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1

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....

2

John Muir Exhibit  

NSDL National Science Digital Library

Compiled by Harold Wood and Harvey Chinn and hosted by the Sierra Club, this site features interesting information on the father of modern conservation and founder of the Sierra Club. The site contains a list of Muir's publications, favorite quotes, and many other Muir-related items such as: study guides, information on historic sites, live dramatic presentations of Muir, places named after Muir, and songs and music related and dedicated to Muir. Also included is a section on Muir scholarship including an annotated bibliography. Multimedia items include video clips (RealPlayer or VivoActive Player) from portrayals of Muir, and RealAudio recordings of some of the many actors currently performing live portraits of Muir.

3

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,...

4

Ant Colonies for the Traveling Salesman Problem  

Microsoft Academic Search

We describe an artificial ant colony capable of solving the traveling salesman problem (TSP).Ants of the artificial colony are able to generate successively shorter feasible tours by usinginformation accumulated in the form of a pheromone trail deposited on the edges of the TSPgraph. Computer simulations demonstrate that the artificial ant colony is capable of generatinggood solutions to both symmetric and

Luca Maria Gambardella; Marco Dorigo

1997-01-01

5

John Muir Photographs  

NSDL National Science Digital Library

John Muir was a wanderer, a thinker, and a tinkerer of great repute. This digital collection from the University of the Pacific in Stockton, California brings together images of this great American for use by researchers, scholars, and anyone else with a penchant for Muir's life and times. The images come from their special collections, and they include items from the formal John Muir Papers collection and the James Eastman Shone Collection of Muiriana. There are 242 images in the collection, and visitors can look over them at their leisure, or perform their own detailed search. There's much to look at here, as the shots include Muir with Andrew Carnegie in Los Angeles, Muir at his home in Martinez, and a fair number of shots of Muir walking through the wilderness he loved so dearly.

6

Forced Evolution in Silico by Artificial Transposons and their Genetic Operators: The John Muir Ant Problem  

Microsoft Academic Search

Modern evolutionary computation utilizes heuristic optimizations based upon\\u000aconcepts borrowed from the Darwinian theory of natural selection. We believe\\u000athat a vital direction in this field must be algorithms that model the activity\\u000aof genomic parasites, such as transposons, in biological evolution. This\\u000apublication is our first step in the direction of developing a minimal\\u000aassortment of algorithms that simulate

Alexander V. Spirov; Alexander B. Kazansky; Leonid Zamdborg; Juan J. Merelo; Vladimir F. Levchenko

2009-01-01

7

Multiple colony ant algorithm for job-shop scheduling problem  

Microsoft Academic Search

Ant colony optimization (ACO) is a metaheuristic that takes inspiration from the foraging behaviour of a real ant colony to solve the optimization problem. This paper presents a multiple colony ant algorithm to solve the Job-shop Scheduling Problem with the objective that minimizes the makespan. In a multiple colony ant algorithm, ants cooperate to find good solutions by exchanging information

A. Udomsakdigool; V. Kachitvichyanukul

2008-01-01

8

Ant Colony Optimization and Hypergraph Covering Problems  

E-print Network

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

Pat, Ankit

2011-01-01

9

The John Muir Award.  

ERIC Educational Resources Information Center

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…

White, Graham

2002-01-01

10

Reply to James Muir  

ERIC Educational Resources Information Center

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…

White, John

2004-01-01

11

Parallel Ant System for Traveling Salesman Problem on  

E-print Network

Ant Colony Optimization(ACO) is a meta-heuristic introduced in 1991 by Dorigo et al. on TSP problem(Dorigo, 1992). This alorithm is inspired by the natural behavior of real ants. Ants usually communicate via pheromone trail, i.e. an ant would lay down some mount of pheromone on the passed path. An ant’s tendency to choose a specific path is positively correlated to the intensity

Ying-shiuan You

12

JOHN MUIR COLLEGE ENVIRONMENTAL GRANTS APPLICATION 20132014  

E-print Network

JOHN MUIR COLLEGE ENVIRONMENTAL GRANTS APPLICATION 20132014 All application documents to complete their projects by Friday of John Muir Week 2014 (John Muir Week is normally the third week, including the adviser's letter of support, must be received in the Muir College Provost's office by 4:00 p

Gleeson, Joseph G.

13

Page 1 of 2 Muir College  

E-print Network

a Study Abroad Scholarship from John Muir College and if for any reason I do not attend the programPage 1 of 2 Muir College Study Abroad Scholarship Application The Muir College Study Abroad Scholarship is open to Muir College students who will participate in Study Abroad programs during

Talley, Lynne D.

14

JOHN MUIR WILDERNESS, CALIFORNIA.  

USGS Publications Warehouse

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.

Dellinger, David A.; Johnson, Frederick L.

1984-01-01

15

Improved ant colony algorithm for solving assignment problem  

Microsoft Academic Search

Assignment problem is one of the fundamental combinatorial optimization problems, ant colony algorithm is a kind of bionic optimization algorithm. The method of applying improved ant colony algorithm to assignment problem is analyzed. Based on the definitions of migration matrix, cost matrix, pheromone matrix, the node selection strategy, local pheromone updating rules and global pheromone updating rules are introduced in

Chunhui Piao; Xufang Han; Yalan Wu

2010-01-01

16

John Muir National Historic Site  

NSDL National Science Digital Library

John Muir was a man who liked to wander, but with a purpose. His affinity for the natural world in all of its manifestations was omnipresent in his writings as well as in his efforts to assure that future generations would be able to see some of the landscapes that he surveyed in the 19th century. While Muir spent some of his formative years in Wisconsin, after leaving the University of Wisconsin, he journeyed west, and for the remainder of his life he lived with his family in Martinez, California. Muir did not build the home himself, but he and his family took up residence in 1890, and many decades after his death, the John Muir Historic Site was created to preserve this unique place. Recently, the National Park Service created this website to pay homage to the man and his legacy, and in doing so, they have also crafted a site that can also be used to educate young and old alike about Muir's work. Within the various sections, users can learn about Muir's family through slide shows of historic images, and also about his writings.

17

An Ant Colony Optimization Algorithm for Shop Scheduling Problems  

Microsoft Academic Search

We deal with the application of ant colony optimization to group shop scheduling, which is a general shop scheduling problem that includes, among others, the open shop scheduling problem and the job shop scheduling problem as special cases. The contributions of this paper are twofold. First, we propose a neighborhood structure for this problem by extending the well-known neighborhood structure

Christian Blum; Michael Sampels

2004-01-01

18

The John Muir Exhibit: Educational Resources  

NSDL National Science Digital Library

The John Muir Exhibit was created by the Sierra Club to display and commemorate the life of John Muir and his role in the environmental movement. The Educational Resources that are provided are for students and teachers from grade school to graduate school, interested in studying Muir's legacy as a naturalist, writer, conservationist and founder of the Sierra Club. A student page provides research materials from biographies to articles, and study guides assists teachers in preparing commemorations of Muir and his work, with focus on John Muir Day. A listing of John Muir awards provides students with the opportunity to apply for and win scholarships. Other John Muir Education programs are listed such as poster contests and case studies history projects.

19

Ant colony system for a dynamic vehicle routing problem  

E-print Network

Problem (VRP) a fleet of vehicles with limited capacity has to be routed in order to visit a setAnt colony system for a dynamic vehicle routing problem R. Montemanni , L.M. Gambardella, A-6928 Manno-Lugano, Switzerland Abstract An aboundant literature on vehicle routing problems

Gambardella, Luca Maria

20

Hybrid Ant Algorithm and Applications for Vehicle Routing Problem  

NASA Astrophysics Data System (ADS)

Ant colony optimization (ACO) is a metaheuristic method that inspired by the behavior of real ant colonies. ACO has been successfully applied to several combinatorial optimization problems, but it has some short-comings like its slow computing speed and local-convergence. For solving Vehicle Routing Problem, we proposed Hybrid Ant Algorithm (HAA) in order to improve both the performance of the algorithm and the quality of solutions. The proposed algorithm took the advantages of Nearest Neighbor (NN) heuristic and ACO for solving VRP, it also expanded the scope of solution space and improves the global ability of the algorithm through importing mutation operation, combining 2-opt heuristics and adjusting the configuration of parameters dynamically. Computational results indicate that the hybrid ant algorithm can get optimal resolution of VRP effectively.

Xiao, Zhang; Jiang-qing, Wang

21

Ants  

NSDL National Science Digital Library

In this outdoor activity, learners investigate ant behavior by testing ant feeding reactions to different types of food. Learners attempt to discover an ant "superfood" and use that food to try and get some ants from a colony to start a new one at a different location. Based on what learners observe, they also consider how ants communicate with each other.

Science, Lawrence H.

1980-01-01

22

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 such that each agent is controlled by an asynchronous (randomized) finite state machine: they possess a constant actions are controlled by a randomized finite state machine (FSM) operating in an asynchronous en

23

MAX-MIN Ant System and local search for the traveling salesman problem  

Microsoft Academic Search

Ant System is a general purpose algorithm inspired by the study of the behavior of ant colonies. It is based on a cooperative search paradigm that is applicable to the solution of combinatorial optimization problems. We introduce MAX-MIN Ant System, an improved version of basic Ant System, and report our results for its application to symmetric and asymmetric instances of

Thomas Stutzle; Holger Hoos

1997-01-01

24

Sebaceous neoplasia and Torre-Muir syndrome  

PubMed Central

Summary Sebaceous tumours include hyperplasia, adenoma, sebaceoma and carcinoma. Importantly, the latter three are potential markers of Torre–Muir syndrome; the hereditary association of sebaceous neoplasia and internal malignancy, most commonly colorectal carcinoma. The diagnostic features, differential diagnosis, molecular diagnostics and recent advances in pathogenesis of this rare group of tumours are discussed along with Torre–Muir syndrome and recommendations for screening for this important association. PMID:18670585

Lazar, A.J.F.; Lyle, S.; Calonje, E.

2007-01-01

25

Study on the Convergence of Hybrid Ant Colony Algorithm for Job Shop Scheduling Problems  

Microsoft Academic Search

To improve the performance of intelligence optimization algorithm for solving Job Shop Scheduling Problem ,a hybrid ant colony algorithm called tabu search and ant (TSANT) algorithm with global convergence was proposed. In the hybrid ant colony algorithm, the MMAS algorithm was applied to search in the global solution space, and the tabu search algorithm was utilized as the local algorithm.

Xiaoyu Song; Lihua Sun

2010-01-01

26

Ant colony system: a cooperative learning approach to the traveling salesman problem  

Microsoft Academic Search

This paper introduces ant colony system (ACS), a distributed algorithm that is applied to the traveling salesman problem (TSP). In ACS, a set of cooperating agents called ants cooperate to find good solutions to TSPs. Ants cooperate using an indirect form of communication mediated by pheromone they deposit on the edges of the TSP graph while building solutions. We study

Marco Dorigo; Luca Maria Gambardella

1997-01-01

27

Houston, We Have a Problem: Rasberry Crazy Ants  

E-print Network

Since first discovered in Pasadena in 2002 by pest control operator Tom Rasberry, Rasberry crazy ants have spread to 11 southeast Texas counties. Here are facts about these ants, with information for the public about what to do to avoid spreading...

Drees, Bastiaan M.

2009-03-15

28

Combining Lagrangian heuristic and Ant Colony System to solve the Single Source Capacitated Facility Location Problem  

Microsoft Academic Search

The facility location problems have been applied extensively in practice. We describe a Multiple Ant Colony System (MACS) to solve the Single Source Capacitated Facility Location Problem (SSCFLP). Lagrangian heuristics have been shown to produce good solutions for the SSCFLP. A hybrid algorithm, which combines Lagrangian heuristic and Ant Colony System (ACS), LH–ACS, is developed for the SSCFLP. The performance

Chia-Ho Chen; Ching-Jung Ting

2008-01-01

29

An Improved Ant Colony Optimization for Flexible Job Shop Scheduling Problems  

Microsoft Academic Search

An improved ant colony optimization (IACO) algorithm is proposed to the flexible job shop scheduling problem (FJSSP) in this paper. IACO algorithm provides an effective integration between ant colony optimization (ACO) model and knowledge model. In the IACO algorithm, knowledge model learns some available knowledge from the optimization of ACO, and then employs the existing knowledge to guide the current

Dong-sheng Xu; Xiao-yan Ai; Li-ning Xing

2009-01-01

30

A Knowledge-Based Ant Colony Optimization for Flexible Job Shop Scheduling Problems  

Microsoft Academic Search

A Knowledge-Based Ant Colony Optimization (KBACO) algorithm is proposed in this paper for the Flexible Job Shop Scheduling Problem (FJSSP). KBACO algorithm provides an effective integration between Ant Colony Optimization (ACO) model and knowledge model. In the KBACO algorithm, knowledge model learns some available knowledge from the optimization of ACO, and then applies the existing knowledge to guide the current

Li-Ning Xing; Ying-Wu Chen; Peng Wang; Qing-Song Zhao; Jian Xiong

2010-01-01

31

A Hybrid Method of Genetic Algorithms and Ant Colony Optimization to Solve the Traveling Salesman Problem  

Microsoft Academic Search

A new hybrid method iterative extended changing crossover operators which can efficiently obtain the optimum solution of the traveling salesman problem through flexibly alternating ant colony optimization (ACO) which simulates process of learning swarm intelligence in ants' feeding behavior and edge assembly crossover (EAX) which has been recently noticed as an available method for efficient selection of optimum solution with

Ryouei Takahashi

2009-01-01

32

Improved ant colony algorithm for vehicle scheduling problems of military logistics distribution  

Microsoft Academic Search

This paper is aimed to research into military vehicle scheduling problem (VSP) by using ant colony algorithm. A vehicle scheduling model with time windows was built up based on the objective of minimum transportation distance, and the model characteristics and application prospects was analyzed. Based on local search strategies, traditional ant colony algorithm was improved. Then the algorithmic procedures of

Gong Yancheng; Huang Ronggui; Yang Xirui; Shi Hongxing; Li Chang

2010-01-01

33

Ant Colony System: A Cooperative Learning Approach to the Traveling Salesman Problem  

Microsoft Academic Search

This paper introduces ant colony system (ACS), a distributed algorithm that is appliedto the traveling salesman problem (TSP). In ACS, a set of cooperating agents calledants cooperate to find good solutions to TSPs. Ants cooperate using an indirect form ofcommunication mediated by pheromone they deposit on the edges of the TSP graphwhile building solutions. We study ACS by running experiments

Marco Dorigo

1996-01-01

34

Christianity to Ecology: John Muir's Walk through America. John Muir is best remembered today for the role he played in the establishment of the  

E-print Network

Christianity to Ecology: John Muir's Walk through America. John Muir is best remembered today family and brought up according to dogmatic calvinistic tenets, John Muir displayed an usual passion, John Muir kept a journal of his travel. It was published much later as A Thousand-Mile Walk to the Gulf

Paris-Sud XI, Université de

35

Ant Colony Optimisation and Local Search for Bin Packing and Cutting Stock Problems  

E-print Network

Ant Colony Optimisation and Local Search for Bin Packing and Cutting Stock Problems John Levine, bin packing, cutting stock Abstract The Bin Packing Problem and the Cutting Stock Problem are two to solve both Bin Packing and Cutting Stock Problems. We present a pure ACO approach, as well as an ACO

Ducatelle, Frederick

36

The TrampThe Muir Environmental Corps Quarterly Newsletter Spring 2013  

E-print Network

......................................................................................................................2 Upcoming Events - John Muir Week/Earth WeekThe TrampThe Muir Environmental Corps Quarterly Newsletter Spring 2013 #12;The Tramp: 1 Farewell

Gleeson, Joseph G.

37

An empirical test of Muir’s typology of police officers  

Microsoft Academic Search

In 1977 William K. Muir published a treatise that established a theoretical framework for distinguishing police officers according to the way they deal with citizens. This was an invaluable contribution because the scholarly literature on police up to that time had concentrated on the similarities among police officersespecially the common values and patterns of behavior associated with a police subculture

Jeffrey B. Snipes; Stephen D. Mastrofski

1990-01-01

38

36 CFR 7.6 - Muir Woods National Monument.  

Code of Federal Regulations, 2012 CFR

...Property 1 2012-07-01 2012-07-01 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...

2012-07-01

39

36 CFR 7.6 - Muir Woods National Monument.  

Code of Federal Regulations, 2013 CFR

...Property 1 2013-07-01 2013-07-01 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...

2013-07-01

40

36 CFR 7.6 - Muir Woods National Monument.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

41

36 CFR 7.6 - Muir Woods National Monument.  

Code of Federal Regulations, 2011 CFR

...Property 1 2011-07-01 2011-07-01 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...

2011-07-01

42

Muir Glacier in Glacier Bay National Monument 1950  

USGS Multimedia Gallery

This August 1950 photo documents the significant changes that occurred during the 9 years between photographs A and B. Muir Glacier has retreated more than 2 miles, exposing Muir Inlet, and thinned 340 feet or more. However, it still is connected with tributary Riggs Glacier....

43

An Ant Colony Optimization Approach for the MultiLevel Unconstrained Lot-Sizing Problem  

Microsoft Academic Search

An ant colony optimization approach for the multilevel unconstrained lot-sizing problem (MLULSP) is described and evaluated using 176 benchmark problems from the literature, with problem sizes varying from 5 to 500 products and up to 52 periods. The approach consists of a binary encoding of production plans. The lot-sizing decisions are mapped on a routing graph to apply the metaheuristic

Jörg Homberger; Hermann Gehring

2009-01-01

44

Solution Representation for Job Shop Scheduling Problems in Ant Colony Optimisation  

E-print Network

Solution Representation for Job Shop Scheduling Problems in Ant Colony Optimisation James applications for these problems generate solutions by constructing a permutation of the operations, from which solutions. The performance of both approaches is com- pared on a real-world job shop scheduling problem

Montgomery, James

45

Study on MAX-MIN Ant System with Random Selection in Quadratic Assignment Problem  

NASA Astrophysics Data System (ADS)

Ant Colony Optimization (ACO), which is a type of swarm intelligence inspired by ants' foraging behavior, has been studied extensively and its effectiveness has been shown by many researchers. The previous studies have reported that MAX-MIN Ant System (MMAS) is one of effective ACO algorithms. The MMAS maintains the balance of intensification and diversification concerning pheromone by limiting the quantity of pheromone to the range of minimum and maximum values. In this paper, we propose MAX-MIN Ant System with Random Selection (MMASRS) for improving the search performance even further. The MMASRS is a new ACO algorithm that is MMAS into which random selection was newly introduced. The random selection is one of the edgechoosing methods by agents (ants). In our experimental evaluation using ten quadratic assignment problems, we have proved that the proposed MMASRS with the random selection is superior to the conventional MMAS without the random selection in the viewpoint of the search performance.

Iimura, Ichiro; Yoshida, Kenji; Ishibashi, Ken; Nakayama, Shigeru

46

Ant Algorithms for the University Course Timetabling Problem with Regard to the State-of-the-Art  

Microsoft Academic Search

Two ant algorithms solving a simplified version of a typical university course timetabling problem are presented - Ant Colony Sys- tem and MAX -MIN Ant System. The algorithms are tested over a set of instances from three classes of the problem. Results are compared with recent results obtained with several metaheuristics using the same local search routine (or neighborhood definition),

Krzysztof Socha; Michael Sampels; Max Manfrin

2003-01-01

47

Multi-population Binary ant Colony Algorithm with Concrete Behaviors for multi-objective optimization problem  

Microsoft Academic Search

Aiming at solving the drawbacks of the original binary ant colony algorithm on multi-objective optimization problems: easy to fall into the local optimization and difficult to get the Pareto optimal solutions, we proposed Multi-population Binary ant Colony Algorithm with Concrete Behaviors (MPBACB). The algorithm introduced multi-population method to ensure the globe optimization ability, and use environmental evaluation\\/reward model to improve

Ye Qing; Xiong Wei-Qing; Jiang Bao-chuan

2010-01-01

48

Ant Colony Optimization for the Single Machine Total Earliness Tardiness Scheduling Problem  

Microsoft Academic Search

This paper proposes an ant colony optimization hybrid heuristic (ACH) for the total earliness tardiness single machine scheduling\\u000a problem where jobs have different processing times and distinct due dates, and the machine can not be idle. ACH is an ant\\u000a colony system with daemon actions that intensify the search around good quality solutions. The computational results show\\u000a the effectiveness of

Rym M’Hallah; Ali Alhajraf

2008-01-01

49

07/29/08 02:56 PM 1 Who was John Muir?  

E-print Network

07/29/08 02:56 PM 1 Who was John Muir? "Wilderness Prophet," "Citizen of the Universe." · The most of Muir College... #12;07/29/08 02:56 PM 2 John Muir , a "poetico: "Early rising machine" tipped the bed and dumped him out #12;07/29/08 02:56 PM 3 Muir's education

Callender, Craig

50

A MAX-MIN Ant System for the University Course Timetabling Problem  

Microsoft Academic Search

We consider a simplification of a typical university course timetabling problem involving three types of hard and three types of soft constraints. A MAX -MIN Ant System, which makes use of a separate local search routine, is proposed for tackling this problem. We devise an appropriate construction graph and pheromone matrix representation after considering alternatives. The resulting algorithm is tested

Krzysztof Socha; Joshua D. Knowles; Michael Sampels

2002-01-01

51

Ant Colony System Algorithm for the Vehicle Routing Problem with Simultaneous Delivery and Pick-Up  

Microsoft Academic Search

Due to the increased demands for distribution\\/redistribution, recycling and repacking, there has been a significant change in the logistics process. This article presented an ant colony system (ACS) algorithm to solve a vehicle routing problem with simultaneous delivery and pick-up (VRPSDP). The objective of this problem is to determine the optimal set of routes to totally satisfy both the delivery

Felipe Peralta

2009-01-01

52

Combining two Pheromone Structures for Solving the Car Sequencing Problem with Ant  

E-print Network

options (e.g., sun-roof or air-conditioning) on them. Each option is installed by a different stationCombining two Pheromone Structures for Solving the Car Sequencing Problem with Ant Colony Villeurbanne cedex, France Abstract The car sequencing problem involves scheduling cars along an assembly line

Solnon, Christine

53

An Elitist-Ant System for Solving the Post-Enrolment Course Timetabling Problem  

NASA Astrophysics Data System (ADS)

Ant System algorithms are nature-inspired population-based metaheuristics derived from the field of swarm intelligence. Seemingly, the ant system has a lack of search diversity control since it has only a global pheromone update that intensifies the search. Hence, one or more assistant mechanisms are required to strengthen the search of the ant system. Therefore, we propose, in this study, an elitist-ant system to strike a balance between search diversity and intensification while maintaining the quality of solutions. This process is achieved by employing two diversification and intensification mechanisms to assist both pheromone evaporation and elite pheromone updating, in order to gain a good control over the search exploration and exploitation. The diversification mechanism is employed to avoid early convergence, whilst the intensification mechanism is employed to exploore the neighbors of a solution more effectively. In this paper, we test our algorithm on post-enrolment course timetabling problem. Experimental results show that our algorithm produces good quality solutions and outperforms some results reported in the literature (with regards to Socha's instances) including other ant system algorithms. Therefore, we can conclude that our elitist-ant system has performed an efficient problem's specific knowledge exploitation, and an effective guided search exploration to obtain better quality solutions.

Jaradat, Ghaith M.; Ayob, Masri

54

Hybrid ant systems for the dynamic facility layout problem  

Microsoft Academic Search

Today's consumer market demands that manufacturers must be competitive. This requires the efficient operation of manufacturing plants and their ability to quickly respond to changes in product mix and demand. In addition, studies show that material-handling cost make up between 20 and 50 percent of the total operating cost. Therefore, this paper considers the problem of arranging and rearranging, when

Alan R. McKendall Jr.; Jin Shang

2006-01-01

55

Ant System  

Microsoft Academic Search

Ant System, the first Ant Colony Optimization algorithm, sho wed to be a viable method for attacking hard combinatorial optimization problems. Yet, its performance, when com- pared to more fine-tuned algorithms, was rather poor for larg e instances of traditional benchmark problems like the Traveling Salesman Problem. To show that Ant Colony Opti- mization algorithms could be good alternatives to

Libre de Bruxelles; Holger H. Hoos

56

A modified Ant Colony algorithm for the Job Shop Scheduling Problem to minimize makespan  

Microsoft Academic Search

This paper presents a modified Ant Colony Optimization (ACO) algorithm for the Job Shop Scheduling Problem (JSSP) with makespan criterion. The traditional ACO algorithms can be simplified with the elimination of pheromone unimportant to the JSSP solution. Also, this paper suggests a new priority rule served as the heuristic information of the proposed algorithm. In order to improve the convergence

Zhiqiang Zhang; Jing Zhang; Shujuan Li

2010-01-01

57

An ant colony optimization algorithm for the redundancy allocation problem (RAP)  

Microsoft Academic Search

This paper uses an ant colony meta-heuristic optimization method to solve the redundancy allocation problem (RAP). The RAP is a well known NP-hard problem which has been the subject of much prior work, generally in a restricted form where each subsystem must consist of identical components in parallel to make computations tractable. Meta-heuristic methods overcome this limitation, and offer a

Yun-chia Liang; Alice E. Smith

2004-01-01

58

Interactive Fuzzy Multi-objective Ant Colony Optimization with Linguistically Quantified Decision Functions for Flexible Job Shop Scheduling Problems  

Microsoft Academic Search

Scheduling for the flexible job shop is very important in the fields of production management and combinatorial optimization. It proposes an Ant Colony Optimization with Linguistically Quantified Decision Functions (ACO-LQDF) for the Flexible Job Shop Scheduling Problems (FJSSP) in this work. The novelty of the proposed approach is the interactive and fuzzy multi-objective nature of the Ant Colony Optimization (ACO)

Li-ning Xing; Ying-wu Chen; Ke-wei Yang

2007-01-01

59

JOHN MUIR COLLEGE RESIDENTIAL LIFE OFFICE 2014-2015 HOUSE ADVISOR APPLICATION  

E-print Network

JOHN MUIR COLLEGE RESIDENTIAL LIFE OFFICE 2014-2015 HOUSE ADVISOR APPLICATION Instructions in this packet. _____________________________________ __________________ Applicant signature Date #12;JOHN MUIR is applying for the position of House Advisor (HA) at John Muir College for the 2014-2015 academic year. Your

Squire, Larry R.

60

John Muir and the Modern Passion for Nature  

Microsoft Academic Search

If we follow John Muir very long, he will wear us out with his incessant gab. The man never stopped talking, and he talked with everyone he met—white farmers, black freedmen, women of all ages, hordes of children, ministers of the gospel, a canoe full of Tlingits paddling along the Alaska coast. Mostly, they talked, and talked passionately, about nature.

Donald Worster

2005-01-01

61

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

ERIC Educational Resources Information Center

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…

Collister, Rob

1999-01-01

62

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

63

Pareto ant colony optimization based algorithm to solve maintenance and production scheduling problem in parallel machine case  

Microsoft Academic Search

This article presents a new method based on multiobjective Pareto ant colony optimization to resolve the joint production and maintenance scheduling problem. This method is applied to the problem previously developed in for the parallel machines case. This problem was formulated according to a bi-objective approach to find trade-off solutions between both objectives of production and maintenance. Reliability models were

A. Berrichi; M. Mezghiche; L. Amodeo; F. Yalaoui

2009-01-01

64

Study on the combination of genetic algorithms and ant Colony algorithms for solving fuzzy job shop scheduling problems  

Microsoft Academic Search

by using a single algorithm to deal with fuzzy job shop scheduling problems, it is difficult to get a satisfied solution. In this paper we propose a combined strategy of algorithms to solve fuzzy job shop scheduling problems. This startegy adopts genetic algorithms and ant colony algorithms as a parallel asynchronous search algorithm. In addition, according to the characteristics of

Xiaoyu Song; Yunlong Zhu; Chaowan Yin; Fuming Li

2006-01-01

65

Study on the combination of genetic algorithms and ant Colony algorithms for solving fuzzy job shop scheduling problems  

Microsoft Academic Search

By using a single algorithm to deal with fuzzy job shop scheduling problems, it is difficult to get a satisfied solution. In this paper we propose a combined strategy of algorithms to solve fuzzy job shop scheduling problems. This strategy adopts genetic algorithms and ant colony algorithms as a parallel asynchronous search algorithm. In addition, according to the characteristics of

Xiaoyu Song; Yunlong Zhu; Chaowan Yin; Fuming Li

2006-01-01

66

Ant-Q: A Reinforcement Learning Approach to the Traveling Salesman Problem  

Microsoft Academic Search

In this paper we introduce Ant-Q, a family of algorithms which present many similarities with Q-learning (Watkins, 1989), and which we apply to the solution of symmetric and asym- metric instances of the traveling salesman prob- lem (TSP). Ant-Q algorithms were inspired by work on the ant system (AS), a distributed algo- rithm for combinatorial optimization based on the metaphor

Luca Maria Gambardella; Marco Dorigo

1995-01-01

67

John Muir, Yosemite, and the sublime response: A study in the rhetoric of preservationism  

Microsoft Academic Search

In 7890, two essays by John Muir greatly influenced the establishment of Yosemite National Park, and greatly advanced the movement for the preservation of wilderness reserves. Muir used two techniques, the sublime response and the persona of the mountaineer, to secure his readers’ action on behalf of natural scenery.

Christine Oravec

1981-01-01

68

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

E-print Network

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

69

Improved understanding of the searching behavior of ant colony optimization algorithms applied to the water distribution design problem  

NASA Astrophysics Data System (ADS)

Evolutionary algorithms (EAs) have been applied successfully to many water resource problems, such as system design, management decision formulation, and model calibration. The performance of an EA with respect to a particular problem type is dependent on how effectively its internal operators balance the exploitation/exploration trade-off to iteratively find solutions of an increasing quality. For a given problem, different algorithms are observed to produce a variety of different final performances, but there have been surprisingly few investigations into characterizing how the different internal mechanisms alter the algorithm's searching behavior, in both the objective and decision space, to arrive at this final performance. This paper presents metrics for analyzing the searching behavior of ant colony optimization algorithms, a particular type of EA, for the optimal water distribution system design problem, which is a classical NP-hard problem in civil engineering. Using the proposed metrics, behavior is characterized in terms of three different attributes: (1) the effectiveness of the search in improving its solution quality and entering into optimal or near-optimal regions of the search space, (2) the extent to which the algorithm explores as it converges to solutions, and (3) the searching behavior with respect to the feasible and infeasible regions. A range of case studies is considered, where a number of ant colony optimization variants are applied to a selection of water distribution system optimization problems. The results demonstrate the utility of the proposed metrics to give greater insight into how the internal operators affect each algorithm's searching behavior.

Zecchin, A. C.; Simpson, A. R.; Maier, H. R.; Marchi, A.; Nixon, J. B.

