other terrestrial, walking insects that inhabit a complex landscape. PMID:16763839

  17. Protein structure optimization with a "Lamarckian" ant colony algorithm.

    PubMed

    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

  18. Ancient tripartite coevolution in the attine ant-microbe symbiosis.

    PubMed

    Currie, Cameron R; Wong, Bess; Stuart, Alison E; Schultz, Ted R; Rehner, Stephen A; Mueller, Ulrich G; Sung, Gi-Ho; Spatafora, Joseph W; Straus, Neil A

    2003-01-17

    The symbiosis between fungus-growing ants and the fungi they cultivate for food has been shaped by 50 million years of coevolution. Phylogenetic analyses indicate that this long coevolutionary history includes a third symbiont lineage: specialized microfungal parasites of the ants' fungus gardens. At ancient levels, the phylogenies of the three symbionts are perfectly congruent, revealing that the ant-microbe symbiosis is the product of tripartite coevolution between the farming ants, their cultivars, and the garden parasites. At recent phylogenetic levels, coevolution has been punctuated by occasional host-switching by the parasite, thus intensifying continuous coadaptation between symbionts in a tripartite arms race. PMID:12532015

  19. Signals Can Trump Rewards in Attracting Seed-Dispersing Ants

    PubMed Central

    Turner, Kyle M.; Frederickson, Megan E.

    2013-01-01

    Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed appendages called elaiosomes influenced dispersal rates. In removal trials, ants quickly collected diaspores (seeds plus elaiosomes) of Asarum canadense, Trillium grandiflorum, and Sanguinaria canadensis, but largely neglected those of T. erectum. This discrepancy was not explained by differences in the bulk cost-benefit ratio, as assessed by the ratio of seed to elaiosome mass. We also provisioned colonies with diaspores from one of these four plant species or no diaspores as a control. Colonies performed best when fed S. canadensis diaspores, worst when fed T. grandiflorum, and intermediately when fed A. canadense, T. erectum, or no diaspores. Thus, the nutritional rewards in elaiosomes affected colony performance, but did not completely predict seed removal. Instead, high levels of oleic acid in T. grandiflorum elaiosomes may explain why ants disperse these diaspores even though they reduce ant colony performance. We show for the first time that different elaiosome-bearing plants provide rewards of different quality to ant colonies, but also that ants appear unable to accurately assess reward quality when encountering seeds. Instead, we suggest that signals can trump rewards as attractants of ants to seeds. PMID:23967257

  20. Ant plant herbivore interactions in the neotropical cerrado savanna

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

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

  1. Insecticide transfer efficiency and lethal load in Argentine ants

    NASA Astrophysics Data System (ADS)

    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/?g ant, respectively) than did live workers and queens (96.3 and 10.4 amol/?g ant, respectively). Dead workers had significantly more fipronil (420.3 amol/?g ant) than did live workers (208.5 amol/?g ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/?g 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.

  2. Five new records of ants (Hymenoptera: Formicidae) for Nebraska

    USGS Publications Warehouse

    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).

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

    PubMed Central

    Ballantyne, Gavin; Willmer, Pat

    2012-01-01

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

  4. Toxicity of formic acid against red imported fire ants, Solenopsis invicta Buren

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Formic acid is a common defensive chemical of formicine ants. Ants often compete with other ants for resources. However, the toxicity of formic acid to any ant species has not been well understood. This study examined the toxicity of formic acid against the red imported fire ants, Sole...

  5. Ant colony optimisation inversion of surface and borehole magnetic data under lithological constraints

    NASA Astrophysics Data System (ADS)

    Liu, Shuang; Hu, Xiangyun; Liu, Tianyou; Xi, Yufei; Cai, Jianchao; Zhang, Henglei

    2015-01-01

    The ant colony optimisation algorithm has successfully been used to invert for surface magnetic data. However, the resolution of the distributions of the recovered physical property for deeply buried magnetic sources is not generally very high because of geophysical ambiguities. We use three approaches to deal with this problem. First, the observed surface magnetic data are taken together with the three-component borehole magnetic anomalies to recover the distributions of the physical properties. This cooperative inversion strategy improves the resolution of the inversion results in the vertical direction. Additionally, as the ant colony tours the discrete nodes, we force it to visit the nodes with physical properties that agree with the drilled lithologies. These lithological constraints reduce the non-uniqueness of the inversion problem. Finally, we also implement a K-means cluster analysis for the distributions of the magnetic cells after each iteration, in order to separate the distributions of magnetisation intensity instead of concentrating the distribution in a single area. We tested our method using synthetic data and found that all tests returned favourable results. In the case study of the Mengku iron-ore deposit in northwest China, the recovered distributions of magnetisation are in good agreement with the locations and shapes of the magnetite orebodies as inferred by drillholes. Uncertainty analysis shows that the ant colony algorithm is robust in the presence of noise and that the proposed approaches significantly improve the quality of the inversion results.

  6. The rise of army ants and their relatives: diversification of specialized predatory doryline ants

    PubMed Central

    2014-01-01

    Background Army ants are dominant invertebrate predators in tropical and subtropical terrestrial ecosystems. Their close relatives within the dorylomorph group of ants are also highly specialized predators, although much less is known about their biology. We analyzed molecular data generated from 11 nuclear genes to infer a phylogeny for the major dorylomorph lineages, and incorporated fossil evidence to infer divergence times under a relaxed molecular clock. Results Because our results indicate that one subfamily and several genera of dorylomorphs are non-monophyletic, we propose to subsume the six previous dorylomorph subfamilies into a single subfamily, Dorylinae. We find the monophyly of Dorylinae to be strongly supported and estimate the crown age of the group at 87 (74–101) million years. Our phylogenetic analyses provide only weak support for army ant monophyly and also call into question a previous hypothesis that army ants underwent a fundamental split into New World and Old World lineages. Outside the army ants, our phylogeny reveals for the first time many old, distinct lineages in the Dorylinae. The genus Cerapachys is shown to be non-monophyletic and comprised of multiple lineages scattered across the Dorylinae tree. We recover, with strong support, novel relationships among these Cerapachys-like clades and other doryline genera, but divergences in the deepest parts of the tree are not well resolved. We find the genus Sphinctomyrmex, characterized by distinctive abdominal constrictions, to consist of two separate lineages with convergent morphologies, one inhabiting the Old World and the other the New World tropics. Conclusions While we obtain good resolution in many parts of the Dorylinae phylogeny, relationships deep in the tree remain unresolved, with major lineages joining each other in various ways depending upon the analytical method employed, but always with short internodes. This may be indicative of rapid radiation in the early history of the Dorylinae, but additional molecular data and more complete species sampling are needed for confirmation. Our phylogeny now provides a basic framework for comparative biological analyses, but much additional study on the behavior and morphology of doryline species is needed, especially investigations directed at the non-army ant taxa. PMID:24886136

  7. Structural link prediction based on ant colony approach in social networks

    NASA Astrophysics Data System (ADS)

    Sherkat, Ehsan; Rahgozar, Maseud; Asadpour, Masoud

    2015-02-01

    As the size and number of online social networks are increasing day by day, social network analysis has become a popular issue in many branches of science. The link prediction is one of the key rolling issues in the analysis of social network's evolution. As the size of social networks is increasing, the necessity for scalable link prediction algorithms is being felt more. The aim of this paper is to introduce a new unsupervised structural link prediction algorithm based on the ant colony approach. Recently, ant colony approach has been used for solving some graph problems. Different kinds of networks are used for testing the proposed approach. In some networks, the proposed scalable algorithm has the best result in comparison to other structural unsupervised link prediction algorithms. In order to evaluate the algorithm results, methods like the top- n precision, area under the Receiver Operating Characteristic (ROC) and Precision-Recall curves are carried out on real-world networks.

  8. Using Ant Colony Optimization to guide a CP search

    E-print Network

    Wolf, Christian

    Using Ant Colony Optimization to guide a CP search Madjid Khichane1, Patrick Albert1, and Christine;Introduction Ant-CP Car sequencing Results I/D study Conclusion Motivations Constraint Programming High level time to solve some instances add heuristics to guide the search Our goal: use ACO to guide a CP search

  9. Dynamics and shape of large fire ant rafts

    PubMed Central

    Mlot, Nathan J.; Tovey, Craig; Hu, David L.

    2012-01-01

    To survive floods, fire ants link their bodies together to build waterproof rafts. Such rafts can be quite large, exceeding 100,000 individuals in size. In this study, we make two improvements on a previously reported model on the construction rate of rafts numbering between 3,000 and 10,000 individuals. That model was based upon experimental observations of randomly-directed linear ant trajectories atop the raft. Here, we report anomalous behavior of ants atop larger rafts of up to 23,000 ants. As rafts increase in size, the behavior of ants approaches diffusion, which is in closer alignment with other studies on the foraging and scouting patterns of ants. We incorporate this ant behavior into the model. Our modified model predicts more accurately the growth of large rafts. Our previous model also relied on an assumption of raft circularity. We show that this assumption is not necessary for large rafts, because it follows from the random directionality of the ant trajectories. Our predicted relationship between raft size and circularity closely fits experimental data. PMID:23336030

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

    PubMed

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

    2013-11-01

    In mutualistic interactions, partners obtain a net benefit, but there may also be costs associated with the provision of benefits for a partner. The question of whether aphids suffer such costs when attended by ants has been raised in previous work. Transgenerational effects, where offspring phenotypes are adjusted based on maternal influences, could be important in the mutualistic interaction between aphids and ants, in particular because aphids have telescoping generations where two offspring generations can be present in a mature aphid. We investigated the immediate and transgenerational influence of ant tending on aphid life history and reproduction by observing the interaction between the facultative myrmecophile Aphis fabae and the ant Lasius niger over 13 aphid generations in the laboratory. We found that the effect of ant tending changes dynamically over successive aphid generations after the start of tending. Initially, total aphid colony weight, aphid adult weight and aphid embryo size decreased compared with untended aphids, consistent with a cost of ant association, but these differences disappeared within four generations of interaction. We conclude that transgenerational effects are important in the aphid-ant interactions and that the costs for aphids of being tended by ants can vary over generations. PMID:23689730

  11. Do long-lived ants affect soil microbial communities?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to test the hypothesis that desert ant species that build nests that remain viable at a particular point in space for more than a decade produce soil conditions that enhance microbial biomass and functional diversity. We studied the effects of a seed-harvester ant, Pogonomyrm...

  12. The genome of the fire ant Solenopsis invicta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  13. Island biogeography and metapopulation dynamics of Bahamian ants

    E-print Network

    Morrison, Lloyd W.

    Island biogeography and metapopulation dynamics of Bahamian ants Lloyd W. Morrison Section of California, Davis, CA 95616, USA Abstract Aim I examined the island biogeography and metapopulation dynamics of ants inhabiting two archipelagos of small Bahamian islands. Of particular interest were measurement

  14. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... accordance with the provisions contained in 9 CFR 313.2. Immediately after the animal is stunned or killed..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... unconscious shall be in accordance with 9 CFR 313.15 or 313.16. (6) All stunned/slaughtered and bled...

  15. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... accordance with the provisions contained in 9 CFR 313.2. Immediately after the animal is stunned or killed..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... unconscious shall be in accordance with 9 CFR 313.15 or 313.16. (6) All stunned/slaughtered and bled...

  16. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... accordance with the provisions contained in 9 CFR 313.2. Immediately after the animal is stunned or killed..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... unconscious shall be in accordance with 9 CFR 313.15 or 313.16. (6) All stunned/slaughtered and bled...

  17. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... accordance with the provisions contained in 9 CFR 313.2. Immediately after the animal is stunned or killed..., bison and water buffalo are eligible for field ante-mortem inspection. The field ante-mortem designated... unconscious shall be in accordance with 9 CFR 313.15 or 313.16. (6) All stunned/slaughtered and bled...

  18. ANT COMMUNITIES AND LIVESTOCK GRAZING IN THE GREAT BASIN, USA

    EPA Science Inventory

    The objectives of this study were to determine if metrics for ant species assemblages can be used as indicators of rangeland condition, and to determine the influence of vegetation and ground cover variables, factors often influenced by livestock grazing, on ant communities. The ...

  19. The Effects of Ant Mutualism on the Foraging and Diet

    E-print Network

    Pierce, Naomi E.

    12 The Effects of Ant Mutualism on the Foraging and Diet of Lycaenid Caterpillars Matthew Baylis; Atsatt 198 Ib; Cottrell 1984; Pierce 1987). Mutualisms in which the fitness of each partner is increased-ant mutualisms and the responses of Iycaenids to those challenges. We will begin with a brief overview of some

  20. Major evolutionary transitions in ant agriculture Ted R. Schultz

    E-print Network

    Brady, Seán

    Major evolutionary transitions in ant agriculture Ted R. Schultz and Sea´n G. Brady Department) Agriculture is a specialized form of symbiosis that is known to have evolved in only four animal groups that produced the five distinct agricultural systems of the fungus-growing ants, the most well studied

  1. ACOUSTICAL ANALYSIS OF WINGBEAT FREQUENCIES FOR ALATE IMPORTED FIRE ANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red imported fire ant (RIFA), Solenopsis invicta Buren and the black imported fire ant (BIFA), Solenopsis richteri Forel coexist in the state of Mississippi along with reproductively viable F1 hybrids of these two species. The objective of this study was to determine and compare the wingbeat fre...

  2. Butterfly Project Report Ant Farm: A Lightweight Process Programming

    E-print Network

    Scott, Michael L.

    Butterfly Project Report 21 Ant Farm: A Lightweight Process Programming Environment M.L. Scott is a library package for the BBN Butterfly Parallel Processor that allows programs to split computational effort across many lightweight threads of control. On each node of the Butterfly, Ant Farm provides

  3. 7 CFR Appendix to Subpart - Imported Fire Ant

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Imported Fire Ant Appendix to Subpart Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations Costs and charges. Pt. 301, Subpt., App. Appendix...

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

    PubMed

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

    2014-01-01

    Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile), within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers) threats as instigators or secondary (passengers) threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74%) and abundance (81%). Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban 'invasion'. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a "back-seat driver" role and affects pest management strategies. As demonstrated by T. sessile, this article concludes native species can become back-seat drivers of biodiversity loss and potentially thrive as "metro-invasive" species. PMID:25551819

  5. Aphid egg protection by ants: a novel aspect of the mutualism between the tree-feeding aphid Stomaphis hirukawai and its attendant ant Lasius productus

    NASA Astrophysics Data System (ADS)

    Matsuura, Kenji; Yashiro, Toshihisa

    2006-10-01

    Aphids often form mutualistic associations with ants, in which the aphids provide the ants with honeydew and the ants defend the aphids from predators. In this paper, we report aphid egg protection by ants as a novel aspect of the deeply interdependent relationship between a tree-feeding aphid and its attendant ant. The ant Lasius productus harbours oviparous females, males, and eggs of the hinoki cypress-feeding aphid Stomaphis hirukawai in its nests in winter. We investigated the behaviour of ants kept with aphid eggs in petri dishes to examine whether the ants recognise the aphid eggs and tend them or only provide a refuge for the aphids. Workers carried almost all of the aphid eggs into the nest within 24 h. The ants indiscriminately tended aphid eggs collected from their own colonies and those from other ant colonies. The ants cleaned the eggs and piled them up in the nest, and egg tending by ants dramatically increased aphid egg survival rates. Starving the ants showed no significant effect on aphid egg survivorship. Without ants, aphid eggs were rapidly killed by fungi. These results suggested that grooming by the ants protected the aphid eggs, at least, against pathogenic fungi. This hygienic service afforded by the ants seems indispensable for egg survival of these aphids in an environment rich in potentially pathogenic microorganisms.

  6. Invertebrate Memory: Wide-Eyed Ants Retrieve Visual Ants retrieve visual memories to guide them en route to their goal. A new

    E-print Network

    Dispatches Invertebrate Memory: Wide-Eyed Ants Retrieve Visual Snapshots Ants retrieve visual memories to guide them en route to their goal. A new study shows that wood ants use object width that accurately reproduces the ants' behaviour raises questions about the underlying mechanisms. Jeremy E. Niven

  7. Eggs of Mallada desjardinsi (Neuroptera: Chrysopidae) are protected by ants: the role of egg stalks in ant-tended aphid colonies.

    PubMed

    Hayashi, Masayuki; Nomura, Masashi

    2014-08-01

    In ant-aphid mutualisms, ants usually attack and exclude enemies of aphids. However, larvae of the green lacewing Mallada desjardinsi (Navas) prey on ant-tended aphids without being excluded by ants; these larvae protect themselves from ants by carrying aphid carcasses on their backs. Eggs of M. desjardinsi laid at the tips of stalks have also been observed in ant-tended aphid colonies in the field. Here, we examined whether the egg stalks of M. desjardinsi protect the eggs from ants and predators. When exposed to ants, almost all eggs with intact stalks were untouched, whereas 50-80% of eggs in which stalks had been severed at their bases were destroyed by ants. In contrast, most eggs were preyed upon by larvae of the lacewing Chrysoperla nipponensis (Okamoto), an intraguild predator of M. desjardinsi, regardless of whether their stalks had been severed. These findings suggest that egg stalks provide protection from ants but not from C. nipponensis larvae. To test whether M. desjardinsi eggs are protected from predators by aphid-tending ants, we introduced C. nipponensis larvae onto plants colonized by ant-tended aphids. A significantly greater number of eggs survived in the presence of ants because aphid-tending ants excluded larvae of C. nipponensis. This finding indicates that M. desjardinsi eggs are indirectly protected from predators by ants in ant-tended aphid colonies. PMID:25182619

  8. Early Results of Three-Year Monitoring of Red Wood Ants' Behavioral Changes and Their Possible Correlation with Earthquake Events.

    PubMed

    Berberich, Gabriele; Berberich, Martin; Grumpe, Arne; Wöhler, Christian; Schreiber, Ulrich

    2013-01-01

    Short-term earthquake predictions with an advance warning of several hours or days are currently not possible due to both incomplete understanding of the complex tectonic processes and inadequate observations. Abnormal animal behaviors before earthquakes have been reported previously, but create problems in monitoring and reliability. The situation is different with red wood ants (RWA; Formica rufa-group (Hymenoptera: Formicidae)). They have stationary mounds on tectonically active, gas-bearing fault systems. These faults may be potential earthquake areas. For three years (2009-2012), two red wood ant mounds (Formica rufa-group), located at the seismically active Neuwied Basin (Eifel, Germany), have been monitored 24/7 by high-resolution cameras with both a color and an infrared sensor. Early results show that ants have a well-identifiable standard daily routine. Correlation with local seismic events suggests changes in the ants' behavior hours before the earthquake: the nocturnal rest phase and daily activity are suppressed, and standard daily routine does not resume until the next day. At present, an automated image evaluation routine is being applied to the more than 45,000 hours of video streams. Based on this automated approach, a statistical analysis of the ants' behavior will be carried out. In addition, other parameters (climate, geotectonic and biological), which may influence behavior, will be included in the analysis. PMID:26487310

  9. Benomyl treatment decreases fecundity of ant queens.

    PubMed

    Pech, Pavel; Heneberg, Petr

    2015-09-01

    Methyl benzimidazole carbamate fungicides, including benomyl, are widely used in agriculture, and to eliminate entomopathogenic infections. We treated queens of Myrmica rubra (Hymenoptera:Formicidae) infected or not by Rickia wasmannii (Laboulbeniales:Laboulbeniaceae) with benomyl, 1mg/ml p.o. for six weeks. Benomyl did not treat the infection, and the treatment alone caused strong decrease in the fecundity of control healthy queens from 18.0±8.4 to 3.7±5.2eggs per healthy queen. This is the first evidence on severe adverse effects of methyl benzimidazole carbamate fungicide on the fecundity of insects, which might be responsible for altered species composition of ant assemblages in the cultural landscape. PMID:26149821

  10. Ultraviolet radiation as an ant repellent

    SciTech Connect

    Thorvilson, H.G.; Russell, S.A.; Green, B.; Gransberg, D.

    1996-12-31

    In an effort to repel red imported fire ants (RIFA) from electrical devices, such as transformers, ultraviolet (UV) light was tested. Initial tests determined if RIFA`s tolerate a UV-irradiated environment when given a choice between UV-irradiated and non-irradiated. All replications in this test indicated that RIFA`s are intolerant of UV-irradiation and sought to escape it. RIFA`s moved to shaded environments and transported their brood out its well. A second test sought to determine if long-term UV-irradiation of the entire colonies cause increased RIFA mortality. Queenright colonies were exposed to UV irradiation of 254nm constantly for 115 days and colonies had a higher mortality rate than did a control colony. RIFA`s attempted to escape UV light and had increased rate when exposed to UV (254nm), but a practical application of this technique may be detrimental to insulation on electrical wiring.

  11. The origin of the attine ant-fungus mutualism.

    PubMed

    Mueller, U G; Schultz, T R; Currie, C R; Adams, R M; Malloch, D

    2001-06-01

    Cultivation of fungus for food originated about 45-65 million years ago in the ancestor of fungus-growing ants (Formicidae, tribe Attini), representing an evolutionary transition from the life of a hunter-gatherer of arthropod prey, nectar, and other plant juices, to the life of a farmer subsisting on cultivated fungi. Seven hypotheses have been suggested for the origin of attine fungiculture, each differing with respect to the substrate used by the ancestral attine ants for fungal cultivation. Phylogenetic information on the cultivated fungi, in conjunction with information on the nesting biology of extant attine ants and their presumed closest relatives, reveal that the attine ancestors probably did not encounter their cultivars-to-be in seed stores (von Ihering 1894), in rotting wood (Forel 1902), as mycorrhizae (Garling 1979), on arthropod corpses (von Ihering 1894) or ant faeces in nest middens (Wheeler 1907). Rather, the attine ant-fungus mutualism probably arose from adventitious interactions with fungi that grew on walls of nests built in leaf litter (Emery 1899), or from a system of fungal myrmecochory in which specialized fungi relied on ants for dispersal (Bailey 1920) and in which the ants fortuitously vectored these fungi from parent to offspring nests prior to a true fungicultural stage. Reliance on fungi as a dominant food source has evolved only twice in ants: first in the attine ants, and second in some ant species in the solenopsidine genus Megalomyrmex that either coexist as trophic parasites in gardens of attine hosts or aggressively usurp gardens from them. All other known ant-fungus associations are either adventitious or have nonnutritional functions (e.g., strengthening of carton-walls in ant nests). There exist no unambiguous reports of facultative mycophagy in ants, but such trophic ant-fungus interactions would most likely occur underground or in leaf litter and thus escape easy observation. Indirect evidence of fungivory can be deduced from contents of the ant alimentary canal and particularly from the contents of the infrabuccal pocket, a pharyngeal device that filters out solids before liquids pass into the intestine. Infrabuccal pocket contents reveal that ants routinely ingest fungal spores and hyphal material. Infrabuccal contents are eventually expelled as a pellet on nest middens or away from the nest by foragers, suggesting that the pellet provides fungi with a means for the dispersal of spores and hyphae. Associations between such "buccophilous" fungi and ants may have originated multiple times and may have become elaborated and externalized in the case of the attine ant-fungus mutualism. Thus, contrary to the traditional model in which attine fungi are viewed as passive symbionts that happened to come under ant control, this alternative model of a myrmecochorous origin of the attine mutualism attributes an important role to evolutionary modifications of the fungi that preceded the ant transition from hunter-gatherer to fungus farmer. PMID:11409051

  12. A stochastic model of ant trail following with two pheromones

    E-print Network

    Malí?ková, Miriam; Bo?ová, 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...

  13. A theoretical model for uni-directional ant trails

    NASA Astrophysics Data System (ADS)

    Kayacan, Ozhan

    2011-03-01

    A theoretical model of uni-directional ant traffic, motivated by the motion of ants in trail is proposed. Two different type of ants, one of which smells very well and the other does not, are considered. The flux of ants in this model is investigated as functions of the probability of evaporation rate of pheromone. The obtained results indicate that the mean velocity of the ants varies non-monotonically with their density. In addition, it is observed that phase transition in the flux and the mean velocity vs. density occurs at certain density for a fixed evaporation rate. The effective hopping probability is investigated as well depending on the evaporation rate of pheromone. It is worth to note that the proposed model can be generalized for vehicular traffic on freeways.

  14. Do wood ants learn sequences of visual stimuli?

    PubMed

    Riabinina, Olena; de Ibarra, Natalie Hempel; Howard, Lisa; Collett, Thomas S

    2011-08-15

    The visually guided foraging routes of some formicine ants are individually stereotyped, suggesting the importance of visual learning in maintaining these routes. We ask here whether the wood ant Formica rufa learns a sequence of visual features encountered at different stages along a route, as reported for honeybees. We trained ants in several simple mazes to follow two alternative routes. Along each two-stage route, the ants first encountered one of two priming stimuli. The identity of the priming stimulus determined which of two choice stimuli was rewarded in the second stage of the route. As stimuli we used ultraviolet and yellow/green light panels, and two black-and-white patterns. Did ants learn to pair each colour with the appropriate black-and-white pattern? Ants learnt readily to discriminate between the two coloured stimuli or between the two black-and-white patterns. They could also pair coloured and black-and-white patterns, provided that the two were presented simultaneously. The ants' behaviour with sequential stimuli varied according to whether the priming stimulus was a coloured stimulus or a black-and-white pattern. When the priming stimulus was coloured, ants seemed to learn the two sequences, but tests showed that their success was probably caused by the after-effects of colour adaptation. With a black-and-white priming stimulus and a coloured second stage stimulus, robust sequential learning could not be demonstrated, although under certain experimental conditions a tiny proportion of ants did acquire the sequence. Thus, ants perform conditional discriminations reliably when priming and choice stimuli are simultaneous, but they usually fail when the stimuli are sequential. PMID:21795571

  15. Indirect defense in a highly specific ant-plant mutualism

    NASA Astrophysics Data System (ADS)

    Grangier, Julien; Dejean, Alain; Malé, Pierre-Jean G.; Orivel, Jérôme

    2008-10-01

    Although associations between myrmecophytes and their plant ants are recognized as a particularly effective form of protective mutualism, their functioning remains incompletely understood. This field study examined the ant-plant Hirtella physophora and its obligate ant associate Allomerus decemarticulatus. We formulated two hypotheses on the highly specific nature of this association: (1) Ant presence should be correlated with a marked reduction in the amount of herbivory on the plant foliage; (2) ant activity should be consistent with the "optimal defense" theory predicting that the most vulnerable and valuable parts of the plant are the best defended. We validated the first hypothesis by demonstrating that for ant-excluded plants, expanding leaves, but also newly matured ones in the long term, suffered significantly more herbivore damage than ant-inhabited plants. We showed that A. decemarticulatus workers represent both constitutive and inducible defenses for their host, by patrolling its foliage and rapidly recruiting nestmates to foliar wounds. On examining how these activities change according to the leaves’ developmental stage, we found that the number of patrolling ants dramatically decreased as the leaves matured, while leaf wounds induced ant recruitment regardless of the leaf’s age. The resulting level of these indirect defenses was roughly proportional to leaf vulnerability and value during its development, thus validating our second hypothesis predicting optimal protection. This led us to discuss the factors influencing ant activity on the plant’s surface. Our study emphasizes the importance of studying both the constitutive and inducible components of indirect defense when evaluating its efficacy and optimality.

  16. Impact of the red imported fire ant on newly hatched northern bobwhite 

    E-print Network

    Pedersen, Elena Kalleso

    1994-01-01

    to fire ants, locomotion, inactive, sleeping, and pecking at food. Results suggested red imported fire ants can alter the daily activity budgets of northern bobwhite chicks. Time spent responding directly to fire ants affected the amount of time spent...

  17. Colony-level macronutrient regulation in ants: mechanisms, hoarding and associated costs

    E-print Network

    Eubanks, Micky

    of the fire ant Solenopsis invicta to quantify how ants regulate their protein­carbo- hydrate intake when be driving ant foraging behaviour in the field. Ó 2009 The Association for the Study of Animal Behaviour

  18. Fecundity and longevity of Argentine ant (Hymenoptera: Formicidae) queens in response to irradiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products traded between countries. As little is known about irradiation effects on ants, radiotolerance of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae...

  19. Chemical Defense by the Native Winter Ant (Prenolepis imparis) against the Invasive Argentine Ant (Linepithema humile)

    PubMed Central

    Kauhanen, Peter G.; Fitzgerald, Katherine; Sturgis, Shelby J.; Chen, Jimmy; Dijamco, Cheri A.; Basurto, Kimberly N.; Gordon, Deborah M.

    2011-01-01

    The invasive Argentine ant (Linepithema humile) is established worldwide and displaces native ant species. In northern California, however, the native winter ant (Prenolepis imparis) persists in invaded areas. We found that in aggressive interactions between the two species, P. imparis employs a potent defensive secretion. Field observations were conducted at P. imparis nest sites both in the presence and absence of L. humile. These observations suggested and laboratory assays confirmed that P. imparis workers are more likely to secrete when outnumbered by L. humile. Workers of P. imparis were also more likely to secrete near their nest entrances than when foraging on trees. One-on-one laboratory trials showed that the P. imparis secretion is highly lethal to L. humile, causing 79% mortality. The nonpolar fraction of the secretion was chemically analyzed with gas chromatography/mass spectrometry, and found to be composed of long-chain and cyclic hydrocarbons. Chemical analysis of dissected P. imparis workers showed that the nonpolar fraction is derived from the Dufour's gland. Based on these conclusions, we hypothesize that this chemical defense may help P. imparis to resist displacement by L. humile. PMID:21526231

  20. Navigation in ants 1 How to navigate without maps: The power of taxon-like navigation in ants

    E-print Network

    Cheng, Ken

    Navigation in ants 1 How to navigate without maps: The power of taxon-like navigation in ants Ken Cheng Macquarie University Rodents are said to have two different navigational systems, a map-like navigation, and seem to get by with a repertoire of taxon-like strategies. I review how this repertoire

  1. Is extrafloral nectar production induced by herbivores or ants in a tropical facultative ant-plant mutualism?

    E-print Network

    Coley, Phyllis

    Is extrafloral nectar production induced by herbivores or ants in a tropical facultative ant herbivores are absent but shunt energy to defense when herbivores are present. In3 contrast, constitutive defenses are expressed continuously regardless of herbivore presence. Induction has4 been widely documented

  2. antaRNA: ant colony-based RNA sequence design

    PubMed Central

    Kleinkauf, Robert; Mann, Martin; Backofen, Rolf

    2015-01-01

    Motivation: RNA sequence design is studied at least as long as the classical folding problem. Although for the latter the functional fold of an RNA molecule is to be found, inverse folding tries to identify RNA sequences that fold into a function-specific target structure. In combination with RNA-based biotechnology and synthetic biology, reliable RNA sequence design becomes a crucial step to generate novel biochemical components. Results: In this article, the computational tool antaRNA is presented. It is capable of compiling RNA sequences for a given structure that comply in addition with an adjustable full range objective GC-content distribution, specific sequence constraints and additional fuzzy structure constraints. antaRNA applies ant colony optimization meta-heuristics and its superior performance is shown on a biological datasets. Availability and implementation: http://www.bioinf.uni-freiburg.de/Software/antaRNA Contact: backofen@informatik.uni-freiburg.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26023105

  3. Overview of the Distribution, Habitat Association and Impact of Exotic Ants on Native Ant Communities in New Caledonia

    PubMed Central

    Berman, Maïa; Andersen, Alan N.; Hély, Christelle; Gaucherel, Cédric

    2013-01-01

    Ants are among the most ubiquitous and harmful invaders worldwide, but there are few regional studies of their relationships with habitat and native ant communities. New Caledonia has a unique and diverse ant fauna that is threatened by exotic ants, but broad-scale patterns of exotic and native ant community composition in relation to habitat remain poorly documented. We conducted a systematic baiting survey of 56 sites representing the main New Caledonian habitat types: rainforest on ultramafic soils (15 sites), rainforest on volcano-sedimentary soils (13), maquis shrubland (15), Melaleuca-dominated savannas (11) and Acacia spirorbis thickets (2). We collected a total of 49 species, 13 of which were exotic. Only five sites were free of exotic species, and these were all rainforest. The five most abundant exotic species differed in their habitat association, with Pheidole megacephala associated with rainforests, Brachymyrmex cf. obscurior with savanna, and Wasmannia auropunctata and Nylanderia vaga present in most habitats. Anoplolepis gracilipes occurred primarily in maquis-shrubland, which contrasts with its rainforest affinity elsewhere. Multivariate analysis of overall ant species composition showed strong differentiation of sites according to the distribution of exotic species, and these patterns were maintained at the genus and functional group levels. Native ant composition differed at invaded versus uninvaded rainforest sites, in the absence of differences in habitat variables. Generalised Myrmicinae and Forest Opportunists were particularly affected by invasion. There was a strong negative relationship between the abundance of W. auropunctata and native ant abundance and richness. This emphasizes that, in addition to dominating many ant communities numerically, some exotic species, and in particular W. auropunctata, have a marked impact on native ant communities. PMID:23840639

  4. Testing the effects of ant invasions on non-ant arthropods with high-resolution taxonomic data.

    PubMed

    Hanna, Cause; Naughton, Ida; Boser, Christina; Holway, David

    2015-10-01

    Invasions give rise to a wide range of ecological effects. Many invasions proceed without noticeable impacts on the resident biota, whereas others shift species composition and even alter ecosystem function. Ant invasions generate a broad spectrum of ecological effects, but controversy surrounds the extent of these impacts, especially with regard to how other arthropods are affected. This uncertainty in part results from the widespread use of low-resolution taxonomic data, which can mask the presence of other introduced species and make it difficult to isolate the effects of ant invasions on native species. Here, we use high-resolution taxonomic data to examine the effects of Argentine ant invasions on arthropods on Santa Cruz Island, California. We sampled arthropods in eight pairs of invaded and uninvaded plots and then collaborated with taxonomic experts to identify taxa in four focal groups: spiders, bark lice, beetles, and ants. Spiders, bark lice, and beetles made up ~40% of the 9868 non-ant arthropod individuals sampled; the majority of focal group arthropods were putatively native taxa. Although our results indicate strong negative effects of the Argentine ant on native ants, as is well documented, invaded and uninvaded plots did not differ with respect to the richness, abundance, or species composition of spiders, bark lice, and beetles. One common, introduced species of bark louse was more common in uninvaded plots than in invaded plots, and including this species into our analyses changed the relationship between bark louse richness vs. L. humile abundance from no relationship to a significant negative relationship. This case illustrates how failure to differentiate native and introduced taxa can lead to erroneous conclusions about the effects of ant invasions. Our results caution against unqualified assertions about the effects of ant invasions on non-ant arthropods, and more generally demonstrate that accurate assessments of invasion impacts depend on adequate information about species identity. PMID:26591450

  5. Early Results of Three-Year Monitoring of Red Wood Ants’ Behavioral Changes and Their Possible Correlation with Earthquake Events

    PubMed Central

    Berberich, Gabriele; Berberich, Martin; Grumpe, Arne; Wöhler, Christian; Schreiber, Ulrich

    2013-01-01

    Simple Summary For three years (2009–2012), two red wood ant mounds (Formica rufa-group), located at the seismically active Neuwied Basin (Eifel, Germany), have been monitored 24/7 by high-resolution cameras. Early results show that ants have a well-identifiable standard daily routine. Correlation with local seismic events suggests changes in the ants’ behavior hours before the earthquake: the nocturnal rest phase and daily activity are suppressed, and standard daily routine does not resume until the next day. At present, an automated image evaluation routine is being applied to the video streams. Based on this automated approach, a statistical analysis of the ant behavior will be carried out. Abstract Short-term earthquake predictions with an advance warning of several hours or days are currently not possible due to both incomplete understanding of the complex tectonic processes and inadequate observations. Abnormal animal behaviors before earthquakes have been reported previously, but create problems in monitoring and reliability. The situation is different with red wood ants (RWA; Formica rufa-group (Hymenoptera: Formicidae)). They have stationary mounds on tectonically active, gas-bearing fault systems. These faults may be potential earthquake areas. For three years (2009–2012), two red wood ant mounds (Formica rufa-group), located at the seismically active Neuwied Basin (Eifel, Germany), have been monitored 24/7 by high-resolution cameras with both a color and an infrared sensor. Early results show that ants have a well-identifiable standard daily routine. Correlation with local seismic events suggests changes in the ants’ behavior hours before the earthquake: the nocturnal rest phase and daily activity are suppressed, and standard daily routine does not resume until the next day. At present, an automated image evaluation routine is being applied to the more than 45,000 hours of video streams. Based on this automated approach, a statistical analysis of the ants’ behavior will be carried out. In addition, other parameters (climate, geotectonic and biological), which may influence behavior, will be included in the analysis. PMID:26487310

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

    NASA Astrophysics Data System (ADS)

    Rossi, Louis

    2005-11-01

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

  7. Contact rate modulates foraging efficiency in leaf cutting ants

    PubMed Central

    Bouchebti, S.; 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 artificially decreasing the rate of head-on collisions between individuals. We show that head-on collisions do not influence the rate of recruitment in these ants but do influence foraging efficiency, i.e. the proportion of ants returning to the nest with a leaf fragment. Surprisingly, both unladen and laden ants returning to the nest participate in the modulation of foraging efficiency: foraging efficiency decreases when the rate of contacts with both nestbound laden or unladen ants decreases. These results suggest that outgoing ants are able to collect information from inbound ants even when these latter do not carry any leaf fragment and that this information can influence their foraging decisions when reaching the end of the trail. PMID:26686557

  8. Interactions Increase Forager Availability and Activity in Harvester Ants

    PubMed Central

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

    2015-01-01

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

  9. Patterns of Positive Selection in Seven Ant Genomes

    PubMed Central

    Roux, Julien; Privman, Eyal; Moretti, Sébastien; Daub, Josephine T.; Robinson-Rechavi, Marc; Keller, Laurent

    2014-01-01

    The evolution of ants is marked by remarkable adaptations that allowed the development of very complex social systems. To identify how ant-specific adaptations are associated with patterns of molecular evolution, we searched for signs of positive selection on amino-acid changes in proteins. We identified 24 functional categories of genes which were enriched for positively selected genes in the ant lineage. We also reanalyzed genome-wide data sets in bees and flies with the same methodology to check whether positive selection was specific to ants or also present in other insects. Notably, genes implicated in immunity were enriched for positively selected genes in the three lineages, ruling out the hypothesis that the evolution of hygienic behaviors in social insects caused a major relaxation of selective pressure on immune genes. Our scan also indicated that genes implicated in neurogenesis and olfaction started to undergo increased positive selection before the evolution of sociality in Hymenoptera. Finally, the comparison between these three lineages allowed us to pinpoint molecular evolution patterns that were specific to the ant lineage. In particular, there was ant-specific recurrent positive selection on genes with mitochondrial functions, suggesting that mitochondrial activity was improved during the evolution of this lineage. This might have been an important step toward the evolution of extreme lifespan that is a hallmark of ants. PMID:24782441

  10. Ant-mediated seed dispersal in a warmed world

    PubMed Central

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

    2014-01-01

    Climate change affects communities both directly and indirectly via changes in interspecific interactions. One such interaction that may be altered under climate change is the ant-plant seed dispersal mutualism common in deciduous forests of eastern North America. As climatic warming alters the abundance and activity levels of ants, the potential exists for shifts in rates of ant-mediated seed dispersal. We used an experimental temperature manipulation at two sites in the eastern US (Harvard Forest in Massachusetts and Duke Forest in North Carolina) to examine the potential impacts of climatic warming on overall rates of seed dispersal (using Asarum canadense seeds) as well as species-specific rates of seed dispersal at the Duke Forest site. We also examined the relationship between ant critical thermal maxima (CTmax) and the mean seed removal temperature for each ant species. We found that seed removal rates did not change as a result of experimental warming at either study site, nor were there any changes in species-specific rates of seed dispersal. There was, however, a positive relationship between CTmax and mean seed removal temperature, whereby species with higher CTmax removed more seeds at hotter temperatures. The temperature at which seeds were removed was influenced by experimental warming as well as diurnal and day-to-day fluctuations in temperature. Taken together, our results suggest that while temperature may play a role in regulating seed removal by ants, ant plant seed-dispersal mutualisms may be more robust to climate change than currently assumed. PMID:24688863

  11. Species richness, equitability, and abundance of ants in disturbed landscapes

    USGS Publications Warehouse

    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.