2012-09-01

70

Using Commitment Contracts to Further Ex Ante Freedoms: The Twin Problems of Substitution and Ego Depletion  

Microsoft Academic Search

For an economist to think about the project of furthering individual freedom, it is natural to think about the unavoidable tension between ex ante freedoms. When should individuals have the right to restrict their future rights? I frequently ask my contracts students whether the spousal notification ruling in Planned Parenthood v. Casey should just be a default rule. By this,

Ian Ayres

2011-01-01

71

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

ERIC Educational Resources Information Center

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)

Oravec, Christine

1981-01-01

72

Using Commitment Contracts to Further Ex Ante Freedoms: The Twin Problems of Substitution and Ego Depletion  

Microsoft Academic Search

For an economist to think about the project of furthering individual freedom, it is natural to think about the unavoidable tension between ex ante freedom. When should individuals have the right to restrict their future rights?\\u000aI frequently ask my contracts students whether the spousal notification ruling in Casey should just be a default rule. By this, I mean whether

Ian Ayres

2010-01-01

73

Incorporating Hopfield Neural Networks into Ant Colony System for Traveling Salesman Problem  

Microsoft Academic Search

In this paper, the approach of incorporating Hopfield neural networks (HNN) into ant colony systems (ACS) is proposed and\\u000a studied. In the proposed approach (HNNACS), HNN is used to find a plausibly good solution, which is then used in ACS as the\\u000a currently best tour for the offline pheromone trail update. The idea is to deposit additional pheromone to ACS

Yu-Lin Weng; Chou-Yuan Lee; Zne-Jung Lee

74

Ant Colony Optimisation and Local Search for Bin Packing and Cutting Stock Problems  

Microsoft Academic Search

The Bin Packing Problem and the Cutting Stock Problem are two related classes of NP-hard combi- natorial optimisation problems. Exact solution methods can only be used for very small instances, so for real-world problems we have to rely on heuristic methods. In recent years, researchers have started to apply evolutionary approaches to these problems, including Genetic Algorithms and Evolutionary Pro-

John Levine; Frederick Ducatelle

2002-01-01

75

Ant colony optimization and local search for bin packing and cutting stock problems  

Microsoft Academic Search

The Bin Packing Problem and the Cutting Stock Problem are two related classes of NP-hard combinatorial optimization problems. Exact solution methods can only be used for very small instances, so for real-world problems, we have to rely on heuristic methods. In recent years, researchers have started to apply evolutionary approaches to these problems, including Genetic Algorithms and Evolutionary Programming. In

J Levine; F Ducatelle

2004-01-01

76

Hybridizing tabu search with ant colony optimization for solving job shop scheduling problems  

Microsoft Academic Search

The manufacturing industry continues to be a prime contributor and it requires an efficient schedule. Scheduling is the allocation\\u000a of resources to activities over time and it is considered to be a major task done to improve shop-floor productivity. Job\\u000a shop problem comes under this category and is combinatorial in nature. Research on optimization of the job shop problem is

V. P. Eswaramurthy; A. Tamilarasi

2009-01-01

77

Turning Points of Wisconsin: Original Manuscript Letters of John Muir, 1861-1914  

NSDL National Science Digital Library

From his days as a young man studying at the University of Wisconsin to his time in the wilderness areas of California, John Muir evolved from a "fundamental Christian to tree-hugging Transcendentalist", and these rather glorious letters that he wrote during this long period are now available on this site, provided by the Wisconsin Historical Society. Here visitors can peruse more than 100 pages of original letters written by Muir which deal with a wide range of topics, including his student days in Madison, the birth of his first child, and the publication of his now famous autobiography. Perusing the collection, visitors can view the original handwritten letters side by side with typed versions and their transcriptions. Overall, this is a fine collection, and anyone with an interest in Muir or the history of the American conservation movement will enjoy it.

78

An ant colony algorithm for solving budget constrained and unconstrained dynamic facility layout problems  

Microsoft Academic Search

The main characteristic of today's manufacturing environments is volatility. Under a volatile environment, demand is not stable. It changes from one production period to another. To operate efficiently under such environments, the facilities must be adaptive to changing production requirements. From a layout point of view, this situation requires the solution of the dynamic layout problem (DLP). DLP is a

Adil Baykasoglu; Turkay Dereli; Ibrahim Sabuncu

2006-01-01

79

Elucidating a layout problem in the fashion industry by using an ant optimisation approach  

Microsoft Academic Search

The clothing industry increasingly emphasises the production of high-fashion garments. Particular factors, such as various consumer behaviours, and the development of ‘fast fashion’, have motivated the manufacturers to reduce the production time. The most economic cutting patterns can be identified rapidly to control cost and reduce production time. This study focuses on a layout problem for cutting patterns in the

Chang-Lin Yang; Rong-Hwa Huang; Hsiao-Ling Huang

2011-01-01

80

Hybridization of Ant Colony Optimization Strategies in Tabu Search for Solving Job Shop Scheduling Problems  

Microsoft Academic Search

The prime contributor to the development of the competitive market is the manufacturing industry which requires a good schedule. Scheduling is the allocation of resources to activities over time. Scheduling is considered to be a major task done to improve the shop-floor productivity. The job shop problem is under this category and is combinatorial in nature. Research on optimization of

V. P. Eswaramurthy; A. Tamilarasi

81

Ant hill  

NSDL National Science Digital Library

Ants build ant hills as a result of digging underground. They dig several different chambers underground to live in and raise young ants in. As they make these chambers, the ants bring the unneeded soil to the surface, forming what we see as an ant hill.

Peter N/A (None;)

2006-01-10

82

Honey Ants.  

ERIC Educational Resources Information Center

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)

Conway, John R.

1984-01-01

83

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

Microsoft Academic Search

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

Lissy Goralnik; Michael P. Nelson

2011-01-01

84

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

ERIC Educational Resources Information Center

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…

Goralnik, Lissy; Nelson, Michael P.

2011-01-01

85

Ants Meeting Algorithms  

E-print Network

Ant robots have very low computational power and limited memory. They communicate by leaving pheromones in the environment. In order to create a cooperative intelligent behavior, ants may need to get together; however, they may not know the locations of other ants. Hence, we focus on an ant variant of the rendezvous problem, in which two ants are to be brought to the same location in finite time. We introduce two algorithms that solve this problem for two ants by simulating a bidirectional search in different environment settings. An algorithm for an environment with no obstacles and a general algorithm that handles all types of obstacles. We provide detailed discussion on the different attributes, size of pheromone required, and the performance of these algorithms.

Asaf Shiloni; Alon Levy; Ariel Felner; Meir Kalech

86

Rasberry Crazy Ant  

E-print Network

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, posing problems for people...

Drees, Bastiaan M.

2009-05-04

87

Ant Algorithms for Discrete Optimization  

E-print Network

ant-based al- gorithms to many different discrete optimization problems [5, 21]. Recent applications. Ants can smell pheromone, and when choosing their way, they tend to choose, in probability, pathsAnt Algorithms for Discrete Optimization Marco Dorigo Gianni Di Caro IRIDIA CP 194/6 Universit

Libre de Bruxelles, Université

88

An ant colony optimization algorithm for the mobile ad hoc network routing problem based on AODV protocol  

Microsoft Academic Search

In this paper, we present a modified on-demand routing algorithm for mobile ad-hoc networks (MANETs). The proposed algorithm is based on both the standard Ad-hoc On-demand Distance Vector (AODV) protocol and ant colony based optimization. The modified routing protocol is highly adaptive, efficient and scalable. The main goal in the design of the protocol was to reduce the routing overhead,

Ahmed M. Abdel-Moniem; Marghny H. Mohamed; Abdel-Rahman Hedar

2010-01-01

89

A Modified Clustering Method with Fuzzy Ants  

NASA Astrophysics Data System (ADS)

Ant-based clustering due to its flexibility, stigmergic and self-organization has been applied in variety areas from problems arising in commerce, to circuit design, and to text-mining, etc. A modified clustering method with fuzzy ants has been presented in this paper. Firstly, fuzzy ants and its behavior are defined; secondly, the new clustering algorithm has been constructed based on fuzzy ants. In this algorithm, we consider multiple ants based on Schockaert's algorithm. This algorithm can be accelerated by the use of parallel ants, global memory banks and density-based `look ahead' method. Experimental results show that this algorithm is more efficient to other ant clustering methods.

Chen, Jianbin; Fang, Deying; Xue, Yun

90

Ant Colony System for JSP  

Microsoft Academic Search

\\u000a This paper discusses the application of ACS metaheuristics (based on behaviour of real ants: stigmergy and synergetic effect\\u000a among ants) for Job-Shop Scheduling problem (JSP). This algorithm is improved by introducing the concept of critical events,\\u000a in which two new techniques will be applied. Thus, a more flexible heuristic technique is obtained, which improves the performance\\u000a of ant colony system

Urszula Boryczka

2004-01-01

91

A quickly convergent continuous ant colony optimization algorithm with Scout Ants  

Microsoft Academic Search

Many studies on ants behavior have demonstrated that their food searching process starts with Scout Ants’ scouting all around for food. In this paper, we propose a novel Scout Ant Continuous Optimization (SACO) algorithm which can simulate the food searching process of the Scout Ants. In this algorithm, the solution space of an optimization problem is divided into m subspaces.

Qingbao Zhu; Zhijun Yang; Wei Ma

2011-01-01

92

Farming ants run microbe motels  

NSDL National Science Digital Library

The ants that grow fungus in little gardens face a problem that is well known to human farmers - pests. Scientists have just discovered that farming ants are covered in little "motel rooms" that serve as shelter for bacteria that protect their crops.

American Association for the Advancement of Science (AAAS;)

2006-01-05

93

Fire ants  

MedlinePLUS

Fire ants are red-colored insects that sting and deliver a harmful substance, called venom, into your skin. This is for information only and not for use in the treatment or management ... as 911) or the National Poison Control Center at 1-800-222-1222.

94

Hang Gliding, Ant Style  

NSF Publications Database

... Press Release 05-020Hang Gliding, Ant Style Tree-dwelling ants falling from the rainforest canopy ... rainforest ants use ?directed descent? when recovering from a treetop fall. The ants purposefully ...

95

Evolutional Ant Colony Method Using PSO  

NASA Astrophysics Data System (ADS)

The ant colony method is one of heuristic methods capable of solving the traveling salesman problem (TSP), in which a good tour is generated by the artificial ant's probabilistic behavior. However, the generated tour length depends on the parameter describing the ant's behavior, and the best parameters corresponding to the problem to be solved is unknown. In this technical note, the evolutional strategy is presented to find the best parameter of the ant colony by using Particle Swarm Optimization (PSO) in the parameter space. Numerical simulations for benchmarks demonstrate effectiveness of the evolutional ant colony method.

Morii, Nobuto; Aiyoshi, Eitarou

96

The muir-torre syndrome: a rare variant of hereditary nonpolyposis colorectal cancer associated with hmsh2 mutation  

Microsoft Academic Search

The Muir-Torre syndrome is a rare autosomal dominant disorder characterized by the association of visceral malignancies with typical skin lesions. This syndrome is now considered a subtype of the more common hereditary nonpolyposis colorectal cancer syndrome (HNPCC). This last condition has been ascribed to mutations in four mismatch repair genes, and similar mutations, mostly located at hMSH2 gene, are now

Alexandra Suspiro; Paulo Fidalgo; Mar??lia Cravo; Cristina Albuquerque B. S; Eunice Ramalho B. S; C. Nobre Leitão; F. Costa Mira

1998-01-01

97

REVIEW of APPLICATION of ANT COLONY OPTIMIZATION  

E-print Network

Ant colony optimization is a technique for optimization that was introduced in the early 1990's. The inspiring source of ant colony optimization is the foraging behavior of real ant colonies.Ant colony optimization is new meta-heuristic that has proven it’s quality & versatility on various combinatorial optimization problems such as Traveling Salesman Problem, Vehicle routing problem. The main characteristic of this model are positive feedback, distributed computation, and the use of a constructive greedy heuristic. Positive feedback accounts for rapid discovery of good solutions,distributed computations avoids premature convergence, and greedy heuristic helps find acceptable solutions in early stages of the search process.In Ant Colony System, a set of cooperating agents called ants cooperate to find good solutions to TSP as well as VRP like problems. Ants cooperate using an indirect communication mediated by a pheromone they deposit on the edges of the graph.This behavior is exploited in artificial ant colonies for the search of approximate solutions to discrete optimization problems, to continuous optimization problems, and to important problems in telecommunications, such as routing and load balancing. First, we deal with the biological inspiration of ant colony optimization algorithms. We show how this biological inspiration can be transferred into an algorithm for discrete optimization.

Miss Hiteshri S. Khandre

98

Optimization Algorithms Inspired by Biological Ants and Swarm Behavior  

E-print Network

Ants are simple creatures that inspire many researchers in the field of Computer Science to develop new solutions for optimization and artificial intelligence problems. Some aspects of ant behavior can be implemented in a computer environment in order to solve a particular problem or to derive emergent behavior similar to ant colonies behavior. In this paper we give a brief overview of some functions of biological ants and the colony behavior generated from the interaction of a swarm of ants. Following we review the main existing work from the main researchers in the field on applying the ant metaphor in solving hard combinatorial optimization problems.

Paulo Eduardo Merloti

2004-01-01

99

Optimization Algorithms Inspired by Biological Ants and Swarm Behavior  

Microsoft Academic Search

Ants are simple creatures that inspire many researchers in the field of Computer Science to develop new solutions for optimization and artificial intelligence problems. Some aspects of ant behavior can be implemented in a computer environment in order to solve a particular problem or to derive emergent behavior similar to ant colonies behavior. In this paper we give a brief

Paulo Eduardo Merloti

100

Management of Imported Fire Ants in Cattle Production Systems  

E-print Network

This publication can help ranch managers develop integrated pest management plans for managing fire ant problems in cattle operations. It covers the specifics of managing fire ants in hay pastures and rangelands, around farm ponds, and near...

Fuchs, Thomas W.; Drees, Bastiaan M.

2004-03-31

101

ANT COLONY OPTIMIZATION MARCO DORIGO  

E-print Network

to the same food source are discovered, the colony is more likely to select the short- est one because ants algorithms is the use of a positive feedback loop implemented by iterative modifications of the artificial additional techniques such as problem-specific solution improvement proce- dures. The development

Libre de Bruxelles, Université

102

Ant Colony Optimization and its Applications  

Microsoft Academic Search

Ant colony optimization is a metaheuristics approach which is inspired from the behavior of real ants. It was introduced in the early 1990's as a new method to tackle hard combinatorial optimization problems. We review the origin of the ACO and introduce ACO in a way that suits its theoretical study. Then we make a summary of the recent application

Dengfeng Xu; Liping Fu

2009-01-01

103

Heterogeneous sensitive ant model for combinatorial optimization  

Microsoft Academic Search

A new metaheuristic called Sensitive Ant Model (SAM) for solving combinatorial optimization problems is proposed. SAM improves and extends the Ant Colony System approach by enhancing each agent of the model with properties that induce heterogeneity. SAM agents are endowed with different pheromone sensitivity levels. Highly-sensitive agents are essentially influenced in the decision making process by stigmergic information and thus

Camelia Chira; D. Dumitrescu; Camelia-mihaela Pintea

2008-01-01

104

Fire Ants and Their Control.  

E-print Network

fire ant control usually are labeled only for certain treatment sites. The techniques for applying these products also vary with the treatment sites. Care must be taken to select the best combination of control agents and application methods... in each situation to attain optimum 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...

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

1986-01-01

105

The ant raft  

NASA Astrophysics Data System (ADS)

To survive floods, fire ants link their arms together to assemble a raft with their own bodies. Because ants are nearly as dense as water, this cooperative behavior requires that a portion of the ant colony must sacrifice itself by remaining underwater to support the colony's weight. Surprisingly, few ants drown during this process due to a striking metamorphosis of the raft: as we show using time-lapse photography, the raft morphs from a spherical to a pancake shape. This pancake configuration--a monolayer of floating ants supporting their dry counterparts--allows all ants to both breathe and remain united as a colony. Data is presented in the form of the dimensions and the rates of formation of the ant raft. We use the statics of small floating bodies to account for the equilibrium raft size as a function of the initial mass and density of the ants.

Mlot, Nathan; Hu, David; Equabai, Solomon

2009-11-01

106

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

USGS Publications Warehouse

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.

Meyer, R.W.

1994-01-01

107

Steve Yanoviak's Gliding Ants  

NSDL National Science Digital Library

Home page of the gliding ant research of Steve Yanoviak including many videos of ants falling and swerving back to the tree, comparison videos of non-gliding ants are given for comparison. This is a fascinating insect behavior that may be an evolutionary step in insect flight.

0002-11-30

108

Fire Ant Allergy  

MedlinePLUS

Share | Fire Ant Allergy This article has been reviewed by Thanai Pongdee, MD, FAAAAI Fire ants are a stinging insect typically found in ... a Serious Reaction For people with fire ant allergy, stings may cause a life-threatening reaction called ...

109

Ant–seed mutualisms  

Microsoft Academic Search

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

Jennifer A Zettler; Timothy P Spira; Craig R Allen

2001-01-01

110

Taste test for ants  

NSDL National Science Digital Library

Scientists put a bunch of ants through a taste test. In particular, the new research looks at the relationship between the ants that protect certain plants from other insects, plants and diseases. In return for their work, the ants get a place to live as well as nectar to eat.

American Association for the Advancement of Science (AAAS;)

2005-04-21

111

Ant colony optimization with the characteristic of social work division  

Microsoft Academic Search

In order to solve the continuous space optimization problems, an ant colony optimization with the characteristic of social work division is presented. The decimal coding rule of the variables in continuous space is explained. The paper presents six behaviors of artificial ant, the function of the promotion team ant colony and the three-dimensional coordinate pheromone system. Computer simulation results indicate

Li Xinxin; Luo Yi; Zhang Juntao

2008-01-01

112

Fire Ants: Ecological Bullies  

NSDL National Science Digital Library

This two-minute radio program looks at factors that contribute to Brazilian fire ants' dominance over native ant species in the southeastern United States. An ecologist describes some of these factors, including a lack of control agents, which allow Brazilian fire ants to out compete local ants. The program includes examples of the sounds that Brazilian fire ants use to help coordinate their invasions. The archived program, part of the Pulse of the Planet radio show, is available here in text and audio formats. Copyright 2005 Eisenhower National Clearinghouse

Planet, Pulse O.

2007-01-26

113

Effectiveness of Emerged Pheromone Communication in an Ant Foraging Model  

E-print Network

The collective behavior of social insects has been a puzzling problem for scientists for a long time. In particular, it is well known that ants solve difficult problems, for instance selecting the shortest pathway by communicating with each other via pheromone. How is it possible for such simple creatures to coordinate their behaviors and to solve problems as a whole? This paper focuses on the emergence of the pheromone communication system based on an ant foraging model in which neural networks of ant agents evolve according to the result of foraging. The computer experiments show that the ant agents using emerged communication with one type of pheromone are more adaptive than the ant agents not using pheromone communication or the ant agents using human-designed communication with 2 types of pheromone. This paper also discusses the reason for this superiority of the evolved pheromone communication. Key words: ant colony, pheromone communication, swarm intelligence, artificial life. 1

Yoshiyuki Nakamichi; Takaya Arita

2005-01-01

114

Ant Colony Optimisation for Bin Packing and  

E-print Network

Ant Colony Optimisation for Bin Packing and Cutting Stock Problems Frederick Ducatelle T H E U N I of Informatics University of Edinburgh 2001 #12; Abstract The bin packing and the cutting stock problems are two and evolutionary programming. In this dissertation, I try to solve the bin packing and the cutting stock problem

Ducatelle, Frederick

115

A SURVEY ON ANT COLONY OPTIMIZATION  

E-print Network

Abstract: This paper deals with Ant Colony Optimization, a heuristic algorithm with strong robustness and the ability of finding the optimal solution which has been applied to a number of combinatorial optimization (CO) problems, of which the most important one is the traveling salesman problem (TSP). Ants of the colony have the ability to generate shorter feasible tours through information, which is accumulated, in the form of a pheromone trail deposited on the TSP graph’s edges. For solving the TSP problem, ACO is one of the high performance computing methods but still has some drawbacks, which include stagnation behavior, computational time, which is longer, and premature convergence problem.

Jaskiran Kaur; Inderpal Singh

116

An Analysis of Human Pathogens Found in Horse\\/Mule Manure Along the John Muir Trail in Kings Canyon and Sequoia and Yosemite National Parks  

Microsoft Academic Search

Objective.—To determine the prevalence of microorganisms that are potentially pathogenic for humans in horse\\/mule manure along the John Muir Trail (JMT). Methods.—Random samples of horse\\/mule manure were collected along sections of the JMT in Yosemite, Kings Canyon, and Sequoia national parks (NP), as well as in portions of the Pacific Crest Trail (PCT) and selected JMT\\/PCT access trails. Convenience samples

Robert Wayne Derlet; James Reynolds Carlson

2002-01-01

117

Managing Household Ant Pests  

E-print Network

workers and not ants in the nest. Boric acid products are commonly formu- lated in sugar water (25 percent sucrose) and placed in a dispenser. Concentrations of 0.5 to 3.7 percent are most attractive to Argentine ants. Higher concentrations are less... attractive. Boric acid is a slow-acting stomach poison. Be careful using it outdoors because it is toxic to plants. For pharaoh ants, if the nest cannot be located, use a bait (e.g., Drax ? Ant Kill Gel containing 5 percent orthoboric acid or Terro...

Drees, Bastiaan M.

2005-12-02

118

AntHeaps: A New Hybrid Image Segmentation Algorithm using Ant Colonies  

E-print Network

During the last few years, the Segmentation problem has been tackled from different disciplines. Many algorithms have been developed to solve this problem. AntClust algorithm is an antbased algorithm that uses the self-organizing and autonomous brood sorting behavior observed in real ants for unsupervised partitioning. A population of artificial ants provides an image segmentation of the relevant classes without any previous knowledge about the number of classes needed. This paper proposes a hybrid solution based on AntClust algorithm and data mining (e.g., Kmeans). Experimental results demonstrate that the proposed solution is able to extract the correct number of clusters with better clustering quality and execution time compared to the results obtained from AntClust algorithm.

Asmaa Reda; Hala Abdel-galil; Atef Z. Ghalwash

119

Ant-Based Computing  

E-print Network

Abstract. We propose a biologically and physically plausible model for ants and pheromones, and show this model to be sufficiently powerful to simulate the computation of arbitrary logic circuits. We thus establish that coherent deterministic and centralized computation can emerge from the collective behavior of simple distributed markovian processes as those followed by ants. 1

Loizos Michael

120

The ants of Tokelau  

Microsoft Academic Search

This paper combines published and new collection records to provide a comprehensive list of ant species collected on Tokelau, a Pacific island nation with the world's smallest land area. Twenty?eight ant species have been recorded since the late 1950s, 10 in recent surveys, and the majority of which are tramp species. Known invasive species such as Anoplolepis gracilipes, Monomorium pharaonis,

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

2006-01-01

121

The Ants Have It!  

NSDL National Science Digital Library

This memorable activity creatively applied students' knowledge of ants--and it all started with a wonderful Lawrence Hall GEMS guide and a teacher with a sweet tooth. The students learned that the success of the colony depends on each ant doing its job. Th

Daugherty, Belinda

2001-02-01

122

Surface water quality along the Central John Muir Trail in the Sierra Nevada Mountains: coliforms and algae.  

PubMed

The John Muir Trail (JMT) in the Sierra Nevada Mountains of California is one of the most popular alpine wilderness trails in the United States, where backpackers depend on trailside water sources for more than 335 km (208 miles). This study addressed the risk of acquiring waterborne disease by analyzing prevalence and changes in coliform bacteria and Escherichia coli (E. coli) in lakes and streams adjacent to the central JMT. Chlorophyll-a levels were also measured as an indicator of high elevation eutrophication. Categories of environmental land use which might affect water quality were defined as: Pristine areas rarely traversed by humans; Backpack off-trail areas not traversed by pack or stock animals; and Multiuse areas with backpacker and animal use. We analyzed surface water at 36 different sites three separate times over an eight week period in the summer of 2008. Chlorophyll-a concentration increased significantly in Backpack and Multiuse sites over the summer months, but not in Pristine sites. Similar results were obtained for coliforms, with prevalence also increasing significantly over the summer months in Backpack and Multiuse sites. There was a much higher prevalence of E. coli in Multiuse sites compared to Pristine and Backpack sites. Our study provides evidence pack and stock animals serve as a source of microbial contamination of water along this section of trail. PMID:20039816

Ursem, Carling; Evans, C Scott; Ger, Kemal Ali; Richards, John R; Derlet, Robert W

2009-01-01

123

The Effects of Invasive Ants on Prospective Ant Mutualists  

Microsoft Academic Search

Ants are recognized for their abilities both to engage in mutualistic interactions with diverse taxa, and to invade and dominate habitats outside their native geographic range. Here, we review the effects of invasive ants on three guilds of mutualists: ant-dispersed plants, ant-tended arthropods, and ant-tended plants. We contrast how those three guilds are affected by invasions, how invasive ants differ

J. H. Ness; J. L. Bronstein

2004-01-01

124

Reservoir Operation by Ant Colony Optimization Algorithms M. R. ...  

E-print Network

called ants, the near-optimum solution to the reservoir operation can be effectively ... to different combinatorial optimization problems like the traveling salesman problem and the quadratic ... By smelling the pheromone, there is a higher ...

Jalali

2000-11-05

125

Japanese Ant Image Database  

NSDL National Science Digital Library

The 2003 revised edition of the Japanese Ant Image Database was developed under the direction of the Japanese Ant Database Group (JADG). The website, which merges taxonomic information and stunning photographs, will no doubt delight myrmecologists and others. Information about different types of ants can be accessed through browseable, hyperlinked lists organized by subfamily, genus, and species. Genus and species profiles include images, references, descriptive information, simple distribution maps, and more. The site includes a Japanese Ant Image Library with hundreds of quality images, and a smaller SEM Image Library as well. The site also offers sections with Type Specimens and Taxonomic Keys. Please note that the site has not been updated since 2003; there are future plans to revisit the project when updates and corrections become necessary.

126

Ants of Tonga  

Microsoft Academic Search

This paper presents combined published, unpublished, and new ant records from 17 islands of Tonga representing all four island groups: Tongatapu (Tongatapu, 'Eua, 'Onevai, Pangaimotu), Ha'apai (Lifuka, Kao, Tofua, 'Uonu- kahahake, Nomuka, Nomuka-iki, Mango, Telekitonga), Vava'u (Vava'u, Nua- papu, Kapa), and the Niuas (Niuatoputapu, Niuafo'ou). These records increase the list of ants known from Tonga to 53 species. Ten species,

James K. Wetterer

2002-01-01

127

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

SciTech Connect

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.

Hunter, L.E.; Powell, R.D. (Northern Illinois Univ., Dekalb, IL (United States). Dept. of Geology)

1992-01-01

128

An Ant-Based Fast Text Clustering Approach Using Pheromone  

Microsoft Academic Search

Fast, effective text clustering has been playing an important role in organizing web text information. Due to its self-organization, robustness, flexibility, and visualization, the ant-based clustering approach has been applied to text clustering. In this approach, however, the ant's moving is random, which leads to the convergence speed too slow. Aims at above mentioned problem, an ant-based fast text clustering

Fuzhi Zhang; Yujing Ma; Na Hou; Hui Liu

2008-01-01

129

Visual Simulation of Ants Behaviour  

Microsoft Academic Search

Abbstract: - We study the behavior of ants moving in random on an environment that contains a randomly distributed source of food. Ants move with some simple rules and sometimes change direction with environmental information. In nature, each ant moves randomly but if we viewed as a whole ants are shown group work to make a path and collect food.

MOHAMED HAMADA; YOSHITAKA NAKAMURA

130

ACS-TS: train scheduling using ant colony system  

Microsoft Academic Search

This paper develops an algorithm for the train scheduling problem using the ant colony system metaheuristic called ACS-TS. At first, a mathematical model for a kind of train scheduling problem is developed and then the algorithm based on ACS is presented to solve the problem. The problem is considered as a traveling salesman problem (TSP) wherein cities represent the trains.

Keivan Ghoseiri; Fahimeh Morshedsolouk

2006-01-01

131

Innate aversion to ants (Hymenoptera: Formicidae) and ant mimics: experimental findings from mantises (Mantodea): ANT MIMICRY  

Microsoft Academic Search

ABSTRACT Field data suggest that ants may be important predators of mantises which, in turn, may be important predators of jumping spiders (Salticidae). Using a tropical fauna from the Philippines as a case study, the reactions of mantises to ants, myrmecomorphic salticids (i.e., jumping spiders that resemble ants) and ordinary salticids (i.e., jumping spiders that do not resemble ants) were

XIMENA J. NELSON; ROBERT R. JACKSON; DAIQIN LI; ALBERTO T. BARRION; G. B. EDWARDS

2006-01-01

132

Ants and ant scent reduce bumblebee pollination of artificial flowers.  

PubMed

Ants on flowers can disrupt pollination by consuming rewards or harassing pollinators, but it is difficult to disentangle the effects of these exploitative and interference forms of competition on pollinator behavior. Using highly rewarding and quickly replenishing artificial flowers that simulate male or female function, we allowed bumblebees (Bombus impatiens) to forage (1) on flowers with or without ants (Myrmica rubra) and (2) on flowers with or without ant scent cues. Bumblebees transferred significantly more pollen analogue both to and from ant-free flowers, demonstrating that interference competition with ants is sufficient to modify pollinator foraging behavior. Bees also removed significantly less pollen analogue from ant-scented flowers than from controls, making this the first study to show that bees can use ant scent to avoid harassment at flowers. Ant effects on pollinator behavior, possibly in addition to their effects on pollen viability, may contribute to the evolution of floral traits minimizing ant visitation. PMID:24334742

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

2014-01-01

133

Embedding Malaysian House Red Ant Behavior into an Ant Colony System  

Microsoft Academic Search

Problem statement: Ant Colony System (ACS) is the most popular algorithm used to find a shortest path solution in Traveling Salesman Problem (TSP). Several ACS versions have been proposed which aim to achieve an optimum solution by adjusting pheromone levels. However, it still has a room on an improvement. This research aims to improve the algorithm by embedding individual Malaysian

Zulaiha Ali Othman; Abdul Razak Hamdan

2008-01-01

134

A New Ant Algorithm for Graph Coloring  

Microsoft Academic Search

Let G = (V; E) be a graph with vertex set V and edge set E. The k-coloring problem is to assign a color (a number chosen in f1; : : : ; kg) to each vertex of V so that no edge has both endpoints with the same color. We describe in this paper a new ant algorithm for

Alain Hertz; Nicolas Zuer

135

Ants, Crickets and Frogs in Cyclic Pursuit  

E-print Network

Ants, Crickets and Frogs in Cyclic Pursuit A.M. Bruckstein 1 , N. Cohen 2 , A. Efrat 1 Abstract. We and with preassigned, varying speeds. We also consider two discrete analogs, in which crickets or frogs are engaged with synchronized crickets that jump together every unit of time. Here the relative complexity of the problem

Efrat, Alon

136

Clustering Web Search Results Using Fuzzy Ants  

E-print Network

Clustering Web Search Results Using Fuzzy Ants Steven Schockaert,* Martine De Cock, Chris Cornelis and Uncertainty Modelling Research Unit, Krijgslaan 281 (S9), B-9000 Gent, Belgium Algorithms for clustering Web existing approaches and illustrates how our algorithm can be applied to the problem of Web search results

Gent, Universiteit

137

Ant Colony Optimization with Immigrants Schemes in Dynamic Environments  

E-print Network

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

Yang, Shengxiang

138

INVESTIGATION OF ANT COLONY ALGORITHM IN MULTIPLE TRAFFIC FLOW ENVIRONMENTS  

Microsoft Academic Search

The conventional approaches to routing and bandwidth allocation, the two major components of traffic engineering, have proved insufficient to address QoS requirements of flows while optimizing utilization for complex communication networks. In this paper we consider ant colony algorithms to address this problem. Our studies show that the ant-based routing models are sensitive to initial parameters settings. Only careful adjustments

Ali Tizghadam; Massoud Hashemi; Alberto Leon-Garcia

2009-01-01

139

Flooding and Fire Ants  

E-print Network

within the first 15 to 20 minutes. Some people report that the irrita- tion of a fire ant sting can be relieved by applying a 50:50 solution of bleach and water. Other home remedies include ammonia, meat tenderizer, tea tree oil and camphor... within the first 15 to 20 minutes. Some people report that the irrita- tion of a fire ant sting can be relieved by applying a 50:50 solution of bleach and water. Other home remedies include ammonia, meat tenderizer, tea tree oil and camphor...

Nester, Paul

2008-08-05

140

Routing Vehicles with Ants  

NASA Astrophysics Data System (ADS)

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.

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

141

FDTD-ANT User Manual  

NASA Technical Reports Server (NTRS)

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.

Zimmerman, Martin L.

1995-01-01

142

Tiny, Powerful Awesome Ants!  

NSDL National Science Digital Library

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.

Tate, Kathleen

2007-11-01

143

An effective ant colony optimization-based algorithm for flow shop scheduling  

Microsoft Academic Search

This article presents a modified scheme named local search ant colony optimization algorithm on the basis of alternative ant colony optimization algorithm for solving flow shop scheduling problems. The flow shop problem (FSP) is confirmed to be an NP-hard sequencing scheduling problem, which has been studied by many researchers and applied to plenty of applications. Restated, the flow shop problem

Ruey-Maw Chen; Shih-Tang Lo; Chung-Lun Wu; Tsung-Hung Lin

2008-01-01

144

Journal of the Chinese Institute of Industrial Engineers, Vol. 23, No. 5, pp. 403-414 (2006) 403 AN ANT COLONY APPROACH TO THE ORIENTEERING  

E-print Network

AN ANT COLONY APPROACH TO THE ORIENTEERING PROBLEM Yun-Chia Liang Department of Industrial Engineering is insensitive to seed, problem instance, problem size and degree of constraint. Keywords: ant colony

Smith, Alice E.

145

Face to Face with Ants  

NSDL National Science Digital Library

Imagine being the size of an ant. Be careful - a face-to-face encounter with an ant would be scary and potentially life-threatening! But, if you avoided being eaten, you could learn a lot about ant anatomy from a close-up view. Ants have many body parts that are normally hard to see without a magnifying glass or microscope. And each structure has its own special function.

Biology

2009-09-22

146

Ant Algorithms for Discrete Optimization  

E-print Network

. Ants can smell pheromone and, when choosing their way, they tend to choose, in probability, pathsAnt Algorithms for Discrete Optimization Marco Dorigo and Gianni Di Caro IRIDIA, Universit#19;e, Switzerland luca@idsia.ch Abstract This paper overviews recent work on ant algorithms, that is, algorithms

Ducatelle, Frederick

147

Floral volatiles controlling ant behaviour  

Microsoft Academic Search

Summary 1. Ants show complex interactions with plants, both facultative and mutualistic, ranging from grazers through seed predators and dispersers to herders of some herbivores and guards against others. But ants are rarely pollinators, and their visits to flowers may be detrimental to plant fitness. 2. Plants therefore have various strategies to control ant distributions, and restrict them to foliage

Pat G. Willmer; Clive V. Nuttman; Nigel E. Raine; Graham N. Stone; Jonathan G. Pattrick; Kate Henson; Philip Stillman; Lynn McIlroy; Simon G. Potts; Jeffe T. Knudsen

2009-01-01

148

Ant Algorithms for Discrete Optimization  

E-print Network

called pheromone, forming in this way a pheromone trail. Ants can smell pheromone and, when choosingAnt 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

Gambardella, Luca Maria

149

Ant Algorithms for Discrete Optimization  

E-print Network

a substance called pheromone, forming in this way a pheromone trail. Ants can smell pheromone, and whenAnt 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

Hutter, Frank

150

Comparative Analysis of Variations of Ant-Miner by Varying Input Parameters  

E-print Network

Ant Colony Optimization (ACO) studies artificial systems that take inspiration from the behavior of real ant colonies and which are used to solve discrete optimization problems. ACO can be applied to the data mining field to extract rule-based classifiers. This paper presents variations of Ant-Miner named cAnt-Miner (Ant-Miner coping with continuous attributes), which incorporates an entropy-based discretization method in order to cope with continuous attributes during the rule construction process and Ant-Tree-Miner (constructing decision trees based on ACO) which generates classifications rules always in graphical form (Decision Tree). Three algorithms (Ant-Miner, Ant-Tree-Miner and cAnt-Miner) are compared against input parameters with respect to predictive accuracy and simplicity of the discovered rules.

Sonal P. Rami; Mahesh H. Panchal

151

The Frugal Cosmic Ant  

NASA Astrophysics Data System (ADS)

Using ESO's Very Large Telescope Interferometer and its unique ability to see small details, astronomers have uncovered a flat, nearly edge-on disc of silicates in the heart of the magnificent Ant Nebula. The disc seems, however, too 'skinny' to explain how the nebula got its intriguing ant-like shape. ESO PR Photo 42/07 ESO PR Photo 42/07 A Disc in the Ant Nebula The Ant Nebula is one of the most striking planetary nebulae known. Planetary nebulae - whose name arises because most are spherical and looked like planets when they were first discovered through older, less powerful telescopes - are glowing structures of gas cast off by solar-like stars at the ends of their lives. The morphology of the Ant Nebula - a bright core, three nested pairs of bipolar lobes and a ring-like outflow - is so unique that it was nicknamed the 'Chamber of Horrors' of planetary nebulae in the late 1950s. But how can a spherical star produce such complex structures? The answer, many astronomers think, requires understanding of the discs surrounding the central star. By their nature, these discs bear witness to the phenomena that lead to the asymmetrical structures of planetary nebulae. "The challenge is to actually detect these discs," explains team leader Olivier Chesneau, from the Observatoire de la Côte d'Azur, France. "Most astronomical instruments do not have a sharp enough view to find, let alone study them. The Very Large Telescope Interferometer however, with its exceptionally high spatial resolution, is a powerful disc-hunter." The disc of the Ant Nebula, which cannot be detected with a single 8.2-m VLT Unit Telescope, was uncovered in the interferometric mode where two 8.2-m Unit Telescopes were used to combine light, through the MID-infrared Interferometric instrument (MIDI). The observations reveal a flat, nearly edge-on disc whose major axis is perpendicular to the axis of the bipolar lobes. The disc extends from about 9 times the mean distance between the Earth and the Sun (9 Astronomical Units or 9 AU) to more than 500 AU. At the distance of the Ant Nebula, this corresponds to having detected structures that subtend an angle of only 6 milli-arcseconds. This is similar to distinguishing a two-storey building on the Moon. The dust mass stored in the disc appears to be only one hundred thousandth the mass of the Sun and is a hundred times smaller than the mass found in the bipolar lobes. "We must therefore conclude that the disc is too light to have a significant impact on the outflowing material and cannot explain the shape of the Ant Nebula", says Chesneau. "Instead, it looks more like this disc is some remnant of the material expelled by the star." The observations also provide unquestionable evidence that the disc is primarily composed of amorphous silicate. "This," says Chesneau, "most likely indicates that the disc is young, perhaps as young as the planetary nebula itself." The astronomers favour the possibility that the large quantity of material in the lobes was propelled by several large-scale events, triggered with the help of a cool stellar companion. The solution of the mystery thus resides in the core of the system, and requires better characterisation of the hot central star and its putative companion, currently hidden from our view by the dusty disc.

2007-09-01

152

Red Harvester Ants  

E-print Network

of red harvester ants may be necessary. Destruction of their nests and habitat through regular discing and mowing may eliminate them without resort- ing to use of insecticides. If pesticides are select- ed, use registered products selectively and care... pesticides must be registered and labeled for use by the Environmental Protection Agency and the Texas Department of Agriculture. The status of pesticide label clearances is subject to change and may have changed since this publication was printed. County...

Drees, Bastiaan M.

2006-04-24

153

Ants and Sustainable Agriculture  

Microsoft Academic Search

\\u000a 60% of the world’s ecosystems are not used in a sustainable way. Modern agriculture is blamed for declining soil carbon and\\u000a biodiversity. Climate change, habitat fragmentation and other obstacles impede the movement of many animal species, and distribution\\u000a changes are projected to continue. Therefore, we need alternative management strategies. The colony organisation of social\\u000a insects, especially of ants, is seen

Gero Benckiser

154

A castration parasite of an ant-plant mutualism  

PubMed Central

Exploring the factors governing the maintenance and breakdown of cooperation between mutualists is an intriguing and enduring problem for evolutionary ecology, and symbioses between ants and plants can provide useful experimental models for such studies. Hundreds of tropical plant species have evolved structures to house and feed ants, and these ant–plant symbioses have long been considered classic examples of mutualism. Here, we report that the primary ant symbiont, Allomerus cf. demerarae, of the most abundant ant-plant found in south-east Peru, Cordia nodosa Lam., castrates its host plant. Allomerus workers protect new leaves and their associated domatia from herbivory, but destroy flowers, reducing fruit production to zero in most host plants. Castrated plants occupied by Allomerus provide more domatia for their associated ants than plants occupied by three species of Azteca ants that do not castrate their hosts. Allomerus colonies in larger plants have higher fecundity. As a consequence, Allomerus appears to benefit from its castration behaviour, to the detriment of C. nodosa. The C. nodosa–ant system exhibits none of the retaliatory or filtering mechanisms shown to stabilize cheating in other cooperative systems, and appears to persist because some of the plants, albeit a small minority, are inhabited by the three species of truly mutualistic Azteca ants.

Yu, D. W.; Pierce, N. E.

1998-01-01

155

Ant-Based Cyber Security  

SciTech Connect

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.

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

2011-07-12

156

The Dynamics of Foraging Ants  

NASA Astrophysics Data System (ADS)

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.

Baxter, G. William

2009-03-01

157

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

NASA Astrophysics Data System (ADS)

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).

Vlachos, D. S.

2008-11-01

158

Modelling foraging ants in a dynamic and confined environment.  

PubMed

In social insects, the superposition of simple individual behavioral rules leads to the emergence of complex collective patterns and helps solve difficult problems inherent to surviving in hostile habitats. Modelling ant colony foraging reveals strategies arising from the insects' self-organization and helps develop of new computational strategies in order to solve complex problems. This paper presents advances in modelling ants' behavior when foraging in a confined and dynamic environment, based on experiments with the Argentine ant Linepithema humile in a relatively complex artificial network. We propose a model which overcomes the problem of stagnation observed in earlier models by taking into account additional biological aspects, by using non-linear functions for the deposit, perception and evaporation of pheromone, and by introducing new mechanisms to represent randomness and the exploratory behavior of the ants. PMID:21236313

Bandeira de Melo, Elton B; Araújo, Aluízio F R

2011-04-01

159

Solving Symmetric and Asymmetric TSPs by Ant Colonies  

Microsoft Academic Search

In this paper we present ACS, a distributed algorithm for the solution of combinatorial optimization problems which was inspired by the observation of real colonies of ants. We apply ACS to both symmetric and asymmetric traveling salesman problems. Results show that ACS is able to find good solutions to these problems.

Luca Maria Gambardella; Marco Dorigo

1996-01-01

160

Ant Colony Optimisation for Bin Packing and Cutting Stock Frederick Ducatelle  

E-print Network

Ant Colony Optimisation for Bin Packing and Cutting Stock Problems Frederick Ducatelle Division@aiai.ed.ac.uk Abstract The Bin Packing and Cutting Stock Problems are well- known NP-hard combinatorial optimisation of Dorigo's Ant Colony Optimisation meta-heuristic to solve Bin Packing and Cutting Stock Problems. We show

Levine, John

161

Non-native Ants Are Smaller than Related Native Ants.  

PubMed

I compare the sizes of non-native and native ants to evaluate how worker size may be related to the ability of a species to invade new habitats. I compare the size of 78 non-native ant species belonging to 26 genera with the size of native congeneric species; native ants are larger than non-native ants in 22 of 26 genera. Ants were sorted by genera into fighting and nonfighting groups, based on observations of interspecific interactions with other ant species. In all of the genera with monomorphic worker castes that fight during competition, the non-native species were smaller than the native species. The genera that engage in combat had a higher frequency of significantly smaller size in non-native ants. I selected Wasmannia auropunctata for further studies, to compare native and non-native populations. Specimens of W. auropunctata from non-native populations were smaller than conspecific counterparts from its native habitat. I consider hypotheses to explain why non-native ants are smaller in size than native ants, including the role of colony size in interspecific fights, changes in life history, the release from intraspecific fighting, and climate. The discovery that fighting non-natives are smaller than their closest native relatives may provide insight into the mechanisms for success of non-native species, as well as the role of worker size and colony size during interspecific competition. PMID:10600613

McGlynn

1999-12-01

162

Chaos-order transition in foraging behavior of ants.  

PubMed

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

Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

2014-06-10

163

Temperature: Human Regulating, Ants Conforming  

ERIC Educational Resources Information Center

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.

Clopton, Joe R.

2007-01-01

164

Literature for 1915 on ants and myrmecophils  

Microsoft Academic Search

Reviews the literature of 23 publications (1915) on the behavior of ants and myrmecophils. The following have been included in the review: wintering activities of Formica picea; parasitism of Lasius fuliginosus; ant behavior; behavior of Lasius umbratus; habitat and breeding of ants; study on Formica fusca var. subsericea; Donisthorpe's book on ants; fungi in British ants; study on experimental societies

Morris M. Wells

1916-01-01

165

Multiroute memories in desert ants  

PubMed Central

When offered a permanent food source, central Australian desert ants, Melophorus bagoti, develop individually distinct, view-based foraging routes, which they retrace with amazing accuracy during each foraging trip. Using a particular channel setup connected to an artificial feeder, we trained M. bagoti ants to either two or three inward routes that led through different parts of their maze-like foraging grounds. Here, we show that ants are able to adopt multiple habitual paths in succession and that they preserve initially acquired route memories even after they have been trained to new routes. Individual ants differ in the consistency with which they run along habitual pathways. However, those ants that follow constant paths retain their route-specific memories for at least 5 days of suspended foraging, which suggests that even multiple route memories, once acquired, are preserved over the entire lifetime of a forager. PMID:18160534

Sommer, Stefan; von Beeren, Christoph; Wehner, Rudiger

2008-01-01

166

USING ANT COMMUNITIES FOR RAPID ASSESSMENT OF TERRESTRIAL ECOSYSTEM HEALTH  

SciTech Connect

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.

Wike, L; Doug Martin, D; Michael Paller, M; Eric Nelson, E

2007-01-12

167

College of Arts and Sciences ANT Anthropology  

E-print Network

College of Arts and Sciences ANT Anthropology KEY: # = new course * = course changed =coursedropped University of Kentucky 2013-2014 Undergraduate Bulletin 1 ANT 101 INTRODUCTION TO ANTHROPOLOGY. (3 the instructor has worked. ANT 220 INTRODUCTION TO CULTURAL ANTHROPOLOGY. (3

MacAdam, Keith

168

FORMIDABEL: The Belgian Ants Database  

PubMed Central

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

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

2013-01-01

169

How to Use Ants for Hierarchical Clustering  

E-print Network

Abstract. We present in this paper, a new model for document hierarchical clustering, which is inspired from the self-assembly behavior of real ants. We have simulated the way ants build complex structures with different functions by connecting themselves to each other. Ants may thus build ”chains of ants ” or form ”drops of ants”. The artificial ants that we have defined will similarly build a tree. Each ant represents one document. The way ants move, disconnect or connect themselves depends on the similarity between these documents. The result obtained is presented as a hierarchical structure with a series of HTML files with hyperlinks. 1

H. Azzag; C. Guinot; G. Venturini

170

Allee effects in ants.  

PubMed

1. Allee effects occur when the aggregation of individuals result in mutually beneficial intraspecific interactions whereby individual fitness, or per capita growth rate, increases with the number of individuals. Allee effects are common in social species due to their cooperative behaviours, such as breeding, feeding or defence. Allee effects have important implications for many aspects of basic and applied ecology. Over the past decades, the study of Allee effects has influenced population dynamics, community ecology, endangered species management and invasion biology. 2. Despite the fact that cooperation is the basis of their social structure, Allee effects have received little attention among eusocial insects. Extreme cooperation is common, and reproductive specialization of individuals occurs due to division of labour. These life-history traits suggest that the potential contribution of each caste to reproduction and survival may be differential and nonadditive. 3. We studied Allee effects in the invasive Argentine ant (Linepithema humile). In this species, many queens and workers are present in colonies, which allowed us to explore the differential effects of castes on the presence of Allee effects. In the laboratory, we measured brood production and individual survival in experimental colonies that differed in the initial numbers of queens and workers.4. Our results highlight the differential effect of queens and workers on survival and productivity. We found three positive density-dependent relationships indicative of component Allee effects at the colony level: both workers and queens had a positive effect on the productivity of the other caste, and queens had a positive effect on worker survivorship. 5. Our experimental results suggest a potential positive feedback between worker and queen abundance, which may have contributed to the evolution of large colony sizes. Our study provides the first evidence of Allee effects in eusocial insects and highlights the need to consider castes separately in population dynamics. Division of labour and differential reproductive rates are factors that should be integrated into the study of Allee effects. PMID:23672650

Luque, Gloria M; Giraud, Tatiana; Courchamp, Franck

2013-09-01

171

Trap-mulching Argentine ants.  

PubMed

Argentine ant, Linepithema humile (Mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. Management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. This concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band of pine (Pinus spp.) needle mulch (trap) within a much larger patch of repellent aromatic cedar (Juniperus spp.) mulch. After ants reestablished around the trees, the pine needle mulch band was treated with 0.06% fipronil (Termidor). Poor results were obtained when the trap extended from the tree trunk to the edge of the mulched area. When the trap was applied as a circular band around the tree trunk reductions in the number of foraging ants were recorded through 14 d compared with an untreated mulch control, but not for longer periods. Reductions in the number of ant nests within mulch were no different between the trap mulch and any of the other treatments. We conclude that trap-mulching offers limited benefits, and that successful management of Argentine ants will require implementation of complementary or perhaps alternative strategies. PMID:17066809

Silverman, Jules; Sorenson, Clyde E; Waldvogel, Michael G

2006-10-01

172

Do ants make direct comparisons?  

PubMed Central

Many individual decisions are informed by direct comparison of the alternatives. In collective decisions, however, only certain group members may have the opportunity to compare options. Emigrating ant colonies (Temnothorax albipennis) show sophisticated nest-site choice, selecting superior sites even when they are nine times further away than the alternative. How do they do this? We used radio-frequency identification-tagged ants to monitor individual behaviour. Here we show for the first time that switching between nests during the decision process can influence nest choice without requiring direct comparison of nests. Ants finding the poor nest were likely to switch and find the good nest, whereas ants finding the good nest were more likely to stay committed to that nest. When ants switched quickly between the two nests, colonies chose the good nest. Switching by ants that had the opportunity to compare nests had little effect on nest choice. We suggest a new mechanism of collective nest choice: individuals respond to nest quality by the decision either to commit or to seek alternatives. Previously proposed mechanisms, recruitment latency and nest comparison, can be explained as side effects of this simple rule. Colony-level comparison and choice can emerge, without direct comparison by individuals. PMID:19386652

Robinson, Elva J.H.; Smith, Faith D.; Sullivan, Kathryn M.E.; Franks, Nigel R.

2009-01-01

173

Specializations of birds that attend army ant raids: an ecological approach to cognitive and behavioral studies.  

PubMed

Tropical birds forage at army ant raids on several continents. Obligate foraging at army ant raids evolved several times in the Neotropical true antbird family (Thamnophilidae), and recent evidence suggests a diversity of bird species from other families specialize to varying degrees on army ant exploitation. Army ant raids offer access to high prey densities, but the ant colonies are mobile and widely spaced. Successful army ant exploitation requires solving a complex foraging problem because army ant raids are unpredictable in space and time. Birds can counteract the challenges posed by the ants by using strategies that raise their chances of detecting army ant raids, and birds can use additional strategies to track army ant colonies they have located. Some features of army ant biology, such as their conspicuous swarms and columns, above-ground activity, and regular cycles of behavior, provide opportunities for birds to increase their effectiveness at exploiting raids. Changes in sensory, cognitive and behavioral systems may all contribute to specialized army ant exploitation in a bird population. The combination of specializations that are employed may vary independently among bird species and populations. The degree of army ant exploitation by birds varies geographically with latitude and elevation, and with historical patterns such as centers of distribution of obligate thamnophilid antbirds. We predict the set of specializations a given bird population exhibits will depend on local ecology, as well as phylogenetic history. Comparative approaches that focus on these patterns may indicate ecological and evolutionary factors that have shaped the costs and benefits of this foraging strategy. The development of army ant exploitation in individual birds is poorly understood, and individual expression of these specializations may depend on a combination of genetic adaptation with cognitive plasticity, possibly including social and experiential learning. Future studies that measure developmental changes and quantify individual differences in army ant exploitation are needed to establish the mechanisms underlying this behavior. PMID:23036666

O'Donnell, Sean; Logan, Corina J; Clayton, Nicola S

2012-11-01

174

MOEA/D-ACO: a multiobjective evolutionary algorithm using decomposition and AntColony.  

PubMed

Combining ant colony optimization (ACO) and the multiobjective evolutionary algorithm (EA) based on decomposition (MOEA/D), this paper proposes a multiobjective EA, i.e., MOEA/D-ACO. Following other MOEA/D-like algorithms, MOEA/D-ACO decomposes a multiobjective optimization problem into a number of single-objective optimization problems. Each ant (i.e., agent) is responsible for solving one subproblem. All the ants are divided into a few groups, and each ant has several neighboring ants. An ant group maintains a pheromone matrix, and an individual ant has a heuristic information matrix. During the search, each ant also records the best solution found so far for its subproblem. To construct a new solution, an ant combines information from its group's pheromone matrix, its own heuristic information matrix, and its current solution. An ant checks the new solutions constructed by itself and its neighbors, and updates its current solution if it has found a better one in terms of its own objective. Extensive experiments have been conducted in this paper to study and compare MOEA/D-ACO with other algorithms on two sets of test problems. On the multiobjective 0-1 knapsack problem,MOEA/D-ACO outperforms the MOEA/D with conventional genetic operators and local search on all the nine test instances. We also demonstrate that the heuristic information matrices in MOEA/D-ACO are crucial to the good performance of MOEA/D-ACO for the knapsack problem. On the biobjective traveling salesman problem, MOEA/D-ACO performs much better than the BicriterionAnt on all the 12 test instances. We also evaluate the effects of grouping, neighborhood, and the location information of current solutions on the performance of MOEA/D-ACO. The work in this paper shows that reactive search optimization scheme, i.e., the "learning while optimizing" principle, is effective in improving multiobjective optimization algorithms. PMID:23757576

Ke, Liangjun; Zhang, Qingfu; Battiti, Roberto

2013-12-01

175

Test Automation Ant JUnit Test Automation  

E-print Network

Test Automation Ant JUnit Test Automation Mohammad Mousavi Eindhoven University of Technology, The Netherlands Software Testing 2012 Mousavi: Test Automation #12;Test Automation Ant JUnit Outline Test Automation Ant JUnit Mousavi: Test Automation #12;Test Automation Ant JUnit Why? Challenges of Manual Testing

Mousavi, Mohammad

176

AntWeb - The Adaptive Web Server Based on the Ants? Behavior  

Microsoft Academic Search

We present the AntWeb system, developed under the research area of Web Intelligence (WI). Our approach to AntWeb application is inspired by the ant colonies foraging behavior, to adaptively mark the most significant links, by means of the shortest route to arrive to target pages. We consider the Web users as artificial ants, and use the ant theory as a

Wesley Martins Teles; Weigang Li; Célia Ghedini Ralha

2003-01-01

177

The effect of host structure on the distribution and abundance of the island sugarcane planthopper, Eumetopina flavipes Muir, vector of Ramu stunt disease of sugarcane.  

PubMed

The island sugarcane planthopper, Eumetopina flavipes Muir, is the only known vector for Ramu stunt disease of sugarcane. This study examined the relationship between host plant distribution and abundance, and E. flavipes distribution, abundance and levels of population connectivity in Papua New Guinea (PNG), the Torres Strait (TS) and northern peninsula area (NPA) of Australia, as a first step in establishing E. flavipes invasion potential through the TS/NPA. Results show that E. flavipes utilises a wide range of Saccharum host species in PNG and that the occupation rates and abundances differed significantly among host types. For hosts in common, the proportion of plants occupied in PNG was significantly greater than in TS/NPA. This is likely the result of greater overall host density and connectivity in PNG. E. flavipes abundance per plant did not differ significantly between the two regions suggesting a possible plant-specific abundance and/or dispersal threshold independent of location. Whilst E. flavipes presence and persistence was highly variable at some TS/NPA locations, large and stable infestations occurred down the western edge of the TS archipelago. These populations appear to link PNG to the NPA and offer a potential incursion route for Ramu stunt disease. The stability of these populations appears to be associated with the availability and persistence of host material, which in turn is significantly affected by variation in cultivation practices. In the TS/NPA, implementation of pre-emptive management of E. flavipes via cultivation techniques, such as simultaneous tip-pruning, may be an effective means of control for the pest, and would be simpler and preferable to the direct management of Ramu stunt disease should it be detected in the TS/NPA. PMID:19428738

Anderson, Kylie L; Sallam, Nader; Congdon, Bradley C

2009-05-01

178

Ant Algorithms 4.1 4 Some applications of distributed  

E-print Network

intelligence: ant algorithms There is some degree of communication among the ants, just enough to keep them from wandering off completely at random. By this minimal communication they can remind each other that they are not alone but are cooperating with teammates. D. Hofstader (1979) In the previous chapter we looked at a number of examples of distributed systems. Among others, we saw that ants are capable of finding the shortest path to a food source via a process of self-organization mediated through pheromone trails (Chapter 3, Section 3.2). Through such stigmergic interactions 1, i.e. interactions mediated by modifications of the environment (deposition of pheromones), ants manage to solve a complex optimization problem. In addition to solving such a problem, their behavior is robust, i.e. the “solution ” is immune to noise. The ants remain also adaptive, in the sense that if the environmental situation changes, for example if a path is no longer present or a shortcut becomes available, they find

unknown authors

179

The Ants of West Africa  

NSDL National Science Digital Library

Brian Taylor, of the University of Nottingham, has created this impressive resource on the ants of West Africa. Targeted "for anyone wishing to know more of how invertebrate populations are structured and determined," the site offers detailed taxonomic information, keys, and illustrations for "over 850 species and numerous 'forms' (from 85 genera and eleven subfamilies)," in addition to type locations, geographical information, and notes on bionomics. The five main sections (chapters) cover Geography & History, Ant Mosaics, Economic Importance of Ants, Biodiversity and Niches, and Taxonomy. Hundreds of references (since 1945) are available for download; a glossary offers explanations of key terms, and the text has extensively links, "including indices to a vast number of species names (subspecies, junior synonyms, varieties, etc.)."

Gilbert, Francis S.; Taylor, Brian.

1998-01-01

180

NOVA: Lord of the Ants  

NSDL National Science Digital Library

As a young man growing up in Depression-era Alabama, E.O.Wilson spent a great time outdoors observing everything from butterflies to ants. His fascination with ants grew into a lifelong passion, and amidst his many accomplishments in later life, he would win a Pulitzer Prize for his 1991 work "The Ants". Today Wilson continues to be well-known as a strong advocate for the protection of the environment and his work in the field of sociobiology. Wilson was recently profiled in an episode of the popular PBS program "NOVA, and this site allows visitors to watch the program in its entirety as well as view a transcript or purchase a DVD of the program.

2008-05-20

181

Automated Selection of Appropriate Pheromone Representations in Ant Colony Optimisation  

E-print Network

) with little or no modification [1]. Traditional operations research techniques such as branch and bound have be applied to a wide range of problems with little or no modification. However, the sys- tem we propose may, an artificial analogue of the chemical used by real ants to mark trails from the nest to food sources. In ACO

Montgomery, James

182

Improved ant colony algorithm for customization system into supply chain  

Microsoft Academic Search

To establish the configuration relations of complex product structure in the process of customization into supply chain, a new product structure configuration model based on polychromatic graph theory was put forward. Then the optimum product structure configuration mathematical model was got and the improved ant colony algorithm was employed to solve the problem. The results showed that the solution quality

Xingyu Jiang; Jiaqi Jin; Kai Zhao; Wanshan Wang

2010-01-01

183

Dynamic Wavelength Routing in WDM Networks via Ant Colony Optimization  

E-print Network

Dynamic Wavelength Routing in WDM Networks via Ant Colony Optimization Ryan M. Garlick1 and Richard Methodist University, Dallas, TX 75275 USA Abstract. This study considers the routing and wavelength assignment problem (RWA) in optical wavelength-division multiplexed networks. The focus is dynamic traffic

Barr, Richard

184

Generic cabling with restrictions based on ant colony algorithm  

Microsoft Academic Search

Generic cabling is the key component and one of the basic foundations of intelligent buildings. According to the analysis of the theory and operation flow in generic cabling, generic cabling is a multiplex cable wiring problem and we have evolved the known conditions and the index constraints affecting generic cabling. A mathematical model was built based on ant the colony

Yunlong Wang; Guiming Luo

2010-01-01

185

The differential ant-stigmergy algorithm Peter Korosec a,b,*, Jurij Silc a,c  

E-print Network

Ljubljana, Slovenia d Department of Intelligent Systems, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia a r t i c l e i n f o Article history: Received 15 August 2009 Received in revised form-dimensional problems Swarm intelligence Stigmergy Ant-Colony Optimization a b s t r a c t Ant-Colony Optimization (ACO

Silc, Jurij

186

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

E-print Network

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...

Morris, John Robert

2012-06-07

187

Research article Behavioral interactions of the invasive Argentine ant with native ant species  

E-print Network

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 California. There was no relation between the frequency of aggression by any ant species and the outcome of encounters, though Argentine ants were more likely than ants of native species to behave aggressively. When an ant of one species initiated an encounter of any kind with an ant of another species, the ant that did not initiate was likely to retreat. This was true of all species studied. Most encounters between ants were initiated by Argentine ants. Thus the native species tended to retreat more frequently than Argentine ants. Interactions between Argentine ants and native species at food resources, causing ants of native species to retreat, may help Argentine ants to displace native species from invaded areas. Key words: Linepithema humile, aggression, behavior, resource competition, interference, invasion, Argentine ant. reproduce by budding (Keller, 1991). Where it invades, the Argentine ant generally displaces native ant species and often other native arthropod species as well (Erickson, 1971;

Insectes Sociaux; K. G. Human; D. M. Gordon

1998-01-01

188

Improved Robustness through Population Variance in Ant Colony Optimization  

NASA Astrophysics Data System (ADS)

Ant Colony Optimization algorithms are population-based Stochastic Local Search algorithms that mimic the behavior of ants, simulating pheromone trails to search for solutions to combinatorial optimization problems. This paper introduces Population Variance, a novel approach to ACO algorithms that allows parameters to vary across the population over time, leading to solution construction differences that are not strictly stochastic. The increased exploration appears to help the search escape from local optima, significantly improving the robustness of the algorithm with respect to suboptimal parameter settings.

Matthews, David C.; Sutton, Andrew M.; Hains, Doug; Whitley, L. Darrell

189

The evolution of invasiveness in garden ants.  

PubMed

It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects. PMID:19050762

Cremer, Sylvia; Ugelvig, Line V; Drijfhout, Falko P; Schlick-Steiner, Birgit C; Steiner, Florian M; Seifert, Bernhard; Hughes, David P; Schulz, Andreas; Petersen, Klaus S; Konrad, Heino; Stauffer, Christian; Kiran, Kadri; Espadaler, Xavier; d'Ettorre, Patrizia; Aktaç, Nihat; Eilenberg, Jørgen; Jones, Graeme R; Nash, David R; Pedersen, Jes S; Boomsma, Jacobus J

2008-01-01

190

ANTBIRDS PARASITIZE FORAGING ARMY ANTS  

Microsoft Academic Search

In the tropical forests of Central and South America, army ants of the Eci- tonini tribe, and the numerous animals that follow them through the understory, share a complex relationship that has far-reaching effects on population dynamics and community structure. Although considerable study has been made of various participants in this re- lationship, no research has explicitly examined the nature

Peter H. Wrege; Martin Wikelski; James T. Mandel; Thomas Rassweiler; Iain D. Couzin

2005-01-01

191

Interactive evolution of ant paintings  

Microsoft Academic Search

We present how we use an interactive genetic algorithm to find the best parameters to build an artificial art work according to user's aesthetic taste. Ants are used to spread colors on a numerical painting and behave with very simple rules to follow and deposit colors. These rules and colors are considered as parameters for the evolutionary process. This work

S. Aupetit; V. Bordeau; N. Monmarche; M. Slimane; G. Venturini

2003-01-01

192

Combined effect of hemipteran control and liquid bait on Argentine ant populations.  