  12. Contact rate modulates foraging efficiency in leaf cutting ants.

    PubMed

    Bouchebti, S; 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 artificially decreasing the rate of head-on collisions between individuals. We show that head-on collisions do not influence the rate of recruitment in these ants but do influence foraging efficiency, i.e. the proportion of ants returning to the nest with a leaf fragment. Surprisingly, both unladen and laden ants returning to the nest participate in the modulation of foraging efficiency: foraging efficiency decreases when the rate of contacts with both nestbound laden or unladen ants decreases. These results suggest that outgoing ants are able to collect information from inbound ants even when these latter do not carry any leaf fragment and that this information can influence their foraging decisions when reaching the end of the trail. PMID:26686557

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

    NASA Astrophysics Data System (ADS)

    Lapierre, Louis; Hespenheide, Henry; Dejean, Alain

    2007-12-01

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

  14. Competitive assembly of South Pacific invasive ant communities

    PubMed Central

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

    2009-01-01

    Background The relative importance of chance and determinism in structuring ecological communities has been debated for nearly a century. Evidence for determinism or assembly rules is often evaluated with null models that randomize the occurrence of species in particular locales. However, analyses of the presence or absence of species ignores the potential influence of species abundances, which have long been considered of major importance on community structure. Here, we test for community assembly rules in ant communities on small islands of the Tokelau archipelago using both presence-absence and abundance data. We conducted three sets of analyses on two spatial scales using three years of sampling data from 39 plots on 11 islands. Results First, traditional null model tests showed support for negative species co-occurrence patterns among plots within islands, but not among islands. A plausible explanation for this result is that analyses at larger spatial scales merge heterogeneous habitats that have considerable effects on species occurrences. Second, analyses of ant abundances showed that samples with high ant abundances had fewer species than expected by chance, both within and among islands. One ant species, the invasive yellow crazy ant Anoplolepis gracilipes, appeared to have a particularly strong effect on community structure correlated with its abundance. Third, abundances of most ant species were inversely correlated with the abundances of all other ants at both spatial scales. This result is consistent with competition theory, which predicts species distributions are affected by diffuse competition with suites of co-occurring species. Conclusion Our results support a pluralistic explanation for ant species abundances and assembly. Both stochastic and deterministic processes interact to determine ant community assembly, though abundance patterns clearly drive the deterministic patterns in this community. These deterministic patterns were observed at two spatial scales. Results indicate that abundance-based null models may be more sensitive in detecting non-random patterns in community assembly than species co-occurrences analyses. PMID:19166617

  15. Weaver ant role in cashew orchards in Vietnam.

    PubMed

    Peng, Renkang; Lan, La Pham; Christian, Keith

    2014-08-01

    Cashew (Anacardium occidentale L.) is a very important source of income for more than 200,000 farmer households in Vietnam. The present cashew productivity in Vietnam is low and unstable, and pest damage is partly responsible for this. Cashew farmers rely on pesticides to minimize the damage, resulting in adverse impacts on farm environment and farmers' health. Weaver ants (Oecophylla spp) are effective biocontrol agents of a range of cashew insect pests in several cashew-growing countries, and these ants are widely distributed in Vietnam. The aim of this study is to evaluate the potential of weaver ants in cashew orchards in Vietnam. Field surveys and field experiment were conducted in five cashew orchards from July 2006 to January 2008 in Binh Phuoc, Dong Nai, and Ba Ria Vung Tau provinces, Vietnam. Based on the field surveys, the most important pests that damage flushing foliar and floral shoots and young cashew fruits and nuts were mosquito bugs, brown shoot borers, blue shoot borers, and fruit-nut borers. The damage caused by each of these pests was significantly lower on trees with weaver ants compared with trees without the ants, showing that the ants were able to keep these pest damages under the control threshold. Regular monitoring of the field experiment showed that weaver ants were similar to insecticides for controlling mosquito bugs, blue shoot borers, fruit-nut borers, leaf rollers, and leaf miners. Aphids did not become major pests in plot with weaver ants. To manage insect pest assemblage in cashew orchards, an integrated pest management using weaver ants as a major component is discussed. PMID:25195419

  16. Ants of the national park of American Samoa

    USGS Publications Warehouse

    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, Ta?? 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 Ta?? 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.

  17. What's eating you? ant-induced alopecia (pheidole).

    PubMed

    Feily, Amir; Lal, Karan; Elston, Dirk M

    2015-10-01

    Ant-induced alopecia is a rare cause of acute, localized, nonscarring hair loss. It is most commonly caused by Pheidole pallidula ants, which can be found worldwide but are most common in Iran. The resulting alopecia can have many morphologic patterns (eg, patch, linear, nondiscrete) and thus ant-induced alopecia should be considered in the differential diagnosis for patients from endemic areas who present with new-onset localized hair loss. The condition is self-limited; however, patients should be evaluated for other more common causes of alopecia, especially in the absence of a convincing history. PMID:26682285

  18. Fatty Amines from Little Black Ants, Monomorium minimum, and Their Biological Activities Against Red Imported Fire Ants, Solenopsis invicta.

    PubMed

    Wang, Lei; Chen, Jian

    2015-08-01

    Red imported fire ants, Solenopsis invicta, are significant invasive pests. Certain native ant species can compete with S. invicta, such as the little black ant, Monomorium minimum. Defensive secretions may contribute to the competition capacity of native ants. The chemistry of ant defensive secretions in the genus Monomorium has been subjected to extensive research. The insecticidal alkaloids, 2,5-dialkyl-pyrrolidines and 2,5-dialkyl-pyrrolines have been reported to dominate the venom of M. minimum. In this study, analysis of defensive secretions of workers and queens of M. minimum revealed two primary amines, decylamine and dodecylamine. Neither amine has been reported previously from natural sources. Toxicity and digging suppression by these two amines against S. invicta were examined. Decylamine had higher toxicity to S. invicta workers than dodecylamine, a quicker knockdown effect, and suppressed the digging behavior of S. invicta workers at lower concentration. However, the amount of fatty amines in an individual ant was not enough to knockdown a fire ant or suppress its digging behavior. These amines most likely work in concert with other components in the chemical defense of M. minimum. PMID:26254063

  19. Disruption of a protective ant-plant mutualism by an invasive ant increases elephant damage to savanna trees.

    PubMed

    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

  20. Symbiotic mutualism with a community of opportunistic ants: protection, competition, and ant occupancy of the myrmecophyte Barteria nigritana (Passifloraceae)

    NASA Astrophysics Data System (ADS)

    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.

  1. MUIR DATA SYSTEMS, INC. Wind Industry Segments &

    E-print Network

    ........................................................................................12 Figure 5: Siemens Oil & Gas Product Overview..........................................................................................14 Figure 6: Siemens Oil & Gas Summary of Benefits

  2. A Possibility of the Aeromagnetic Survey by a Small Unmanned Aerial Vehicles, Ant-Plane

    NASA Astrophysics Data System (ADS)

    Funaki, M.

    2004-12-01

    Magnetic surveys by helicopters and airplanes are a useful technique to estimate the geological structure under the ice sheets in Antarctica. However, it is not easy to employ this due to the transportation of the planes, logistic supports, security, and financial problems. Members of Ant-Plane Project have investigated the unmanned aerial vehicles (UAV, Ant-Plane) for the solution of the problems. Recently the aeromagnetic survey is verified by a model airplane navigated by GPS and a magneto-resistant (MR) magnetometer. The airplane (Ant-Plane) consists of 2m wing length, 2-cycles and 2-cylinder 85cc gasoline engine, GPS navigation system by microcomputer and radio telemeter system. The total weight is 15kg including 2 litter fuels, the MR magnetometer, a video camera and an emergency parachute. The speed is 130 km/h and maximum height is 2000m. The magnetometer system consists of a 3- component MR magnetometer, GPS and data logger. Three components of magnetic field, latitude, longitude, altitude, number of satellite and time are recorded in every second during 3 hours. The sensitivity of the magnetometer is 7 nT and we use a total magnetic field intensity for magnetic analysis due to unknown heading of the plane. November 2003 we succeeded the magnetic survey by the Ant-Plane at the slope of Sakurajima Volcano, Kyushu, Japan. The plane rotated 9 times along the programmed route of about 4x1 km, total flight distance of 80 km, keeping the altitude of 700 m. Consequently we obtained almost similar field variation on the route. The maximum deviation of each course was less than 100 m. Therefore, we concluded that the aeromagnetic survey in the relatively large anomaly areas can be performed by Ant-Plane with the MR magnetometer system. Finally the plane flew up 1400m with a video camera to take the photo of active volcano Sakurajima (1117m). It succeeded to take photos of craters through steam from the volcano.

  3. Analysis of a chemotaxis system modeling ant Ricardo Alonso1

    E-print Network

    Goudon, Thierry

    management or fungus gardening. Even more striking is the fact that many of these activities, especially. When an individual ant, foraging at random, encounters a food source, it typically travels back

  4. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (1) Reindeer, elk, deer, antelope, bison and water buffalo are eligible for field ante-mortem inspection. The...1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection....

  5. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (1) Reindeer, elk, deer, antelope, bison and water buffalo are eligible for field ante-mortem inspection. The...1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection....

  6. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (1) Reindeer, elk, deer, antelope, bison and water buffalo are eligible for field ante-mortem inspection. The...1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection....

  7. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (1) Reindeer, elk, deer, antelope, bison and water buffalo are eligible for field ante-mortem inspection. The...1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection....

  8. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (1) Reindeer, elk, deer, antelope, bison and water buffalo are eligible for field ante-mortem inspection. The...1) Reindeer, elk, deer, antelope, bison, and water buffalo are eligible for transport vehicle inspection....

  9. Ants of Ambon Island – diversity survey and checklist

    PubMed Central

    Latumahina, Fransina; Borovanska, Michaela; Musyafa; Sumardi; Putra, Nugroho Susetya; Janda, Milan

    2015-01-01

    Abstract The present checklist of ants (Hymenoptera: Formicidae) of Ambon is the first comprehensive overview of ant species recorded on the island during the last 150 years. The species list is based on literature and museum collections’ records combined with data from our field survey in 2010. In total, there are 74 ant species and subspecies representing 34 genera and six subfamilies known from Ambon. Five of the species found in undisturbed forest were exotic and indicate the overall habitat degradation on the island. The largest proportion of Ambon ant fauna are species with affinities to the Oriental region and species of Oriental-Austro-Melanesian origin. At least 20% of the species are regional endemics. In comparison to other islands in the region, the Ambon fauna seems more diverse and better sampled; however it is clear that a large part of it still remains to be described. PMID:25632248

  10. Simple cellular automata to mimic foraging ants submitted to abduction

    E-print Network

    Tejera, F

    2015-01-01

    Many species of ants forage by building up two files: an outbound one moving from the nest to the foraging area, and a nestbound one, returning from it to the nest. Those files are eventually submitted to different threats. If the danger is concentrated at one point of the file, one might expect that ants returning to the nest will pass danger information to their nestmates moving in the opposite direction towards the danger area. In this paper, we construct simple cellular automata models for foraging ants submitted to localized abduction, were danger information is transmitted using different protocols, including the possibility of no transmission. The parameters we have used in the simulations have been estimated from actual experiments under natural conditions. So, it would be easy to test our information-transmission hypothese in real experiments. Preliminary experimental results published elsewhere suggest that the behavior of foraging ants of the species Atta insularis is best described using the hypot...

  11. Ant groups optimally amplify the effect of transiently informed individuals

    PubMed Central

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

    2015-01-01

    To cooperatively transport a large load, it is important that carriers conform in their efforts and align their forces. A downside of behavioural conformism is that it may decrease the group's responsiveness to external information. Combining experiment and theory, we show how ants optimize collective transport. On the single-ant scale, optimization stems from decision rules that balance individuality and compliance. Macroscopically, these rules poise the system at the transition between random walk and ballistic motion where the collective response to the steering of a single informed ant is maximized. We relate this peak in response to the divergence of susceptibility at a phase transition. Our theoretical models predict that the ant-load system can be transitioned through the critical point of this mesoscopic system by varying its size; we present experiments supporting these predictions. Our findings show that efficient group-level processes can arise from transient amplification of individual-based knowledge. PMID:26218613

  12. Bat aggregation mediates the functional structure of ant assemblages.

    PubMed

    Dejean, Alain; Groc, Sarah; Hérault, Bruno; Rodriguez-Pérez, Héctor; Touchard, Axel; Céréghino, Régis; Delabie, Jacques H C; Corbara, Bruno

    2015-10-01

    In the Guianese rainforest, we examined the impact of the presence of guano in and around a bat roosting site (a cave). We used ant communities as an indicator to evaluate this impact because they occupy a central place in the functioning of tropical rainforest ecosystems and they play different roles in the food web as they can be herbivores, generalists, scavengers or predators. The ant species richness around the cave did not differ from a control sample situated 500m away. Yet, the comparison of functional groups resulted in significantly greater numbers of detritivorous fungus-growing and predatory ant colonies around the cave compared to the control, the contrary being true for nectar and honeydew feeders. The role of bats, through their guano, was shown using stable isotope analyses as we noted significantly greater ?(15)N values for the ant species captured in and around the cave compared to controls. PMID:26302832

  13. Ante rem Structuralism and the Myth of Identity Criteria 

    E-print Network

    Siu, Ho Kin

    2010-01-20

    reasons why the thesis has to be dropped. (i) The purported metaphysical and epistemic purchase of adopting the thesis can be put into doubt. (ii) Primitive identity within a mathematical structure is more in line with ante rem structuralist's commitment...

  14. Pollution diminishes intra-specific aggressiveness between wood ant colonies.

    PubMed

    Sorvari, Jouni; Eeva, Tapio

    2010-07-15

    A variety of common environmental pollutants are known to affect the animal behaviour, but the occurrence and extent of pollution-induced behavioural changes in wild populations are practically unknown. Here we show that heavy metal pollution reduces the normal intra-specific aggressive behaviour in wild populations of the wood ant, Formica aquilonia, a dominant territorial ant species in boreal forests. Ants exposed to long-term pollution around a copper smelter showed higher heavy metal concentrations and were less aggressive towards the member of foreign unpolluted colony than the ants from an uncontaminated area. A pollution-related decline in the level of aggressiveness in this keystone general predator species may potentially affect the structure of invertebrate community of boreal and temperate forests. Further studies are needed to find out whether the change in aggressiveness is directly caused by metal toxicity or indirectly via secondary pollution effects, such as changed resource levels. PMID:20434195

  15. Ant groups optimally amplify the effect of transiently informed individuals

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    To cooperatively transport a large load, it is important that carriers conform in their efforts and align their forces. A downside of behavioural conformism is that it may decrease the group's responsiveness to external information. Combining experiment and theory, we show how ants optimize collective transport. On the single-ant scale, optimization stems from decision rules that balance individuality and compliance. Macroscopically, these rules poise the system at the transition between random walk and ballistic motion where the collective response to the steering of a single informed ant is maximized. We relate this peak in response to the divergence of susceptibility at a phase transition. Our theoretical models predict that the ant-load system can be transitioned through the critical point of this mesoscopic system by varying its size; we present experiments supporting these predictions. Our findings show that efficient group-level processes can arise from transient amplification of individual-based knowledge.

  16. Dentigerumycin: a bacterial mediator of an ant-fungus symbiosis

    PubMed Central

    Oh, Dong-Chan; Poulsen, Michael; Currie, Cameron R.; Clardy, Jon

    2009-01-01

    Fungus-growing ants engage in mutualistic associations with both the fungus they cultivate for food and actinobacteria (Pseudonocardia spp.) that produce selective antibiotics to defend that fungus from specialized fungal parasites. In the first system to be analyzed at the molecular level, the bacterium associated with the ant Apterostigma dentigerum produces dentigerumycin, a cyclic depsipeptide with highly modified amino acids, to selectively inhibit the parasitic fungus (Escovopsis sp.). PMID:19330011

  17. Improved ant colony algorithm and its simulation study

    NASA Astrophysics Data System (ADS)

    Wang, Zongjiang

    2013-03-01

    Ant colony algorithm is development a new heuristic algorithm through simulation ant foraging. For its convergence rate slow, easy to fall into local optimal solution proposed for the adjustment of key parameters, pheromone update to improve the way and through the issue of TSP experiments, results showed that the improved algorithm has better overall search capabilities and demonstrated the feasibility and effectiveness of this method.

  18. Scope of Various Random Number Generators in ant System Approach for TSP

    NASA Technical Reports Server (NTRS)

    Sen, S. K.; Shaykhian, Gholam Ali

    2007-01-01

    Experimented on heuristic, based on an ant system approach for traveling salesman problem, are several quasi- and pseudo-random number generators. This experiment is to explore if any particular generator is most desirable. Such an experiment on large samples has the potential to rank the performance of the generators for the foregoing heuristic. This is mainly to seek an answer to the controversial issue "which generator is the best in terms of quality of the result (accuracy) as well as cost of producing the result (time/computational complexity) in a probabilistic/statistical sense."

  19. Adapting an Ant Colony Metaphor for Multi-Robot Chemical Plume Tracing

    PubMed Central

    Meng, Qing-Hao; Yang, Wei-Xing; Wang, Yang; Li, Fei; Zeng, Ming

    2012-01-01

    We consider chemical plume tracing (CPT) in time-varying airflow environments using multiple mobile robots. The purpose of CPT is to approach a gas source with a previously unknown location in a given area. Therefore, the CPT could be considered as a dynamic optimization problem in continuous domains. The traditional ant colony optimization (ACO) algorithm has been successfully used for combinatorial optimization problems in discrete domains. To adapt the ant colony metaphor to the multi-robot CPT problem, the two-dimension continuous search area is discretized into grids and the virtual pheromone is updated according to both the gas concentration and wind information. To prevent the adapted ACO algorithm from being prematurely trapped in a local optimum, the upwind surge behavior is adopted by the robots with relatively higher gas concentration in order to explore more areas. The spiral surge (SS) algorithm is also examined for comparison. Experimental results using multiple real robots in two indoor natural ventilated airflow environments show that the proposed CPT method performs better than the SS algorithm. The simulation results for large-scale advection-diffusion plume environments show that the proposed method could also work in outdoor meandering plume environments. PMID:22666056

  20. Chemical signals associated with life inhibit necrophoresis in Argentine ants

    PubMed Central

    Choe, Dong-Hwan; Millar, Jocelyn G.; Rust, Michael K.

    2009-01-01

    One of the most conspicuous and stereotyped activities of social insects such as ants and honey bees is necrophoresis, the removal of dead colony members from the nest. Previous researchers suggested that decomposition products such as fatty acids trigger necrophoric behavior by ant workers. However, fatty acids elicit both foraging and necrophoric responses, depending on the current nest activities (e.g., feeding or nest maintenance). Furthermore, workers often carry even freshly killed workers (dead for <1 h) to refuse piles before significant decomposition has a chance to occur. Here, we show that the cuticular chemistry of Argentine ant workers, Linepithema humile, undergoes rapid changes after death. When the workers are alive or freshly killed, relatively large amounts of 2 characteristic ant-produced compounds, dolichodial and iridomyrmecin, are present on the ants' cuticle. However, these compounds disappear from the cuticle within about 1 h after death. We demonstrate how this phenomenon supports an alternative mechanism of ant necrophoresis in which the precise recognition and rapid removal of dead nestmates are elicited by the disappearance of these chemical signals associated with life. PMID:19416815

  1. Ant Colonies Prefer Infected over Uninfected Nest Sites

    PubMed Central

    Pontieri, Luigi; Vojvodic, Svjetlana; Graham, Riley; Pedersen, Jes Søe; Linksvayer, Timothy A.