PubMed

The invasive Argentine ant, Linepithema humile (Mayr), has become a worldwide problem capable of inflicting significant ecological and economic injury on urban, agricultural, and natural environments. The mobility of this pest ant has long been noted, rapidly moving nests to new food resources and then away as resources are depleted. This ant, like many pest ant species, has a special affinity for honeydew excreted by phloem-feeding Hemiptera. We investigated the effect of various hemipteran control strategies on terrapin scale densities and measured their indirect effect on local Argentine ant densities and foraging effort. We then determined whether this indirect treatment strategy improved the performance of an ant bait. We predicted that Argentine ants would move nests away from trees treated for Hemiptera and then move nests back when a liquid bait was offered, followed by a decline in ant numbers due to intake of the toxicant. A horticultural oil spray and soil application of the systemic insecticide, imidacloprid, had no effect on terrapin scale numbers. However, trunk-injected dicrotophos caused a reduction in scale and a decline in local Argentine ant nest density and canopy foraging effort. We also recorded a reduction in local Argentine ant ground foraging when large amounts of liquid bait were applied, and we found no evidence that combining dicrotophos with liquid ant bait performed better than each treatment alone. We suggest that a strategy of combined hemipteran control plus application of liquid ant bait can reduce local Argentine ant densities, when both components of this system are highly efficacious. PMID:21061981

Brightwell, R J; Bambara, S B; Silverman, J

2010-10-01

193

Ant Colony Optimization: A Swarm Intelligence based Technique  

E-print Network

The growing complexity of real-world problems has motivated computer scientists to search for efficient problemsolving methods. Divide and conquer techniques are one way to solve large and difficult problems. Division of large work into smaller parts and combining the solution of small problems to get the solution of large one has been a practice in computer research since long time. Swarm also exhibits the behavior of division of work and cooperation to achieve difficult tasks. Evolutionary computation and swarm intelligence meta-heuristics are outstanding examples which show that nature has been an unending source of inspiration. Artificial Swarm/Ant foraging utilizes various forms of indirect communication, involving the implicit transfer of information from agent to agent through modification of the environment. Using this approach, one can design efficient searching methods that can find solution to complex optimization problems. Over times, several algorithms have been designed and used that are inspired by the foraging behavior of real ants colonies to find solutions to difficult problems. In this paper the idea of Ant Colonies is presented with brief introduction to its applications in different areas of problem solving in computer science.

unknown authors

194

Natural selection drives the evolution of ant life cycles.  

PubMed

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

Wilson, Edward O; Nowak, Martin A

2014-09-01

195

Natural selection drives the evolution of ant life cycles  

PubMed Central

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

Wilson, Edward O.; Nowak, Martin A.

2014-01-01

196

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

PubMed

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

Buczkowski, Grzegorz; Bennett, Gary W

2008-06-01

197

FORMIS: A Master Bibliography of Ant Literature  

NSDL National Science Digital Library

FORMIS is a composite of several ant literature databases. It contains citations for a large fraction of the world's ant literature (about 38,000 references). FORMIS contains all known ant taxonomic literature (through 1996). It also contains comprehensive bibliographies of leaf-cutting ants, fire ants, and Russian wood ants. FORMIS is also the only database which covers ant literature before the 1970s. For further details please see contributions and credits. This database is designed to allow convenient searches of titles, keywords and abstracts when available (online searches or downloads). Citations from this database can be exported to create specialty databases or personal reprint indexes. FORMIS is only updated every year or two, so it is not a source for the most recent ant literature.

0002-11-30

198

A Multi-Objective Ant Colony Optimization Algorithm for Infrastructure Routing  

E-print Network

An algorithm is presented that is capable of producing Pareto-optimal solutions for multi-objective infrastructure routing problems: the Multi-Objective Ant Colony Optimization (MOACO). This algorithm offers a constructive search technique...

McDonald, Walter

2012-07-16

199

Using Ants to Investigate the Environment  

ERIC Educational Resources Information Center

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…

Hagevik, Rita A.

2005-01-01

200

Using Ants to Investigate the Environment  

Microsoft Academic Search

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 impact on it. The three inquiry-based activities

Rita A Hagevik

2005-01-01

201

Red Imported Fire Ant Biology Red imported fire ants live in colonies that contain  

E-print Network

Red Imported Fire Ant Biology Red imported fire ants live in colonies that contain cream-colored are between 1 and 6 months under warmer outdoor conditions. Queens live an average of 6 to 7 years. Fire ants/or lipids to sustain themselves throughout the year. Fire ants are only able to ingest liquids. Solid

Balasundaram, Balabhaskar "Baski"

202

The AntSynNet Algorithm: Network Synthesis using Ant Colony Optimization Simon Wilkinson, Tony White  

E-print Network

pheromone, forming in this way a pheromone trail. Ants can smell pheromone and, when choosing their wayThe AntSynNet Algorithm: Network Synthesis using Ant Colony Optimization Simon Wilkinson, Tony@scs.carleton.ca Abstract Ant Colony Optimization (ACO) is a meta-heuristic that has been applied to a diverse set

White, Tony

203

Revolutionizing Remote Exploration with ANTS  

NASA Astrophysics Data System (ADS)

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

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

2002-05-01

204

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

E-print Network

: 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

Fernandez, Thomas

205

Quantifying ant activity using vibration measurements.  

PubMed

Ant behaviour is of great interest due to their sociality. Ant behaviour is typically observed visually, however there are many circumstances where visual observation is not possible. It may be possible to assess ant behaviour using vibration signals produced by their physical movement. We demonstrate through a series of bioassays with different stimuli that the level of activity of meat ants (Iridomyrmex purpureus) can be quantified using vibrations, corresponding to observations with video. We found that ants exposed to physical shaking produced the highest average vibration amplitudes followed by ants with stones to drag, then ants with neighbours, illuminated ants and ants in darkness. In addition, we devised a novel method based on wavelet decomposition to separate the vibration signal owing to the initial ant behaviour from the substrate response, which will allow signals recorded from different substrates to be compared directly. Our results indicate the potential to use vibration signals to classify some ant behaviours in situations where visual observation could be difficult. PMID:24658467

Oberst, Sebastian; Baro, Enrique Nava; Lai, Joseph C S; Evans, Theodore A

2014-01-01

206

The Ant Colony Optimization Metaheuristic: Algorithms, Applications, and Advances  

Microsoft Academic Search

The field of ACO algorithms is very lively, as testified, for example, by the successful biannual workshop (ANTS—From Ant Colonies to Artificial Ants: A Series of International Workshops on Ant Algorithms; http:\\/\\/iridia.ulb.ac.be\\/~ants\\/) where researchers meet to discuss the properties of ACO and other ant algorithms, both theoretically and experimentally.

Marco Dorigo; Thomas Stützle

207

Distribution System Reconfiguration for Loss Reduction Based on Ant Colony Behavior  

Microsoft Academic Search

The problem of reconfiguration of distribution systems to minimize power loss was formulated as an optimization problem. This formulation takes into account the operational constraints on line flows and voltages and the radial topology. To solve this problem, the authors propose a method to optimize this reconfiguration of the distribution system, based on the behavior of colonies of ants. To

F. S. Pereira; K. Vittori; G. R. M. da Costa

2006-01-01

208

8.EE Ants versus humans  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The average mass of an adult human is about 65 kilograms while the average mass of an ant is approximately $4 \\times 10^{-3}$ grams. The total human po...

209

Spectacular Batesian mimicry in ants  

NASA Astrophysics Data System (ADS)

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.

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

2004-10-01

210

Texture Segmentation using Ant Tree Clustering  

E-print Network

Abstract — Motivated by the self-assembling behavior of real ants, we present a novel algorithm for texture segmentation which is based on ant tree clustering of wavelet features. In a pattern recognition setting, wavelet features are extracted using either of the two subband filtering methods: discrete wavelet transform (DWT) or discrete wavelet packet transform (DWPT). The feature classification process is inspired by the self-assembling behavior observed in real ants where ants progressively become attached to an existing support and then successively to other attached ants thus building trees based on the similarity of feature vectors. The results thus obtained compare favorably to those of other recently published filtering based texture segmentation algorithms. Key words: texture segmentation & analysis, wavelet transform, feature extraction, ant tree clustering. I.

Arshad Hussain Channa; Nasir Mahmood Rajpoot; Kashif Mahmood Rajpoot

211

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

PubMed

In this investigation, detection dogs are trained and used in identifying red imported fire ants, Solenopsis invicta Buren, and their nests. The methodology could assist in reducing the frequency and scope of chemical treatments for red imported fire ant management and thus reduce labor costs and chemical use as well as improve control and quarantine efficiency. Three dogs previously trained for customs quarantine were retrained to detect the scents of red imported fire ants. After passing tests involving different numbers of live red imported fire ants and three other ant species--Crematogaster rogenhoferi Mayr, Paratrechina longicornis Latreille, and Pheidole megacephala F.--placed in containers, ajoint field survey for red imported fire ant nests by detection dogs and bait traps was conducted to demonstrate their use as a supplement to conventional detection methods. The most significant findings in this report are (1) with 10 or more red imported fire ants in scent containers, the dogs had >98% chance in tracing the red imported fire ant. Upon the introduction of other ant species, the dogs still achieved on average, a 93% correct red imported fire ant indication rate. Moreover, the dogs demonstrated great competence in pinpointing emerging and smaller red imported fire ant nests in red imported fire ant-infested areas that had been previously confirmed by bait trap stations. (2) Along with the bait trap method, we also discovered that approximately 90% of red imported fire ants foraged within a distance of 14 m away from their nests. The results prove detection dogs to be most effective for red imported fire ant control in areas that have been previously treated with pesticides and therefore containing a low density of remaining red imported fire ant nests. Furthermore, as a complement to other red imported fire ant monitoring methods, this strategy will significantly increase the efficacy of red imported fire ant control in cases of individual mount treatment. PMID:21404862

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

2011-02-01

212

An Adaptive Multi-Agent Routing Algorithm Combining AntNet and Interconnected Learning Automata  

E-print Network

Learning Automata (LA) is an abstract model which can be used to guide action selection at any stage of a system by past actions and environment responses to improve some overall performance function. The use of intelligent algorithms based on learning automata can be efficient for traffic control. How ever, these learning schemes have been focused only to unimodal routing problem in connection oriented networks. The field of Ant Colony Optimization (ACO) models real ant colony behavior using artificial ant algorithms and find its application in a whole range of optimization problems. Ant algorithms experimentally prove to work very well in static and dynamic optimization problems and match perfectly with some model of interconnected LA. In this paper, an adaptive multi-agent routing algorithm called LA-AntNet is proposed for both source and nonsource routing in communication networks. In this algorithm, mobile ant agents form AntNet routing system (Dicaro & Dorigo 1998) are combined to a system of static distributed LA agents, statically connected to the network nodes and directly responsible for routing decisions. The mobile ant agents improve local decisions of LA and adapt it with network conditions by moving over the network and colleting information about traffic distribution. In this algorithm the decision policy of LA is modified to involve a heuristic parameter which is a suggestion coming from ACO field and can guide learning process and improve convergence results. The proposed algorithm is implemented on several topologies to obtain performance metrics namely, throughput and total delay. The results are compared to the ones obtained from AntNet and a learning automata technique.

Z. Farhadpour; M. R. Meybodi

213

The production scheduling model of optical components oriented ant colony optimization algorithm  

NASA Astrophysics Data System (ADS)

Optical components production belongs to the typical jobbing work, and its scheduling problem is a significant research in advanced optical manufacture technique. According to the manufacturing technology for high precision optical components, the production scheduling model which is combined workshop scheduling theory with improved Ant Colony Algorithm (ACA) is introduced in this paper. In order to reduce the inherent deficiency of traditional ant algorithm for local optimal solution and stagnation, an improved algorithm which can simulate real ant colony sensation and consciousness may enhance the efficiency of basic ACA. The simulation experiment shows the robustness for this improved algorithm.

Wang, Juan; Wang, Jian; Tang, Dingyong

2010-10-01

214

Ants-Like Agents: A Model and Analysis Based on Natural Ants Behavior  

Microsoft Academic Search

Ants are social insects that work in groups to collectively achieve certain goals that cannot be achieved by a single ant.\\u000a One of the most interesting ants’ behaviors is the highly optimized path that ants follow, in their foraging, between the\\u000a source of food and the colony’s nest. Researchers are inspired by such optimized behavior in several applications. In this

Mohamed Hamada; Aizu Wakamatsu

2009-01-01

215

BioAnt - biologically plausible computer simulation of an environment with ants  

Microsoft Academic Search

The system BioAnt, presented here, is an artificial life system that simulates an environment with ants. Each ant moves inside the environment on the basis of a biologically plausible artificial neural network, which employs the algorithm GeneRec for supervised learning. In order to obtain an initial configuration, a symbolic algorithm (based on a set of production rules) was created. The

MarvinOliver Schneider; J. L. G. Rosa

2005-01-01

216

Prevalence of Oryzopsis hymenoides near harvester ant mounds: indirect facilitation by ants  

Microsoft Academic Search

The distribution of plants in relation to harvester ant mounds was investigated at two study areas to examine associations between ants and plants in semiarid, sagebrush steppe vegetation. The bunchgrass Oryzopsis hymenoides usually was the closest plant to the center of Pogonomyrmex owyheei ant mounds and often was the only plant found within the disk-shaped areas around mounds that is

R. S. Nowak; C. L. Nowak; T. DeRocher; N. Cole; M. A. Jones

1990-01-01

217

Long-term impact of exotic ants on the native ants of Madeira  

Microsoft Academic Search

The earliest exotic records for two notorious invasive ants, the big-headed ant ( Pheidole megacephala ) and the Argentine ant ( Linepithema humile ), both come from the Atlantic islands of Madeira, where the two species underwent population explosions in the 1850s and 1890s respectively. Researchers have long assumed that these invaders spread across all of Madeira and exterminated most

JAMES K. WETTERER; XAVIER ESPADALER; ANDREA L. WETTERER; DORA AGUIN-POMBO; ANTONIO M. FRANQUINHO-AGUIAR

2006-01-01

218

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

ERIC Educational Resources Information Center

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.

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

2010-01-01

219

Distribution and Ecology of Invasive Ants  

Microsoft Academic Search

This project examines exactly how invasive specific types of ants are, and what effect that has on the ecosystem. To do so, most of the research must be compiled for the first time, as there is a lack of knowledge and research on this subject. Through former research, Tillberg finds that there are invasive pavement ants in Oregon state parks,

Chad Tillberg; Frank Andrews; Carson Moscoso; Lily Ratliff; Claire Steele; Chris Turpin; Ben Edmonds; Alex Freauff; Erik Grimstad; Sara Grusing

2010-01-01

220

Butterfly larvae fool ants into mothering them  

NSDL National Science Digital Library

Danish researchers have found that in some areas in their country, beautiful blue Alcon butterflies fool ants into raising the butterfly larvae instead of their own, a report explains. The reason? The butterflies have developed an outer coating that mimics that of the ants.

American Association for the Advancement of Science (AAAS;)

2008-01-03

221

Generalized Langton's Ant: Dynamical Behavior and Complexity  

Microsoft Academic Search

Langton's ant is a simple discrete dynamical system, with a surprisingly complex behavior. We study its extension to general pla- nar graphs. First we give some relations between characteristics of nite graphs and the dynamics of the ant on them. Then we consider the in- nite bi-regular graphs of degrees 3 and 4, where we prove the universality of the

Anah Gajardo; Eric Goles

222

Modeling Ant Behavior Under a Variable Environment  

Microsoft Academic Search

This paper studies the behavior of ants when moving in an artificial network composed of several interconnected paths linking their nest to a food source. The ant responses when temporarily blocking the access to some branches of the maze were observed in order to study which factors influenced their local decisions about the paths to follow. We present a mathematical

Karla Vittori; Jacques Gautrais; Aluizio F. R. Araújo; Vincent Fourcassié; Guy Theraulaz

2004-01-01

223

The Use of Ants in Field Work.  

ERIC Educational Resources Information Center

Provided is a brief description of the biology and taxonomy of British ants. Suggested are a range of exercises which could be used for class or project work in secondary biology classes. Illustrates many ecological, behavioral and physiological points regarding the species of ants found in Great Britain. (Author/CW)

Skinner, Gary J.

1988-01-01

224

Managing Imported Fire Ants in Urban Areas  

E-print Network

The imported fire ant is found in much of Texas and across the southeastern U.S. This publication describes options for managing the pest in specific locations such as home lawns, gardens and buildings. Other topics include fire ant treatment...

Drees, Bastiaan M.

2006-08-17

225

PAGES 131-142 in: Ant -Plant  

E-print Network

1987). In a great many lycaenids,larval-ant relationships appear to be mutualistic in ways and ants brings an extra dimension to bear.on such relationships by introducing an additional trophic Icvcl aspects of mutualisms is that they vary widely, from facultative, indirect and/or diffuse relationships

Pierce, Naomi E.

226

What is ANTS? Focuses on those students  

E-print Network

· Informational meetings and service opportunities · Informal peer support network of people just like you Business Policies and Procedures, no alcohol or illegal substances will be permitted. The SUB is a no of the assigned space. Interpretation of these rules is subject to review by the ANTS Officers, the ANTS Board

New Mexico, University of

227

Determining possible avenues of approach using ANTS  

Microsoft Academic Search

Threat assessment is an important part of level 3 data fusion. Here we study a subproblem of this, worst- case risk assessment. Inspired by agent-based models used for simulation of trail formation for urban planning, we use ant colony optimization (ANTS) to determine possible av- enues of approach for the enemy, given a situation picture. One way of determining such

Pontus Svenson; Hedvig Sidenbladh

2003-01-01

228

Imported Fire Ants: An Agricultural Pest and a  

E-print Network

Imported Fire Ants: An Agricultural Pest and a Human Health Hazard Imported fire ants (Solenopsis. The black imported fire ant was brought to Mobile, AL, in 1918. The red imported fire ant arrived) Animal and Plant Health Inspection Service (APHIS) for advice about how to manage imported fire ants

Balasundaram, Balabhaskar "Baski"

229

Ants defend aphids against lethal disease.  

PubMed

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

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

2010-04-23

230

Solving a combinatorial problem using a local optimization in ant ...  

E-print Network

tions found during the search with an effective mechanism for avoiding early search stagnation. ... The use of only one solution is the most important means of search ..... Systems, Man, and Cybernetics-Part B, 26(1):29-41, 1996. [5] M.

2005-12-24

231

Ant Colony Optimization for the Total Weighted Tardiness Problem  

E-print Network

-1098 SJ Amsterdam, The Netherlands ^ Universite Libre de Bruxelles, IRIDIA, Avenue Franklin Roosevelt available for processing at time zero. The tardiness of a job j is defined as Tj = maxjO, Cj -- d^}, where

Libre de Bruxelles, Université

232

Particle Swarm and Ant Colony Approaches in Multiobjective Optimization  

NASA Astrophysics Data System (ADS)

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.

Rao, S. S.

2010-10-01

233

A Hybrid Ant Colony Algorithm for Loading Pattern Optimization  

NASA Astrophysics Data System (ADS)

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.

Hoareau, F.

2014-06-01

234

Influence of Argentine and coastal brown ant (Hymenoptera: Formicidae) invasions on ant communities in Perth gardens, Western Australia  

Microsoft Academic Search

A survey examined the influence of Argentine (Linepithema humile (Mayr)) and coastal brown ant (Pheidole megacephala (Fabricius)) populations on other ants in the Perth metropolitan area, Western Australia. Twelve gardens (yards) were sampled; four infested by Argentine ants, three infested by coastal brown ants, and five controls where these two tramp ants were absent or collected only as isolated strays.

B. E. Heterick; J. Casella; J. D. Majer

2000-01-01

235

Research on Double Objective Optimization of Master Production Schedule Based on Ant Colony Algorithm  

Microsoft Academic Search

The master production schedule (MPS) problem is a typical NP-hard problem. In this work, A MPS optimization model whose objectives are maximum utilization of equipment and minimum ratio between storage expenses and overdue fines is established with equipment capacity and product lead time as constraints. Then this model is implemented using a product encoding method and newly designed ant path

Wu Zheng-jia; Wang Wen; Zhou Jin; Ren Fen-fen; Zhang Cheng

2010-01-01

236

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

E-print Network

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

Solnon, Christine

237

Ant Colony System Vector Quantization effect on image data hiding  

Microsoft Academic Search

Ant colony system (ACS) is a combinatorial optimization method motivated by the behaviour of real ants. Ant Colony System Vector Quantization (ACS-VQ) is lossy compression technique, which utilizes zerotree vectors from the wavelet transform of a number o

Usman Ali; Shahid Khan; Nasir Rajpoot

2004-01-01

238

The agricultural pathology of ant fungus gardens  

PubMed Central

Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure “monocultures.” We conducted extensive isolations of “alien” (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites that are only known from attine gardens and that are found in most attine nests. These specialized garden parasites, belonging to the microfungus genus Escovopsis (Ascomycota: anamorphic Hypocreales), are horizontally transmitted between colonies. Consistent with theory of virulence evolution under this mode of pathogen transmission, Escovopsis is highly virulent and has the potential for rapid devastation of ant gardens, leading to colony mortality. The specialized parasite Escovopsis is more prevalent in gardens of the more derived ant lineages than in gardens of the more “primitive” (basal) ant lineages. Because fungal cultivars of derived attine lineages are asexual clones of apparently ancient origin whereas cultivars of primitive ant lineages were domesticated relatively recently from free-living sexual stocks, the increased virulence of pathogens associated with ancient asexual cultivars suggests an evolutionary cost to cultivar clonality, perhaps resulting from slower evolutionary rates of cultivars in the coevolutionary race with their pathogens. PMID:10393936

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

1999-01-01

239

Pheromone disruption of Argentine ant trail integrity  

USGS Publications Warehouse

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.

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

2008-01-01

240

Pheromone disruption of Argentine ant trail integrity.  

PubMed

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

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

2008-12-01

241

Ant Colony Optimization and its Application to Boolean Satisfiability for  

E-print Network

Ant Colony Optimization (ACO) [8] is a nondeterministic algorithm framework that mimics the foraging behavior of ants to solve difficult optimization problems. Several researchers have successfully applied ACO framework in different fields of engineering, but never in VLSI testing. In this paper, we first describe the basics of the ACO framework and ways to formulate different optimization problems within an ACO framework. We then present our own ACO algorithm to simultaneously solve multiple Boolean SAT instances for digital VLSI circuits. Experiments conducted on scanned versions of ISCASÊ89 benchmark circuits produced astonishing results. ACO framework for Boolean Satisifiability was found 200 times faster than spectral meta-heuristics [36] run in combinational mode. ACO framework has proven to be a promising optimization technique in large number of other fields. Since ACO can be used to solve different types of optimization and search problems, we believe that the concepts presented in this paper can open the gates for researchers solving different optimization problems that exist in VLSI testing more efficiently. 1

Rajamani Sethuram; Manish Parashar

2007-01-01

242

How to Control Ants at Home  

E-print Network

homemade bait can be prepared using boric acid. Remember that although boric acid is not dangerous to handle, it can be toxic if eaten. Keep it clearly labeled and away from food con- tainers to avoid accidents. Directions to mix bait Choose an attractive... food for the ants (jelly or peanut butter). Mix 1 teaspoon of boric acid with 1 cup of food. Do not add more boric acid because this reduces its effectiveness. Place the bait where you have seen ants, then watch and follow ants to their nest. Keep...

Merchant, Michael E.

2002-08-23

243

An Ant-Based Computer Simulator  

E-print Network

Collaboration in nature is often illustrated through the collective behavior of ants. Although entomological studies have shown that certain goals are well-served by this collective behavior, the extent of what such a collaboration can achieve is not immediately clear. We extend past work that has argued that ants are, in principle, able to collectively compute logical circuits, and illustrate through a simulation that indeed such computations can be carried out meaningfully and robustly in situations that involve complex interactions between the ants.

Loizos Michael; Anastasios Yiannakides

244

Major evolutionary transitions in ant agriculture Ted R. Schultz  

E-print Network

). Attine ant agriculture is the product of an ancient, quadri- partite, symbiotic relationship between: humans, bark beetles, ter- mites, and ants. Here, we reconstruct the major evolutionary transitions

Schultz, Ted

245

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

PubMed

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

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

2010-10-01

246

Spatial Structuring and Floral Avoidance Behavior Prevent Ant-Pollinator Conflict in a Mexican Ant-Acacia  

Microsoft Academic Search

Ant-acacias represent a classic insect-plant mutualism: the ants defend the plant from attack by herbivores, and in return are provided with trophic rewards and living space within swollen thorns. A potential drawback of this and other ant-plant mutualisms is that ant-guards may drive away useful insects, particularly pollinators. We assess the potential for ant-pollinator conflict in a Mexican ant-acacia, Acacia

Nigel E. Raine; Pat Willmer; Graham N. Stone

2002-01-01

247

Phylogenomics resolves evolutionary relationships among ants, bees, and wasps.  

PubMed

Eusocial behavior has arisen in few animal groups, most notably in the aculeate Hymenoptera, a clade comprising ants, bees, and stinging wasps [1-4]. Phylogeny is crucial to understanding the evolution of the salient features of these insects, including eusociality [5]. Yet the phylogenetic relationships among the major lineages of aculeate Hymenoptera remain contentious [6-12]. We address this problem here by generating and analyzing genomic data for a representative series of taxa. We obtain a single well-resolved and strongly supported tree, robust to multiple methods of phylogenetic inference. Apoidea (spheciform wasps and bees) and ants are sister groups, a novel finding that contradicts earlier views that ants are closer to ectoparasitoid wasps. Vespid wasps (paper wasps, yellow jackets, and relatives) are sister to all other aculeates except chrysidoids. Thus, all eusocial species of Hymenoptera are contained within two major groups, characterized by transport of larval provisions and nest construction, likely prerequisites for the evolution of eusociality. These two lineages are interpolated among three other clades of wasps whose species are predominantly ectoparasitoids on concealed hosts, the inferred ancestral condition for aculeates [2]. This phylogeny provides a new framework for exploring the evolution of nesting, feeding, and social behavior within the stinging Hymenoptera. PMID:24094856

Johnson, Brian R; Borowiec, Marek L; Chiu, Joanna C; Lee, Ernest K; Atallah, Joel; Ward, Philip S

2013-10-21

248

Structure and formation of ant transportation networks.  

PubMed

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

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

2011-09-01

249

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

E-print Network

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

Parisi, Daniel R; Josens, Roxana

2014-01-01

250

Generalized Langton's Ant: Dynamical Behavior and Complexity  

Microsoft Academic Search

Abstract. Langton’s ant is a simple discrete dynamical system, with a surprisingly complex behavior. We study its extension to general pla- nar graphs. First we give some relations between characteristics of,nite graphs and the dynamics of the ant on them. Then we consider the in- nite bi-regular graphs of degrees 3 and 4, where we prove the universality of the

Anahí Gajardo; Andrés Moreira

2001-01-01

251

Ant eating behavior of mountain gorillas  

Microsoft Academic Search

Eleven cases of feeding on driver ants (Dorylus sp.) by mountain gorillas (Gorilla gorilla beringei) are described. Ant eating provides the gorillas with more animal protein and other nutrients per unit feeding time than\\u000a do other forms of insectivory that contribute to their diet, but it is so rare that it is unlikely to be of real nutritional\\u000a significance. Gorillas

David P. Watts

1989-01-01

252

Science Nation: Leaf-cutter Ants  

NSDL National Science Digital Library

In established colonies, millions of leaf-cutter ants cut and carry sections of leaves larger than their own bodies as part of a well choreographed, highly functioning society. With support from the National Science Foundation (NSF),bacteriologist Cameron Currie and his team study ants and their complex, productive societies to help address some of human society's most pressing challenges, such as better drugs and cleaner energy.

253

Visualization of Ant Pheromone Based Path Following  

E-print Network

Nest Control screns (lower left, lower center) and a ?death? animation (center). (1991, Maxis Software) MacLennan developed a rudimentary simulation of ant pheromone behavior modeled using the simulation engine NetLogo [MacLennan 2008], as shown... Nest Control screns (lower left, lower center) and a ?death? animation (center). (1991, Maxis Software) MacLennan developed a rudimentary simulation of ant pheromone behavior modeled using the simulation engine NetLogo [MacLennan 2008], as shown...

Sutherland, Benjamin T.

2010-07-14

254

Interference competition by Argentine ants displaces native ants: implications for biotic resistance to invasion  

Microsoft Academic Search

The Argentine ant Linepithema humile (Dolichoderinae) is one of the most widespread invasive ant species in the world. Throughout its introduced range, it is\\u000a associated with the loss or reduced abundance of native ant species. The mechanisms by which these native species are displaced\\u000a have received limited attention, particularly in Australia. The role of interference competition in the displacement of

Alexei D. Rowles; Dennis J. O’Dowd

2007-01-01

255

Ant assemblages in the taiga biome: testing the role of territorial wood ants  

Microsoft Academic Search

Ants were collected with sets of pitfall traps in four coniferous-forest habitats in southern Finland. A three-level competition hierarchy concept was used to generate predictions on ant community structure. The levels of the hierarchy, and the respective predictions, from top to bottom were: (1) The dominant territorial wood ants (Formica rufa-group species), expected to exclude each other. (2) The other

R. Savolainen; K. Vepsäläinen; H. Wuorenrinne

1989-01-01

256

Detection and dispersal of explosives by ants  

NASA Astrophysics Data System (ADS)

The ability of animals to detect explosives is well documented. Mammalian systems, insects and even single celled organisms have all been studied and in a few cases employed to detect explosives. This paper will describe the potential ability of ants to detect, disperse and possibly neutralize bulk explosives. In spring 2008 a team of DRDC and Itres scientists conducted experiments on detecting surface-laid and buried landmines, improvised explosive devices (IEDs) and their components. Measurements were made using state-of-the-art short wave and thermal infrared hyperspectral imagers mounted on a personnel lift. During one of the early morning measurement sessions, a wispy, long linear trail was seen to emanate several meters from piles of explosives that were situated on the ground. Upon close visual inspection, it was observed that ants had found the piles of explosives and were carrying it to their ant hill, a distance of almost 20 meters from the piles. Initial analysis of the hyperspectral images clearly revealed the trail to the ant hill of explosives, despite being present in quantities not visible to the unaided eye. This paper details these observations and discusses them in the context of landmine and IED detection and neutralization. Possible reasons for such behaviour are presented. A number of questions regarding the behaviour, many pertinent to the use of ants in a counter-landmine/IED role, are presented and possible methods of answering them are discussed. Anecdotal evidence from deminers of detection and destruction of explosives by ants are presented.

McFee, John E.; Achal, Steve; Faust, Anthony A.; Puckrin, Eldon; House, Andrew; Reynolds, Damon; McDougall, William; Asquini, Adam

2009-05-01

257

Microfungal "weeds" in the leafcutter ant symbiosis.  