    2014-01-01

    During colony relocation, the selection of a new nest involves exploration and assessment of potential sites followed by colony movement on the basis of a collective decision making process. Hygiene and pathogen load of the potential nest sites are factors worker scouts might evaluate, given the high risk of epidemics in group-living animals. Choosing nest sites free of pathogens is hypothesized to be highly efficient in invasive ants as each of their introduced populations is often an open network of nests exchanging individuals (unicolonial) with frequent relocation into new nest sites and low genetic diversity, likely making these species particularly vulnerable to parasites and diseases. We investigated the nest site preference of the invasive pharaoh ant, Monomorium pharaonis, through binary choice tests between three nest types: nests containing dead nestmates overgrown with sporulating mycelium of the entomopathogenic fungus Metarhizium brunneum (infected nests), nests containing nestmates killed by freezing (uninfected nests), and empty nests. In contrast to the expectation pharaoh ant colonies preferentially (84%) moved into the infected nest when presented with the choice of an infected and an uninfected nest. The ants had an intermediate preference for empty nests. Pharaoh ants display an overall preference for infected nests during colony relocation. While we cannot rule out that the ants are actually manipulated by the pathogen, we propose that this preference might be an adaptive strategy by the host to “immunize” the colony against future exposure to the same pathogenic fungus. PMID:25372856

  2. Metabolism and the rise of fungus cultivation by ants.

    PubMed

    Shik, Jonathan Z; Santos, Juan C; Seal, Jon N; Kay, Adam; Mueller, Ulrich G; Kaspari, Michael

    2014-09-01

    Most ant colonies are comprised of workers that cooperate to harvest resources and feed developing larvae. Around 50 million years ago (MYA), ants of the attine lineage adopted an alternative strategy, harvesting resources used as compost to produce fungal gardens. While fungus cultivation is considered a major breakthrough in ant evolution, the associated ecological consequences remain poorly understood. Here, we compare the energetics of attine colony-farms and ancestral hunter-gatherer colonies using metabolic scaling principles within a phylogenetic context. We find two major energetic transitions. First, the earliest lower-attine farmers transitioned to lower mass-specific metabolic rates while shifting significant fractions of biomass from ant tissue to fungus gardens. Second, a transition 20 MYA to specialized cultivars in the higher-attine clade was associated with increased colony metabolism (without changes in garden fungal content) and with metabolic scaling nearly identical to hypometry observed in hunter-gatherer ants, although only the hunter-gatherer slope was distinguishable from isometry. Based on these evolutionary transitions, we propose that shifting living-tissue storage from ants to fungal mutualists provided energetic storage advantages contributing to attine diversification and outline critical assumptions that, when tested, will help link metabolism, farming efficiency, and colony fitness. PMID:25141145

  3. Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects

    PubMed Central

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

    2013-01-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

  4. Adaptive social immunity in leaf-cutting ants.

    PubMed

    Walker, Tom N; Hughes, William O H

    2009-08-23

    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 twice to the parasite and then compared their social immune response with that of naive mini-nests that had not been experimentally exposed to the parasite. Ants allogroomed individuals exposed to the parasite, doing this both for those freshly treated with the parasite, which were infectious but not yet infected, and for those treated 2 days previously, which were already infected but no longer infectious. We found that ants exposed to the parasite received more allogrooming in immunized mini-nests than in naive mini-nests. This increased the survival of the freshly treated ants, but not those that were already infected. The results thus indicate that the social immune response of this leaf-cutting ant is adaptive, with the group exhibiting a greater and more effective response to a parasite that it has previously been exposed to. PMID:19411266

  5. Trail Pheromone Disruption of Argentine Ant Trail Formation and Foraging

    USGS Publications Warehouse

    Suckling, D.M.; Peck, R.W.; Stringer, L.D.; Snook, K.; Banko, P.C.

    2010-01-01

    Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2-3 m s-1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments. ?? Springer Science+Business Media, LLC 2010.

  6. Using ant-behavior-based simulation model AntWeb to improve website organization

    NASA Astrophysics Data System (ADS)

    Li, Weigang; Pinheiro Dib, Marcos V.; Teles, Wesley M.; Morais de Andrade, Vlaudemir; Alves de Melo, Alba C. M.; Cariolano, Judas T.

    2002-03-01

    Some web usage mining algorithms showed the potential application to find the difference among the organizations expected by visitors to the website. However, there are still no efficient method and criterion for a web administrator to measure the performance of the modification. In this paper, we developed an AntWeb, a model inspired by ants' behavior to simulate the sequence of visiting the website, in order to measure the efficient of the web structure. We implemented a web usage mining algorithm using backtrack to the intranet website of the Politec Informatic Ltd., Brazil. We defined throughput (the number of visitors to reach their target pages per time unit relates to the total number of visitors) as an index to measure the website's performance. We also used the link in a web page to represent the effect of visitors' pheromone trails. For every modification in the website organization, for example, putting a link from the expected location to the target object, the simulation reported the value of throughput as a quick answer about this modification. The experiment showed the stability of our simulation model, and a positive modification to the intranet website of the Politec.

  7. Deterrency and Toxicity of Essential Oils to Argentine and Red Imported Fire Ants (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory assays were conducted to evaluate deterrency and contact toxicity of six essential oils to the Argentine ant, Linepithema humile (Mayr), and the red imported fire ant, Solenopsis invicta Buren. In choice tests, both Argentine ants and fire ants crossed barriers treated with multiple rates...

  8. Establishment and dispersal of the fire ant decapitating fly Pseudacteon tricuspis in North Florida

    E-print Network

    Morrison, Lloyd W.

    as a self-sustaining biocontrol agent of the red imported fire ant, Solenopsis invicta Buren. Several releases used parasitized fire ant workers while most involved adult flies released over disturbed antEstablishment and dispersal of the fire ant decapitating fly Pseudacteon tricuspis in North Florida

  9. Draft Genome Sequence of the Ant-Associated Fungus Phialophora attae (CBS 131958)

    PubMed Central

    Moreno, Leandro F.; Stielow, J. Benjamin; de Vries, Michel; Weiss, Vinicius A.; Vicente, Vania A.

    2015-01-01

    The black yeast Phialophora attae was isolated from the cuticle of tropical ant gynes. The ant-fungus association is sustained due to symbiotic evolutionary adaptations that allow fungal assimilation and tolerance of toxic compounds produced by the ant. The genome sequence of the first ant-associated fungus, P. attae, is presented here. PMID:26586868

  10. Antaphid mutualism: the influence of ants on the aphid summer cycle

    E-print Network

    Leimar, Olof

    61 Ant­aphid mutualism: the influence of ants on the aphid summer cycle Karolina Tegelaar, Mattias on the effects on aphids of being tended by ants. The aim of this study is to investigate how the presence of ants influences settling decisions by colonizing aphids and the post-settlement growth and survival

  11. Tracing the Rise of Ants -Out of the Ground Andrea Lucky1,2

    E-print Network

    Lucky, Andrea

    Tracing the Rise of Ants - Out of the Ground Andrea Lucky1,2 *, Michelle D. Trautwein3,4 , Benoit S The evolution of ants (Hymenoptera: Formicidae) is increasingly well-understood due to recent phylogenetic regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic

  12. Ants of British Columbia (Hymenoptera: Formicidae) Robert J. Higgins and B. Staffan Lindgren

    E-print Network

    Higgins, Robert J.

    Ants of British Columbia (Hymenoptera: Formicidae) Robert J. Higgins and B. Staffan Lindgren the great diversity of habitats and the abundance of ants in many areas, surveys of the ant fauna in British° latitude. Fortunately, what sparse literature does exist with respect to ant species, geography

  13. Box 12.1 Trap-jaw ants Andrew V. Suarez and Joseph C. Spagna

    E-print Network

    Suarez, Andrew V.

    Box 12.1 Trap-jaw ants Andrew V. Suarez and Joseph C. Spagna The success of ants is often attributed to their remarkable social behaviour and cooperation. Group foraging species such as army ants can insect or even a small vertebrate. How- ever, not all ants are social hunters -- some of the most

  14. PERSPECTIVES Stoichiometric relations in an ant-treehopper Adam D. Kay,1

    E-print Network

    Thomas, David D.

    IDEAS AND PERSPECTIVES Stoichiometric relations in an ant-treehopper mutualism Adam D. Kay,1 * Sara) contained lower N concentrations than treehoppers on plants from which ants were excluded. Ant presence also affected nutrient concentra- tions in host plants: on plants with ants, leaves contained uniformly low

  15. Diversification and phylogeographic structure in widespread Azteca plant-ants from the northern

    E-print Network

    Gordon, Deborah

    the evolutionary dynamics of this widespread ant­plant mutualism. Keywords: ant­plant mutualism, Cordia alliodora partners at both the species and population levels. In symbiotic ant­plant mutualisms, host plants provideDiversification and phylogeographic structure in widespread Azteca plant-ants from the northern

  16. Red imported fire ant impact on native ants and litter removal in the post oak savannah of central Texas 

    E-print Network

    Bedford, Theresa Louise

    2006-08-16

    Mieres, always were there for me with insights, encouragement, and laughter. Likewise, the Entomology Research Lab staff and graduate students: Ken Helms, Jim Martin, Asha Rao, Indira Kuriachan, Steve Rauth, and Sean O?Keefe, could be counted... and native ants. ......................................... 26 15 Mean mass of litter removed per litter removal station can, in grams, per period, for red imported fire ants, Monomorium minimum, Paratrechina species, and Forelius pruinosus...

  17. Foraging ants trade off further for faster: use of natural bridges and trunk trail permanency in carpenter ants

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    Trail-making ants lay pheromones on the substrate to define paths between foraging areas and the nest. Combined with the chemistry of these pheromone trails and the physics of evaporation, trail-laying and trail-following behaviours provide ant colonies with the quickest routes to food. In relatively uniform environments, such as that provided in many laboratory studies of trail-making ants, the quickest route is also often the shortest route. Here, we show that carpenter ants ( Camponotus rufipes), in natural conditions, are able to make use of apparent obstacles in their environment to assist in finding the fastest routes to food. These ants make extensive use of fallen branches, twigs and lianas as bridges to build their trails. These bridges make trails significantly longer than their straight line equivalents across the forest floor, but we estimate that ants spend less than half the time to reach the same point, due to increased carriage speed across the bridges. We also found that these trails, mainly composed of bridges, are maintained for months, so they can be characterized as trunk trails. We suggest that pheromone-based foraging trail networks in field conditions are likely to be structured by a range of potentially complex factors but that even then, speed remains the most important consideration.

  18. Field evaluation of aerial applications of hydramethylnon and metaflumizone to control the red imported fire ant, Solenopsis invicta (Buren) and related ant species (Hymenoptera: formicidae) 

    E-print Network

    Thompson, Aaron Neal

    2009-05-15

    OF AERIAL APPLICATIONS OF HYDRAMETHYLNON AND METAFLUMIZONE TO CONTROL THE RED IMPORTED FIRE ANT, SOLENOPSIS INVICTA (BUREN), AND RELATED ANT SPECIES (HYMENOPTERA: FORMICIDAE) A Thesis by AARON NEAL THOMPSON Submitted... OF HYDRAMETHYLNON AND METAFLUMIZONE TO CONTROL THE RED IMPORTED FIRE ANT, SOLENOPSIS INVICTA (BUREN), AND RELATED ANT SPECIES (HYMENOPTERA: FORMICIDAE) A Thesis by AARON NEAL THOMPSON Submitted to Texas A&M University in partial...

  19. Multiple endosymbionts in populations of the ant Formica cinerea

    PubMed Central

    2010-01-01

    Background Many insects, including ants, are infected by maternally inherited Wolbachia endosymbiotic bacteria though other secondary endosymbionts have not been reported in ants. It has been suggested that the ability of Wolbachia to invade and remain in an ant population depends on the number of coexisting queens in a colony. We study the genetic and social structure of populations in the ant Formica cinerea which is known to have populations with either monogynous or polygynous colonies. We screen populations for several endosymbiotic bacteria to evaluate the presence of different endosymbionts, possible association between their prevalence and the social structure, and the association between endosymbiont prevalence and genetic differentiation of ant populations. Results We found three endosymbiotic bacteria; 19% of the nests were infected by Wolbachia, 3.8% by Cardinium and 33% by Serratia. There was significant variation among the populations regarding the proportion of nests infected by Serratia, Wolbachia and the pooled set of all the endosymbionts. Some individuals and colonies carried two of the bacteria, the frequency of double infections agreeing with the random expectation. The proportion of infected ants (individuals or colonies) did not correlate significantly with the population level relatedness values. The difference in the prevalence of Wolbachia between population pairs correlated significantly with the genetic distance (microsatellites) of the populations. Conclusions The discovery of several endosymbionts and co-infections by Wolbachia and Cardinium demonstrate the importance of screening several endosymbionts when evaluating their possible effects on social life and queen-worker conflicts over sex allocation. The low prevalence of Wolbachia in F. cinerea departs from the pattern observed in many other Formica ants in which all workers have been infected. It is likely that the strain of Wolbachia in F. cinerea differs from those in other Formica species. The correlation between the difference in Wolbachia prevalence and the pair-wise genetic distance of populations suggests that spreading of the bacteria is restricted by the isolation of the host populations. PMID:21040533

  20. Widespread Chemical Detoxification of Alkaloid Venom by Formicine Ants.

    PubMed

    LeBrun, Edward G; Diebold, Peter J; Orr, Matthew R; Gilbert, Lawrence E

    2015-10-01

    The ability to detoxify defensive compounds of competitors provides key ecological advantages that can influence community-level processes. Although common in plants and bacteria, this type of detoxification interaction is extremely rare in animals. Here, using laboratory behavioral assays and analyses of videotaped interactions in South America, we report widespread venom detoxification among ants in the subfamily Formicinae. Across both data sets, nine formicine species, representing all major clades, used a stereotyped grooming behavior to self-apply formic acid (acidopore grooming) in response to fire ant (Solenopsis invicta and S. saevissima) venom exposure. In laboratory assays, this behavior increased the survivorship of species following exposure to S. invicta venom. Species expressed the behavior when exposed to additional alkaloid venoms, including both compositionally similar piperidine venom of an additional fire ant species and the pyrrolidine/pyrroline alkaloid venom of a Monomorium species. In addition, species expressed the behavior following exposure to the uncharacterized venom of a Crematogaster species. However, species did not express acidopore grooming when confronted with protein-based ant venoms or when exposed to monoterpenoid-based venom. This pattern, combined with the specific chemistry of the reaction of formic acid with venom alkaloids, indicates that alkaloid venoms are targets of detoxification grooming. Solenopsis thief ants, and Monomorium species stand out as brood-predators of formicine ants that produce piperidine, pyrrolidine, and pyrroline venom, providing an important ecological context for the use of detoxification behavior. Detoxification behavior also represents a mechanism that can influence the order of assemblage dominance hierarchies surrounding food competition. Thus, this behavior likely influences ant-assemblages through a variety of ecological pathways. PMID:26385230

  1. Taking trophic cascades up a level: behaviorally-modified effects of phorid flies on ants and ant prey in coffee agroecosystems

    E-print Network

    prey in coffee agroecosystems Stacy M. Philpott, Jorge Maldonado, John Vandermeer and Ivette Perfecto: behaviorally-modified effects of phorid flies on ants and ant prey in coffee agroecosystems. Á/ Oikos 105: 141Á: Noctuidae) in the coffee agroecosystem. We investigated the effects of phorid flies on ant behavior

  2. Expression of human and mouse adenine nucleotide translocase (ANT) isoform genes in adipogenesis.

    PubMed

    Gavaldà-Navarro, Aleix; Domingo, Pere; Viñas, Octavi; Mampel, Teresa

    2015-07-01

    Adenine nucleotide translocases (ANTs) are mitochondrial proteins encoded by nuclear DNA that catalyze the exchange of ATP generated in the mitochondria for ADP produced in cytosol. There are four ANT isoforms in humans (hANT1-4) and three in mice (mANT1, mANT2 and mANT4), all encoded by distinct genes. The aim of this study was to quantify expression of ANT isoform genes during the adipogenesis of mouse 3T3-L1 and human Simpson-Golabi-Behmel syndrome (SGBS)-derived preadipocytes. We also studied the effects of the adipogenesis regulators, insulin and rosiglitazone, on ANT isoform expression in differentiated adipocytes and examined the expression of ANT isoforms in subcutaneous and visceral white adipose tissue (WAT) from mice and humans. We found that adipogenesis was associated with an increase in the expression of ANT isoforms, specifically mANT2 in mouse 3T3-L1 cells and hANT3 in human SGBS cells. These changes could be involved in the increases in oxidative metabolism and decreases in lactate production observed during differentiation. Insulin and rosiglitazone induced mANT2 gene expression in mature 3T3-L1 cells and hANT2 and hANT3 gene expression in SGBS adipocytes. Furthermore, human WAT expressed greater amounts of hANT3 than hANT2, and the expression of both of these isoforms was greater in subcutaneous WAT than in visceral WAT. Finally, inhibition of ANT activity by atractyloside or bongkrekic acid impaired proper adipocyte differentiation. These results suggest that changes in the expression of ANT isoforms may be involved in adipogenesis in both human and mouse WAT. PMID:25817039

  3. Multi-trait mimicry of ants by a parasitoid wasp

    PubMed Central

    Malcicka, Miriama; Bezemer, T. Martijn; Visser, Bertanne; Bloemberg, Mark; Snart, Charles J. P.; Hardy, Ian C. W.; Harvey, Jeffrey A.

    2015-01-01

    Many animals avoid attack from predators through toxicity or the emission of repellent chemicals. Defensive mimicry has evolved in many species to deceive shared predators, for instance through colouration and other morphological adaptations, but mimicry hardly ever seems to involve multi-trait similarities. Here we report on a wingless parasitoid wasp that exhibits a full spectrum of traits mimicing ants and affording protection against ground-dwelling predators (wolf spiders). In body size, morphology and movement Gelis agilis (Ichneumonidae) is highly similar to the black garden ant (Lasius niger) that shares the same habitat. When threatened, G. agilis also emits a volatile chemical that is similar to an ant-produced chemical that repels spiders. In bioassays with L. niger, G. agilis, G. areator, Cotesia glomerata and Drosophila melanogaster, ants and G. agilis were virtually immune to spider attack, in contrast the other species were not. Volatile characterisation with gas chromatography-mass spectrometry identified G. agilis emissions as 6-methyl-5-hepten-2-one, a known insect defence semiochemical that acts as an alarm pheromone in ants. We argue that multi-trait mimicry, as observed in G. agilis, might be much more common among animals than currently realized. PMID:25622726

  4. Endophytic fungi reduce leaf-cutting ant damage to seedlings.

    PubMed

    Bittleston, L S; Brockmann, F; Wcislo, W; Van Bael, S A

    2011-02-23

    Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (E(high)) or low (E(low)) densities of endophytes. The E(high) seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the E(low) treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from E(low) relative to E(high) seedlings and had a tendency to recruit more ants to E(low) plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

  5. Prey Capture Behavior in an Arboreal African Ponerine Ant

    PubMed Central

    Dejean, Alain

    2011-01-01

    I studied the predatory behavior of Platythyrea conradti, an arboreal ponerine ant, whereas most species in this subfamily are ground-dwelling. The workers, which hunt solitarily only around dusk, are able to capture a wide range of prey, including termites and agile, nocturnal insects as well as diurnal insects that are inactive at that moment of the Nyctemeron, resting on tree branches or under leaves. Prey are captured very rapidly, and the antennal palpation used by ground-dwelling ponerine species is reduced to a simple contact; stinging occurs immediately thereafter. The venom has an instant, violent effect as even large prey (up to 30 times the weight of a worker) never struggled after being stung. Only small prey are not stung. Workers retrieve their prey, even large items, singly. To capture termite workers and soldiers defending their nest entrances, ant workers crouch and fold their antennae backward. In their role as guards, the termites face the crouching ants and end up by rolling onto their backs, their legs batting the air. This is likely due to volatile secretions produced by the ants' mandibular gland. The same behavior is used against competing ants, including territorially-dominant arboreal species that retreat further and further away, so that the P. conradti finally drive them from large, sugary food sources. PMID:21589941

  6. Spatiotemporal resource distribution and foraging strategies of ants (Hymenoptera: Formicidae)

    PubMed Central

    Lanan, Michele

    2014-01-01

    The distribution of food resources in space and time is likely to be an important factor governing the type of foraging strategy used by ants. However, no previous systematic attempt has been made to determine whether spatiotemporal resource distribution is in fact correlated with foraging strategy across the ants. In this analysis, I present data compiled from the literature on the foraging strategy and food resource use of 402 species of ants from across the phylogenetic tree. By categorizing the distribution of resources reported in these studies in terms of size relative to colony size, spatial distribution relative to colony foraging range, frequency of occurrence in time relative to worker life span, and depletability (i.e., whether the colony can cause a change in resource frequency), I demonstrate that different foraging strategies are indeed associated with specific spatiotemporal resource attributes. The general patterns I describe here can therefore be used as a framework to inform predictions in future studies of ant foraging behavior. No differences were found between resources collected via short-term recruitment strategies (group recruitment, short-term trails, and volatile recruitment), whereas different resource distributions were associated with solitary foraging, trunk trails, long-term trail networks, group raiding, and raiding. In many cases, ant species use a combination of different foraging strategies to collect diverse resources. It is useful to consider these foraging strategies not as separate options but as modular parts of the total foraging effort of a colony. PMID:25525497

  7. Catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria

    PubMed Central

    Lapeva-Gjonova, Albena; Antonova, Vera; Radchenko, Alexander G.; Atanasova, Maria

    2010-01-01

    Abstract The present catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria is made on a base of critical reconsideration of literature (covering the period from 1892 till 2009 and part of 2010) as well as on examination of the authors‘ and several museum‘s collections. A lot of data were omitted in the previous Bulgarian monograph on ants, lots of new data were recently added and many important additions and alterations were made due to taxonomic revisions of Eurasian Formicidae during the last three decades. Two new species are reported for the country [Temnothorax graecus (Forel, 1911) and Temnothorax cf. korbi (Emery, 1924)]. This catalogue contains a list of 163 ant species belonging to 40 genera of 6 subfamilies now known from Bulgaria. Synonyms and information on the previously reported names in relevant publications are given. Known localities of the species are grouped by geographic regions. Maps with concrete localities or regions for each species were prepared. The conservation status of 13 ant species is given as they are included in IUCN Red List of Threatened Species and Bulgarian Biodiversity Act. In comparison with adjacent Balkan regions the ant fauna of Bulgaria is quite rich and its core is composed of South European elements. PMID:21594018

  8. The global expansion of a single ant supercolony

    PubMed Central

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

    2010-01-01

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

  9. New fossil ants in French Cretaceous amber (Hymenoptera: Formicidae)

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    Recent studies on the ant phylogeny are mainly based on the molecular analyses of extant subfamilies and do not include the extinct, only Cretaceous subfamily Sphecomyrminae. However, the latter is of major importance for ant relationships, as it is considered the most basal subfamily. Therefore, each new discovery of a Mesozoic ant is of high interest for improving our understanding of their early history and basal relationships. In this paper, a new sphecomyrmine ant, allied to the Burmese amber genus Haidomyrmex, is described from mid-Cretaceous amber of France as Haidomyrmodes mammuthus gen. and sp. n. The diagnosis of the tribe Haidomyrmecini is emended based on the new type material, which includes a gyne (alate female) and two incomplete workers. The genus Sphecomyrmodes, hitherto known by a single species from Burmese amber, is also reported and a new species described as S. occidentalis sp. n. after two workers remarkably preserved in a single piece of Early Cenomanian French amber. The new fossils provide additional information on early ant diversity and relationships and demonstrate that the monophyly of the Sphecomyrminae, as currently defined, is still weakly supported.

  10. Immune priming and pathogen resistance in ant queens

    PubMed Central

    Gálvez, Dumas; Chapuisat, Michel

    2014-01-01

    Growing empirical evidence indicates that invertebrates become more resistant to a pathogen following initial exposure to a nonlethal dose; yet the generality, mechanisms, and adaptive value of such immune priming are still under debate. Because life-history theory predicts that immune priming and large investment in immunity should be more frequent in long-lived species, we here tested for immune priming and pathogen resistance in ant queens, which have extraordinarily long life span. We exposed virgin and mated queens of Lasius niger and Formica selysi to a low dose of the entomopathogenic fungus Beauveria bassiana, before challenging them with a high dose of the same pathogen. We found evidence for immune priming in naturally mated queens of L. niger. In contrast, we found no sign of priming in virgin queens of L. niger, nor in virgin or experimentally mated queens of F. selysi, which indicates that immune priming in ant queens varies according to mating status and mating conditions or species. In both ant species, mated queens showed higher pathogen resistance than virgin queens, which suggests that mating triggers an up-regulation of the immune system. Overall, mated ant queens combine high reproductive output, very long life span, and elevated investment in immune defense. Hence, ant queens are able to invest heavily in both reproduction and maintenance, which can be explained by the fact that mature queens will be protected and nourished by their worker offspring. PMID:24963375

  11. Specificity and transmission mosaic of ant nest-wall fungi

    PubMed Central

    Schlick-Steiner, Birgit C.; Steiner, Florian M.; Konrad, Heino; Seifert, Bernhard; Christian, Erhard; Moder, Karl; Stauffer, Christian; Crozier, Ross H.

    2008-01-01

    Mutualism, whereby species interact to their mutual benefit, is extraordinary in a competitive world. To recognize general patterns of origin and maintenance from the plethora of mutualistic associations proves a persisting challenge. The simplest situation is believed to be that of a single mutualist specific to a single host, vertically transmitted from one host generation to the next. We characterized ascomycete fungal associates cultured for nest architecture by the ant subgenera Dendrolasius and Chthonolasius. The ants probably manage their fungal mutualists by protecting them against fungal competitors. The ant subgenera display different ant-to-fungus specificity patterns, one-to-two and many-to-one, and we infer vertical transmission, in the latter case overlaid by horizontal transmission. Possible evolutionary trajectories include a reversal from fungiculture by other Lasius subgenera and inheritance of fungi through life cycle interactions of the ant subgenera. The mosaic indicates how specificity patterns can be shaped by an interplay between host life-cycles and transmission adaptations. PMID:18195358

  12. Improved packing of protein side chains with parallel ant colonies

    PubMed Central

    2014-01-01

    Introduction The accurate packing of protein side chains is important for many computational biology problems, such as ab initio protein structure prediction, homology modelling, and protein design and ligand docking applications. Many of existing solutions are modelled as a computational optimisation problem. As well as the design of search algorithms, most solutions suffer from an inaccurate energy function for judging whether a prediction is good or bad. Even if the search has found the lowest energy, there is no certainty of obtaining the protein structures with correct side chains. Methods We present a side-chain modelling method, pacoPacker, which uses a parallel ant colony optimisation strategy based on sharing a single pheromone matrix. This parallel approach combines different sources of energy functions and generates protein side-chain conformations with the lowest energies jointly determined by the various energy functions. We further optimised the selected rotamers to construct subrotamer by rotamer minimisation, which reasonably improved the discreteness of the rotamer library. Results We focused on improving the accuracy of side-chain conformation prediction. For a testing set of 442 proteins, 87.19% of X1 and 77.11% of X12 angles were predicted correctly within 40° of the X-ray positions. We compared the accuracy of pacoPacker with state-of-the-art methods, such as CIS-RR and SCWRL4. We analysed the results from different perspectives, in terms of protein chain and individual residues. In this comprehensive benchmark testing, 51.5% of proteins within a length of 400 amino acids predicted by pacoPacker were superior to the results of CIS-RR and SCWRL4 simultaneously. Finally, we also showed the advantage of using the subrotamers strategy. All results confirmed that our parallel approach is competitive to state-of-the-art solutions for packing side chains. Conclusions This parallel approach combines various sources of searching intelligence and energy functions to pack protein side chains. It provides a frame-work for combining different inaccuracy/usefulness objective functions by designing parallel heuristic search algorithms. PMID:25474164

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

    PubMed Central

    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. Chemical analyses of cuticular hydrocarbons showed that chemical congruency varied among Arhopala species; A. dajagaka matched well the host plant-ants, A. amphimuta did not match, and unexpectedly, A. zylda lacked hydrocarbons. Behaviorally, the larvae and dummies coated with cuticular chemicals of A. dajagaka were well attended by the plant-ants, especially by those of the host. A. amphimuta was often attacked by all plant-ants except for the host plant-ants toward the larvae, and those of A. zylda were ignored by all plant-ants. Our results suggested that conspicuous variations exist in the chemical strategies used by the myrmecophilous butterflies that allow them to avoid ant attack and be accepted by the plant-ant colonies. PMID:25853675

  14. The scent of mixtures: rules of odour processing in ants

    PubMed Central

    Perez, Margot; Giurfa, Martin; d'Ettorre, Patrizia

    2015-01-01

    Natural odours are complex blends of numerous components. Understanding how animals perceive odour mixtures is central to multiple disciplines. Here we focused on carpenter ants, which rely on odours in various behavioural contexts. We studied overshadowing, a phenomenon that occurs when animals having learnt a binary mixture respond less to one component than to the other, and less than when this component was learnt alone. Ants were trained individually with alcohols and aldehydes varying in carbon-chain length, either as single odours or binary mixtures. They were then tested with the mixture and the components. Overshadowing resulted from the interaction between chain length and functional group: alcohols overshadowed aldehydes, and longer chain lengths overshadowed shorter ones; yet, combinations of these factors could cancel each other and suppress overshadowing. Our results show how ants treat binary olfactory mixtures and set the basis for predictive analyses of odour perception in insects. PMID:25726692

  15. Managing leaf-cutting ants: peculiarities, trends and challenges.

    PubMed

    Della Lucia, Terezinha M C; Gandra, Lailla C; Guedes, Raul N C

    2014-01-01

    Leaf-cutting ants are generally recognized as important pest species in Neotropical America. They are eusocial insects that exhibit social organization, foraging, fungus-cultivation, hygiene and a complex nest structure, which render their management notoriously difficult. A lack of economic thresholds and sampling plans focused on the main pest species preclude the management of leaf-cutting ants; such management would facilitate their control and lessen insecticide overuse, particularly the use of insecticidal baits. Recent restrictions on the use of synthetic compounds for such purposes impose additional challenges for the management of leaf-cutting ants. Considerable effort has been exerted regarding these challenges, which are addressed herein, but which also remain challenges that are yet to be conquered. PMID:24115496

  16. Landmarks and ant search strategies after interrupted tandem runs.

    PubMed

    Basari, Norasmah; Bruendl, Aisha C; Hemingway, Charlotte E; Roberts, Nicholas W; Sendova-Franks, Ana B; Franks, Nigel R

    2014-03-15

    During a tandem run, a single leading ant recruits a single follower to an important resource such as a new nest. To examine this process, we used a motorized gantry, which has not previously been used in ant studies, to track tandem running ants accurately in a large arena and we compared their performance in the presence of different types of landmark. We interrupted tandem runs by taking away the leader and moved a large distant landmark behind the new nest just at the time of this separation. Our aim was to determine what information followers might have obtained from the incomplete tandem run they had followed, and how they behaved after the tandem run had been interrupted. Our results show that former followers search by using composite random strategies with elements of sub-diffusive and diffusive movements. Furthermore, when we provided more landmarks former followers searched for longer. However, when all landmarks were removed completely from the arena, the ants' search duration lasted up to four times longer. Hence, their search strategy changes in the presence or absence of landmarks. Even after extensive search of this kind, former followers headed back to their old nest but did not return along the path of the tandem run they had followed. The combination of the position to which the large distant landmark behind the new nest was moved and the presence or absence of additional landmarks influenced the orientation of the former followers' paths back to the old nest. We also found that these ants exhibit behavioural lateralization in which they possibly use their right eye more than their left eye to recognize landmarks for navigation. Our results suggest that former follower ants learn landmarks during tandem running and use this information to make strategic decisions. PMID:24198259

  17. Understanding the shape of ant craters: a continuum model.

    PubMed

    Picardo, Jason R; Pushpavanam, S

    2015-03-01

    The disposal of soil grains by ants, during excavation of their nest, results in the formation of axisymmetric craters around the nest entrance. We give a simple explanation for the shape of these biological constructs based on basic processes underlying grain transport and grain dropping. We propose that the tendency of an ant to drop a grain, in its next step, keeps increasing as it carries the grain farther away from the nest. Based on this hypothesis, a continuum mathematical model is developed to describe the soil dumping activity of ants, averaged over space and time. Consisting of a single, first-order differential equation, the model resembles that used to describe simultaneous convection and reaction of a chemical species, thus establishing a connection between ant craters and reacting flows. The model is shown to accurately describe the soil disposal data for two species of ants—M. barbarus and P. ambigua—using only two adjustable parameters- one less than previous empirical distributions. The characteristic single-hump shape of the crater is explained as follows: While the tendency to drop grains is greater at distances further away from the nest, the density of grain-bearing ants is highest close to the nest, thus most of the grains are dropped at an intermediate location and form a peak. The model predicts that steep craters with a sharp peak are always located closer to the nest entrance than craters which are more spread out; this new prediction is verified by data for M. barbarus and P. ambiguaants. PMID:25631852

  18. Five New Records of Ants (Hymenoptera: Formicidae) From Morocco

    PubMed Central

    Taheri, Ahmed; Reyes-López, Joaquin L.

    2015-01-01

    A recent catalogue of the rich ant fauna of Morocco included 214 species, with later studies adding an additional 12 species. Following recent fieldwork in the north of Morocco, we report five new records for the country (Plagiolepis pygmaea Latreille, 1798, Ponera testacea Emery, 1895, Strumigenys tenuipilis Emery, 1915, Temnothorax pardoi Tinaut, 1987, and Tetramorium parvioculum Guillem & Bensusan, 2009) and we present new data on the distribution and natural history of six additional species. This work brings the total number of ants known from Morocco to 233, taking into account two species which were omitted in the list of Cagniant. PMID:25843590

  19. The Trail Pheromone of the Venomous Samsum Ant, Pachycondyla sennaarensis

    PubMed Central

    Mashaly, Ashraf Mohamed Ali; Ahmed, Ashraf Mohamed; Al—Abdullah, Mosa Abdullah; Al—Khalifa, Mohamed Saleh

    2011-01-01

    Ant species use branching networks of pheromone trails for orientation between nest and resources. The current study demonstrated that workers of the venomous samsum ant, Pachycondyla sennaarensis (Mayr) (Hymenoptera: Formicidae: Ponerinae), employ recruitment trail pheromones discharged from the Dufour's gland. Secretions of other abdomen complex glands, as well as hindgut gland secretions, did not evoke trail following. The optimum concentration of trail pheromone was found to be 0.1 gland equivalent/40 cm trail. This concentration demonstrated effective longevity for about one hour. This study also showed that P. sennaarensis and Tapinoma simrothi each respond to the trail pheromones of the other species as well as their own. PMID:21529253

  20. Phylogeny of the Ants: Diversification in the Age of Angiosperms

    NASA Astrophysics Data System (ADS)

    Moreau, Corrie S.; Bell, Charles D.; Vila, Roger; Archibald, S. Bruce; Pierce, Naomi E.

    2006-04-01

    We present a large-scale molecular phylogeny of the ants (Hymenoptera: Formicidae), based on 4.5 kilobases of sequence data from six gene regions extracted from 139 of the 288 described extant genera, representing 19 of the 20 subfamilies. All but two subfamilies are recovered as monophyletic. Divergence time estimates calibrated by minimum age constraints from 43 fossils indicate that most of the subfamilies representing extant ants arose much earlier than previously proposed but only began to diversify during the Late Cretaceous to Early Eocene. This period also witnessed the rise of angiosperms and most herbivorous insects.

  1. Traits allowing some ant species to nest syntopically with the fire ant Solenopsis saevissima in its native range.

    PubMed

    Dejean, Alain; Corbara, Bruno; Céréghino, Régis; Leponce, Maurice; Roux, Olivier; Rossi, Vivien; Delabie, Jacques H C; Compin, Arthur

    2015-04-01

    Supercolonies of the red fire ant Solenopsis saevissima (Smith) develop in disturbed environments and likely alter the ant community in the native range of the species. For example, in French Guiana only 8 ant species were repeatedly noted as nesting in close vicinity to its mounds. Here, we verified if a shared set of biological, ecological, and behavioral traits might explain how these 8 species are able to nest in the presence of S. saevissima. We did not find this to be the case. We did find, however, that all of them are able to live in disturbed habitats. It is likely that over the course of evolution each of these species acquired the capacity to live syntopically with S. saevissima through its own set of traits, where colony size (4 species develop large colonies), cuticular compounds which do not trigger aggressiveness (6 species) and submissive behaviors (4 species) complement each other. PMID:25813245

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

    PubMed

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

    2014-01-01

    This study investigated the effects of ant attendance on the parasitoid community and parasitism of lac insect Kerria yunnanensis aggregations in Yunnan province, China. We manipulated ant attendance to establish three treatments: (1) ant exclusion; (2) low ant attendance by several ant species; and (3) high ant attendance by Crematogaster macaoensis. Five parasitoid species were collected, with two species contributing 82.7 and 13.2% of total abundance respectively. Total parasitoid abundance was lowest in the February sample when K. yunnanensis was in its younger life stage, being significantly lower in the ant exclusion treatment. In April, all three treatments had significantly different parasitoid abundances, being highest in the ant exclusion treatment and the lowest in the high ant attendance treatment. When ants were present, there were strong negative relationships between total parasitoid abundance and ant abundance, with the relationships being dependent upon the ant species composition and abundance. The patterns of total parasitoid abundance were driven by the two most abundant parasitoid species. Parasitoid species richness did not differ among treatments or between sample times, however, multivariate analysis confirmed that overall parasitoid community structure differed significantly among treatments and between sample times, with the high ant attendance treatment differing most from the other two treatments. Interestingly the absence of ants did not result in increased parasitism from four of the five parasitoids. Ants in lac insect farming systems have a clear role for agricultural pest management. A full understanding of the asymmetric abilities of ants to influence parasitoid communities, and affect parasitism of hosts will require further experimental manipulation to assess the relative roles of 1) the abundance of each individual ant species on parasitoid access to hosts, 2) competition among parasitoids, and 3) the interaction between the first two factors. PMID:24887398

  3. Mitochondrial ATP transporter Ant2 depletion impairs erythropoiesis and B lymphopoiesis.

    PubMed

    Cho, J; Seo, J; Lim, C H; Yang, L; Shiratsuchi, T; Lee, M-H; Chowdhury, R R; Kasahara, H; Kim, J-S; Oh, S P; Lee, Y J; Terada, N