PubMed

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

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

2008-11-01

258

A Stochastic Inversion Method for Potential Field Data: Ant Colony Optimization  

NASA Astrophysics Data System (ADS)

Simulating natural ants' foraging behavior, the ant colony optimization (ACO) algorithm performs excellently in combinational optimization problems, for example the traveling salesman problem and the quadratic assignment problem. However, the ACO is seldom used to inverted for gravitational and magnetic data. On the basis of the continuous and multi-dimensional objective function for potential field data optimization inversion, we present the node partition strategy ACO (NP-ACO) algorithm for inversion of model variables of fixed shape and recovery of physical property distributions of complicated shape models. We divide the continuous variables into discrete nodes and ants directionally tour the nodes by use of transition probabilities. We update the pheromone trails by use of Gaussian mapping between the objective function value and the quantity of pheromone. It can analyze the search results in real time and promote the rate of convergence and precision of inversion. Traditional mapping, including the ant-cycle system, weaken the differences between ant individuals and lead to premature convergence. We tested our method by use of synthetic data and real data from scenarios involving gravity and magnetic anomalies. The inverted model variables and recovered physical property distributions were in good agreement with the true values. The ACO algorithm for binary representation imaging and full imaging can recover sharper physical property distributions than traditional linear inversion methods. The ACO has good optimization capability and some excellent characteristics, for example robustness, parallel implementation, and portability, compared with other stochastic metaheuristics.

Liu, Shuang; Hu, Xiangyun; Liu, Tianyou

2014-07-01

259

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

PubMed

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

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

2009-01-01

260

A Model and Analysis for Ants-li e Agents  

Microsoft Academic Search

Ants are social insects that work in groups to collectively achieve certain goals that can not be achieved by a single ant. One of the most interesting ants' behaviors is the highly optimized path that ants follow, in their foraging, between the source of food and the colony's nest. Researchers are inspired by such optimized behavior in several applications. In

M. Hamada

2006-01-01

261

State Information-based Ant Colony Clustering Algorithm  

Microsoft Academic Search

State information-based ant colony clustering algorithm is proposed in the paper. The data object is denoted as an ant which has behaviors such as moving or sleeping, the state information's influence on the ants' behaviors is paid more attention. The reference value of ants' information in the static and active state is increased or decreased respectively. State information is taken

Jie Shen; Kun He; Liu-hua Wei; Lei Bi; Rong-shuang Sun; Fa-yan Xu

2008-01-01

262

An Improved Ant Algorithm for Network Traffic Control  

Microsoft Academic Search

This paper proposed an improved ant algorithm with feedback function extension and dynamic pheromone design (dynamicAnt) for the network traffic management issue. The scheme first mapped the network traffic path delay and bandwidth metrics into the parameters of the basic ant algorithm. And then extended the network feedback function to the basic ant algorithm by simulated it as the food

Qi Bing; Jun Lu; Yan Long

2008-01-01

263

A theoretical model for uni-directional ant trails  

Microsoft Academic Search

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

Ozhan Kayacan

2011-01-01

264

Research of the Image Segmentation Based on Ant Colony Algorithm  

Microsoft Academic Search

Ant colony algorithm, based on behavior of real ants, is a natural approach to establish from their nest to food source. An ant moves randomly and detects a previously laid pheromone on a path in order to find the shortest way between their nest and the food source. Ant system algorithm is an important methodology to apply on non-linear optimal

Zhe Yan; Han-ming Gu

2009-01-01

265

Deterministic Ants in Labyrinth — Information Gained by Map Sharing  

NASA Astrophysics Data System (ADS)

A few ant robots are placed in a labyrinth, formed by a square lattice with a small number of corridors removed. Ants move according to a deterministic algorithm designed to explore all corridors. Each ant remembers the shape of corridors which it has visited. Once two ants meet, they share the information acquired. We evaluate how the time of getting a complete information by an ant depends on the number of ants, and how the length known by an ant depends on time. Numerical results are presented in the form of scaling relations.

Malinowski, Janusz; Kantelhardt, Jan W.; Ku?akowski, Krzysztof

2013-06-01

266

Using ants' behavior based simulation model AntWeb to improve website organization  

Microsoft Academic Search

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

Li Weigang; Marcos Vinícius; Pinheiro Dibb; Wesley Martins Telesa; Cristina Magalhães; Alves de Meloa

267

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

Microsoft Academic Search

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

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

2002-01-01

268

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

E-print Network

Koptur et al.: Ants and Plants on Andros, Bahamas 89 ANTS AND PLANTS WITH EXTRAFLORAL NECTARIES IN FIRE SUCCESSIONAL HABITATS ON ANDROS (BAHAMAS) SUZANNE KOPTUR, PASCALE WILLIAM AND ZURIANY OLIVE successional habitats of rocklands on Andros Island, Bahamas. Vegetation was sampled in pineyard and coppice

Koptur, Suzanne

269

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

E-print Network

California. There was no relation between the frequency of aggression by any ant species and the outcome of encounters, though Argentine ants were more likely than ants of native species to behave aggressively. When humile, aggression, behavior, resource competition, interference, invasion, Argentine ant

Gordon, Deborah

270

Defensive behavior of ants in a mutualistic relationship with aphids  

Microsoft Academic Search

Mutualistic relationships between ants and aphids are well studied but it is unknown if aphid-attending ants place a greater relative importance on defending aphids from aphid-predators or from competing ant colonies. We tested the hypothesis that aphid-attending ants defend their aphids against aphid-predators more aggressively than against ants from neighboring colonies. We conducted introduction trials by placing an individual non-predatory

Iain D. Phillips; Craig K. R. Willis

2005-01-01

271

The distribution of weaver ant pheromones on host trees  

Microsoft Academic Search

.  The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking\\u000a down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested for correlations between spot density,\\u000a ant activity and the likelihood of being detected by an

J. Offenberg

2007-01-01

272

We have all had ants invade or at least appear in our honey bee hives -most often they are carpenter ants. Carpenter ants  

E-print Network

Bigheaded ant, Pheidole megacephala (Fabricius), minor (upper left) and major (lower right) workers and have taken over nuc boxes. Another exotic invader is the pan-tropical big-headed ant, Pheidole megaceph

Jawitz, James W.

273

Induced responses to herbivory in the Neotropical ant-plant association between Azteca ants and Cecropia trees: response of ants to potential inducing cues  

Microsoft Academic Search

Plant defense against herbivores often involves constitutive and inducible mechanisms of resistance. Obligate ant-plants,\\u000a which provide food and housing for ants, are thought to primarily rely on ants for defense against herbivores. This form of\\u000a plant defense has largely been viewed as static. We have been investigating the dynamic nature of Azteca ants as an inducible defense of Cecropia trees.

Anurag A. Agrawal; Benjamin J. Dubin-Thaler

1999-01-01

274

Desert Ants Learn Vibration and Magnetic Landmarks  

PubMed Central

The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context. PMID:22412989

Buehlmann, Cornelia

2012-01-01

275

Efficient and Inefficient Ant Coverage Methods  

E-print Network

this article, we study real-time (heuristic) search methods because they fit the capabilities of ants well. Ants that use real-time search methods operate with a very limited look-ahead and perform only very simple operations within this look-ahead. They do not need to maintain a map of the terrain nor compute complete paths. Rather, they only have to leave markings in the terrain, sense the markings at their neighboring locations, and change the marking of their current location. This is similar to what some insects do. We study the behavior of ants for covering terrain, as required for one-time or continuous vacuum cleaning or lawn mowing. We study, both theoretically and experimentally, two simple real-time search methods that differ only in how the markings are updated. Both real-time search methods are algorithmically similar, and experimental results indicate that their cover time is similar in some terrains. Our analysis is therefore surprising. We show that the cover time of ants that use one of the real-time search methods is guaranteed to be polynomial in the number of locations, whereas the cover time of ants that use the other real-time search method can be exponential in (the square root of) the number of locations even in simple terrains that correspond to (planar) undirected trees. This shows that ants that use two similar real-time search meth- ods for coverage do not always perform similarly, which motivates the importance of theoretical results

Sven Koenig; Boleslaw Szymanski; Yaxin Liu

276

Desert ants compensate for navigation uncertainty.  

PubMed

During foraging trips, desert ants Cataglyphis fortis do not rely only on their well-studied path integration system, they also use olfactory cues when approaching a familiar food source. When a wind is blowing from a constant direction, as is characteristic of their desert habitat, the ants do not approach the feeder directly. They rather steer some distance downwind of the food source to pick up odour filaments emanating from the food. They follow this odour trail upwind, and find the source quickly and reliably. This approach behaviour was examined in more detail in order to identify the underlying orientation strategy. First, the ants may employ a 'goal expansion strategy', using odour spread as a spatially limited indicator for the presence of food. In that case, the distance steered downwind of the feeder should be determined by the range of the odour plume (and, for instance, wind speed). It should be independent of the distance between nest and feeder. Second, the ants may apply an 'error compensation strategy', using odour filaments as a guideline towards the food source. Steering downwind by a margin just exceeding their maximum navigation error will lead the ants safely across the odour guide. In that case, the distance steered downwind of the feeder should increase more or less linearly with the nest-feeder distance. Our results unambiguously support the second strategy. When feeders were established at distances of 5-75 m from the nest, the distances steered downwind of the food increased from 0.7 m to 3.4 m in a linear fashion. This result was independent of wind speed or wind direction. It translates into an ant's estimate of its navigation error within a range of 3 degrees to 8 degrees. PMID:16272245

Wolf, Harald; Wehner, Rüdiger

2005-11-01

277

Ant visitation of extrafloral nectaries of Passiflora : the effects of nectary attributes and ant behavior on patterns in facultative ant-plant mutualisms  

Microsoft Academic Search

Extrafloral nectary (EFN) plants are widespread and can be quite species-rich in some communities. Thus, ants that utilize extrafloral nectar may have the opportunity to discriminate among a wide variety of nectar sources, resulting in variation in the ant attention EFN plants receive. In this study, we compare ant visitation rates of three Passiflora species that coexist in an early

J. Apple; D. Feener Jr.

2001-01-01

278

Induced responses to herbivory in the Neotropical ant-plant association between Azteca ants and Cecropia trees: response of ants to potential inducing cues  

Microsoft Academic Search

Received: 23 March 1998 \\/Accepted after revision: 5 July 1998 Abstract Plant defense against herbivores often involves constitutive and inducible mechanisms of resistance. Obligate ant-plants, which provide food and housing for ants, are thought to primarily rely on ants for defense against herbivores. This form of plant defense has largely been viewed as static. We have been investigating the dynamic

B. J. Dubin-Thaler

279

Theoretical Study of Ant-based Algorithms for Multi-Agent Patrolling  

Microsoft Academic Search

This paper addresses the multi-agent patrolling problem, which consists for a set of autonomous agents to visit all the places of an unknown environment as regularly as possible. The proposed approach is based on the ant paradigm. Each agent can only mark and move according to its local perception of the environment. We study EVAW, a pheromone-based variant of the

Arnaud Glad; Olivier Simonin; Olivier Buffet; François Charpillet

2008-01-01

280

Theoretical Study of Ant-based Algorithms for Multi-Agent Patrolling  

E-print Network

-based variant of the EVAP [3] and VAW [12]. The main novelty of the paper is the proof of some emergent spatial.lastname@loria.fr the EVAP algorithm, introduced in [3], that just uses the pheromone evaporation process, and we compare the EVAP and VAW ant-based algorithms allowing to deal with covering and patrolling problems, and we show

Boyer, Edmond

281

Behavioral plasticity of Myrmica rubra ants during learning in a multi-alternative symmetrical labyrinth  

Microsoft Academic Search

The problem of behavioral plasticity in insects was studied with red ants,Myrmica rubra, by altering a habit developed in a multi-alternative labyrinth with care for offspring as motivation. In altering the habit, location of reinforcement was changed: in the first series, the brood was transferred from the target areas to relatively symmetrical areas of the transverse axis of the labyrinth;

B. A. Dashevskii; G. P. Udalova

1990-01-01

282

On some applications of ant colony optimization metaheuristic to plane truss optimization  

Microsoft Academic Search

Ant colony optimization metaheuristic (ACO) represents a new class of algorithms particularly suited to solve real-world combinatorial optimization problems. ACO algorithms, published for the first time in 1991 by M. Dorigo [Optimization, learning and natural algorithms (in Italian). Ph.D. Thesis, Dipartimento di Elettronica, Politecnico di Milano, Milan, 1992] and his coworkers, have been applied, particularly starting from 1999 (Bonabeau et

M. Serra; P. Venini

2006-01-01

283

A load balancing model for web cache proxy based on ant colony behavior  

Microsoft Academic Search

Proxy cache which is an important device to guarantee the quality of Web service works with a poor efficiency when hot-spot appears. To solve this problem, load balancing method should be applied. In this paper, a load balancing model based on ant colony behavior is put forward. In the model, agent monitors the status of proxy server it has been

Yang Wang; Guang-Yu Du; Tian-Shu Huang; Yu Wang

2008-01-01

284

Mining Spatial Trends by a Colony of Cooperative Ant Agents Ashkan Zarnani  

E-print Network

Mining Spatial Trends by a Colony of Cooperative Ant Agents Ashkan Zarnani Masoud Rahgozar Abstract the highly demanding field of spatial data mining. So far many optimization problems have been better solved the huge search space encountered in the discovery of this knowledge. We apply an effective greedy

Bailey-Kellogg, Chris

285

Ant Colony Optimization for Markowitz Mean-Variance Portfolio Model  

NASA Astrophysics Data System (ADS)

This work presents Ant Colony Optimization (ACO), which was initially developed to be a meta-heuristic for combinatorial optimization, for solving the cardinality constraints Markowitz mean-variance portfolio model (nonlinear mixed quadratic programming problem). To our knowledge, an efficient algorithmic solution for this problem has not been proposed until now. Using heuristic algorithms in this case is imperative. Numerical solutions are obtained for five analyses of weekly price data for the following indices for the period March, 1992 to September, 1997: Hang Seng 31 in Hong Kong, DAX 100 in Germany, FTSE 100 in UK, S&P 100 in USA and Nikkei 225 in Japan. The test results indicate that the ACO is much more robust and effective than Particle swarm optimization (PSO), especially for low-risk investment portfolios.

Deng, Guang-Feng; Lin, Woo-Tsong

286

Ant interactions with soil organisms and associated semiochemicals.  

PubMed

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

Vander Meer, Robert

2012-06-01

287

Ant-plant mutualisms should be viewed as symbiotic communities  

PubMed Central

Ant-plants provide food and nesting space (domatia) for ants that protect them against herbivores. These mutualisms are often very specific and are usually considered as bipartite, or tripartite when ants use hemipterans as trophobionts. However, fungi growing inside domatia have been recorded by a few authors. Here we report on their occurrence on additional ant-plants from Africa, Asia and South America. We demonstrated the symbiotic nature of the relationship between the plant, the ant and the fungus in the model plant Leonardoxa africana africana and its mutualistic ant Petalomyrmex phylax. Moreover, data suggest the ant-fungus relationship is mutualistic. Here we discuss the most probable role of the fungus and the potential implications on the understanding of nutritional ecology of ant-plant symbioses. The fungus is also associated with the presence of nematodes and bacteria. Many ant-plant symbioses previously considered to be bipartite will soon likely prove to be multipartite symbiotic communities. PMID:19816123

Bouamer, Salah; Morand, Serge; Selosse, Marc-Andre

2009-01-01

288

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

PubMed

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

Lanan, M C; Bronstein, J L

2013-07-01

289

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

NSDL National Science Digital Library

[PDF] Article from The American Biology Teacher, Vol. 72, No. 3, pages 173Â176. ISSN 0002-7685, electronic ISSN 1938Â4211. ©2010 by National Association of Biology Teachers. This is an article about providing urban students with a field site for ecological studies, using ants and their mounds. The authors 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.

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

290

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

PubMed Central

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

Solis, Daniel Russ; Rossi, Monica Lanzoni; Fox, Eduardo Goncalves Paterson; Nogueira, Neusa de Lima; Tanaka, Francisco Andre Ossamu; Bueno, Odair Correa

2013-01-01

291

WORKER LONGEVITY IN HARVESTER ANTS (POGONOMYRMEX)  

E-print Network

other tasks. METHODS P. barbatus Longevity data were collected near Rodeo, New Mexico in July- August, increased energy expenditures, predation, and environ- mental fluctuations may all contribute to shorten.m., for the presence of marked ants. P. rugosus Observations were made near Rodeo, New Mexico in July-Au- gust 1986

Gordon, Deborah

292

Animal behavior: The Truman Show for ants.  

PubMed

A new tracking setup allows researchers to monitor the behavior of individual ants inside a colony. The first results demonstrate a link between age, spatial organization and division of labor, and quantify the dynamics of the colony's social network. PMID:23845245

Saragosti, Jonathan; Kronauer, Daniel J C

2013-07-01

293

Ants, Crickets and Frogs in Cyclic Pursuit  

Microsoft Academic Search

. We consider a deterministic continuous pursuit, in which n ants chase each otherin cyclic order and with preassigned, varying speeds. We also consider two discrete analogs, inwhich crickets or frogs are engaged in cyclic pursuit with constant and equal speeds. We examinethe possible evolutions of these pursuits as time goes to infinity: collision, limit points, equilibriumstates and periodic motion.IntroductionImagine

A. m. Bruckstein; N. Cohen; A. Efrat

1991-01-01

294

Disassembly sequence planning approach for product virtual maintenance based on improved max–min ant system  

Microsoft Academic Search

In order to realize automation and intelligence of product disassembly process in a virtual maintenance environment, an improved\\u000a max–min ant system based methodology for product disassembly sequence planning was proposed. The feasibility graph for product\\u000a disassembly process was defined and the mathematic model of product disassembly sequence planning problem was set up. Thus,\\u000a the problem of product disassembly sequence planning

Xinhua Liu; Gaoliang Peng; Xiumei Liu; Youfu Hou

295

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

NASA Astrophysics Data System (ADS)

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.

Gómez, Crisanto; Oliveras, Jordi

2003-04-01

296

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

PubMed Central

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.

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

2014-01-01

297

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

PubMed Central

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

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

2011-01-01

298

9 The Ecological Consequences of a Fragmentation Mediated Invasion: The Argentine Ant, Linepithema  

E-print Network

inadvertently introduced worldwide (Williams 1994). Many species, such as the big headed ant (Pheidole megacephala), the little fire ant (Wasmannia auropunctata), the imported fire ant (Solenopsis invicta

Suarez, Andrew V.

299

ORIGINAL PAPER Habitat alteration increases invasive fire ant abundance  

E-print Network

ORIGINAL PAPER Habitat alteration increases invasive fire ant abundance to the detriment been suggested to facilitate red imported fire ant (Solenopsis invicta) colonization and dispersal woody debris retained; and a clearcut with coarse woody debris removed. Additionally, we compared

Todd, Brian

300

Taxonomic Revision of the Ant Genus Linepithema (Hymenoptera: Formicidae)  

E-print Network

many other ant genera, suggesting that mating behavior inants show a stereotypical nesting and feeding behavior.behavior of this species in the field, leading to changes in the ecological dominance hierarchy in the ant

Wild, Alexander L.

2014-01-01

301

Farmers, Warriors, Builders: The Hidden Life of Ants  

NSDL National Science Digital Library

The website of the Smithsonian National Museum of Natural History has a highly informative and just plain delightful interactive exhibit on ants. The exhibit explains how, much like humans, "ants achieve domination by being social creatures". Dividing the ants' lives into "food", "warriors", "shelter" and "communication", the exhibit offers an array of photos in its photo gallery to illustrate the variety of ant life and behavior on earth. Clicking on the thumbnails will enlarge the photos and reveal a brief description of the photo. More than half a dozen videos of ants taken throughout the world can be found under the "Ant Videos" link on the left side of the page. Visitors interested in learning more about myrmecology (ant science) would be remiss if they didn't visit the "Ant Web Links" section of the website, which can also be found on the left side of the page.

302

9 CFR 352.10 - Ante-mortem inspection.  

Code of Federal Regulations, 2012 CFR

...Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE...INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.10 Ante-mortem...ante-mortem inspection of an exotic animal shall, where...

2012-01-01

303

Exploring with PAM: Prospecting ANTS Missions for Solar System Surveys  

Microsoft Academic Search

ANTS (Autonomous Nano Technology Swarm of hundreds of picoclass autonomous spacecraft) have many applications. A version designed for surveying and the resource potential of the asteroid belt, called PAM (Prospecting ANTS Mission), is examined here.

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

2003-01-01

304

9 CFR 354.121 - Ante-mortem inspection.  

Code of Federal Regulations, 2012 CFR

...MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Inspection Procedures; Ante-Mortem Inspections § 354.121 Ante-mortem inspection. An...

2012-01-01

305

9 CFR 354.121 - Ante-mortem inspection.  

Code of Federal Regulations, 2011 CFR

...MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Inspection Procedures; Ante-Mortem Inspections § 354.121 Ante-mortem inspection. An...

2011-01-01

306

9 CFR 354.121 - Ante-mortem inspection.  

Code of Federal Regulations, 2013 CFR

...MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Inspection Procedures; Ante-Mortem Inspections § 354.121 Ante-mortem inspection. An...

2013-01-01

307

Global path planning approach based on ant colony optimization algorithm  

Microsoft Academic Search

Ant colony optimization (ACO) algorithm was modified to optimize the global path. In order to simulate the real ant colonies,\\u000a according to the foraging behavior of ant colonies and the characteristic of food, conceptions of neighboring area and smell\\u000a area were presented. The former can ensure the diversity of paths and the latter ensures that each ant can reach the

Zhi-qiang Wen; Zi-xing Cai

2006-01-01

308

Interactions between ants and aphidophagous and coccidophagous ladybirds  

Microsoft Academic Search

Aphidophagous and coccidophagous coccinellids come into conflict with homopteran-tending ants for access to food. Antagonistic\\u000a interactions between coccinellids and ants may be competitive or non-competitive. Competitive interactions occur when coccinellids\\u000a attack aphids or coccids that are being tended by ants for honeydew. Non-competitive interactions include all interactions\\u000a away from ant-tended homopteran colonies. We here review observations and studies of such

Michael E. N. Majerus; John J. Sloggett; Jean-François Godeau; Jean-Louis Hemptinne

2007-01-01

309

Why Ants Do but Honeybees Do Not Construct Satellite Nests  

Microsoft Academic Search

Synopsis: Ants and honeybees are both social insects that share many characteristics in common. But there is a fundamental\\u000a difference between ants and bees. Ants can and do construct main nests with satellite nests, whereas bees construct only a\\u000a main nest with no satellite nests. In this paper we explain the difference between the socio-economic organization of ants\\u000a and bees:

JANET T. LANDA; Gordon Tullock

2003-01-01

310

Competition between harvester ants and rodents in the cold desert  

Microsoft Academic Search

Local distribution patterns of three rodent species (Perognathus parvus, Peromyscus maniculatus, Reithrodontomys megalotis) were studied in areas of high and low densities of harvester ants (Pogonomyrmex owyheei) in Raft River Valley, Idaho. Numbers of rodents were greatest in areas of high ant-density during May, but partially reduced in August; whereas, the trend was reversed in areas of low ant-density. Seed

D. S. Landeen; C. D. Jorgensen; H. D. Smith

1979-01-01

311

LIVING WITH THE ENEMY: JUMPING SPIDERS THAT MIMIC WEAVER ANTS  

Microsoft Academic Search

Ants prey on salticids, and encounters with weaver ants (Oecophylla smaragdina(Fabri- cius 1775)) appear to be especially dangerous for many salticids. In the Philippines, Myrmarachne assimilis Banks 1930 is a salticid that mimics Oecophylla smaragdina. We tested for the abilities of four categories of salticids, plus M. assimilis, to survive in the proximity of weaver ants. The four categories were:

Ximena J. Nelson; Robert R. Jackson; G. B. Edwards; Alberto T. Barrion

2005-01-01

312

Leaf-cutting ants revisited: Towards rational management and control  

Microsoft Academic Search

Leaf-cutting ants, being the principal herbivores and ecosystem engineers in the Neotropics, have been considered to be a keystone species in natural ecosystems and agroecosystems, due to the direct and indirect effects of their plant defoliation activities. This review summarizes current concepts of the biological and ecological importance of leaf-cutting ants. The ants' pest status is briefly assessed from both

James Montoya-Lerma; Carolina Giraldo-Echeverri; Inge Armbrecht; Alejandro Farji-Brener; Zoraida Calle

2012-01-01

313

Model Specification Searches Using Ant Colony Optimization Algorithms  

ERIC Educational Resources Information Center

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.

Marcoulides, George A.; Drezner, Zvi

2003-01-01

314

Arboreal ant diversity (Hymenoptera: Formicidae) in a central African forest  

Microsoft Academic Search

Like many developing tropical areas, central Africa is subject to substantial anthropogenic disturbance associ- ated with the large-scale harvesting of natural resources. We surveyed the ants of the forest canopy at an oil extraction site near Gamba, Gabon. Ants were collected by hand and with tuna baits from nine tree crowns in late secondary forest. Thirty-six ant species were collected

S. P. Yanoviak; B. L. Fisher; A. Alonso

2007-01-01

315

The effect of using evolutionary algorithms on Ant Clustering Techniques.  

E-print Network

The effect of using evolutionary algorithms on Ant Clustering Techniques. Claus Aranha1 and Hitoshi@iba.k.u-tokyo.ac.jp Abstract. Ant-based clustering is a biologically inspired data cluster- ing technique. In this technique, hunting and foraging food [5, 2]. The coordination of an ant colony is of local nature, composed mainly

Fernandez, Thomas

316

Retina Vessel Detection Using Fuzzy Ant Colony Algorithm  

Microsoft Academic Search

Vessel extraction in retina images is a primary and important step in studying diseases including vasculature changes. In this paper, a fuzzy clustering method based on Ant Colony Algorithm, inspired by food-searching natural behavior of ants, is described. Features of color retina images are extracted by eigenvalues analysis of Hessian matrix and Gabor filter bank. Artificial ants in the image

Sina Hooshyar; Rasoul Khayati

2010-01-01

317

The Effects of Mutualistic Ants on Aphid Life History Traits  

Microsoft Academic Search

The relationship between homopterans and ants is generally thought to be mutualistic, as both partners seem to benefit from an association. In aphids, previous studies have shown that ant tending improves the survival and reproduction of aphid colonies, mainly by protection of aphids from enemy attack. However, the effects of ant tending on the fitness of individual aphids have rarely

Thomas Flatt; Wolfgang W. Weisser

2000-01-01

318

Spatiotemporal patterns of intraspecific aggression in the invasive Argentine ant  

Microsoft Academic Search

The Argentine ant, Linepithema humile, is a widespread invasive species characterized by reduced intraspecific aggression within introduced populations. To illuminate the mechanisms underlying nestmate recognition in Argentine ants, we studied the spatial and temporal fidelity of intraspecific aggression in an introduced population of Argentine ants within which intraspecific aggression does occur. We quantified variation in the presence or absence of

Andrew V. Suarez; David A. Holway; Dangsheng Liang; Neil D. Tsutsui; Ted J. Case

2002-01-01

319

Invertebrate conservation in urban areas: Ants in the Brazilian Cerrado  

Microsoft Academic Search

We evaluated the potential of different types of urban green spaces for conservation of ground-dwelling ants. The study area, which included 12 public squares, two urban parks, and three natural reserves, is within the highly threatened Cerrado biome of central Brazil. We compared ant species richness and composition among the different types of urban green spaces, and evaluated how ant

Renata Pacheco; Heraldo L. Vasconcelos

2007-01-01

320

Native and Exotic Ants of the Azores (Hymenoptera: Formicidae)  

Microsoft Academic Search

The Azores, a North Atlantic archipelago, has 14 known ant species. Although some earlier researchers have regarded all ants in the Azores to be exotic, we believe several are native (i.e., predating human arrival). Five ant species found in relatively undisturbed environments and not widely distributed beyond the Azores, neighboring Madeira, and the Mediterranean, we judge to be native to

James K. Wetterer; Xavier Espadaler; Andrea L. Wetterer; Susana G. M. Cabral

321

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

E-print Network

I examined the impacts of the invasive red imported fire ant (RIFA, Solenopsis invicta) on native ants (Monomorium minimum, Paratrechina sp., S. krockowi, Pheidole metallescens, Forelius pruinosus, and Camponotus americanus) and litter removal in a...

Bedford, Theresa Louise

2006-08-16

322

The Ants: A Community of Microrobots  

NSDL National Science Digital Library

A community of cubic-inch microrobots called "ants" is located at the Massachusetts Institute of Technology artificial intelligence laboratory. As part of a larger initiative to develop technologies for planetary exploration, the two main goals of the Ants project are "to push the limit of microrobotics by integrating many sensors and actuators into a small package, and to form a structured robotic community from the interactions of many simple individuals." Information pertaining to topics such as Hardware, Software, Related Research at the MIT AI Lab, Related Research Elsewhere, and Related Web Sites is listed under these subheadings. At the Website, the user will also find links to related MIT project sites such as Explosive Ordnance Disposal and Mars Exploration. These projects are an example of the many applications of robotic communities.

1997-01-01

323

Optic disc detection using ant colony optimization  

NASA Astrophysics Data System (ADS)

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.

Dias, Marcy A.; Monteiro, Fernando C.

2012-09-01

324

Experimental tests of the mechanism for ant-enhanced growth in an ant-tended lycaenid butterfly  

Microsoft Academic Search

In a previous laboratory study, larvae of the ant-tended lycaenid butterfly Hemiargus isola developed into larger adults when reared with the ant Formica perpilosa than when reared without ants. Ants neither fed butterfly larvae nor significantly delayed developmental duration. We investigated\\u000a two non-exclusive hypotheses for the mechanism of this effect: larvae tended by F. perpilosa (1) consume more food, and

Diane Wagner; Carlos Martínez del Rio

1997-01-01

325

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

Microsoft Academic Search

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

Champlain Djiéto-Lordon; Alain Dejean; Marc Gibernau; Martine Hossaert-McKey; Doyle McKey

2004-01-01

326

Polydomy in the ant Ectatomma opaciventre  

PubMed Central

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.

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

2014-01-01

327

Influence of urbanization on ant distribution in parks of Tokyo and Chiba City, Japan I. Analysis of ant species richness  

Microsoft Academic Search

To investigate how progressive urbanization influences the distribution of ant species in cities, I compared the ant species richness in urban parks of different areas and ages of Tokyo, the most intensively developed urban region in Japan, and its developing neighbor, Chiba City. A total of 43 ant species were found from 98 parks. Multiple regression analysis revealed that park

Takeshi YAMAGUCHI

2004-01-01

328

Ants on the Move: Resource Limitation of a Litter-nesting Ant Community in Costa Rica1  

Microsoft Academic Search

The leaf litter of tropical wet forests is replete with itinerant ant nests. Nest movement may help ants evade the constraints of stress and disturbance and increase access to resources. I studied how nest relocation and environmental factors may explain the density, size, and growth of leaf litter ant nests. I decoupled the relationships among litter depth, food abundance, and

Terrence P. McGlynn

2006-01-01

329

Path integration controls nest-plume following in desert ants.  

PubMed

The desert ant Cataglyphis fortis is equipped with sophisticated navigational skills for returning to its nest after foraging. The ant's primary means for long-distance navigation is path integration, which provides a continuous readout of the ant's approximate distance and direction from the nest. The nest is pinpointed with the aid of visual and olfactory landmarks. Similar landmark cues help ants locate familiar food sites. Ants on their outward trip will position themselves so that they can move upwind using odor cues to find food. Here we show that homing ants also move upwind along nest-derived odor plumes to approach their nest. The ants only respond to odor plumes if the state of their path integrator tells them that they are near the nest. This influence of path integration is important because we could experimentally provoke ants to follow odor plumes from a foreign, conspecific nest and enter that nest. We identified CO(2) as one nest-plume component that can by itself induce plume following in homing ants. Taken together, the results suggest that path-integration information enables ants to avoid entering the wrong nest, where they would inevitably be killed by resident ants. PMID:22405868

Buehlmann, Cornelia; Hansson, Bill S; Knaden, Markus

2012-04-10

330

Fast and flexible: argentine ants recruit from nearby trails.  