    2015-09-01

    Adenine nucleotide translocases (ANTs) transport ADP and ATP through mitochondrial inner membrane, thus playing an essential role for energy metabolism of eukaryotic cells. Mice have three ANT paralogs, Ant1 (Slc25a4), Ant2 (Slc25a5) and Ant4 (Slc25a31), which are expressed in a tissue-dependent manner. While knockout mice have been characterized with Ant1 and Ant4 genes, which resulted in exercise intolerance and male infertility, respectively, the role of the ubiquitously expressed Ant2 gene in animal development has not been fully demonstrated. Here, we generated Ant2 hypomorphic mice by targeted disruption of the gene, in which Ant2 expression is largely depleted. The mice showed apparently normal embryonic development except pale phenotype along with a reduced birth rate. However, postnatal growth was severely retarded with macrocytic anemia, B lymphocytopenia, lactic acidosis and bloated stomach, and died within 4 weeks. Ant2 depletion caused anemia in a cell-autonomous manner by maturation arrest of erythroid precursors with increased reactive oxygen species and premature deaths. B-lymphocyte development was similarly affected by Ant2 depletion, and splenocytes showed a reduction in maximal respiration capacity and cellular ATP levels as well as an increase in cell death accompanying mitochondrial permeability transition pore opening. In contrast, myeloid, megakaryocyte and T-lymphocyte lineages remained apparently intact. Erythroid and B-cell development may be particularly vulnerable to Ant2 depletion-mediated mitochondrial dysfunction and oxidative stress. PMID:25613378

  4. First Results of 3 Year Monitoring of Red Wood Ants' Behavioural Changes and Their Possible Correlation with Earthquake Events

    NASA Astrophysics Data System (ADS)

    Berberich, Gabriele; Berberich, Martin; Grumpe, Arne; Wöhler, Christian; Schreiber, Ulrich

    2013-04-01

    Short-term earthquake predictions with an advance warning of several hours or days can currently not be performed reliably and remain limited to only a few minutes before the event. Abnormal animal behaviours prior to earthquakes have been reported previously but their detection creates problems in monitoring and reliability. A different situation is encountered for red wood ants (RWA; Formica rufa-group (Hymenoptera: Formicidae). They have stationary nest sites on tectonically active, gas-bearing fault systems. These faults may be potential earthquake areas and are simultaneously information channels deeply reaching into the crust. A particular advantage of monitoring RWA is their high sensitivity to environmental changes. Besides an evolutionarily developed extremely strong temperature sensitivity of 0.25 K, they have chemoreceptors for the detection of CO2 concentrations and a sensitivity for electromagnetic fields. Changes of the electromagnetic field are discussed or short-lived "thermal anomalies" are reported as trigger mechanisms for bioanomalies of impending earthquakes. For 3 years, we have monitored two Red Wood Ant mounds (Formica rufa-group), located at the seismically active Neuwied Basin (Eifel, Germany), 24/7 by high-resolution cameras equipped with a colour and infrared sensor. In the Neuwied Basin, an average of about 100 earthquakes per year with magnitudes up to M 3.9 occur located on different tectonic fault regimes (strike-slip faults and/or normal or thrust faults). The RWA mounds are located on two different fault regimes approximately 30 km apart. First results show that the ants have a well-identifiable standard daily routine. Correlation with local seismic events suggests changes in the ants' behaviour hours before the earthquake event: The nocturnal rest phase and daily activity are suppressed, and standard daily routine is continued not before the next day. Additional parameters that might have an effect on the ants' daily routine (including climate data, earth tides, lunar phases and biological parameters) are recorded and correlated with the analysed daily activity. Additionally, nest air measurements (CO2, Helium, Radon, H2S and CH4) are performed at intervals. At present, an automated image analysis routine is being applied to the acquired more than 45,000 hours of video stream data. It is a valuable tool to objectively identify and classify the ants' activity on top of mounds and to examine possible correlations with earthquakes. Based on this automated approach, a statistical analysis of the ants' behaviour is intended. The investigation and results presented here are a first access to a completely new research complex. The key question is whether the ants' behavioural changes and their correlation with earthquake events are statistically significant and if a detection by an automated system is possible. Long-term studies have to show whether confounding factors and climatic influences can clearly be distinguished. Although the first results suggest that it is promising to consolidate and extend the research to determine a pattern for exceptional situations, there is, however, still a long way to go for a usable automated earthquake warning system. References Berberich G (2010): Identifikation junger gasführender Störungszonen in der West- und Hocheifel mit Hilfe von Bioindikatoren. Dissertation. Essen, 293 S. Berberich G, Klimetzek D, Wöhler C., and Grumpe A (2012): Statistical Correlation between Red Wood Ant Sites and Neotectonic Strike-Slip Faults. Geophysical Research Abstracts Vol. 14, EGU2012-3518 Berberich G, Berberich M, Grumpe A, Wöhler C., and Schreiber U (2012): First Results of 3 Year Monitoring of Red Wood Ants' Behavioural Changes and Their Possible Correlation with Earthquake Events. Animals, ISSN 2076-2615,. Special Issue "Biological Anomalies Prior to Earthquakes") (in prep.) Dologlou E. (2010): Recent aspects on possible interrelation between precursory electric signals and anomalous bioeffects. Nat. Hazards Earth Syst. Sci., 10, 1951-1955. Kir

  5. ANTS: Exploring the Solar System with an Autonomous Nanotechnology Swarm

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    ANTS (Autonomous Nano-Technology Swarm), a NASA advanced mission concept, calls for a large (1000 member) swarm of pico-class (1 kg) totally autonomous spacecraft to prospect the asteroid belt. Additional information is contained in the original extended abstract.

  6. Mapping the navigational knowledge of individually foraging ants, Myrmecia croslandi

    PubMed Central

    Narendra, Ajay; Gourmaud, Sarah; Zeil, Jochen

    2013-01-01

    Ants are efficient navigators, guided by path integration and visual landmarks. Path integration is the primary strategy in landmark-poor habitats, but landmarks are readily used when available. The landmark panorama provides reliable information about heading direction, routes and specific location. Visual memories for guidance are often acquired along routes or near to significant places. Over what area can such locally acquired memories provide information for reaching a place? This question is unusually approachable in the solitary foraging Australian jack jumper ant, since individual foragers typically travel to one or two nest-specific foraging trees. We find that within 10 m from the nest, ants both with and without home vector information available from path integration return directly to the nest from all compass directions, after briefly scanning the panorama. By reconstructing panoramic views within the successful homing range, we show that in the open woodland habitat of these ants, snapshot memories acquired close to the nest provide sufficient navigational information to determine nest-directed heading direction over a surprisingly large area, including areas that animals may have not visited previously. PMID:23804615

  7. ECOLOGY AND POPULATION BIOLOGY Mermithid Nematode Parasitism of Solenopsis Ants

    E-print Network

    Ronquist, Fredrik

    ECOLOGY AND POPULATION BIOLOGY Mermithid Nematode Parasitism of Solenopsis Ants (Hymenoptera nematodes, parasitism SINCE ITS INTRODUCTION into the United States more than half a century ago,the red,S.invicta Buren, andS. pergandei Forel intheApalachicola National Forest were parasitized occasionally bya large

  8. Three-dimensional sampling method for characterizing ant mounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field-portable 3D laser scanner was employed as a means of digitizing the surface of fire ant (Solenopsis invicta Buren) mounds for analysis of shape and orientation in Mississippi and Oklahoma. Estimates of above-ground mound volume obtained through manual measurements of mound length, width, an...

  9. Automatic Programming with Ant Colony Optimization Jennifer Green

    E-print Network

    Kent, University of

    search technique is then carried out on a space of graphs where the nodes represent functions, variables and constants and the graph overall represents a parse tree for that function. Functions are usually definedAutomatic Programming with Ant Colony Optimization Jennifer Green University of Kent jg9@kent

  10. Seed harvester ants (Polonomyrmex rugosus) as "pulse" predators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed harvesting ants, Pogonomyrmex rugosus, collected grass cicadas at a high rate (>5 min-1 taken into the nest) at one location where cicada emergence exceeded 3m-2. Dry conditions in the winter-spring resulted in no annual plants in the northern Chihuahuan Desert. P. rugosus colonies were inactiv...

  11. A model of ant route navigation driven by scene familiarity.

    PubMed

    Baddeley, Bart; Graham, Paul; Husbands, Philip; Philippides, Andrew

    2012-01-01

    In this paper we propose a model of visually guided route navigation in ants that captures the known properties of real behaviour whilst retaining mechanistic simplicity and thus biological plausibility. For an ant, the coupling of movement and viewing direction means that a familiar view specifies a familiar direction of movement. Since the views experienced along a habitual route will be more familiar, route navigation can be re-cast as a search for familiar views. This search can be performed with a simple scanning routine, a behaviour that ants have been observed to perform. We test this proposed route navigation strategy in simulation, by learning a series of routes through visually cluttered environments consisting of objects that are only distinguishable as silhouettes against the sky. In the first instance we determine view familiarity by exhaustive comparison with the set of views experienced during training. In further experiments we train an artificial neural network to perform familiarity discrimination using the training views. Our results indicate that, not only is the approach successful, but also that the routes that are learnt show many of the characteristics of the routes of desert ants. As such, we believe the model represents the only detailed and complete model of insect route guidance to date. What is more, the model provides a general demonstration that visually guided routes can be produced with parsimonious mechanisms that do not specify when or what to learn, nor separate routes into sequences of waypoints. PMID:22241975

  12. Evolving Deep Recurrent Neural Networks Using Ant Colony Optimization

    E-print Network

    Hu, Wen-Chen

    for designing and training neural networks such as convolutional and deep learning strategies, popular withinEvolving Deep Recurrent Neural Networks Using Ant Colony Optimization Travis Desell1 , Sophine colony optimization (ACO) to evolve the structure of deep recurrent neural networks. While versions

  13. A Model of Ant Route Navigation Driven by Scene Familiarity

    PubMed Central

    Baddeley, Bart; Graham, Paul; Husbands, Philip; Philippides, Andrew

    2012-01-01

    In this paper we propose a model of visually guided route navigation in ants that captures the known properties of real behaviour whilst retaining mechanistic simplicity and thus biological plausibility. For an ant, the coupling of movement and viewing direction means that a familiar view specifies a familiar direction of movement. Since the views experienced along a habitual route will be more familiar, route navigation can be re-cast as a search for familiar views. This search can be performed with a simple scanning routine, a behaviour that ants have been observed to perform. We test this proposed route navigation strategy in simulation, by learning a series of routes through visually cluttered environments consisting of objects that are only distinguishable as silhouettes against the sky. In the first instance we determine view familiarity by exhaustive comparison with the set of views experienced during training. In further experiments we train an artificial neural network to perform familiarity discrimination using the training views. Our results indicate that, not only is the approach successful, but also that the routes that are learnt show many of the characteristics of the routes of desert ants. As such, we believe the model represents the only detailed and complete model of insect route guidance to date. What is more, the model provides a general demonstration that visually guided routes can be produced with parsimonious mechanisms that do not specify when or what to learn, nor separate routes into sequences of waypoints. PMID:22241975

  14. Evolutionarily advanced ant farmers rear polyploid fungal crops.

    PubMed

    Kooij, P W; Aanen, D K; Schiøtt, M; Boomsma, J J

    2015-11-01

    Innovative evolutionary developments are often related to gene or genome duplications. The crop fungi of attine fungus-growing ants are suspected to have enhanced genetic variation reminiscent of polyploidy, but this has never been quantified with cytological data and genetic markers. We estimated the number of nuclei per fungal cell for 42 symbionts reared by 14 species of Panamanian fungus-growing ants. This showed that domesticated symbionts of higher attine ants are polykaryotic with 7-17 nuclei per cell, whereas nonspecialized crops of lower attines are dikaryotic similar to most free-living basidiomycete fungi. We then investigated how putative higher genetic diversity is distributed across polykaryotic mycelia, using microsatellite loci and evaluating models assuming that all nuclei are either heterogeneously haploid or homogeneously polyploid. Genetic variation in the polykaryotic symbionts of the basal higher attine genera Trachymyrmex and Sericomyrmex was only slightly enhanced, but the evolutionarily derived crop fungi of Atta and Acromyrmex leaf-cutting ants had much higher genetic variation. Our opposite ploidy models indicated that the symbionts of Trachymyrmex and Sericomyrmex are likely to be lowly and facultatively polyploid (just over two haplotypes on average), whereas Atta and Acromyrmex symbionts are highly and obligatorily polyploid (ca. 5-7 haplotypes on average). This stepwise transition appears analogous to ploidy variation in plants and fungi domesticated by humans and in fungi domesticated by termites and plants, where gene or genome duplications were typically associated with selection for higher productivity, but allopolyploid chimerism was incompatible with sexual reproduction. PMID:26265100

  15. Stabilities of ant nests and their adjacent soils

    NASA Astrophysics Data System (ADS)

    Echezona, B. C.; Igwe, C. A.

    2012-10-01

    Nests habour ants and termites and protect them from harsh environmental conditions. The structural stabilities of nests were studied to ascertain their relative vulnerability to environmental stresses. Arboreal-ant nests were pried from different trees, while epigeous-termite nests were excavated from soil surface within the sample area. Soils without any visible sign of ant or termite activity were also sampled 6 m away from the nests as control. Laboratory analysis result showed that irrespective of the tree hosts, the aggregate stabilities of the ant nests were lower than those of the ground termite, with nests formed on Cola nitida significantly showing lower aggregate stability (19.7%) than other antnest structures. Clay dispersion ratio, moisture content, water stable aggregate class <0.25mm and sand mass were each negatively correlated with aggregate stability, while water stable aggregate class1.00-0.50 mm gave a positive correlation. Nest structures were dominated more by water stable aggregate class >2.00 mm but path analysis demonstrated that water stable aggregate class <0.25 mm contributed most to the higher aggregate stability of the termite nest than the other nest. Nest aggregates had greater structural stability compared to the control soil. The higher structural stability of termite nests over other nest and soil was considered a better adaptive mechanism against body desiccation.

  16. Hybridization in East African swarm-raiding army ants

    PubMed Central

    2011-01-01

    Background Hybridization can have complex effects on evolutionary dynamics in ants because of the combination of haplodiploid sex-determination and eusociality. While hybrid non-reproductive workers have been found in a range of species, examples of gene-flow via hybrid queens and males are rare. We studied hybridization in East African army ants (Dorylus subgenus Anomma) using morphology, mitochondrial DNA sequences, and nuclear microsatellites. Results While the mitochondrial phylogeny had a strong geographic signal, different species were not recovered as monophyletic. At our main study site at Kakamega Forest, a mitochondrial haplotype was shared between a "Dorylus molestus-like" and a "Dorylus wilverthi-like" form. This pattern is best explained by introgression following hybridization between D. molestus and D. wilverthi. Microsatellite data from workers showed that the two morphological forms correspond to two distinct genetic clusters, with a significant proportion of individuals being classified as hybrids. Conclusions We conclude that hybridization and gene-flow between the two army ant species D. molestus and D. wilverthi has occurred, and that mating between the two forms continues to regularly produce hybrid workers. Hybridization is particularly surprising in army ants because workers have control over which males are allowed to mate with a young virgin queen inside the colony. PMID:21859477

  17. Evolutionary transitions in enzyme activity of ant fungus gardens.

    PubMed

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

    2010-07-01

    Fungus-growing (attine) ants and their fungal symbionts passed through several evolutionary transitions during their 50 million year old evolutionary history. The basal attine lineages often shifted between two main cultivar clades, whereas the derived higher-attine lineages maintained 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 toward partial degradation of plant cell walls, reflecting a plesiomorphic state of nondomesticated 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 breakdown of cell walls. The adaptive significance of the lower-attine symbiont shifts remains unclear. One of these shifts was obligate, but digestive advantages remained ambiguous, whereas the other remained facultative despite providing greater digestive efficiency. PMID:20067517

  18. Three energy variables predict ant abundance at a geographical scale

    E-print Network

    O'Donnell, Sean

    local abundance of ectotherms to geographical gradients in temperature. A survey of 49 New World in seasonal sites with longer, colder winters (r2 0.082) that help ectotherm taxa sequester harvested energy; ants; ectotherms; climate change 1. INTRODUCTION Abiotic conditions have long been known to shape

  19. Fire ant baits and biocontrol with pathogens update

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The insect growth regulator (IGR) methoprene (isopropyl-(2E,4E,7R,S)-11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate) has been shown to have deleterious effects on red imported fire ants, Solenopsis invicta. It interferes with normal development of worker caste brood and reduces queen egg production...

  20. The genome of the fire ant Solenopsis invicta.

    PubMed

    Wurm, Yannick; Wang, John; Riba-Grognuz, Oksana; Corona, Miguel; Nygaard, Sanne; Hunt, Brendan G; Ingram, Krista K; Falquet, Laurent; Nipitwattanaphon, Mingkwan; Gotzek, Dietrich; Dijkstra, Michiel B; Oettler, Jan; Comtesse, Fabien; Shih, Cheng-Jen; Wu, Wen-Jer; Yang, Chin-Cheng; Thomas, Jerome; Beaudoing, Emmanuel; Pradervand, Sylvain; Flegel, Volker; Cook, Erin D; Fabbretti, Roberto; Stockinger, Heinz; Long, Li; Farmerie, William G; Oakey, Jane; Boomsma, Jacobus J; Pamilo, Pekka; Yi, Soojin V; Heinze, Jürgen; Goodisman, Michael A D; Farinelli, Laurent; Harshman, Keith; Hulo, Nicolas; Cerutti, Lorenzo; Xenarios, Ioannis; Shoemaker, Dewayne; Keller, Laurent

    2011-04-01

    Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta, are also major pests. Here, we present a draft genome of S. invicta, assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothers. We used comparative genomic methods to obtain insight into the unique features of the S. invicta genome. For example, we found that this genome harbors four adjacent copies of vitellogenin. A phylogenetic analysis revealed that an ancestral vitellogenin gene first underwent a duplication that was followed by possibly independent duplications of each of the daughter vitellogenins. The vitellogenin genes have undergone subfunctionalization with queen- and worker-specific expression, possibly reflecting differential selection acting on the queen and worker castes. Additionally, we identified more than 400 putative olfactory receptors of which at least 297 are intact. This represents the largest repertoire reported so far in insects. S. invicta also harbors an expansion of a specific family of lipid-processing genes, two putative orthologs to the transformer/feminizer sex differentiation gene, a functional DNA methylation system, and a single putative telomerase ortholog. EST data indicate that this S. invicta telomerase ortholog has at least four spliceforms that differ in their use of two sets of mutually exclusive exons. Some of these and other unique aspects of the fire ant genome are likely linked to the complex social behavior of this species. PMID:21282665

  1. RESEARCH ARTICLE Macronutrient regulation in the Rasberry crazy ant

    E-print Network

    Eubanks, Micky

    RESEARCH ARTICLE Macronutrient regulation in the Rasberry crazy ant (Nylanderia sp. nr. pubens) S that strong macronutrient regulation occurs at the colony level. Here, we explored regulation of protein foods (14­42% total macronutrient content) having a range of fixed p:c ratios in a series of choice

  2. A BARREL of fun in AntARcticA

    E-print Network

    Christian, Eric

    A BARREL of fun in AntARcticA National Aeronautics and Space Administration www.nasa.gov Volume 10 balloon scientists, are having a BARREL of fun in Antarctica. The Balloon Array for Radiation belt--to launch over Antarctica. The balloon-borne instruments will gather data on magnetic systems and send

  3. Dynamic Thermal Structure of Imported Fire Ant Mounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was undertaken to characterize surface temperatures of imported fire ant (Solenopsis invicta Buren, S. richteri Forel, and their hybrid) mounds as it relates to sun position and shape of the mounds, to better understand factors that affect absorption of solar radiation by the nest mound and ...

  4. A Review of the Biological Control of Fire Ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The suppression of well-established invasive ants will likely require biological control by natural enemies. This approach is self-sustaining and can impact undetected or inaccessible populations that are the source of the continual presence and expansion of the invaders. There is an ongoing effor...

  5. Modeling Ant Navigation with an Autonomous Agent Ralf Moller?

    E-print Network

    Moeller, Ralf

    Modeling Ant Navigation with an Autonomous Agent Ralf Moller? , Dimitrios Lambrinos? , Rolf Pfeifer are illustrated in our recent studies, in which an autonomous agent navigated by us- ing directional information The ability to navigate in a complex environment is crucial for both animals and robots. Many animals use

  6. Three spectrally distinct photoreceptors in diurnal and nocturnal Australian ants.

    PubMed

    Ogawa, Yuri; Falkowski, Marcin; Narendra, Ajay; Zeil, Jochen; Hemmi, Jan M

    2015-06-01

    Ants are thought to be special among Hymenopterans in having only dichromatic colour vision based on two spectrally distinct photoreceptors. Many ants are highly visual animals, however, and use vision extensively for navigation. We show here that two congeneric day- and night-active Australian ants have three spectrally distinct photoreceptor types, potentially supporting trichromatic colour vision. Electroretinogram recordings show the presence of three spectral sensitivities with peaks (?max) at 370, 450 and 550 nm in the night-active Myrmecia vindex and peaks at 370, 470 and 510 nm in the day-active Myrmecia croslandi. Intracellular electrophysiology on individual photoreceptors confirmed that the night-active M. vindex has three spectral sensitivities with peaks (?max) at 370, 430 and 550 nm. A large number of the intracellular recordings in the night-active M. vindex show unusually broad-band spectral sensitivities, suggesting that photoreceptors may be coupled. Spectral measurements at different temporal frequencies revealed that the ultraviolet receptors are comparatively slow. We discuss the adaptive significance and the probability of trichromacy in Myrmecia ants in the context of dim light vision and visual navigation. PMID:25994678

  7. Mitochondrial genome evolution in fire ants (Hymenoptera: Formicidae)

    PubMed Central

    2010-01-01

    Background Complete mitochondrial genome sequences have become important tools for the study of genome architecture, phylogeny, and molecular evolution. Despite the rapid increase in available mitogenomes, the taxonomic sampling often poorly reflects phylogenetic diversity and is often also biased to represent deeper (family-level) evolutionary relationships. Results We present the first fully sequenced ant (Hymenoptera: Formicidae) mitochondrial genomes. We sampled four mitogenomes from three species of fire ants, genus Solenopsis, which represent various evolutionary depths. Overall, ant mitogenomes appear to be typical of hymenopteran mitogenomes, displaying a general A+T-bias. The Solenopsis mitogenomes are slightly more compact than other hymentoperan mitogenomes (~15.5 kb), retaining all protein coding genes, ribosomal, and transfer RNAs. We also present evidence of recombination between the mitogenomes of the two conspecific Solenopsis mitogenomes. Finally, we discuss potential ways to improve the estimation of phylogenies using complete mitochondrial genome sequences. Conclusions The ant mitogenome presents an important addition to the continued efforts in studying hymenopteran mitogenome architecture, evolution, and phylogenetics. We provide further evidence that the sampling across many taxonomic levels (including conspecifics and congeners) is useful and important to gain detailed insights into mitogenome evolution. We also discuss ways that may help improve the use of mitogenomes in phylogenetic analyses by accounting for non-stationary and non-homogeneous evolution among branches. PMID:20929580

  8. SHORT COMMUNICATION Attraction of ants by an invasive Acacia

    E-print Network

    Obbard, Darren

    SHORT COMMUNICATION Attraction of ants by an invasive Acacia MARKUS P. EICHHORN, LOUISE C. RATLIFFE be deprived of their co-evolved mutualists. In southern Portugal Acacia dealbata has become naturalised induction, extra-floral nectaries, invasive species, Linepithema humile, Portugal. Introduction Acacia trees

  9. Worker senescence and the sociobiology of aging in ants

    PubMed Central

    Giraldo, Ysabel Milton; Traniello, James F. A.

    2014-01-01

    Senescence, the decline in physiological and behavioral function with increasing age, has been the focus of significant theoretical and empirical research in a broad array of animal taxa. Preeminent among invertebrate social models of aging are ants, a diverse and ecologically dominant clade of eusocial insects characterized by reproductive and sterile phenotypes. In this review, we critically examine selection for worker lifespan in ants and discuss the relationship between functional senescence, longevity, task performance, and colony fitness. We did not find strong or consistent support for the hypothesis that demographic senescence in ants is programmed, or its corollary prediction that workers that do not experience extrinsic mortality die at an age approximating their lifespan in nature. We present seven hypotheses concerning how selection could favor extended worker lifespan through its positive relationship to colony size and predict that large colony size, under some conditions, should confer multiple and significant fitness advantages. Fitness benefits derived from long worker lifespan could be mediated by increased resource acquisition, efficient division of labor, accuracy of collective decision-making, enhanced allomaternal care and colony defense, lower infection risk, and decreased energetic costs of workforce maintenance. We suggest future avenues of research to examine the evolution of worker lifespan and its relationship to colony fitness, and conclude that an innovative fusion of sociobiology, senescence theory, and mechanistic studies of aging can improve our understanding of the adaptive nature of worker lifespan in ants. PMID:25530660

  10. Management of Imported Fire Ants in Cattle Production Systems 

    E-print Network

    Fuchs, Thomas W.; Drees, Bastiaan M.

    2004-03-31

    reactions and even death of livestock and humans. Figur e 2. T exas A&M fir e ant image galler y 2 Alabama Cooperative Extension System livestock injury or death or equipment damage, is low and may only happen once over a period of years. Losses associated...

  11. Textural defect detect using a revised ant colony clustering algorithm

    NASA Astrophysics Data System (ADS)

    Zou, Chao; Xiao, Li; Wang, Bingwen

    2007-11-01

    We propose a totally novel method based on a revised ant colony clustering algorithm (ACCA) to explore the topic of textural defect detection. In this algorithm, our efforts are mainly made on the definition of local irregularity measurement and the implementation of the revised ACCA. The local irregular measurement defined evaluates the local textural inconsistency of each pixel against their mini-environment. In our revised ACCA, the behaviors of each ant are divided into two steps: release pheromone and act. The quantity of pheromone released is proportional to the irregularity measurement; the actions of the ants to act next are chosen independently of each other in a stochastic way according to some evaluated heuristic knowledge. The independency of ants implies the inherent parallel computation architecture of this algorithm. We apply the proposed method in some typical textural images with defects. From the series of pheromone distribution map (PDM), it can be clearly seen that the pheromone distribution approaches the textual defects gradually. By some post-processing, the final distribution of pheromone can demonstrate the shape and area of the defects well.

  12. Nest Relocation in Harvester Ants DEBORAH M. GORDON*

    E-print Network

    Gordon, Deborah

    Nest Relocation in Harvester Ants DEBORAH M. GORDON* Centre for Population Biology, Imperial been suggested that colonies of the genus Pogonomyrmex relocate their nests in response to crowding by neighboring colonies. Nest relocations and dis- tances moved were observed in a population of about 250

  13. General Dissection of Female Ant Reproductive System and Brain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dissection of the reproductive system of ant workers and queens can be useful for answering many questions. Observations of ovarian status in both female castes can be used to identify relationships between other factors and the ovaries, determine whether an individual has laid eggs, and, with more ...

  14. Identification, Distribution, and Biology of Fire Ants in Texas. 

    E-print Network

    Hung, Akey C.F.; Barlin, Margaret R.; Vinson, S. Bradleigh

    1977-01-01

    in protein. The venom of fire ants is unique in containing alkaloids with a relatively small amount of pro te in (Brand et a/., 1972). The venom is used to immobilize or kill prey for food; in addition, it possesses insec? ticidal, bactericidal...

  15. 9 CFR 352.10 - Ante-mortem inspection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Ante-mortem inspection. 352.10 Section 352.10 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND...

  16. MODELING DYNAMIC THERMAL PROPERTIES OF IMPORTED FIRE ANT MOUNDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ground-based thermal infrared imagery, 3-dimensional modeling, and spatial analyses were used to model daily fluctuation in the temperature of imported fire ant mounds and their surroundings. The thermal center of the mound moved in a predictable fashion from east-southeast to west-southwest during...

  17. Reproductive phenologies in a diverse temperate ant fauna

    USGS Publications Warehouse

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

    2007-01-01

    1. Ant nuptial flights are central to understanding ant life history and ecology but have been little studied. This study examined the timing of nuptial flights, the synchronicity of nuptial flights (as a potential index of mating strategy), and variation in nuptial flights with elevation and among years in a diverse temperate ant fauna. 2. Flights occurred throughout the year, but were concentrated in the beginning of summer and in early fall (autumn). Relative to the entire flight season, closely related species tended to be more likely than expected by chance to fly at similar times, perhaps because of phylogenetic constraints on life history evolution. 3. Flights were relatively synchronous within species for nearly all species considered, but synchronicity did not appear to be a robust estimate of overall mating strategy. 4. Overall patterns in nuptial flights among species and the timing of flights for individual species varied with elevation, but did not vary greatly among years. 5. Although this study is one of the most comprehensive on the reproductive flight phenologies of ants, much remains to be learned about the causes and consequences of such spatial and temporal variation in flight phenology. ?? 2007 The Royal Entomological Society.

  18. Bilingualism Aids Conflict Resolution: Evidence from the ANT Task

    ERIC Educational Resources Information Center

    Costa, Albert; Hernandez, Mirea; Sebastian-Galles, Nuria

    2008-01-01

    The need of bilinguals to continuously control two languages during speech production may exert general effects on their attentional networks. To explore this issue we compared the performance of bilinguals and monolinguals in the attentional network task (ANT) developed by Fan et al. [Fan, J., McCandliss, B.D. Sommer, T., Raz, A., Posner, M.I.…

  19. VideoANT: Extending Online Video Annotation beyond Content Delivery

    ERIC Educational Resources Information Center

    Hosack, Bradford

    2010-01-01

    This paper expands the boundaries of video annotation in education by outlining the need for extended interaction in online video use, identifying the challenges faced by existing video annotation tools, and introducing Video-ANT, a tool designed to create text-based annotations integrated within the time line of a video hosted online. Several…

  20. ANT 3631 : CHANGEMENT SOCIAL ET LINGUISTIQUE Plan de cours

    E-print Network

    Leclercq, Remi

    relation entre l'acquisition des langues et le changement linguistique? Peut-on retracer le parcours1 ANT 3631 : CHANGEMENT SOCIAL ET LINGUISTIQUE Plan de cours ENSEIGNANTE Nom : Renée Lambert changent pour toutes sortes de raisons. Les changements linguistiques de grande envergure se produisent le

  1. Juvenile Hormone Extraction, Purification, and Quantification in Ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile hormone (JH) is an important insect hormone known to have many effects on development, reproduction, and behavior in both solitary and social insects. A number of questions using ants as a model involve JH. This procedure allows for quantification of circulating levels of JH III, which can ...

  2. Global invasion history of the Fire Ant Solenopsis invicta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fire ant Solenopsis invicta is a serious agricultural, ecological, and public health pest that was inadvertently introduced into the southern USA almost a century ago and into California and other regions of the world more recently. An assessment of genetic variation at a diverse set of molecula...

  3. Multiple functions of fire ant, Solenopsis invicta, mandibular gland products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Alarm pheromones are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality in social insects. Recently, we identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of the fire ant, Solenopsis invicta. We continu...

  4. HOST LOCATION BEHAVIOR IN A PARASITOID OF IMPORTED FIRE ANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Female parasitoids use a hierarchy of cues to locate suitable hosts. We conducted a series of field observations and experiments to examine host location behavior in Pseudacteon tricuspis Borgmeier, a phorid fly parasitoid of Solenopsis invicta Buren worker ants. The parasitoids were frequently at...

  5. Aerial manoeuvrability in wingless gliding ants (Cephalotes atratus)

    PubMed Central

    Yanoviak, Stephen P.; Munk, Yonatan; Kaspari, Mike; Dudley, Robert

    2010-01-01

    In contrast to the patagial membranes of gliding vertebrates, the aerodynamic surfaces used by falling wingless ants to direct their aerial descent are unknown. We conducted ablation experiments to assess the relative contributions of the hindlegs, midlegs and gaster to gliding success in workers of the Neotropical arboreal ant Cephalotes atratus (Hymenoptera: Formicidae). Removal of hindlegs significantly reduced the success rate of directed aerial descent as well as the glide index for successful flights. Removal of the gaster alone did not significantly alter performance relative to controls. Equilibrium glide angles during successful targeting to vertical columns were statistically equivalent between control ants and ants with either the gaster or the hindlegs removed. High-speed video recordings suggested possible use of bilaterally asymmetric motions of the hindlegs to effect body rotations about the vertical axis during targeting manoeuvre. Overall, the control of gliding flight was remarkably robust to dramatic anatomical perturbations, suggesting effective control mechanisms in the face of adverse initial conditions (e.g. falling upside down), variable targeting decisions and turbulent wind gusts during flight. PMID:20236974

  6. The Ant and the Grasshopper: Fast and Accurate Pointer Analysis for Millions of Lines of Code

    E-print Network

    Patt, Yale

    The Ant and the Grasshopper: Fast and Accurate Pointer Analysis for Millions of Lines of Code Ben. The precision and performance of 1 Hence the reference to Aesop's fable "The Ant and the Grasshopper" [1

  7. COMMUNITY AND ECOSYSTEM ECOLOGY Plant Resources and Colony Growth in an Invasive Ant: The

    E-print Network

    Helms, Ken

    may often be determined di- rectly or indirectly by diet. Many ants are generalist omnivores that animal tissues are important to omnivorous ants, whereas the importance of plant- based resources is less

  8. Activity of Bifenthrin, Chlorfenapyr, Fipronil, and Thiamethoxam against Red Imported Fire Ants (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr). Mobility impairment and lethal times were determined following topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and thi...

  9. The genomic impact of 100 million years of social evolution in seven ant species

    PubMed Central

    Gadau, Jürgen; Helmkampf, Martin; Nygaard, Sanne; Roux, Julien; Simola, Daniel F.; Smith, Chris R.; Suen, Garret; Wurm, Yannick; Smith, Christopher D.

    2011-01-01

    Ants (Hymenoptera, Formicidae) represent one of the most successful eusocial taxa in terms of both their geographic distribution and species number. The publication of seven ant genomes within the past year was a quantum leap for socio- and ant genomics. The diversity of social organization in ants makes them excellent model organisms to study the evolution of social systems. Comparing the ant genomes with those of the honeybee, a lineage that evolved eusociality independently from ants, and solitary insects suggests that there are significant differences in key aspects of genome organization between social and solitary insects, as well as among ant species. Altogether, these seven ant genomes open exciting new research avenues and opportunities for understanding the genetic basis and regulation of social species, and adaptive complex systems in general. PMID:21982512

  10. Activity of Bifenthrin, Chlorfenapyr, Fipronil, and Thiamethoxam against Argentine Ants (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr). Mobility impairment and lethal times were determined following topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and th...

  11. 9 CFR 352.19 - Ante-mortem inspection and applicable requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Horses § 352.19 Ante-mortem inspection and applicable...official establishment that wishes to slaughter horses can apply for voluntary ante-mortem...

  12. 9 CFR 352.19 - Ante-mortem inspection and applicable requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Horses § 352.19 Ante-mortem inspection and applicable...official establishment that wishes to slaughter horses can apply for voluntary ante-mortem...

  13. 9 CFR 352.19 - Ante-mortem inspection and applicable requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Horses § 352.19 Ante-mortem inspection and applicable...official establishment that wishes to slaughter horses can apply for voluntary ante-mortem...

  14. 9 CFR 352.19 - Ante-mortem inspection and applicable requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Horses § 352.19 Ante-mortem inspection and applicable...official establishment that wishes to slaughter horses can apply for voluntary ante-mortem...

  15. 9 CFR 352.19 - Ante-mortem inspection and applicable requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Horses § 352.19 Ante-mortem inspection and applicable...official establishment that wishes to slaughter horses can apply for voluntary ante-mortem...

  16. Of Ants and Elephants Asaf Shiloni, Noa Agmon and Gal A. Kaminka

    E-print Network

    Kaminka, Gal A.

    - vestigate if one dominates the other. We present two algorithms: AntEater, which allows Elephant robots and thus, they are incomparable. We present two algorithms: AntEater, which allows Elephant robots to exe

  17. Pathophysiology and transmission of Thelohania solenopsae in the red imported fire ants, Solenopsis invicta 

    E-print Network

    Chen, Johnny Shou-Chung

    2005-11-01

    Thelohania solenopsae are intracellular pathogens found in the red imported fire ant, Solenopsis invicta. These pathogens cause detrimental effects to their fire ant hosts. The present study revealed that the midgut and the meconium materials from...

  18. Uni-directional trail sharing by two species of ants a Monte Carlo study

    NASA Astrophysics Data System (ADS)

    Kunduraci, T.; Kayacan, O.

    2015-06-01

    We study insect traffic, specifically ant traffic on a uni-directional trail which is shared by two species of ants, one of which is ‘good’ at smelling and the other ‘poor’. The two distinct species of ants are placed mixed on the same trail and individuals of both are permitted to make a U-turn when they encounter another ant in front of them. The theoretical scheme for the ant traffic is based on an asymmetric simple exclusion model. The ant traffic on the uni-directional trail is studied as a function of the number of ‘good-smelling’ ants and the evaporation probability of pheromones by keeping the number of ‘poor-smelling ants’ constant during Monte Carlo simulations.

  19. Researcharticle Evolution at Two Levels in Fire Ants: The Relationship between

    E-print Network

    Yi, Soojin

    Researcharticle Evolution at Two Levels in Fire Ants: The Relationship between Patterns of Gene the relationship between protein coding sequence evolution and gene expression patterns in the fire ants Solenopsis

  20. Yellow jackets may be an underestimated component of an ant-seed mutualism

    USGS Publications Warehouse

    Bale, M.T.; Zettler, J.A.; Robinson, B.A.; Spira, T.P.; Allen, C.R.

    2003-01-01

    Yellow jackets (Hymenoptera: Vespidae) are attracted to the typically ant-dispersed seeds of trilliums and will take seeds from ants in the genus Aphaenogaster. To determine if yellow jacket, Vespula maculifrons (Buysson), presence interferes with seed foraging by ants, we presented seeds of Trillium discolor Wray to three species (A. texana carolinensis Wheeler, Formica schaufussi Mayr, and Solenopsis invicta Buren) of seed-carrying ants in areas where vespids were present or excluded. We found that interspecific aggression between yellow jackets and ants is species specific. Vespid presence decreased average foraging time and increased foraging efficiency of two of the three ant species studied, a situation that might reflect competition for a limited food source. We also found that yellow jackets removed more seeds than ants, suggestive that vespids are important, albeit underestimated, components of ant-seed mutualisms.

  1. MODIFICATIONS OF FINE- AND COARSE-TEXTURED SOIL MATERIAL CAUSED BY THE ANT FORMICA SUBSERICEA

    E-print Network

    Drager, Kim

    2015-05-31

    The majority of ant-related bioturbation research has focused on physiochemical properties of the nest mound. However, ants are also known to line subsurface nest components (chambers and galleries) with coarse material, and may expand or backfill...

  2. Impact of imidacloprid on new queens of imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neonicotinoid insecticides are commonly used in managing pest ants, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicot...