PubMed

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

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

2013-01-01

331

Exploring with PAM: Prospecting ANTS Missions for Solar System Surveys  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

332

Fast and Flexible: Argentine Ants Recruit from Nearby Trails  

PubMed Central

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

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

2013-01-01

333

USDA: FORMIS: A Master Bibliography of Ant Literature  

NSDL National Science Digital Library

Hosted by the USDA's Center for Medical, Agricultural, and Veterinary Entomology, this Master Bibliography of Ant Literature, entitled FORMIS, "is a composite of several ant literature databases. It contains citations for a large fraction of the world's ant literature (about 32,000 references). FORMIS contains all known ant taxonomic literature (through 1996)." In addition, FORMIS features comprehensive bibliographies of fire ants, Russian wood ants, and leaf-cutting ants. The website offers options for online searches and downloads. The site was last modified in April 2004; however, it should be noted that FORMIS has not been updated since 2003, thus users should not expect to find the most recent literature. Despite the lack of up-to-date literature, FORMIS remains a substantial resource for myrmecologists and other researchers. Furthermore, the editors are requesting assistance for the continued expansion and updating of FORMIS.

334

Effects of vegetation cover, presence of a native ant species, and human disturbance on colonization by Argentine ants.  

PubMed

The spread of non-native invasive species is affected by human activity, vegetation cover, weather, and interaction with native species. We analyzed data from a 17-year study of the distribution of the non-native Argentine ant (Linepithema humile) and the native winter ant (Prenolepis imparis) in a preserve in northern California (U.S.A.). We conducted logistic regressions and used model selection to determine whether the following variables were associated with changes in the distribution of each species: presence of conspecifics at neighboring sites, distance to development (e.g., roads, buildings, and landscaped areas), proportion of vegetation cover taller than 0.75 m, elevation, distance to water, presence of both species at a site, temperature, and rainfall. Argentine ants colonized unoccupied sites from neighboring sites, but the probability of appearance and persistence decreased as distance to development, vegetation cover, and elevation increased. Winter ants appeared and persisted in sites with relatively high vegetation cover (i.e., highly shaded sites). Presence of the 2 species was negatively associated in sites with high vegetation cover (more winter ants) and sites near development (more Argentine ants). Probability of colonization of Argentine ants decreased where winter ants were most persistent. At sites near development within the preserve, abundant Argentine ant populations may be excluding winter ants. The high abundance of Argentine ants at these sites may be due to immigration from suburban areas outside the preserve, which are high-quality habitat for Argentine ants. In the interior of the preserve, distance from development, low-quality habitat, and interaction with winter ants may in combination exclude Argentine ants. Interactions among the variables we examined were associated with low probabilities of Argentine ant colonization in the preserve. PMID:22533673

Fitzgerald, Katherine; Gordon, Deborah M

2012-06-01

335

The significance of direct sunlight and polarized skylight in the ant’s celestial system of navigation  

PubMed Central

As textbook knowledge has it, bees and ants use polarized skylight as a backup cue whenever the main compass cue, the sun, is obscured by clouds. Here we show, by employing a unique experimental paradigm, that the celestial compass system of desert ants, Cataglyphis, relies predominantly on polarized skylight. If ants experience only parts of the polarization pattern during training but the full pattern in a subsequent test situation, they systematically deviate from their true homeward courses, with the systematics depending on what parts of the skylight patterns have been presented during training. This “signature” of the polarization compass remains unaltered, even if the ants can simultaneously experience the sun, which, if presented alone, enables the ants to select their true homeward courses. Information provided by direct sunlight and polarized skylight is picked up by different parts of the ant’s compound eyes and is channeled into two rather separate systems of navigation. PMID:16888039

Wehner, Rüdiger; Müller, Martin

2006-01-01

336

Biodiversity below ground: probing the subterranean ant fauna of Amazonia  

NASA Astrophysics Data System (ADS)

Ants are abundant, diverse, and ecologically dominant in tropical forests. Subterranean ants in particular are thought to have a significant environmental impact, although difficulties associated with collecting ants underground and examining their ecology and behavior have limited research. In this paper, we present the results of a study of subterranean ant diversity in Amazonian Ecuador that employs a novel probe to facilitate the discovery of species inhabiting the soil horizon. Forty-seven species of ants in 19 genera, including new and apparently rare species, were collected in probes. Approximately 19% of the species collected at different depths in the soil were unique to probe samples. Analysis of similarity (ANOSIM) results showed that the species composition of ants collected with the probe was significantly different from samples collected using other techniques. Additionally, ANOSIM computations indicated the species assemblage of ants collected 12.5 cm below the surface was significantly different from those found at 25, 37.5, and 50 cm. Ant diversity and species accumulation rates decreased with increasing depth. There were no species unique to the lowest depths, suggesting that subterranean ants may not be distributed deep in the soil in Amazonia due to the high water table. The technique we describe could be used to gain new insights into the distribution and biology of subterranean ant species and other members of the species-rich soil invertebrate macrofauna.

Ryder Wilkie, Kari T.; Mertl, Amy L.; Traniello, James F. A.

2007-09-01

337

Homing abilities of the Australian intertidal ant Polyrhachis sokolova.  

PubMed

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

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

2013-10-01

338

Chemically armed mercenary ants protect fungus-farming societies  

PubMed Central

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

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

2013-01-01

339

Chemically armed mercenary ants protect fungus-farming societies.  

PubMed

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

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

2013-09-24

340

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

341

A Quality of Service Routing Scheme for Packet Switched Networks based on Ant Colony Behavior  

Microsoft Academic Search

Abstract. Quality of Service (QoS) guarantees must be supported in a ,network ,that intends to carry ,real-time multimedia traffic effectively. A key ,problem in providing QoS guarantees is routing which consists of finding a path ina,network ,that satisfies several constraints such as bandwidth, delay, delay jitter, etc. This paper proposes a novel,QoS routing scheme ,called AntNet-QoS which provides QoS by

Liliana Carrillo; J. L Marzo; Pere Vilà; Lluís Fàbrega; Carles Guadall

2004-01-01

342

Ant-aphid mutualisms: the impact of honeydew production and honeydew sugar composition on ant preferences  

Microsoft Academic Search

The honeydew composition and production of four aphid species feeding on Tanacetum vulgare, and mutualistic relationships with the ant Lasius niger were studied. In honeydew of Metopeurum fuscoviride and Brachycaudus cardui, xylose, glucose, fructose, sucrose, maltose, melezitose, and raffinose were detected. The proportion of trisaccharides (melezitose,\\u000a raffinose) ranged between 20% and 35%. No trisaccharides were found in honeydew of Aphis

Wolfgang Völkl; Joseph Woodring; Melanie Fischer; Matthias W. Lorenz; Klaus H. Hoffmann

1999-01-01

343

AntHocNet: an Ant-Based Hybrid Routing Algorithm for Mobile Ad Hoc Networks  

E-print Network

are equal and there is no centralized control or overview. There are no designated routers: all nodes can present AntHocNet, a new algorithm for routing in mobile ad hoc networks. Due to the ever changing, multiple paths are set up between the source and des- tination of a data session, and during the course

Ducatelle, Frederick

344

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

PubMed Central

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

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

2014-01-01

345

The Argentine ant: challenges in managing an invasive unicolonial pest.  

PubMed

The Argentine ant, Linepithema humile, has invaded urban, agricultural, and natural habitats worldwide, causing economic damage and disrupting ecosystem processes. Introduced populations of L. humile and those of many other invasive ants tend to be unicolonial, forming expansive, multiqueened supercolonies that dominate native ant communities and challenge control practices in managed habitats. Argentine ant management typically entails the application of residual insecticide liquids, granules, or baits to only a portion of the colony, resulting in fairly rapid reinfestation. We suggest that prevailing control methodologies are incomplete and not compatible with the behavior, nesting habits, and population structure of this ant, and therefore, more aggressive management strategies are required. Successful eradication efforts against other invasive unicolonial ant species can provide useful insights for local-scale L. humile eradication. PMID:17877449

Silverman, Jules; Brightwell, Robert John

2008-01-01

346

Where and how Argentine ant (Linepithema humile) spreads in Corsica?  

PubMed

The Argentine ant, Linepithema humile (Dolichoderinae), is one of the most widespread invasive ant species in the world. When established in optimal habitat, this species usually excludes most other local ants and can heavily impact other arthropods as well. Although Argentine ants have been present in southern Europe for more than 100 years, they were first noted in Corsica, a French Mediterranean island, in 1957 in only one urban station. In this study, we aimed to map precisely their geographical distribution in Corsica and to quantify their presence by using an infestation index. We recorded changes in the distribution of Argentine ants in Corsica over the past decade. Argentine ants appeared to be well established within their introduced range and spreading along the Corsican coasts principally through Human-mediated jump-dispersal but not homogenously. PMID:19632658

Blight, Olivier; Orgeas, Jérôme; Renucci, Marielle; Tirard, Alain; Provost, Erick

2009-08-01

347

Reduced Chitinase Activities in Ant Plants of the Genus Macaranga  

NASA Astrophysics Data System (ADS)

Many plant species have evolved mutualistic associations with ants, protecting their host against detrimental influences such as herbivorous insects. Letourneau (1998) reported in the case of Piper that ants defend their plants principally against stem-boring insects and also reduce fungal infections on inflorescences. Macaranga plants that were experimentally deprived of their symbiotic Crematogaster ants suffered heavily from shoot borers and pathogenic fungi (Heil 1998). Here we report that ants seem to reduce fungal infections actively in the obligate myrmecophyte Macarangatriloba (Euphorbiaceae), while ant-free plants can be easily infected. We also found extremely low chitinase activity in Macaranga plants. The plants' own biochemical defense seems to be reduced, and low chitinase activity perhaps may represent a predisposition for the evolution of myrmecophytism. These plants are therefore highly dependent on their ants, which obviously function not only as an antiherbivore defense but also as an effective agent against fungal pathogens.

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

348

Cascading trait-mediated interactions induced by ant pheromones  

PubMed Central

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

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

2012-01-01

349

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

350

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

Microsoft Academic Search

Recent studies on the ant phylogeny are mainly based on the molecular analyses of extant subfamilies and do not include the\\u000a extinct, only Cretaceous subfamily Sphecomyrminae. However, the latter is of major importance for ant relationships, as it\\u000a is considered the most basal subfamily. Therefore, each new discovery of a Mesozoic ant is of high interest for improving\\u000a our understanding

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

2008-01-01

351

Habitat complexity facilitates coexistence in a tropical ant community.  

PubMed

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

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

2006-09-01

352

Weeding and grooming of pathogens in agriculture by ants  

Microsoft Academic Search

The ancient mutualism between fungus-growing ants and the fungi they cultivate for food is a textbook example of symbiosis. Fungus-growing ants'ability to cultivate fungi depends on protection of the garden from the aggressive microbes associated with the substrate added to the garden as well as from the specialized virulent garden parasite Escovopsis. We examined ants' ability to remove alien microbes

Cameron R. Currie; Alison E. Stuart

2001-01-01

353

Scavenging in Mediterranean ecosystems: effect of the invasive Argentine ant  

Microsoft Academic Search

Above-ground invertebrates may represent a high proportion of animal biomass, but few data are available on their fate after\\u000a death. In Mediterranean ant communities, they are frequently scavenged by ants. Here, we assessed the consequences of Argentine\\u000a ant invasion on the removal of arthropod corpses in Doñana National Park (SW Spain). In three natural habitats that differed\\u000a in their degree

Elena Angulo; Stéphane Caut; Xim Cerdá

2011-01-01

354

Automatic Generation of Web Portals Using Artificial Ants  

E-print Network

We present in this work a new model (named AntTree) based on artificial ants for document hierarchical clustering . This model is inspired from the self-assembly behavior of real ants. We have simulated this behavior to build a hierarchical tree-structured partitioning of a set of documents, according to the similarities between these documents. We have successfully compared our results to those obtained by ascending hierarchical clustering.

Hanene Azzag Polytech; Hanene Azzag

2005-01-01

355

Wasps robbing food from ants: a frequent behavior?  

Microsoft Academic Search

Food robbing, or cleptobiosis, has been well documented throughout the animal kingdom. For insects, intrafamilial food robbing\\u000a is known among ants, but social wasps (Vespidae; Polistinae) taking food from ants has, to the best of our knowledge, never\\u000a been reported. In this paper, we present two cases involving social wasps robbing food from ants associated with myrmecophytes.\\u000a (1) Polybioides tabida

Louis Lapierre; Henry Hespenheide; Alain Dejean

2007-01-01

356

Anting in a Semifree-ranging Group of Cebus apella  

Microsoft Academic Search

Capuchins apply many organic materials, especially leaves, to their skin. Protection against ectoparasites is the most commonly\\u000a discussed explanation for the behavior. We describe fur rubbing with carpenter ants(Camponotus rufipes) by semifree-ranging tufted capuchins(Cebus apella) in the Tietê Ecological Park, São Paulo, Brazil. Carpenter ants produce and secrete high concentrations of formic acid, which\\u000a repels tick nymphs. Anting occurred significantly

M. P. Verderane; T. Falótico; B. D. Resende; M. B. Labruna; P. Izar; E. B. Ottoni

2007-01-01

357

Directed Aerial Descent Behavior in African Canopy Ants (Hymenoptera: Formicidae)  

Microsoft Academic Search

Several species of neotropical ants direct their aerial descent toward tree trunks during a fall from the forest canopy. The\\u000a primary goal of this study was to determine if afrotropical arboreal ants exhibit similar gliding behavior. Ants were collected\\u000a from nine tree crowns in late secondary forest at a hydrocarbon extraction site near Gamba, Gabon. Of the 32 species tested,

S. P. Yanoviak; B. L. Fisher; A. Alonso

2008-01-01

358

The Evolution of Communication in Two AntPlant Mutualisms  

Microsoft Academic Search

Myrmecophytes are plants that provide nesting sites and food to ants that protect them against herbivores. Plant signals function\\u000a to synchronize ant patrolling with the probability of herbivory. We compared the communication signals in two symbioses involving\\u000a ant and plant pairs that are closely related. The two plants emitted the same volatile compounds upon damage. These compounds\\u000a are simple molecules

Marion Vittecoq; Champlain Djieto-Lordon; Bruno Buatois; Laurent Dormont; Doyle McKey; Rumsaïs Blatrix

359

International Conference on Advanced Computer Control An Adaptive Multi-Agent Routing Algorithm Combining AntNet and Interconnected Learning Automata  

E-print Network

Learning Automata (LA) is an abstract model which can be used to guide action selection at any stage of a system by past actions and environment responses to improve some overall performance function. The use of intelligent algorithms based on learning automata can be efficient for traffic control. How ever, these learning schemes have been focused only to unimodal routing problem in connection oriented networks. The field of Ant Colony Optimization (ACO) models real ant colony behavior using artificial ant algorithms and find its application in a whole range of optimization problems. Ant algorithms experimentally prove to work very well in static and dynamic optimization problems and match perfectly with some model of interconnected LA. In this paper, an adaptive multi-agent routing algorithm called LA-AntNet is proposed for both source and nonsource routing in communication networks. In this algorithm, mobile ant agents form AntNet routing system (Dicaro & Dorigo 1998) are combined to a system of static distributed LA agents, statically connected to the network nodes and directly responsible for routing decisions. The mobile ant agents improve local decisions of LA and adapt it with network conditions by moving over the network and colleting information about traffic distribution. In this algorithm the decision policy of LA is modified to involve a heuristic parameter which is a suggestion coming from ACO field and can guide learning process and improve convergence results. The proposed algorithm is implemented on several topologies to obtain performance metrics namely, throughput and total delay. The results are compared to the ones obtained from AntNet and a learning automata technique.

Z. Farhadpour; M. R. Meybodi

360

Looking and homing: how displaced ants decide where to go.  

PubMed

We caught solitary foragers of the Australian Jack Jumper ant, Myrmecia croslandi, and released them in three compass directions at distances of 10 and 15 m from the nest at locations they have never been before. We recorded the head orientation and the movements of ants within a radius of 20 cm from the release point and, in some cases, tracked their subsequent paths with a differential GPS. We find that upon surfacing from their transport vials onto a release platform, most ants move into the home direction after looking around briefly. The ants use a systematic scanning procedure, consisting of saccadic head and body rotations that sweep gaze across the scene with an average angular velocity of 90° s(-1) and intermittent changes in turning direction. By mapping the ants' gaze directions onto the local panorama, we find that neither the ants' gaze nor their decisions to change turning direction are clearly associated with salient or significant features in the scene. Instead, the ants look most frequently in the home direction and start walking fast when doing so. Displaced ants can thus identify home direction with little translation, but exclusively through rotational scanning. We discuss the navigational information content of the ants' habitat and how the insects' behaviour informs us about how they may acquire and retrieve that information. PMID:24395961

Zeil, Jochen; Narendra, Ajay; Stürzl, Wolfgang

2014-01-01

361

Evolution and ecology of directed aerial descent in arboreal ants.  

PubMed

Directed aerial descent (DAD) is used by a variety of arboreal animals to escape predators, to remain in the canopy, and to access resources. Here, we build upon the discovery of DAD in ants of tropical canopies by summarizing its known phylogenetic distribution among ant genera, and within both the subfamily Pseudomyrmecinae and the genus Cephalotes. DAD has multiple evolutionary origins in ants, occurring independently in numerous genera in the subfamilies Myrmicinae, Formicinae, and Pseudomyrmecinae. Ablation experiments and video recordings of ants in a vertical wind tunnel showed that DAD in Cephalotes atratus is achieved via postural changes, specifically orientation of the legs and gaster. The occurrence of DAD in Formicinae indicates that the presence of a postpetiole is not essential for the behavior. Evidence to date indicates that gliding behavior is accomplished by visual targeting mediated by the compound eyes, and is restricted to diurnally active ants that nest in trees. Occlusion of ocelli in Pseudomyrmex gracilis workers had no effect on their success or performance in gliding. Experimental assessment of the fate of ants that fall to the understory showed that ants landing in water are 15 times more likely to suffer lethal attacks than are ants landing in leaf litter. Variation in both the aerodynamic mechanisms and selective advantages of DAD merits further study given the broad taxonomic diversity of arboreal ants that engage in this intriguing form of flight. PMID:21562023

Yanoviak, Stephen P; Munk, Yonatan; Dudley, Robert

2011-12-01

362

Signals Can Trump Rewards in Attracting Seed-Dispersing Ants  

PubMed Central

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

Turner, Kyle M.; Frederickson, Megan E.

2013-01-01

363

A Clustering Algorithm Based on the Ants Self-Assembly Behavior  

Microsoft Academic Search

\\u000a We have presented in this paper an ants based clustering algorithm which is inspired from the self-assembling behavior observed\\u000a in real ants. These ants progressively become connected to an initial point called the support and then successively to other\\u000a connected ants. The artificial ants that we have defined similarly build a tree where each ant represents a node\\/data. Ants\\u000a use

Hanene Azzag; Nicolas Monmarché; Mohamed Slimane; Christiane Guinot; Gilles Venturini

2003-01-01

364

Optimal Screening Policies for Diabetic Retinopathy Using a Combined Discrete-Event Simulation and Ant Colony Optimization Approach  

Microsoft Academic Search

In this paper, we present the first published healthcare application of discrete-event simulation embedded in an ant colony optimization model. We consider the problem of choosing optimal screening policies for retinopathy, a serious complication of diabetes. In order to minimize the screening cost per year of sight saved, compared with a situation with no screening, individuals aged between 30 and

Marion S. Rauner; Walter J. Gutjahr; Sally C. Brailsford; Wolfgang Zeppelzauer

365

Combined Discrete-event Simulation and Ant Colony Optimisation Approach for Selecting Optimal Screening Policies for Diabetic Retinopathy  

Microsoft Academic Search

In this paper we present the first application to a healthcare problem of discrete-event simulation (DES) embedded in an ant colony optimisation (ACO) model. We are concerned with choosing optimal screening policies for retinopathy, a sight-threatening complication of diabetes. The early signs of retinopathy can be detected by screening before the patient is aware of symptoms, and blindness prevented by

Sally C. Brailsford; Walter J. Gutjahr; Marion S. Rauner; Wolfgang Zeppelzauer

2007-01-01

366

Task partitioning in a ponerine ant.  

PubMed

This paper reports a study of the task partitioning observed in the ponerine ant Ectatomma ruidum, where prey-foraging behaviour can be subdivided into two categories: stinging and transporting. Stingers kill live prey and transporters carry prey corpses back to the nest. Stinging and transporting behaviours are released by certain stimuli through response thresholds; the respective stimuli for stinging and transporting appear to be the number of live prey and the number of prey corpses. A response threshold model, the parameters of which are all measured empirically, reproduces a set of non-trivial colony-level dynamical patterns observed in the experiments. This combination of modelling and empirical work connects explicitly the level of individual behaviour with colony-level patterns of work organization. PMID:12069491

Theraulaz, Guy; Bonabeau, Eric; Sole, Ricard V; Schatz, Bertrand; Deneubourg, Jean-Louis

2002-04-21

367

Significance of the tropical fire ant Solenopsis geminata (hymenoptera: formicidae) as part of the natural enemy complex responsible for successful biological control of many tropical irrigated rice pests.  

PubMed

The tropical fire ant Solenopsis geminata (Fabricius) often nests very abundantly in the earthen banks (bunds) around irrigated rice fields in the tropics. Where some farmers habitually drain fields to the mud for about 3-4 days, the ants can quickly spread up to about 20 m into the fields where they collect food, including pest prey such as the eggs and young of the apple snail Pomacea caniculata (Lamarck) and insects such as lepidopterous larvae and hoppers, notably Nilaparvata lugens (Stäl) the brown planthopper (Bph) and green leafhoppers Nephotettix spp. Even in drained fields, the activity of S. geminata is restricted by rainfall in the wet season. The relatively few ant workers that forage characteristically into drained fields and on to the transplanted clumps of rice plants (hills) kill the normally few immigrant Bph adults but are initially slower acting than other species of the natural enemy complex. However, larger populations of Bph are fiercely attacked and effectively controlled by rapidly recruited ant workers; whereas, in the absence of the ant, the other natural enemies are inadequate. In normal circumstances, there is no ant recruitment in response to initially small populations of immigrant Bph and no evidence of incompatibility between ant foragers and other natural enemies such as spiders. However, when many ants are quickly and aggressively recruited to attack large populations of Bph, they temporarily displace some spiders from infested hills. It is concluded that, in suitable weather conditions and even when insecticides kill natural enemies within the rice field, periodic drainage that enables S. geminata to join the predator complex is valuable for ant-based control of pests such as snails and Lepidoptera, and especially against relatively large populations of Bph. Drainage practices to benefit ants are fully compatible with recent research, which shows that periodic drainage combats problems of 'yield decline' in intensively irrigated tropical rice and is also needed in South East Asia to make better use of seriously declining water supplies for irrigation. PMID:19203401

Way, M J; Heong, K L

2009-10-01

368

Articulated navigation testbed (ANT): an example of adaptable intrinsic mobility  

Microsoft Academic Search

An important but oft overlooked aspect of any robotic system is the synergistic benefit of designing the chassis to have high intrinsic mobility which complements rather than limits, its system capabilities. This novel concept continues to be investigated by the Defence Research Establishment Suffield (DRES) with the Articulated Navigation Testbed (ANT) Unmanned Ground Vehicle (UGV). The ANT demonstrates high mobility

Chris A. Brosinsky; Doug M. Hanna; Steven G. Penzes

2000-01-01

369

Tracing the Rise of Ants - Out of the Ground  

PubMed Central

The evolution of ants (Hymenoptera: Formicidae) is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions of crown-group ants through time, focusing on where they nest and forage (in the canopy, litter, or soil). Based on ancestral character reconstructions, we show that in contrast to the current consensus based on verbal arguments that ants evolved in tropical leaf litter, the soil is supported as the ancestral stratum of all ants. We also find subsequent movements up into the litter and, in some cases, into the canopy. Given the global importance of ants, because of their diversity, ecological influence and status as the most successful eusocial lineage on Earth, understanding the early evolution of this lineage provides insight into the factors that made this group so successful today. PMID:24386323

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

2013-01-01

370

Self-Organizing Information Matching in InformANTS  

Microsoft Academic Search

In current information systems, information is passive. People act upon it, either sending it to known destinations or pulling it from known sources. InformANTS makes information active, enabling it to move actively from one user to another. This paper introduces the InformANTS vision and describes one of its major system components, the Information Matching System. Particular emphasis is placed on

Rainer Hilscher; Sven Brueckner; Theodore C. Belding; H. Van Dyke Parunak

2007-01-01

371

ORIGINAL PAPER New fossil ants in French Cretaceous amber  

E-print Network

ORIGINAL PAPER New fossil ants in French Cretaceous amber (Hymenoptera: Formicidae) Vincent history and basal relationships. In this paper, a new sphecomyrmine ant, allied to the Burmese amber genus workers remarkably preserved in a single piece of Early Cenoma- nian French amber. The new fossils provide

Villemant, Claire

372

Dynamics and shape of large fire ant rafts  

PubMed Central

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

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

2012-01-01

373

SYSTEMATICS Taxonomy and Distribution of the Argentine Ant, Linepithema humile  

E-print Network

SYSTEMATICS Taxonomy and Distribution of the Argentine Ant, Linepithema humile (Hymenoptera Ann. Entomol. Soc. Am. 97(6): 1204Ð1215 (2004) ABSTRACT The taxonomy of an invasive pest species humile, taxonomy, invasive species THE ARGENTINE ANT, Linepithema humile (Mayr) 1868, is among the world

Villemant, Claire

374

Commercial agrochemical applications in vineyards do not influence ant communities.  

PubMed

Ants have been widely used as bioindicators for various terrestrial monitoring and assessment programs but are seldom considered in evaluation of nontarget pesticide effect. Much chemical assessment has been biased toward laboratory and bioassay testing for control of specific pest ant species. Several field studies that did explore the nontarget impacts of pesticides on ants have reported contradictory findings. To address the impact of chemical applications on ants, we tested the response of epigeal ant assemblages and community structure to three pesticide gradients (cumulative International Organization for Biological and Integrated Control toxicity rating, chlorpyrifos use rate, and sulfur use rate) in 19 vineyards. Ordination analyses using nonmetric multidimensional scaling detected community structures at species and genus levels, but the structures were not explained by any pesticide variables. There was no consistent pattern in species and genus percentage complementarities and ant assemblages along pesticide gradients. In contrast, ant community structure was influenced by the presence of shelterbelts near the sampling area. Reasons for the resilience of ants to pesticides are given and assessment at the colony level instead of workers abundance is suggested. The presence of Linepithema humile (Mayr) is emphasized. PMID:18284765

Chong, Chee Seng; Hoffmann, Ary A; Thomson, Linda J

2007-12-01

375

Size and Behavior in Ants: Constraints on Complexity  

Microsoft Academic Search

In this paper I investigate the behavioral complexity of ants in relation to brain size. The volume of the corpora pedunculata, involved in the selection of motor programs, and the antennal lobes, involved in processing olfactory information, are directly related to the volume of the brain of an ant. The volume of the optic lobe, involved in visual processing, is

Blaine J. Cole

1985-01-01

376

Zombie fire ant workers: behavior controlled by decapitating fly parasitoids  

Microsoft Academic Search

.  Laboratory observations were conducted on four separate red imported fire ant, Solenopsis invicta, colonies that contained workers parasitized by the decapitating fly, Pseudacteon tricuspis. Parasitized S. invicta workers remained inside the nest during parasitoid larval development and left the nest approximately 8 – 10 hours before\\u000a decapitation by the parasitoid. When parasitized ants left the nest, they were highly mobile,

D. C. Henne; S. J. Johnson

2007-01-01

377

ANT2 Isoform Required for Cancer Cell Glycolysis  

Microsoft Academic Search

The three adenine nucleotide translocator ({ANT1} to {ANT3}) isoforms, differentially expressed in human cells, play a crucial role in cell bioenergetics by catalyzing ADP and ATP exchange across the mitochondrial inner membrane. In contrast to differentiated tissue cells, transformed cells, and their ?0 derivatives, i.e. cells deprived of mitochondrial DNA, sustain a high rate of glycolysis. We compared the expression

Arnaud Chevrollier; Dominique Loiseau; Béatrice Chabi; Gilles Renier; Olivier Douay; Yves Malthièry; Georges Stepien

2005-01-01

378

Science News: Ants Take a Cue From Facebook  

NSDL National Science Digital Library

A new study finds that, whereas most red harvester ants share information with a small number of nestmates, a few convey news to a wide network of others. The results help explain how ant colonies quickly respond to predators and natural disasters.

Carrie Arnold (AAAS;)

2011-04-12

379

Enhanced Generalized Ant Programming (EGAP) School of Computer Science  

E-print Network

of automatic programming while emphasizing the technique of Ant Programming (AP). AP uses an ant foraging modification, program synthesis. I.2.11 [Computing Methodologies]: Distributed Artificial Intelligence) technique. In automatic programming, the goal of the desired program is first specified; then, based upon

Fernandez, Thomas

380

Optimization of power electronic circuits using ant colony system  

Microsoft Academic Search

Ant colony optimization (ACO) is typically used to search paths through graphs. The concept is based on simulating the behavior of ants in finding paths from the colony to food. Its searching mechanism is applicable for optimizing electric circuits with components, like resistors and capacitors, available in discrete values. In this paper, an extended ACO (eACO) that can search the

Jun Zhang; H. S. H. Chung; A. W. L. Lo; Tao Huang

2008-01-01

381

Extended Ant Colony Optimization Algorithm for Power Electronic Circuit Design  

Microsoft Academic Search

Ant colony optimization (ACO) is typically used to search paths through graphs. The concept is based on simulating the behavior of ants in finding paths from the colony to food. Its searching mechanism is applicable for optimizing electric circuits with components, like resistors and capacitors, available in discrete values. However, power electronic circuits (PECs) generally consist of components, like inductors,

Jun Zhang; Henry Shu-Hung Chung; Alan Wai-Lun Lo; Tao Huang

2009-01-01

382

THE EARLIEST KNOWN FOSSIL ANT (FIRST SOUTHERN HEMISPHERE MESOZOIC RECORD)  

E-print Network

THE EARLIEST KNOWN FOSSIL ANT (FIRST SOUTHERN HEMISPHERE MESOZOIC RECORD) (HYMENOPTERA: FORMICIDAE are scarce in Cretaceous deposits. Sphecomyrma freyi Wilson & Brown (1967) was the first fossil ant assigned.S.A. (Magothy Formation). This formation was at the time referred to the lower part of the Upper Cretaceous

Villemant, Claire

383

The Effects of Ant Mutualism on the Foraging and Diet  

E-print Network

of butterfly ecology. Lycaenid-ant associations can be parasitic, commensal, or mutualistic (Hinton 1951 likely that ants in the majority of these relationships are harvesting substantial food rewards on these mutualistic associations. This chapter will examine the nature of the nutritional hurdles imposed by Iycaenid

Pierce, Naomi E.

384

Ant–plant–herbivore interactions in the neotropical cerrado savanna  

Microsoft Academic Search

The Brazilian cerrado savanna covers nearly 2 million km 2 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

Paulo S. Oliveira; André V. L. Freitas

2004-01-01

385

The recovery of ant communities in regenerating temperate conifer forests  

Microsoft Academic Search

Although ants perform many critical functions in forested ecosystems, little is known about how they respond to timber harvesting, especially in temperate systems. We examined ground-foraging ant communities and 11 forest characteristics in temperate conifer forests of southwestern Oregon, USA that ranged in age from 5 to 427 years. Seven forest characteristics were related to stand age and were summarized

Jennifer D. Palladini; Maureen G. Jones; Nathan J. Sanders; Erik S. Jules

2007-01-01

386

ANTS\\/PAM: Future Exploration of the Asteroid Belt  

Microsoft Academic Search

The Autonomous Nano-Technology Swarm (ANTS) is applied to the Prospecting Asteroid Mission (PAM) concept, as part of a NASA RASC study. The ANTS architecture is inspired by success of social insect colonies, based on the division of labor within the colonies: 1) within their specialties, individual specialists generally outperform general-ists, and 2) with sufficiently efficient social interaction and coordination, the

P. E. Clark; S. A. Curtis; M. L. Rilee; C. Y. Cheung

2004-01-01

387

Research article Contact between supercolonies elevates aggression in Argentine ants  

E-print Network

Research article Contact between supercolonies elevates aggression in Argentine ants M. L. Thomas1 a variety of different cues, but the relative importance of these cues can change in relation to the fitness ants are characterized by a social structure known as unicolonial- ity where intraspecific aggression

Suarez, Andrew V.

388

Fire ant polymorphism: the ergonomics of brood production  

Microsoft Academic Search

Social organization is generally assumed to increase colony efficiency and survival; however, little quantitative information is available to support this assumption. Polymorphism is an important aspect of labor division in colonies of the fire ant, Solenopsis invicta. Our objective was to investigate the effect of fire ant polymorphism on brood production efficiency. We set up standardized polymorphic colonies with a

Sanford D. Porter; Walter R. Tschinkel

1985-01-01

389

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

E-print Network

October 1977 Identification, Distribution, and Biology of Fire Ants in Texas The Texas Agricultural Experiment Station / Neville P. Clarke, Acting Director / College Station, Texas/The Texas A&M University System Contents Summary....................................................................................................................7 Key to the Fire Ants of Texas ................................................................................. 9 Major W o rke rs ................................................................................................... 9 M inor W...

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

1977-01-01

390

Chemical defense by the native winter ant (Prenolepis imparis) against the invasive Argentine ant (Linepithema humile).  

PubMed

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

Sorrells, Trevor R; Kuritzky, Leah Y; Kauhanen, Peter G; Fitzgerald, Katherine; Sturgis, Shelby J; Chen, Jimmy; Dijamco, Cheri A; Basurto, Kimberly N; Gordon, Deborah M

2011-01-01

391

Incremental Construction of Neighborhood Graphs Using the Ants Self-Assembly Behavior  

Microsoft Academic Search

In this paper we present a new incremental algorithm for building neighborhood graphs between data. It is inspired from the self-assembly behavior observed in real ants where ants progressively become attached to an existing support and then successively to other attached ants. Each artificial ant represents one data. The way ants move and build a graph depends on the similarity

Julien Lavergne; Hanane Azzag; Christiane Guinot; Gilles Venturini

2007-01-01

392

Application of ant colony optimization (ACO) algorithm to remote sensing image classification  

NASA Astrophysics Data System (ADS)

Ant Colony Optimization (ACO) algorithm takes inspiration from the coordinated behavior of ant swarms, which has been applied in many study fields as a novel evolutionary technology to solve optimization problems. But it has rarely been used to process remote sensing data. Using the ACO algorithm to remote sensing image classification does not assume an underlying statistical distribution for the pixel data, the contextual information can be taken into account, and it has strong robustness. In this paper, taking Landsat TM data as an example, the process of ACO method in remote sensing data classification is introduced in detail, and has achieved a good result. The study results suggest that ACO become a new effective method for remote sensing data processing.

Dai, Qin; Liu, Jianbo

2007-11-01

393

Unit Commitment by Hybrid Ant System/Priority List Method based Probabilistic Approach  

NASA Astrophysics Data System (ADS)

This paper presents a new method to solve the unit commitment problem by using a hybrid ant system/priority list method based probabilistic approach (HASP). The proposed methodology employs ant system (AS) in cooperating with the priority list method to commit generating units probabilistically corresponding to the specific conditions as means of mutually combining the advantages of them in that a flexibility of the priority list method is reinforced, while AS algorithm can gain the benefit of using a set of heuristics for improving its performance during search process under the operating constraints. The proposed methodology including its effective techniques has been tested on a system up to 100 generating units with a scheduling time horizon of 24 hours. The simulation results show that HASP gives better economical saving in total operating cost as well as faster computational time when compared to the earlier literature results.

Nualhong, Dulyatat; Chusanapiputt, Songsak; Jantarang, Sujate

394

Testing baits to control Argentine ants (Hymenoptera: Formicidae) in vineyards.  

PubMed

Liquid baits were evaluated for control of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), and associated mealybug and soft scale pests in California vineyards. In 2003, liquid baits with small doses ofimidacloprid, boric acid, or thiamethoxam dissolved in 25% sucrose water resulted in lower ant and mealybug densities and fruit damage, compared with an untreated control. Similar treatments in a soft scale-infested vineyard showed only a reduction of ant density and fruit infestation in only the boric acid and thiamethoxam treatments. In 2004, commercial and noncommercial formulations of liquid baits reduced ant densities in three separate trials, but they had inconsistent effects on mealybug densities and fruit infestation; granular protein bait had no effect. Using large plots and commercial application methodologies, liquid bait deployed in June resulted in lower ant density and fruit infestation, but it had no effect on mealybug density. Across all trials, liquid bait treatments resulted in lower ant density (12 of 14 trials) and fruit damage (11 of 14 sites), presenting the first report of liquid baits applied using commercial methodologies that resulted in a reduction of ants and their associated hemipteran crop damage. For commercialization of liquid baits, we showed that any of the tested insecticides can suppress Argentine ants when properly delivered in the crop system. For imidacloprid, bait dispensers must be protected from sunlight to reduce photodegradation. Results suggest that incomplete ant suppression can suppress mealybug densities. However, after ant populations are suppressed, there may be a longer period before hemipteran populations are effectively suppressed. Therefore, liquid baits should be considered part of a multiseason program rather than a direct, in-season control of hemipteran pest populations. PMID:18613568

Daane, Kent M; Cooper, Monica L; Sime, Karen R; Nelson, Erik H; Battany, Mark C; Rust, Michael K

2008-06-01

395

Indirect defense in a highly specific ant-plant mutualism.  

PubMed

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. PMID:18496661

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

2008-10-01

396

Extraordinary Predation by the Neotropical Army Ant Cheliomyrmex andicola: Implications for the Evolution of the Army Ant Syndrome1  

Microsoft Academic Search

Workers of the genus Cheliomyrmex are unique among the New world army ants (subfamily Ecitoninae) in that their mandibles are armed with elongate, spine-like teeth. We present the first prey records for this genus. Cheliomyrmex andicola prey on large-bodied ground dwelling invertebrates and, possibly, on vertebrates. Unlike other army ants, C. andicola workers use their sting during prey capture. The

Sean O'Donnell; Michael Kaspari; John Lattke

2005-01-01

397

A South East Asian ponerine ant of the genus Leptogenys (Hym., Form.) with army ant life habits  

Microsoft Academic Search

The emigration and raiding behavior of the SE Asian ponerine ant Leptogenys sp. 1, which resembles L. mutabilis, were observed in the field (Ulu Gombak, Malaysia). The ants formed monogynous colonies that consisted of up to 52 100 workers. The bivouac sites of this species were found in leaf litter, rotten logs, ground cavities, etc., and were rarely modified by

U. Maschwitz; S. Steghaus-Kovac; R. Gaube; H. Hänel

1989-01-01

398

Of ants and urns: estimation of the parameters of a reinforced random walk and application to ants  

E-print Network

Of ants and urns: estimation of the parameters of a reinforced random walk and application to ants behavior Line Le Goff Philippe Soulier May 9, 2014 Abstract In applications, reinforced random walks findings do not contradict the biological literature, but we give statistical significance to the values

Paris-Sud XI, Université de

399

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

E-print Network

high.31 Most examples of defense induced by herbivores have been in plants from temperate ecosystems demonstrating34 herbivore-induced defenses from tropical forests. Tropical plants, especially young leavesIs extrafloral nectar production induced by herbivores or ants in a tropical facultative ant-plant

Coley, Phyllis

400

Colonisation by a dominant ant facilitated by anthropogenic disturbance: effects on ant assemblage composition, biomass and resource use  

Microsoft Academic Search

Dominant species are thought to regulate species composition and assemblage structure. Invasion by a dominant species is thus likely to alter assemblages and anthropogenic disturbance often facilitates such invasions. In this study we examined the association of a dominant ant, Iridomyrmex purpureus, native to south-eastern Australia, with fire trails in national parks and its effects on ant assemblages. Association with

Heloise Gibb; Dieter F. Hochuli

2003-01-01

401

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

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) A Thesis by AARON NEAL... EVALUATION 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...

Thompson, Aaron Neal

2009-05-15

402

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)

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.

Matsuura, Kenji; Yashiro, Toshihisa

2006-10-01

403

Meat ants as dominant members of Australian ant communities: an experimental test of their influence on the foraging success and forager abundance of other species  

Microsoft Academic Search

Meat ants (Iridomyrmex purpureus and allies) are perceived to be dominant members of Australian ant communities because of their great abundance, high rates of activity, and extreme aggressiveness. Here we describe the first experimental test of their influence on other ant species, and one of the first experimental studies of the influence of a dominant species on any diverse ant

A. N. Andersen; A. D. Patel

1994-01-01

404

Elevated dominance of extrafloral nectary-bearing plants is associated with increased abundances of an invasive ant and reduced native ant richness  

Microsoft Academic Search

Aim Invasive ants can have substantial and detrimental effects on co-occurring community members, especially other ants. However, the ecological factors that promote both their population growth and their negative influences remain elusive. Opportunistic associations between invasive ants and extrafloral nectary (EFN)-bearing plants are common and may fuel population expansion and subsequent impacts of invasive ants on native communities. We examined

Amy M. Savage; Jennifer A. Rudgers; Kenneth D. Whitney

2009-01-01

405

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

PubMed Central

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

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

2013-01-01

406

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

PubMed

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

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

2013-01-01

407

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

PubMed Central

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

Berman, Maia; Andersen, Alan N.; Hely, Christelle; Gaucherel, Cedric

2013-01-01

408

Improved Ant Colony Algorithm for Partner Selection  

Microsoft Academic Search

Partner selection is a classical combinatorial optimization problem. Its solution is a list of nodes which are the least value of each link. When the links and candidates are increased continuously, the complexity of partner selection grows exponentially. It is difficult to solve that problem in method of exhaustion. So this paper puts forward an improved algorithm, namely partner selection

Du Hong-wei

2009-01-01

409

9 CFR 354.123 - Segregation of suspects on ante-mortem inspection.  

Code of Federal Regulations, 2010 CFR

...Segregation of suspects on ante-mortem inspection. 354.123 Section 354.123 Animals and Animal Products FOOD SAFETY AND...Inspection Procedures; Ante-Mortem Inspections § 354.123 Segregation of suspects on ante-mortem...

2010-01-01

410

9 CFR 354.122 - Condemnation on ante-mortem inspection.  

Code of Federal Regulations, 2010 CFR

...false Condemnation on ante-mortem inspection. 354.122 Section 354.122 Animals and Animal Products FOOD SAFETY AND...Inspection Procedures; Ante-Mortem Inspections § 354.122 Condemnation on ante-mortem...

2010-01-01

411

Occurrence of antennal glands in ants.  

PubMed

A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 left open the question of the extent to which similar glands occur in the Formicidae family. We wanted to know if these antennal glands are unique to Solenopsis, or they are found in a wider taxonomic group. Using scanning electron microscopy, we examined the antennae of 41 ant species. Presence of the antennal glands was indicated by a characteristic circumferential ring of pores in a distal antennal segment of workers. Pores were found in the 9th antennal segment of all 26 species of Solenopsis examined. Pores were absent in the following: Monomorium minimum, M. pharaonis, Pheidole sp., Crematogaster sp., Linepithema humile, Forelius sp., Dorymyrmex sp., Paratrechina sp., Oecophylla smaragdina, Campanotus sp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex ferruginea. However, pores were found in the antennal club of Tetramorium bicarinatum workers and queens. After KOH digestion of T. bicarinatum antennae, internal canals were observed in both workers and queens, and the canals are connected to spherical reservoirs in queens. T. bicarinatum was the only non-Solenopsis species examined, which showed evidence for antennal glands in the distal funiculus. PMID:18655135

Renthal, Robert; Velasquez, Daniel; Olmos, David; Vinson, S Bradleigh

2008-11-01

412

Public goods dilemma in asexual ant societies.  

PubMed

Cooperation in biological, social, and economic groups is underpinned by public goods that are generated by group members at some personal cost. Theory predicts that public goods will be exploited by cheaters who benefit from the goods by not paying for them, thereby leading to the collapse of cooperation. This situation, described as the "public goods dilemma" in game theory, makes the ubiquity of cooperation a major evolutionary puzzle. Despite this generalization, the demonstration of genetic background and fitness effects of the public goods dilemma has been limited to interactions between viruses and between cells, and thus its relevance at higher levels of organismal complexity is still largely unexplored. Here we provide experimental evidence for the public goods dilemma in a social insect, the ant Pristomyrmex punctatus. In this species, all workers are involved in both asexual reproduction and cooperative tasks. Genetic cheaters infiltrate field colonies, reproducing more than the workers but shunning cooperative tasks. In laboratory experiments, cheaters outcompeted coexisting workers in both survival and reproduction, although a group composed only of cheaters failed to produce offspring. The operations of the public goods dilemma in P. punctatus showed a remarkable convergence with those in microbial societies, not only in fitness consequences but also in behavioral mechanisms. Our study reinforces the evolutionary impact of cheaters on diverse cooperative systems in the laboratory and in the field. PMID:24046364

Dobata, Shigeto; Tsuji, Kazuki

2013-10-01

413

Recognition in Ants: Social Origin Matters  

PubMed Central

The ability of group members to discriminate against foreigners is a keystone in the evolution of sociality. In social insects, colony social structure (number of queens) is generally thought to influence abilities of resident workers to discriminate between nestmates and non-nestmates. However, whether social origin of introduced individuals has an effect on their acceptance in conspecific colonies remains poorly explored. Using egg-acceptance bioassays, we tested the influence of social origin of queen-laid eggs on their acceptance by foreign workers in the ant Formica selysi. We showed that workers from both single- and multiple-queen colonies discriminated against foreign eggs from single-queen colonies, whereas they surprisingly accepted foreign eggs from multiple-queen colonies. Chemical analyses then demonstrated that social origins of eggs and workers could be discriminated on the basis of their chemical profiles, a signal generally involved in nestmate discrimination. These findings provide the first evidence in social insects that social origins of eggs interfere with nestmate discrimination and are encoded by chemical signatures. PMID:21573235

Meunier, Joel; Delemont, Olivier; Lucas, Christophe

2011-01-01

414

Wasps robbing food from ants: a frequent behavior?  

NASA Astrophysics Data System (ADS)

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.

Lapierre, Louis; Hespenheide, Henry; Dejean, Alain

2007-12-01

415

Desert ants benefit from combining visual and olfactory landmarks.  

PubMed

The desert ant, Cataglyphis fortis, uses both visual and olfactory cues to guide its return to the nest. The ants use vision-based path integration for long-distance navigation and memorize the visual and olfactory surrounding of the nest to finally locate the entrance. In the present study we investigated how the visual and the olfactory navigation systems interact. In field experiments ants were trained to associate the nest with a visual cue, an olfactory cue or a combination of both cues. We tested ants after one, five and 15 training runs, to investigate whether the ants would make use of the training cues to pinpoint the nest. We found that they were slow to learn the location of the nest when it was specified by just an olfactory or a visual cue. However, the ants focused their nest search after the first training run with the combined cue. Equally experienced ants responded to the individually presented visual or olfactory cues with the same high accuracy as they did to the combined cue. After 15 training runs, the combined cue still evoked an accurate response in the test, whereas the individually presented cues no longer did. Apparently, C. fortis benefit from combining their visual and olfactory navigational tools, because the bimodal sensory input accelerates the acquisition of landmark information. PMID:21430208

Steck, Kathrin; Hansson, Bill S; Knaden, Markus

2011-04-15

416

Newly discovered sister lineage sheds light on early ant evolution  

PubMed Central

Ants are the world's most conspicuous and important eusocial insects and their diversity, abundance, and extreme behavioral specializations make them a model system for several disciplines within the biological sciences. Here, we report the discovery of a new ant that appears to represent the sister lineage to all extant ants (Hymenoptera: Formicidae). The phylogenetic position of this cryptic predator from the soils of the Amazon rainforest was inferred from several nuclear genes, sequenced from a single leg. Martialis heureka (gen. et sp. nov.) also constitutes the sole representative of a new, morphologically distinct subfamily of ants, the Martialinae (subfam. nov.). Our analyses have reduced the likelihood of long-branch attraction artifacts that have troubled previous phylogenetic studies of early-diverging ants and therefore solidify the emerging view that the most basal extant ant lineages are cryptic, hypogaeic foragers. On the basis of morphological and phylogenetic evidence we suggest that these specialized subterranean predators are the sole surviving representatives of a highly divergent lineage that arose near the dawn of ant diversification and have persisted in ecologically stable environments like tropical soils over great spans of time. PMID:18794530

Rabeling, Christian; Brown, Jeremy M.; Verhaagh, Manfred

2008-01-01

417

Patterns of Positive Selection in Seven Ant Genomes  

PubMed Central

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

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

2014-01-01

418

Trail pheromone disruption of red imported fire ant.  

PubMed

The fire ant, Solenopsis invicta (Hymenoptera: Formicidae), is considered one of the most aggressive and invasive species in the world. Toxic bait systems are used widely for control, but they also affect non-target ant species and cannot be used in sensitive ecosystems such as organic farms and national parks. The fire ant uses recruitment pheromones to organize the retrieval of large food resources back to the colony, with Z,E-alpha-farnesene responsible for the orientation of workers along trails. We prepared Z,E-alpha-farnesene, (91% purity) from extracted E,E-alpha-farnesene and demonstrated disruption of worker trail orientation after presentation of an oversupply of this compound from filter paper point sources (30 microg). Trails were established between queen-right colony cells and food sources in plastic tubs. Trail-following behavior was recorded by overhead webcam, and ants were digitized before and after presentation of the treatment, using two software approaches. The linear regression statistic, r(2) was calculated. Ants initially showed high linear trail integrity (r(2) = 0.75). Within seconds of presentation of the Z,E-alpha-farnesene treatment, the trailing ants showed little or no further evidence of trail following behavior in the vicinity of the pheromone source. These results show that trailing fire ants become disorientated in the presence of large amounts of Z,E-alpha-farnesene. Disrupting fire ant recruitment to resources may have a negative effect on colony size or other effects yet to be determined. This phenomenon was demonstrated recently for the Argentine ant, where trails were disrupted for two weeks by using their formulated trail pheromone, Z-9-hexadecenal. Further research is needed to establish the long term effects and control potential for trail disruption in S. invicta. PMID:20549330

Suckling, David M; Stringer, Lloyd D; Bunn, Barry; El-Sayed, Ashraf M; Vander Meer, Robert K

2010-07-01

419

Competitive assembly of South Pacific invasive ant communities  

PubMed Central

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

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

2009-01-01

420

Research on remote sensing image segmentation based on ant colony algorithm: take the land cover classification of middle Qinling Mountains for example  

NASA Astrophysics Data System (ADS)

Remote sensing image based on the complexity of the background features, has a wealth of spatial information, how to extract huge amounts of data in the region of interest is a serious problem. Image segmentation refers to certain provisions in accordance with the characteristics of the image into different regions, and it is the key of remote sensing image recognition and information extraction. Reasonably fast image segmentation algorithm is the base of image processing; traditional segmentation methods have a lot of the limitations. Traditional threshold segmentation method in essence is an ergodic process, the low efficiency impacts on its application. The ant colony algorithm is a populationbased evolutionary algorithm heuristic biomimetic, since proposed, it has been successfully applied to the TSP, job-shop scheduling problem, network routing problem, vehicle routing problem, as well as other cluster analysis. Ant colony optimization algorithm is a fast heuristic optimization algorithm, easily integrates with other methods, and it is robust. Improved ant colony algorithm can greatly enhance the speed of image segmentation, while reducing the noise on the image. The research background of this paper is land cover classification experiments according to the SPOT images of Qinling area. The image segmentation based on ant colony algorithm is carried out and compared with traditional methods. Experimental results show that improved the ant colony algorithm can quickly and accurately segment target, and it is an effective method of image segmentation, it also has laid a good foundation of image classification for the follow-up work.

Mei, Xin; Wang, Qian; Wang, Quanfang; Lin, Wenfang

2009-10-01

421

Ocelli: A Celestial Compass in the Desert Ant Cataglyphis  

NASA Astrophysics Data System (ADS)

In addition to multifaceted lateral compound eyes, most insects possess three frontal eyes called ocelli. Each ocellus has a single lens, as does the vertebrate eye. The ocelli of some flying insects, locusts and dragonflies, have been shown to function as horizon detectors involved in the visual stabilization of course. In a walking insect, the desert ant Cataglyphis, it is now shown that the ocelli can read compass information from the blue sky. When the ant's compound eyes are occluded and both sun and landmarks are obscured, the ocelli, using the pattern of polarized light in the sky as a compass cue, help in guiding the ant back home.

Fent, Karl; Wehner, Rudiger

1985-04-01

422

Ant network in In-Line dot Routing  

E-print Network

In network the quality of service owing to the inability to reach to the server quickly. So there is a need from an optimum method which provides easy access to the server. This paper presents Ant network in In-Line dot Routing. We bring out the Ant colony Optimization (ACO), a behavior under Ant network in In-Line dot Routing which is used to find the shortest path and the correct path of the server and also provides solutions for getting response without reaching the server and data delivery.

Anil Kumar R; Ajith Kumar R

423

Evolution of specialized spermatheca morphology in ant queens: insight from comparative developmental biology between ants and polistine wasps.  

PubMed

In many ant species, the queens can keep spermatozoa alive in their spermatheca for several years, which goes along with unique morphological characteristics of the queen's spermatheca. The relative spermatheca size in ant queens is prominently larger than that in social wasps. Furthermore, the epithelium lining the spermatheca reservoir of ants consists of columnar cells in the hilar region and squamous cells in the distal region, whereas it is formed by columnar cells only in social wasps. To study the evolution of the unique spermatheca morphology in ant queens, we compared the various processes during spermatheca development between two ponerine ant species of the genus Pachycondyla (=Brachyponera) and three polistine wasp species of the genus Polistes. From histological observations, we can define four developmental events in the ant queens: (1) invagination of the spermatheca primordium, (2) the reservoir wall thickness becomes unequal, (3) the reservoir diameter doubles as the lining epithelial cells become flattened except for the hilar region, and (4) the increase in thickness of the reservoir epithelium is limited to the hilar region which doubles in thickness. In polistine wasps, the second and the third developmental events are absent and the entire epithelium of the spermatheca wall becomes thick in the final step. We therefore conclude that for ant queens the second and third steps are crucial for the enlargement of the spermatheca size, and that the second to the fourth steps are crucial for the specialization of the reservoir wall structure. PMID:19720157

Gotoh, Ayako; Billen, Johan; Hashim, Rosli; Ito, Fuminori

2009-11-01

424

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

NASA Astrophysics Data System (ADS)

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.

Djiéto-Lordon, Champlain; Dejean, Alain; Gibernau, Marc; Hossaert-McKey, Martine; McKey, Doyle

2004-10-01

425

An empirically based simulation of group foraging in the harvesting ant, Messor pergandei.  

PubMed

We present an empirically based group model of foraging interactions in Messor pergandei, the Sonoran desert harvesting ant. M. pergandei colonies send out daily foraging columns consisting of tens of thousands of individual ants. Each day, the directions of the columns may change depending on the resource availability and the neighbor interactions. If neighboring columns meet, ants fight, and subsequent foraging is suppressed. M. pergandei colonies face a general problem which is present in many systems: dynamic spatial partitioning in a constantly changing environment, while simultaneously minimizing negative competitive interactions with multiple neighbors. Our simulation model of a population of column foragers is spatially explicit and includes neighbor interactions. We study how different behavioral strategies influence resource exploitation and space use for different nest distributions and densities. Column foraging in M. pergandei is adapted to the spatial and temporal properties of their natural habitat. Resource and space use is maximized both at the colony and the population level by a model with a behavioral strategy including learning and fast forgetting rates. PMID:23978772

Plowes, Nicola J R; Ramsch, Kai; Middendorf, Martin; Hölldobler, Bert

2014-01-01

426

Lack of intraspecific aggression in the ant Tetramorium bicarinatum: a chemical hypothesis.  

PubMed

Tetramorium bicarinatum (Myrmicinae) is an ant species frequently found in tropical and subtropical areas, particularly in Africa, Southeast Asia (Japan), and South America (Brazil). The species is polygynous, reproduces by budding, and has sterile workers. Since the nests are widely distributed in a given area, the problem arises of territorial defense against conspecifics. Because not all ants defend territories, we assessed the defensive behavior of T. bicarinatum workers through intraspecific and interspecific aggressiveness tests. A detailed behavioral study of the interactions between workers from several different colonies of T. bicarinatum (originating from Japan and Brazil) showed that workers do not discriminate against conspecific nonnestmate individuals, but they are highly aggressive towards allospecifics (Myrmica rubra, Myrmicinae). The results suggest that each colony from this ant species possesses a similar colonial odor. Chemical analyses of the cuticular hydrocarbons of these species were made with gas chromatography coupled to mass spectrometry. Results showed that the different colonies of T. bicarinatum possess a common chemical profile mainly composed of straight-chain alkanes and alkenes, while M. rubra possess more methyl-branched alkanes. We suggest that methyl alkane cues play a determining role in colonial recognition and that these results could explain the underlaying basis of the lack of intraspecific aggressiveness in T. bicarinatum. PMID:11504025

Astruc, C; Malosse, C; Errard, C

2001-06-01

427

CMNIIACA: cloud model and niche-ideology-based improved ant colony algorithm  

NASA Astrophysics Data System (ADS)

In order to improve the convergence properties of basic ant colony algorithm (ACA), a novel type of Cloud Model and Niche Ideology-based Improved Ant Colony Algorithm (CMNIIACA) for solving complex combinational optimization problems is proposed in this paper. Cloud model theory is a powerful tool to convert numerical quantitative analysis to conceptual qualitative analysis. On the basis of introduction of ACA and cloud model theory, a novel qualitative strategy for improving the global optimization properties by use of cloud models is presented in this paper. Then, in order to avoid the stagnation, and to avoid local minima, pseudo-random-proportional action choice rule and elitist preservation strategy are adopted. As the inferior solutions seriously interfered with the searching quality, and inspired by the idea of ecological niche, all the discrete nodes are divided into several groups, the moving scope of each ant agent is then limited. Furthermore, we also limit the trail amount in a maximum-minimum interval. The simulation experiments on CHC150TSP have been performed. The computational results show that the proposed CMNIIACA can effectively improve the global convergence and the evolutional speed of ACA, and the stability of algorithm is also improved effectively. It is obvious that the CMNIIACA presented in this paper is efficient and outperforms ACA.

Duan, Haibin; Wang, Daobo; Yu, Xiufen

2006-11-01

428

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

NASA Astrophysics Data System (ADS)

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.

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

429

Biogeography and diversification of the Pacific ant genus Lordomyrma Emery  

E-print Network

typical of a mature continental ecosystem than of a collection of small remote islands (Raven & Axelrod lizards, canoid boas, elapid snakes and extinct mekosuchine crocodiles. The diversity of ants is equally

Lucky, Andrea

430

Ante rem Structuralism and the Myth of Identity Criteria  

E-print Network

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...

Siu, Ho Kin

2010-01-20

431

Efficient egress of escaping ants stressed with temperature.  

PubMed

In the present work we investigate the egress times of a group of Argentine ants (Linepithema humile) stressed with different heating speeds. We found that the higher the temperature ramp is, the faster ants evacuate showing, in this sense, a group-efficient evacuation strategy. It is important to note that even when the life of ants was in danger, jamming and clogging was not observed near the exit, in accordance with other experiments reported in the literature using citronella as aversive stimuli. Because of this clear difference between ants and humans, we recommend the use of some other animal models for studying competitive egress dynamics as a more accurate approach to understanding competitive egress in human systems. PMID:24312264

Boari, Santiago; Josens, Roxana; Parisi, Daniel R

2013-01-01

432

Simulation of Artificial Ant's Behavior in a Digital Environment  

Microsoft Academic Search

Ants present a very good natural metaphor to evolutionary computation. While their individual computational power is small compared to more evolved species, it is the power of their colonies that inspire computer scientists. This paper presents \\

Paulo E. Merloti; Joseph Lewis

2005-01-01

433

Communal peeing: a new mode of flood control in ants  

NASA Astrophysics Data System (ADS)

The behavioral response of the obligate bamboo-nesting ant Cataulacus muticus to nest flooding was studied in a perhumid tropical rainforest in Malaysia and in the laboratory. The hollow internodes of giant bamboo, in which C. muticus exclusively nests, are prone to flooding by heavy rains. The ants showed a two-graded response to flooding. During heavy rain workers block the nest entrances with their heads to reduce water influx. However, rainwater may still intrude into the nest chamber. The ants respond by drinking the water, leaving the nest and excreting water droplets on the outer stem surface. This cooperative 'peeing' behavior is a new survival mechanism adaptive to the ants' nesting ecology. Laboratory experiments conducted with two other Cataulacus species, C. catuvolcus colonizing small dead twigs and C. horridus inhabiting rotten wood, did not reveal any form of water-bailing behavior.

Maschwitz, Ulrich; Moog, J.

434

REDESCRIPTION OF THE ANT LEPTOTHORAX (S. STR.) SCAMNI RUZSKY, 1905  

E-print Network

to be a rather rare, patchily distributed ant in alpine coniferous forests in the Caucasus (Russia and Armenia. str.) in Turkey (J. H., A. S.) and the Caucasus (A. G. R.), which exactly fit Ruzsky's description

Villemant, Claire

435

Melissotarsus ants are likely able to digest plant polysaccharides.  

PubMed

Melissotarsus ants have an extremely specialized set of behaviours. Both workers and gynes tunnel galleries in their host tree bark. Workers walk with their mesothoracic legs pointing upwards and tend Diaspididae hemiptera for their flesh. The ants use their forelegs to plug the galleries with silk that they secrete themselves. We hypothesised that the ants' energetic needs for nearly constant gallery digging could be satisfied through the absorption of host tree tissues; so, using basic techniques, we examined the digestive capacities of workers from two species. We show that workers are able to degrade oligosaccharides and heterosides as well as, to a lesser degree, polysaccharides. This is one of the rare reports on ants able to digest plant polysaccharides other than starch. PMID:24246892

Mony, Ruth; Dejean, Alain; Bilong, Charles Félix Bilong; Kenne, Martin; Rouland-Lefèvre, Corinne

2013-10-01

436

INVASIVE ANTS Invasive species, those species that demonstrate  

E-print Network

, and ecological roles of invasive ants in the context of the environment and evolutionary processes. Indeed, unicoloniality, gener- alist habits, ecological release, and genetic changes. The final two chapters concern

Suarez, Andrew V.

437

Chimpanzees detect ant-inhabited dead branches and stems: a study of the utilization of plant-ant relationships in the Mahale Mountains, Tanzania.  

PubMed

Chimpanzees in the Mahale Mountains of Tanzania consume several species of stem- and branch-inhabiting ants throughout the year, without tools. Those ants are cryptic species, and it was unknown how to find them constantly. There has been little research on how the chimpanzees locate these ants. In this study, I use behavioral observations of the chimpanzee predators and surveys of the ant fauna and plants across different habitats to test the hypothesis that chimpanzees use plant species as a cue to efficiently locate ant colonies in litter units (dead parts of the plant). Ants were found to be associated with live plants and with spaces within litter units which provide nesting places. Such ant-plant litter relationships were not necessarily as strong as the mutualism often observed between live plants and ants. The proportion of available litter units inhabited by ants was 20 %, and litter units of three plant species (Vernonia subligera, Dracaena usambarensis, and Senna spectabilis) were well occupied by ants in the home range of the chimpanzees. The ant-inhabited ratio in chimpanzee-foraged litter units was higher than that in the available units in the home range. Chimpanzees fed more often on Crematogaster spp. than on other resident ants and at a higher rate than expected from their occurrence in the litter units. Above three plant species were well occupied by Crematogaster sp. 3 or C. sp. 18. It is concluded that chimpanzees locate ants by selecting litter units of plant species inhabited by ants. PMID:23842594

Fuse, Mieko

2013-10-01

438

Examination of Honey in Australian Honey-ants  

Microsoft Academic Search

THE honey-ant (Melophorus inflatus) is found in many parts of central Australia, where it is highly regarded by the aborigines as an article of food1,2. The honey-bearing ants seem to be modified workers which are fed with nectar or honey by ordinary workers until their distended abdomens approach 3\\/8 in. in diameter1. ``In eating them the native seizes each with

G. M. Badger; W. Korytnyk

1956-01-01

439

Carbohydrate supply limits invasion of natural communities by Argentine ants.  