  3. Hydrogel baits with low-dose thiamethoxam for sustainable Argentine ant management in commercial

    E-print Network

    Buczkowski, Grzegorz

    effective for Argentine ant control in fruit orchards when used in low concentrations (0.007%), and (2 as an urban pest (Knight & Rust, 1990), the Argentine ant can also have severe negative impacts on natural

  4. Ant Abundance along a Productivity Gradient: Addressing Two Conflicting Hypotheses

    PubMed Central

    Segev, Udi; Kigel, Jaime; Lubin, Yael; Tielbörger, Katja

    2015-01-01

    The number of individuals within a population or community and their body size can be associated with changes in resource supply. While these relationships may provide a key to better understand the role of abiotic vs. biotic constraints in animal communities, little is known about the way size and abundance of organisms change along resource gradients. Here, we studied this interplay in ants, addressing two hypotheses with opposite predictions regarding variation in population densities along resource gradients- the ‘productivity hypothesis’ and the ‘productivity-based thinning hypothesis’. The hypotheses were tested in two functional groups of ground-dwelling ants that are directly primary consumers feeding on seeds: specialized seed-eaters and generalist species. We examined variations in colony density and foraging activity (a size measurement of the forager caste) in six ant assemblages along a steep productivity gradient in a semi-arid region, where precipitation and plant biomass vary 6-fold over a distance of 250km. An increase in the density or foraging activity of ant colonies along productivity gradients is also likely to affect competitive interactions among colonies, and consequently clinal changes in competition intensity were also examined. Ant foraging activity increased with productivity for both functional groups. However, colony density revealed opposing patterns: it increased with productivity for the specialized seed-eaters, but decreased for the generalist species. Competition intensity, evaluated by spatial partitioning of species at food baits and distribution of colonies, was uncorrelated with productivity in the specialized seed-eaters, but decreased with increasing productivity in the generalists. Our results provide support for two contrasting hypotheses regarding the effect of resource availability on the abundance of colonial organisms- the ‘productivity hypothesis’ for specialized seed-eaters and the ‘productivity-based thinning hypothesis’ for generalist species. These results also stress the importance of considering the role of functional groups in studies of community structure. PMID:26176853

  5. Glass-like dynamics in confined and congested ant traffic.

    PubMed

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

    2015-09-01

    The collective movement of animal groups often occurs in confined spaces. As animal groups are challenged to move at high density, their mobility dynamics may resemble the flow of densely packed non-living soft materials such as colloids, grains, or polymers. However, unlike inert soft-materials, self-propelled collective living systems often display social interactions whose influence on collective mobility are only now being explored. In this paper, we study the mobility of bi-directional traffic flow in a social insect (the fire ant Solenopsis invicta) as we vary the diameter of confining foraging tunnels. In all tunnel diameters, we observe the emergence of spatially heterogeneous regions of fast and slow traffic that are induced through two phenomena: physical obstruction, arising from the inability of individual ants to interpenetrate, and time-delay resulting from social interaction in which ants stop to briefly antennate. Density correlation functions reveal that the relaxation dynamics of high density traffic fluctuations scale linearly with fluctuation size and are sensitive to tunnel diameter. We separate the roles of physical obstruction and social interactions in traffic flow using cellular automata based simulation. Social interaction between ants is modeled as a dwell time (Tint) over which interacting ants remain stationary in the tunnel. Investigation over a range of densities and Tint reveals that the slowing dynamics of collective motion in social living systems are consistent with dynamics near a fragile glass transition in inert soft-matter systems. In particular, flow is relatively insensitive to density until a critical density is reached. As social interaction affinity is increased (increasing Tint) traffic dynamics change and resemble a strong glass transition. Thus, social interactions play an important role in the mobility of collective living systems at high density. Our experiments and model demonstrate that the concepts of soft-matter physics aid understanding of the mobility of collective living systems, and motivate further inquiry into the dynamics of densely confined social living systems. PMID:26106969

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

    PubMed

    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

  7. Fatty amines from little black ants, Monomorium minimum, and their biological activities against red imported fire ants, Solenopsis invicta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemistry of defensive sections in the genus Monomorium has been subjected to rigorous research. The venom of little black ants, Monomorium minimum, has been reported to be dominated by insecticidal alkaloids including 2,5-dialkypyrrolidines and 2,5-dialkypyrrolines. In this study, analysis of def...

  8. Forest Health: Texas Leaf-Cutting Ant http://tfsweb.tamu.edu Page 1 of 2

    E-print Network

    Forest Health: Texas Leaf-Cutting Ant http://tfsweb.tamu.edu Page 1 of 2 Texas leaf-cutting ant material and construct tunnels and chambers, and the small workers maintain fungal gardens and care garden. The nest area of the Texas leaf-cutting ant is marked by characteristic crescent-shaped mounds

  9. Tallgrass prairie ants: their species composition, ecological roles, and response to management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ants are highly influential organisms in terrestrial ecosystems, including the tallgrass prairie, one of the most endangered ecosystems in North America. Through their tunneling, ants affect soil properties and resource availability for animals and plants. Ants also have important ecological roles a...

  10. Thelytokous Parthenogenesis in the Fungus-Gardening Ant Mycocepurus smithii (Hymenoptera: Formicidae)

    E-print Network

    Miller, Scott

    Thelytokous Parthenogenesis in the Fungus-Gardening Ant Mycocepurus smithii (Hymenoptera thelytoky in the asexual fungus-gardening ant, Mycocepurus smithii, in which queens produce female offspring-Santos IA, Mueller UG, et al. (2009) Thelytokous Parthenogenesis in the Fungus-Gardening Ant Mycocepurus

  11. Host-Plant Mediation of Insect Mutualisms: Variable Outcomes in Herbivore-Ant Interactions

    E-print Network

    Cushman, J. Hall

    Host-Plant Mediation of Insect Mutualisms: Variable Outcomes in Herbivore-Ant Interactions J. Hall-plant mediaabn of insect mutualisms: variable outcomes in herbivore-ant interactions J . Hall Cushman, School, the attractiveness of herbivores to ants must vary predictably with intra- andlor interspecific changes in host

  12. LIVESTOCK GRAZING EFFECTS ON ANT COMMUNITIES IN THE EASTERN MOJAVE DESERT, USA

    EPA Science Inventory

    The effects of livestock grazing on composition and structure of ant communities were examined in the eastern Mojave Desert, USA for the purpose of evaluating ant communities as potential indicators of rangeland condition. Metrics for ant communities, vegetation, and other groun...

  13. Research article Protein marking reveals predation on termites by the woodland ant,

    E-print Network

    Buczkowski, Grzegorz

    Research article Protein marking reveals predation on termites by the woodland ant, Aphaenogaster; accepted 26 March 2007. Published Online First 20 April 2007 Abstract. Subterranean termites provide a major poten- tial food source for forest-dwelling ants, yet the inter- actions between ants and termites

  14. COMPARISON OF ANOVA AND KRIGING IN DETECTING ANT RESPONSES TO ENVIRONMENTAL STRESSORS

    EPA Science Inventory

    In an ecosystems, ants effect ecosystem functions such as water infiltration, soil nutrient distribution and composition of the soil seed bank. Ants have also been used as indicators of ecosystems health. In a study, we hypothesized that some ant species would respond to changes ...

  15. ANTS AS BIOLOGICAL INDICATORS FOR MONITORING CHANGES IN ARID ENVIRONMENTS: LESSONS FOR MONITORING PROTECTED AREAS

    EPA Science Inventory

    The responses of ant communities to structural change (removal of an invasive
    were studied in a replicated experiment in a Chihuahuan Desert grassland. The
    results from sampling of ant communities by pit-fall trapping were validated by
    mapping ant colonies on the expe...

  16. ANTS AS BIOLOGICAL INDICATORS FOR MONITORING CHANGES IN ARID ENVIRONMENTS: LESSONS FOR MONITORING PROTECTED AREAS

    EPA Science Inventory

    The responses of ant communities to structural change (removal of an invasive were studied in a replicated experiment in a Chihuahuan Desert grassland. The results from sampling of ant communities by pit-fall trapping were validated by mapping ant colonies on the experimental plo...

  17. PsANT, the adenine nucleotide translocase of Puccinia striiformis, promotes cell death and fungal growth

    PubMed Central

    Tang, Chunlei; Wei, Jinping; Han, Qingmei; Liu, Rui; Duan, Xiaoyuan; Fu, Yanping; Huang, Xueling; Wang, Xiaojie; Kang, Zhensheng

    2015-01-01

    Adenine nucleotide translocase (ANT) is a constitutive mitochondrial component that is involved in ADP/ATP exchange and mitochondrion-mediated apoptosis in yeast and mammals. However, little is known about the function of ANT in pathogenic fungi. In this study, we identified an ANT gene of Puccinia striiformis f. sp. tritici (Pst), designated PsANT. The PsANT protein contains three typical conserved mitochondrion-carrier-protein (mito-carr) domains and shares more than 70% identity with its orthologs from other fungi, suggesting that ANT is conserved in fungi. Immuno-cytochemical localization confirmed the mitochondrial localization of PsANT in normal Pst hyphal cells or collapsed cells. Over-expression of PsANT indicated that PsANT promotes cell death in tobacco, wheat and fission yeast cells. Further study showed that the three mito-carr domains are all needed to induce cell death. qRT-PCR analyses revealed an in-planta induced expression of PsANT during infection. Knockdown of PsANT using a host-induced gene silencing system (HIGS) attenuated the growth and development of virulent Pst at the early infection stage but not enough to alter its pathogenicity. These results provide new insight into the function of PsANT in fungal cell death and growth and might be useful in the search for and design of novel disease control strategies. PMID:26058921

  18. TRAIL PHEROMONE-CONDITIONED ANEMOTAXIS BY THE ARGENTINE ANT, ZRZDOMYRMEX HUMZLZS

    E-print Network

    -conditioned anemotaxis was exhibited by Argentine ant workers, Iridomyrmex humilis (Mayr) to sources of the major trail -Iridomyrmex humihs meters away, Argentine ants do move upwind in a vapor field permeated with 7.9-16 : ALD and to point sources of this compound In the trail-recruitment system of the Argen- tine ant, Iridomyrmex

  19. Ant semiochemicals limit apterous aphid dispersal Thomas H. Oliver1,*, Alla Mashanova2

    E-print Network

    Ant semiochemicals limit apterous aphid dispersal Thomas H. Oliver1,*, Alla Mashanova2 , Simon R in order to obtain benefit. Ants are known to limit alate aphid dispersal by physically removing wings dispersal and higher local densities of aphids, which benefit ants in terms of increased honeydew and prey

  20. Aphid-tending Ants Affect Secondary Users in Leaf Shelters and Rates of Herbivory on

    E-print Network

    Sanders, Nathan J.

    Aphid-tending Ants Affect Secondary Users in Leaf Shelters and Rates of Herbivory on Salix. We studied the effects of a keystone species, the aphid-tending ant (Formica obscuripes California. Leaf shelters on branches with aphid-tending ants had 54% more individuals than shelters

  1. Wars of attrition: colony size determines competitive outcomes in a guild of African acacia ants

    E-print Network

    Palmer, Todd M.

    Wars of attrition: colony size determines competitive outcomes in a guild of African acacia ants competition for nest sites in a guild of acacia ants residing on Acacia drepanolobium. I show that (1 differences in estimated average colony size among the four acacia ant species, and (3) experimental

  2. Integrated Pest Management in and Around the Home Red ImpoRted FIRe Ant

    E-print Network

    Ishida, Yuko

    . Our native southern fire ant (Solenopsis xy- loni) is about the same size and color as the red are all the same size (1/5 inch long) and are red in color (many people refer to these as red ants anything touching their mound or food source. Undisturbed red imported fire ant mounds are frequently dome

  3. Qualitative analysis of red imported fire ant nests constructed in silica gel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red imported fire ants, Solenopsis invicta Buren, build nests by excavating soil. Incorporation of ant-derived chemicals in nesting material has long been known, however only a few chemicals have been identified. This paucity of identified ant-derived chemicals may be due to the interference from ...

  4. Urban ants of North America and Europe: identification, biology, and management by John Klotz, Laurel Hansen,

    E-print Network

    Lucky, Andrea

    Urb-ants Urban ants of North America and Europe: identification, biology, and management by John the much needed link bridging arttaxonomyandappliedentomology.UrbanAntsof North America and Europe combines andnatural historians interested inthe ants that live in urban environments. The authors state their intent

  5. 78 FR 70530 - Notice of Determination; New and Revised Treatments for the Imported Fire Ant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ...and Revised Treatments for the Imported Fire Ant Program AGENCY: Animal and Plant Health...certain treatment schedules for the Imported Fire Ant Program in the Plant Protection and...and revised treatments in the imported fire ant program. Based on the treatment...

  6. SYSTEMATICS Bulldog Ants of the Eocene Okanagan Highlands and History of the

    E-print Network

    Archibald, S. Bruce

    SYSTEMATICS Bulldog Ants of the Eocene Okanagan Highlands and History of the Subfamily (Hymenoptera Ann. Entomol. Soc. Am. 99(3): 487Ð523 (2006) ABSTRACT The presence of the ant subfamily Myrmeciinae ants are treated as Myrmeciites incertae sedis, a male from Falkland and a female (worker or queen

  7. Comparing Adaptivity of Ants using NEAT and Teo Gelles & Mario Sanchez

    E-print Network

    Meeden, Lisa A.

    Comparing Adaptivity of Ants using NEAT and rtNEAT Teo Gelles & Mario Sanchez Swarthmore College Class of 2016 Abstract Although individual ants have an extremely basic intelligence, and are completely incapable of surviving on their own, colonies of ants can develop remarkably sophisticated and biologically

  8. Ants and Reinforcement Learning: A Case Study in Routing in Dynamic Networks

    E-print Network

    Subramanian, Devika

    Ants and Reinforcement Learning: A Case Study in Routing in Dynamic Networks Devika Subramanian on simple biological ''ants'' that explore the network and rapidly learn good routes, using a novel vari by the dynamics of how ant colonies learn the shortest routes to food sources, using very little state

  9. Bacterial gut symbionts are tightly linked with the evolution of herbivory in ants

    E-print Network

    Pierce, Naomi E.

    Bacterial gut symbionts are tightly linked with the evolution of herbivory in ants Jacob A for review March 12, 2009) Ants are a dominant feature of terrestrial ecosystems, yet we know little about. Persistence on these nitrogen-poor food sources raises the question of how ants obtain sufficient nutrition

  10. Sham nepotism as a result of intrinsic differences in brood viability in ants

    E-print Network

    Kümmerli, Rolf

    Sham nepotism as a result of intrinsic differences in brood viability in ants Barbara Holzer , Rolf and latent conflicts due to the selfish interests of individuals are in delicate balance. In many ant species demonstrate that workers of the ant Formica exsecta do not discriminate between highly related and unrelated

  11. Bahamas Naturalist & Journal of Science September 2006 27 THE ANTS OF SMALL

    E-print Network

    Morrison, Lloyd W.

    Bahamas Naturalist & Journal of Science September 2006 27 THE ANTS OF SMALL BAHAMIAN CAYS Lloyd Morrison Missouri State University, Ohio Abstract Ants are ubiquitous in the Bahamas, and are found even on the smallest cays, Surveys for ants on over 260 small cays in four archipelagos (Exuma Cays, Great Exuma

  12. Evaluating alternative hypotheses for the early evolution and diversification of ants

    E-print Network

    Brady, Seán

    Evaluating alternative hypotheses for the early evolution and diversification of ants Sea´n G (received for review July 12, 2006) Ants are the world's most diverse and ecologically dominant eusocial organisms. Resolving the phylogeny and timescale for major ant lineages is vital to understanding how

  13. Individual Rules for Trail Pattern Formation in Argentine Ants (Linepithema humile)

    E-print Network

    Theraulaz, Guy

    Individual Rules for Trail Pattern Formation in Argentine Ants (Linepithema humile) Andrea Perna1 by Argentine ants exploring an empty arena. Using a novel imaging and analysis technique we estimated pheromone the response function of individual ants to pheromone concentrations by looking at correlations between

  14. THE EFFECTS OF ANTS ON THE ENTOMOPHAGOUS BUTTERFLY CATERPILLAR Feniseca tarquinius,

    E-print Network

    Devries, Philip J.

    THE EFFECTS OF ANTS ON THE ENTOMOPHAGOUS BUTTERFLY CATERPILLAR Feniseca tarquinius subfamily Miletinae are predators of ant-tended Homoptera, yet they lack specialized secretory and call-production organs crucial to ant association in other lycaenids. Here, we address the question of how miletine

  15. Ant Agents for Hybrid Multipath Routing in Mobile Ad Hoc Networks

    E-print Network

    Montresor, Alberto

    Ant Agents for Hybrid Multipath Routing in Mobile Ad Hoc Networks Frederick Ducatelle, Gianni Di), and was founded in 1988 by the Dalle Molle Foundation which promoted quality of life. #12;#12;Ant Agents-Lugano, Switzerland {frederick,gianni,luca}@idsia.ch Abstract In this paper we describe AntHocNet, an algorithm

  16. Introduction Ants, one of the most abundant groups of insects, exhibit

    E-print Network

    Cheng, Ken

    570 Introduction Ants, one of the most abundant groups of insects, exhibit diverse navigational strategies. Most of the commonly seen ants adhere to pheromones and reach the nest or the food source by forming long trails. Naïve foragers of some species of ants adhere to established trails when travelling

  17. ARMY ANT RAID ATTENDANCE AND BIVOUAC-CHECKING BEHAVIOR BY NEOTROPICAL MONTANE FOREST BIRDS

    E-print Network

    O'Donnell, Sean

    ARMY ANT RAID ATTENDANCE AND BIVOUAC-CHECKING BEHAVIOR BY NEOTROPICAL MONTANE FOREST BIRDS SEAN O at army ant swarm raids (n 5 48) in a neotropical montane forest. All observations were during seasons when Nearctic migrant birds are present. Bird species differed in army ant raid-attending behavior

  18. An orb-weaver spider exploits an ant–acacia mutualism for enemy-free space

    PubMed Central

    Styrsky, John D

    2014-01-01

    Exploiters of protection mutualisms are assumed to represent an important threat for the stability of those mutualisms, but empirical evidence for the commonness or relevance of exploiters is limited. Here, I describe results from a manipulative study showing that an orb-weaver spider, Eustala oblonga, inhabits an ant-acacia for protection from predators. This spider is unique in the orb-weaver family in that it associates closely with both a specific host plant and ants. I tested the protective effect of acacia ants on E.?oblonga by comparing spider abundance over time on acacias with ants and on acacias from which entire ant colonies were experimentally removed. Both juvenile and adult spider abundance significantly decreased over time on acacias without ants. Concomitantly, the combined abundance of potential spider predators increased over time on acacias without ants. These results suggest that ant protection of the ant-acacia Acacia melanocerus also protects the spiders, thus supporting the hypothesis that E.?oblonga exploits the ant–acacia mutualism for enemy-free space. Although E.?oblonga takes advantage of the protection services of ants, it likely exacts little to no cost and should not threaten the stability of the ant–acacia mutualism. Indeed, the potential threat of exploiter species to protection mutualisms in general may be limited to species that exploit the material rewards traded in such mutualisms rather than the protection services. PMID:24558583

  19. An orb-weaver spider exploits an ant-acacia mutualism for enemy-free space.

    PubMed

    Styrsky, John D

    2014-02-01

    Exploiters of protection mutualisms are assumed to represent an important threat for the stability of those mutualisms, but empirical evidence for the commonness or relevance of exploiters is limited. Here, I describe results from a manipulative study showing that an orb-weaver spider, Eustala oblonga, inhabits an ant-acacia for protection from predators. This spider is unique in the orb-weaver family in that it associates closely with both a specific host plant and ants. I tested the protective effect of acacia ants on E.?oblonga by comparing spider abundance over time on acacias with ants and on acacias from which entire ant colonies were experimentally removed. Both juvenile and adult spider abundance significantly decreased over time on acacias without ants. Concomitantly, the combined abundance of potential spider predators increased over time on acacias without ants. These results suggest that ant protection of the ant-acacia Acacia melanocerus also protects the spiders, thus supporting the hypothesis that E.?oblonga exploits the ant-acacia mutualism for enemy-free space. Although E.?oblonga takes advantage of the protection services of ants, it likely exacts little to no cost and should not threaten the stability of the ant-acacia mutualism. Indeed, the potential threat of exploiter species to protection mutualisms in general may be limited to species that exploit the material rewards traded in such mutualisms rather than the protection services. PMID:24558583

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

    PubMed

    Denison, R Ford

    2014-07-01

    Two recent reports discuss interactions between plants and ants that defend them from herbivores. Acacia trees provide their ant bodyguards with a diet that reduces their ability to benefit from alternate hosts. Provisioning of ants by Cordia trees during drought may buy insurance against extreme defoliation events, not just average-year benefits. PMID:24815041