PubMed

The ability of species to invade new habitats is often limited by various biotic and physical factors or interactions between the two. Invasive ants, frequently associated with human activities, flourish in disturbed urban and agricultural environments. However, their ability to invade and establish in natural habitats is more variable. This is particularly so for the invasive Argentine ant (Linepithema humile). While biotic resistance and low soil moisture limits their invasion of natural habitats in some instances, the effect of food availability has been poorly explored. We conducted field experiments to determine if resource availability limits the spread and persistence of Argentine ants in remnant natural forest in North Carolina. Replicated transects paired with and without sucrose solution feeding stations were run from invaded urban edges into forest remnants and compared over time using baits and direct counts at feeding stations. Repeated under different timing regimes in 2006 and 2007, access to sucrose increased local Argentine ant abundances (1.6-2.5 fold) and facilitated their progression into the forest up to 73 +/- 21% of 50-m transects. Resource removal caused an expected decrease in Argentine ant densities in 2006, in conjunction with their retreat to the urban/forest boundary. However, in 2007, Argentine ant numbers unexpectedly continued to increase in the absence of sugar stations, possibly through access to alternative resources or conditions not available the previous year such as honeydew-excreting Hemiptera. Our results showed that supplementing carbohydrate supply facilitates invasion of natural habitat by Argentine ants. This is particularly evident where Argentine ants continued to thrive following sugar station removal. PMID:19452171

Rowles, Alexei D; Silverman, Jules

2009-08-01

440

Modelling Ant Brood Tending Behavior with Cellular Automata  

Microsoft Academic Search

\\u000a The brood sorting behavior of ants like Leptothorax unifasciatus leads to patterns, where brood items are sorted in concentric\\u000a circles around the nest center. The underlying mechanisms are not fully understood so far and brood tending simulations can\\u000a help to explain the occurrence of these patterns. We reexamine an existing cellular automata based model for ant brood tending.\\u000a This model

Daniel Merkle; Martin Middendorf; Alexander Scheidler

2005-01-01

441

Evolution of influence: signaling in a lycaenid-ant interaction  

Microsoft Academic Search

Some phytophagous insects gain defense from natural enemies by associating with otherwise potentially harmful top predators.\\u000a Many lycaenid butterfly caterpillars are involved in such interactions with ants: larvae provide carbohydrate rewards from\\u000a the dorsal nectary organ (DNO) to associated ants in return for protection from natural enemies. The stability of these interactions\\u000a involves signals that identify the lycaenid caterpillar as

Jeffrey C. OliverLaura; Laura R. Stein

442

The Adaptive Web Server Based on Ant Behavior  

Microsoft Academic Search

This paper presents an approach to establish an adaptive Web site, which is inspired by the ant colonies foraging behavior.\\u000a In this approach, artificial ants metaphorically guide users’ activity and adaptively mark the most significant links, by\\u000a means of the shortest route to target node. By the simulated experiment, we study those factors that influence Web user’s\\u000a behaviors, which can

Ping Guo; Qin Xie

443

Ant Mimicry by an Aphid Parasitoid, Lysiphlebus fabarum  

PubMed Central

In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bean leaf disks in open arenas in the laboratory. Females exploited aphids as hosts and as a source of food, allocating within-patch time as follows: resting - 10.4%, grooming - 8.2%, searching - 11.5%, antennation (host recognition) - 7.5%, antennation (honeydew solicitation mimicking ants) - 31.9%, abdominal bending (attack preparation) 19.7%, probing with the ovipositor (attack) - 10.8%. The mean handling time for each aphid encountered was 2.0 ± 0.5 min. Females encountered an average of 47.4 ± 6.4 aphids per hour, but laid only 1.2 eggs per hour. The ovipositor insertion time for parasitism ranged from 2 sec to longer than a minute, but most insertions did not result in an egg being laid. A. fabae defensive behaviors included kicking, raising and swiveling the body, and attempts to smear the attacker with cornicle secretions, sometimes with lethal results. Food deprivation for 4–6 h prior to testing increased the frequency of ant mimcry by L. fabarum. Females also used ant-like antennation to reduce A. fabae defensive behavior, e.g. the frequency of kicking. L. fabarum attacks primed A. fabae to be more responsive to subsequent honeydew solicitation, such that experienced females improved their feeding success by alternating between the roles of parasitoid and ant mimic. These results reveal the possibility for mutualisms to evolve between L. fabarum and the ant species that tend A. fabae, since L. fabarum receive ant protection for their progeny and may benefit the ants by improving A. fabae responsiveness to honeydew solicitation. PMID:20879920

Rasekh, Arash; Michaud, J.P.; Kharazi-Pakdel, Aziz; Allahyari, Hossein

2010-01-01

444

Ant mimicry by an aphid parasitoid, Lysiphlebus fabarum.  

PubMed

In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bean leaf disks in open arenas in the laboratory. Females exploited aphids as hosts and as a source of food, allocating within-patch time as follows: resting - 10.4%, grooming - 8.2%, searching - 11.5%, antennation (host recognition) - 7.5%, antennation (honeydew solicitation mimicking ants) - 31.9%, abdominal bending (attack preparation) 19.7%, probing with the ovipositor (attack) - 10.8%. The mean handling time for each aphid encountered was 2.0 ± 0.5 min. Females encountered an average of 47.4 ± 6.4 aphids per hour, but laid only 1.2 eggs per hour. The ovipositor insertion time for parasitism ranged from 2 sec to longer than a minute, but most insertions did not result in an egg being laid. A. fabae defensive behaviors included kicking, raising and swiveling the body, and attempts to smear the attacker with cornicle secretions, sometimes with lethal results. Food deprivation for 4-6 h prior to testing increased the frequency of ant mimcry by L. fabarum. Females also used ant-like antennation to reduce A. fabae defensive behavior, e.g. the frequency of kicking. L. fabarum attacks primed A. fabae to be more responsive to subsequent honeydew solicitation, such that experienced females improved their feeding success by alternating between the roles of parasitoid and ant mimic. These results reveal the possibility for mutualisms to evolve between L. fabarum and the ant species that tend A. fabae, since L. fabarum receive ant protection for their progeny and may benefit the ants by improving A. fabae responsiveness to honeydew solicitation. PMID:20879920

Rasekh, Arash; Michaud, J P; Kharazi-Pakdel, Aziz; Allahyari, Hossein

2010-01-01

445

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

NASA Astrophysics Data System (ADS)

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.

Funaki, M.

2004-12-01

446

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

PubMed

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

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

2013-11-01

447

Colony Fusion in a Parthenogenetic Ant, Pristomyrmex punctatus  

PubMed Central

In the ant Pristomyrmex punctatus Smith (Hymenoptera: Formicidae), all young workers lay a small number of eggs parthenogenetically. Some colonies consist of monoclonal individuals that provide high inclusive fitness, according to the kin selection theory. However, in some populations, a majority of the colonies contain multiple lineages. Intracolonial genetic variation of parthenogenetic ants cannot be explained by the multiple mating of single founderesses or by the foundation of a colony by multiple foundresses, which are the usual causes of genetically diverse colonies in social insects. Here, we hypothesized that the fusion of established colonies might facilitate the formation of multiclonal colonies. Colony fusion decreases indirect benefits because of the reduction in intracolonial relatedness. However, when suitable nesting places for overwintering are scarce, colony fusion provides a strategy for the survival of colonies. Here, ants derived from different colonies were allowed to encounter one another in a container with just one nesting place. Initially, high aggression was observed; however, after several days, no aggression was observed and the ants shared the nest. When the fused colonies were allowed to transfer to two alternative nests, ants from different colonies occupied the same nest. This study highlights the importance of limiting the number of nesting places in order to understand the genetic diversity of parthenogenetic ant colonies. PMID:23895053

Satow, Show; Satoh, Toshiyuki; Hirota, Tadao

2013-01-01

448

Ant Colonies Prefer Infected over Uninfected Nest Sites  

PubMed Central

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

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

2014-01-01

449

Social prophylaxis through distant corpse removal in ants  

NASA Astrophysics Data System (ADS)

Living in groups raises important issues concerning waste management and related sanitary risks. Social insects such as ants live at high densities with genetically related individuals within confined and humid nests, all these factors being highly favorable for the spread of pathogens. Therefore, in addition to individual immunity, a social prophylaxis takes place, namely, by the removal of risky items such as corpses and their rejection at a distance from the ant nest. In this study, we investigate how Myrmica rubra workers manage to reduce encounters between potentially hazardous corpses and nestmates. Using both field and laboratory experiments, we describe how the spatial distribution and the removal distance of waste items vary as a function of their associated sanitary risks (inert item vs. corpse). In the field, corpse-carrying ants walked in a rather linear way away from the nest entrance and had an equal probability of choosing any direction. Therefore, they did not aggregate corpses in dedicated areas but scattered them in the environment. In both field and laboratory experiments, ants carrying corpses dropped their load in more remote—and less frequented—areas than workers carrying inert items. However, for equidistant areas, ants did not avoid dropping corpses at a location where they perceived area marking as a cue of high occupancy level by nestmates. Our results suggest that ants use distance to the nest rather than other occupancy cues to limit sanitary risks associated with dead nestmates.

Diez, Lise; Deneubourg, Jean-Louis; Detrain, Claire

2012-10-01

450

Ant Colonies Prefer Infected over Uninfected Nest Sites.  

PubMed

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

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

2014-01-01

451

The role of multiple pheromones in food recruitment by ants.  

PubMed

In this paper we investigate the foraging activity of an invasive ant species, the big headed ant Pheidole megacephala. We establish that the ants' behavior is consistent with the use of two different pheromone signals, both of which recruit nestmates. Our experiments suggest that during exploration the ants deposit a long-lasting pheromone that elicits a weak recruitment of nestmates, while when exploiting food the ants deposit a shorter lasting pheromone eliciting a much stronger recruitment. We further investigate experimentally the role of these pheromones under both static and dynamic conditions and develop a mathematical model based on the hypothesis that exploration locally enhances exploitation, while exploitation locally suppresses exploration. The model and the experiments indicate that exploratory pheromone allows the colony to more quickly mobilize foragers when food is discovered. Furthermore, the combination of two pheromones allows colonies to track changing foraging conditions more effectively than would a single pheromone. In addition to the already known causes for the ecological success of invasive ant species, our study suggests that their opportunistic strategy of rapid food discovery and ability to react to changes in the environment may have strongly contributed to their dominance over native species. PMID:19617426

Dussutour, A; Nicolis, S C; Shephard, G; Beekman, M; Sumpter, D J T

2009-08-01

452

Trail Pheromone Disruption of Argentine Ant Trail Formation and Foraging  

USGS Publications Warehouse

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.

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

2010-01-01

453

Trail pheromone disruption of Argentine ant trail formation and foraging.  

PubMed

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. PMID:20077128

Suckling, David Maxwell; Peck, Robert W; Stringer, Lloyd D; Snook, Kirsten; Banko, Paul C

2010-01-01

454

Balance Problems  

MedlinePLUS

... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady or as ... fall-related injuries, such as hip fracture. Some balance problems are due to problems in the inner ...

455

Cheating the cheater: domatia loss minimizes the effects of ant castration in an Amazonian ant-plant  

Microsoft Academic Search

We studied the relationship between Hirtella myrmecophila (Chrysobalanaceae), a common but little-studied Amazonian ant-plant that produces leaf-pouches as domatia, and its obligate ant partner, Allomerus octoarticulatus. Field observations revealed that H. myrmecophila drops domatia from older leaves, a characteristic that is unique among myrmecophytes. The physiological mechanism for abortion of domatia is currently unknown, but this characteristic allows for the

Thiago J. Izzo; Heraldo L. Vasconcelos

2002-01-01

456

Vegetation of ant-hills in a mountain grassland:effects of mound history and of dominant ant species  

Microsoft Academic Search

Vegetation in grasslands with well-developed long-lastingant-hills in the Slovenské Rudohorie Mts., Slovakia, was studiedin relation to (i) position on the mound, (ii) ant speciesforming the mound, and (iii) history of the mound. Permanent plotrecordings of mound size and dominant ant species started fifteen years priorthe study began provided information on the history of individual mounds.The mound vegetation bears a striking

Pavel Ková?; Marcela Ková?ová; Petr Dostál; TomᚠHerben

2001-01-01

457

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

PubMed

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. PMID:24022667

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

2013-10-01

458

Friend or foe? A behavioral and stable isotopic investigation of an ant–plant symbiosis  

Microsoft Academic Search

In ant–plant symbioses, the behavior of ant inhabitants affects the nature of the interaction, ranging from mutualism to parasitism. Mutualistic species confer a benefit to the plant, while parasites reap the benefits of the interaction without reciprocating, potentially resulting in a negative impact on the host plant. Using the ant–plant symbiosis between Cordia alliodora and its ant inhabitants as a

Chadwick V. Tillberg

2004-01-01

459

Targeted removal of ant colonies in ecological experiments, using hot water  

E-print Network

. An automobile heater fan powered from a 12-v battery provided a draft. Dual bilge pumps pumped water fromTargeted removal of ant colonies in ecological experiments, using hot water Walter R. Tschinkela ants because such baits are not specific to fire ants, or even to ants. Hot water is an extremely

460

Ants ( Azteca sp.) as potential biological control agents in shade coffee production in Chiapas, Mexico  

Microsoft Academic Search

The role of Azteca sp. ants as potential biological control agents was studied in an organic coffee farm in Chiapas, Mexico. Individual larvae of Pieris rapae were placed on trees with artificially enhanced ant activity and both time to disappearance of the larvae and ant activity were recorded. There was a general negative relationship between time to disappearance and ant

John Vandermeer; Ivette Perfecto; Guillermo Ibarra Nuñez; Stacy Phillpott; Alvaro Garcia Ballinas

2002-01-01

461

Induced biotic responses to herbivory and associated cues in the Amazonian ant-plant Maieta poeppigii  

Microsoft Academic Search

Ants inhabiting ant-plants can respond to cues of herbivory, such as the presence of herbivores, leaf damage, and plant sap, but experimental attempts to quantify the dynamic nature of biotic defenses have been restricted to a few associations between plants and ants. We studied the relationship between certain features of the ant-shrub Maieta poeppigii Cogn. (Melastomataceae) and the pres- ence

Alexander V. Christianini; Glauco Machado

2004-01-01

462

BIOTROPICA 35(2): 295300 2003 Contrasting Responses to Induction Cues by Ants Inhabiting  

E-print Network

that ants having mutualistic associations with tropical plants constitute an important category of induced families have putatively mutualistic associations with the ants of 5 subfamilies (Benson 1985, Ho studies investigating induced ant responses is that they have focused on a single species of ant mutualist

Bruna, Emilio M.

463

Argentine and other ants (Hymenoptera: Formicidae) in New Zealand horticultural ecosystems: distribution, hemipteran hosts, and review  

Microsoft Academic Search

Approximately 30 exotic ant species have been introduced into New Zealand, including the Argentine ant Linepithema humile (Mayr). Many of these ant species are known to affect horticulture worldwide by tending hemipteran insects. These ants may protect these hemiptera from their natural enemies, resulting in higher pest densities and potential economic loss. Our aim in this work was to survey

Philip J. Lester; Chris W. Baring; Christopher G. Longson; Stephen Hartley

2003-01-01

464

Interference and exploitation competition of three nectar-thieving invasive ant species  

Microsoft Academic Search

Summary. Plant and insect exudates are known to play a key role in structuring tropical ant communities, but less is known about the utilization of these resources in communities dominated by invasive ants. Invasive ants are thought to require large amounts of carbohydrates such as honeydew or nectar to maintain their high abundances. Invasive ants that consume floral nectar may

L. Lach

2005-01-01

465

Asymmetric Dispersal and Colonization Success of Amazonian Plant-Ants Queens  

Microsoft Academic Search

BackgroundThe dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is

Emilio M. Bruna; Thiago J. Izzo; Brian D. Inouye; Maria Uriarte; Heraldo L. Vasconcelos

2011-01-01

466

An experimental study of competition between fire ants and Argentine ants in their native range.  

PubMed

An understanding of why introduced species achieve ecological success in novel environments often requires information about the factors that limit the abundance of these taxa in their native ranges. Although numerous recent studies have evaluated the importance of natural enemies in this context, relatively few have examined how ecological success may result from differences in the magnitude of interference competition between communities in the native and introduced ranges of nonnative species. Here we examine how native-range competitive environments may relate to invasion success for two important invasive species, the red imported fire ant (Solenopsis invicta) and the Argentine ant (Linepithema humile), in a region of native-range sympatry. At two study sites in northern Argentina, we used stable-isotope analysis, a variety of observational approaches, and two different reciprocal removal experiments to test (1) whether S. invicta competes asymmetrically with L. humile (as suggested by the 20th century pattern of replacement in the southeastern United States) and (2) the extent to which these two species achieve behavioral and numerical dominance. Stable-isotope analysis and activity surveys indicated that S. invicta and L. humile are both omnivores and forage during broadly overlapping portions of the diel cycle. Short-term removal experiments at baits revealed no competitive asymmetry between S. invicta and L. humile. Longer-term colony removal experiments illustrated that S. invicta and L. humile experience an approximately equal competitive release upon removal of the other. Our results indicate that neither S. invicta nor L. humile achieves the same degree of behavioral or ecological dominance where they co-occur in native populations as they do in areas where either is common in their introduced range. These results strongly suggest that interspecific competition is an important limiting factor for both S. invicta and L. humile in South America. PMID:17489455

LeBrun, E G; Tillberg, C V; Suarez, A V; Folgarait, P J; Smith, C R; Holway, D A

2007-01-01

467

Why do house-hunting ants recruit in both directions?  

NASA Astrophysics Data System (ADS)

To perform tasks, organisms often use multiple procedures. Explaining the breadth of such behavioural repertoires is not always straightforward. During house hunting, colonies of Temnothorax albipennis ants use a range of behaviours to organise their emigrations. In particular, the ants use tandem running to recruit naïve ants to potential nest sites. Initially, they use forward tandem runs (FTRs) in which one leader takes a single follower along the route from the old nest to the new one. Later, they use reverse tandem runs (RTRs) in the opposite direction. Tandem runs are used to teach active ants the route between the nests, so that they can be involved quickly in nest evaluation and subsequent recruitment. When a quorum of decision-makers at the new nest is reached, they switch to carrying nestmates. This is three times faster than tandem running. As a rule, having more FTRs early should thus mean faster emigrations, thereby reducing the colony’s vulnerability. So why do ants use RTRs, which are both slow and late? It would seem quicker and simpler for the ants to use more FTRs (and higher quorums) to have enough knowledgeable ants to do all the carrying. In this study, we present the first testable theoretical explanation for the role of RTRs. We set out to find the theoretically fastest emigration strategy for a set of emigration conditions. We conclude that RTRs can have a positive effect on emigration speed if FTRs are limited. In these cases, low quorums together with lots of reverse tandem running give the fastest emigration.

Planqué, R.; Dechaume-Moncharmont, F.-X.; Franks, N. R.; Kovacs, T.; Marshall, J. A. R.

2007-11-01

468

A mathematical model of foraging in a dynamic environment by trail-laying Argentine ants.  

PubMed

Ants live in dynamically changing environments, where food sources become depleted and alternative sources appear. Yet most mathematical models of ant foraging assume that the ants' foraging environment is static. Here we describe a mathematical model of ant foraging in a dynamic environment. Our model attempts to explain recent empirical data on dynamic foraging in the Argentine ant Linepithema humile (Mayr). The ants are able to find the shortest path in a Towers of Hanoi maze, a complex network containing 32,768 alternative paths, even when the maze is altered dynamically. We modify existing models developed to explain ant foraging in static environments, to elucidate what possible mechanisms allow the ants to quickly adapt to changes in their foraging environment. Our results suggest that navigation of individual ants based on a combination of one pheromone deposited during foraging and directional information enables the ants to adapt their foraging trails and recreates the experimental results. PMID:22575583

Ramsch, Kai; Reid, Chris R; Beekman, Madeleine; Middendorf, Martin

2012-08-01

469

Effect of Argentine ant invasions on ground-dwelling arthropods in northern California riparian woodlands  

Microsoft Academic Search

Although the Argentine ant (Linepithema humile) is a widespread invasive species that displaces native ants throughout its introduced range, the effects of these invasions\\u000a on arthropods other than ants remain poorly known. This study documents the consequences of Argentine ant invasions on ants\\u000a and other ground-dwelling arthropods in northern California riparian woodlands. Baits and unbaited pitfall traps were used\\u000a to

David A. Holway

1998-01-01

470

Nest mounds of red wood ants ( Formicaaquilonia ): hot spots for litter-dwelling earthworms  

Microsoft Academic Search

A previously undocumented association between earthworms and red wood ants (Formicaaquilonia Yarr.) was found during an investigation of the influence of wood ants on the distribution and abundance of soil animals\\u000a in boreal forest soil. Ant nest mounds and the surrounding soil of the ant territories were sampled. The ant nest mound surface\\u000a (the uppermost 5-cm layer) harboured a much

Jouni Laakso; Heikki Setälä

1997-01-01

471

Catching ants with honey: an experimental test of distraction and satiation as alternative modes of escape from flower-damaging ants.  

PubMed

According to the distraction hypothesis, extrafloral nectaries (EFN) evolved under selection to entice ants away from floral nectaries, reducing ant-mediated damage to flowers and/or interference with pollinators. Predator-satiation, through production of nectar in either surplus flowers or EFN, provides an alternative mechanism for reducing the impact of ants as flower visitors. I tested these two hypotheses by experimentally adding EFN to flowering plants of the alpine wildflower, Polemonium viscosum, and by surveying the relationship between ant visitation and nectary number in nature. Plants of P. viscosum lack EFN and experience flower damage by ants of Formica neorufibarbus gelida. Ant behavior was compared on plants with five flowers and three experimental EFN and on controls with equal floral display, but no EFN. Addition of EFN increased flower visitation by ants. The effect of EFN on flower visitation did not depend on proximity of EFN to flowers or attractiveness of EFN to ants. Findings suggest that ants perceived patch quality on a whole plant basis, rather than responding to EFN and flowers as distinct nectar patches. Ant visitation did not keep pace with nectary number in nature. The relationship between ant visitation and nectary number per plant was weak and shallow as predicted under satiation. Ant foraging choices on experimental inflorescences showed that ants bypass flowers avoided by earlier ants, enhancing probability of escape via satiation. Results do not support the idea that EFN evolve to reduce flower visitation by ants, but show instead that nectar in surplus flowers can satiate ants and reduce their negative impacts on flower function and integrity. PMID:15800742

Galen, Candace

2005-06-01

472

The triple alliance: how a plant-ant, living in an ant-plant, acquires the third partner, a scale insect  

Microsoft Academic Search

Summary. Mutualistic associations between ants and plants often involve a third partner, scale insects (Hemiptera, Coccoidea). In southeast Asia, plant-ants of the genus Cladomyrma live together with coccoids in hollowed twigs of a wide range of ant-plants (myrmecophytes). Established colonies never lack sap-sucking scale insects and the ants appear to be dependent on the honeydew excretions of their trophobionts. Acquisition

J. Moog; L. G. Saw; R. Hashim; U. Maschwitz

2005-01-01

473

A novel property of spider silk: chemical defence against ants  

PubMed Central

Spider webs are made of silk, the properties of which ensure remarkable efficiency at capturing prey. However, remaining on, or near, the web exposes the resident spiders to many potential predators, such as ants. Surprisingly, ants are rarely reported foraging on the webs of orb-weaving spiders, despite the formidable capacity of ants to subdue prey and repel enemies, the diversity and abundance of orb-web spiders, and the nutritional value of the web and resident spider. We explain this paradox by reporting a novel property of the silk produced by the orb-web spider Nephila antipodiana (Walckenaer). These spiders deposit on the silk a pyrrolidine alkaloid (2-pyrrolidinone) that provides protection from ant invasion. Furthermore, the ontogenetic change in the production of 2-pyrrolidinone suggests that this compound represents an adaptive response to the threat of natural enemies, rather than a simple by-product of silk synthesis: while 2-pyrrolidinone occurs on the silk threads produced by adult and large juvenile spiders, it is absent on threads produced by small juvenile spiders, whose threads are sufficiently thin to be inaccessible to ants. PMID:22113027

Zhang, Shichang; Koh, Teck Hui; Seah, Wee Khee; Lai, Yee Hing; Elgar, Mark A.; Li, Daiqin

2012-01-01

474

Consequences of prescribed fire and grazing on grassland ant communities.  

PubMed

Prescribed fire and livestock grazing are used for the management and restoration of native grasslands the world over; however, the effects of these management techniques on ant communities are unclear. We examined the response of ants to these disturbances in grasslands in northern California. Twenty-four 30 by 30 m plots were established across two sites that received one of four treatments: grazing, fire, grazing and fire, or no treatment. Ants were censused using 240 pitfall traps with one preburn and two postburn samples (14 d and 1 yr after burning). We analyzed ant abundance using broadly defined groups based on feeding habit and/or habitat use and detected no grazing effect but a significant fire effect that differed by group. Immediate postfire sampling showed an increase in cryptic species (particularly Brachymyrmex depilis). One year after the fire, no response was detected for cryptic species, but burned plots had greater abundance of seed harvesters. Analysis of vegetation showed burned plots had significantly greater forb cover, which might have provided greater food resources, and also lower biomass, which might have facilitated foraging. Understanding the effects of these management tools on ant abundance complements our understanding of their effect on vegetation and assists conservation practitioners effectively manage grassland ecosystems both in California and beyond. PMID:19389280

Underwood, Emma C; Christian, Caroline E

2009-04-01

475

Catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria  

PubMed Central

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

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

2010-01-01

476

Timing of dispersal: effect of ants on aphids.  

PubMed

Mutualists can affect many life history traits of their partners, but it is unclear how this translates into population dynamics of the latter. Ant-aphid associations are ideal for studying this question, as ants affect aphids, both positively (e.g., protection against natural enemies) and negatively (e.g., reduction of potential growth rates). The unresolved question is whether these effects, which have been observed at the level of individuals and under controlled environmental conditions, have consequences at the population level. On estimating aerial aphid populations by using weekly suction trap data spanning up to 22 years from different locations in France, we show that in ant-attended aphid species long-distance dispersal occurs significantly later, but that the year-to-year changes in the peak number of migrants are not significantly lower than for non-attended aphids. Host alternation had the same retarding effect on dispersal as ant attendance. We discuss the delay in the timing of dispersal in ant-attended aphids, and potential costs that arise in mutualistic systems. PMID:17351794

Kindlmann, Pavel; Hullé, Maurice; Stadler, Bernhard

2007-07-01

477

Temperature limits trail following behaviour through pheromone decay in ants  

NASA Astrophysics Data System (ADS)

In Mediterranean habitats, temperature affects both ant foraging behaviour and community structure. Many studies have shown that dominant species often forage at lower temperature than subordinates. Yet, the factors that constrain dominant species foraging activity in hot environments are still elusive. We used the dominant ant Tapinoma nigerrimum as a model species to test the hypothesis that high temperatures hinder trail following behaviour by accelerating pheromone degradation. First, field observations showed that high temperatures (> 30°C) reduce the foraging activity of T. nigerrimum independently of the daily and seasonal rhythms of this species. Second, we isolated the effect of high temperatures on pheromone trail efficacy from its effect on worker physiology. A marked substrate was heated during 10 min (five temperature treatments from 25°C to 60°C), cooled down to 25°C, and offered in a test choice to workers. At hot temperature treatments (>40°C), workers did not discriminate the previously marked substrate. High temperatures appeared therefore to accelerate pheromone degradation. Third, we assessed the pheromone decay dynamics by a mechanistic model fitted with Bayesian inference. The model predicted ant choice through the evolution of pheromone concentration on trails as a function of both temperature and time since pheromone deposition. Overall, our results highlighted that the effect of high temperatures on recruitment intensity was partly due to pheromone evaporation. In the Mediterranean ant communities, this might affect dominant species relying on chemical recruitment, more than subordinate ant species, less dependent on chemical communication and less sensitive to high temperatures.

van Oudenhove, Louise; Billoir, Elise; Boulay, Raphaël; Bernstein, Carlos; Cerdá, Xim

2011-12-01

478

Spatio-temporal learning by the ant ectatomma ruidum  

PubMed

We tested, under field and laboratory conditions, whether the neotropical ant Ectatomma ruidum Roger can learn several associations between temporal and spatial changes in the daily pattern of food availability. Honey was shuffled between two or three feeding sites following a fixed daily schedule. Foragers learnt to associate particular sites with the specific times at which food was available, individually marked ants being observed on the correct sites at the correct times. Some ants anticipated the time of food delivery by approximately 30 min, and it was not necessary for them to be rewarded at the first stage of the sequence of food collection to continue their search for honey according to the correct schedule of reward. Ants also followed the same schedule when no honey was supplied at each stage of the sequence, and they stayed at the expected unrewarded site for a period equivalent to the reward period of the corresponding training phase, indicating that they had learnt when and for how long the food was available. Thus, ants rely on their spatio-temporal memory rather than on local cues coming from the honey source to guide them. PMID:10377271

Schatz; Lachaud; Beugnon

1999-07-01

479

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

NASA Astrophysics Data System (ADS)

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.

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

2008-02-01

480

Invasive ants disrupt frugivory by endemic island birds  

PubMed Central

Biological invasions can alter direct and indirect interactions between species, generating far-reaching changes in ecological networks that affect key ecological functions. We used model and real fruit assays to show that the invasion and formation of high-density supercolonies by the yellow crazy ant (YCA), Anoplolepis gracilipes, disrupt frugivory by endemic birds on Christmas Island, Indian Ocean. The overall handling rates of model fruits by birds were 2.2–2.4-fold lower in ant-invaded than in uninvaded rainforest, and pecking rates by two bird species declined by 2.6- and 4.5-fold, respectively. YCAs directly interfered with frugivory; their experimental exclusion from fruiting displays increased fruit handling threefold to sixfold, compounding indirect effects of ant invasion on resources and habitat structure that influence bird abundances and behaviours. This invasive ant, whose high densities are sustained through mutualism with introduced scale insects, rapidly decreases fruit handling by endemic island birds and may erode a key ecological function, seed dispersal. Because most other invasive ant species form expansive, high-density supercolonies that depend in part on association with hemipteran mutualists, the effects that we report here on avian frugivore–plant associations may emerge across their introduced ranges. PMID:19755533

Davis, Naomi E.; O'Dowd, Dennis J.; Mac Nally, Ralph; Green, Peter T.

2010-01-01

481

Invasive ants disrupt frugivory by endemic island birds.  

PubMed

Biological invasions can alter direct and indirect interactions between species, generating far-reaching changes in ecological networks that affect key ecological functions. We used model and real fruit assays to show that the invasion and formation of high-density supercolonies by the yellow crazy ant (YCA), Anoplolepis gracilipes, disrupt frugivory by endemic birds on Christmas Island, Indian Ocean. The overall handling rates of model fruits by birds were 2.2-2.4-fold lower in ant-invaded than in uninvaded rainforest, and pecking rates by two bird species declined by 2.6- and 4.5-fold, respectively. YCAs directly interfered with frugivory; their experimental exclusion from fruiting displays increased fruit handling threefold to sixfold, compounding indirect effects of ant invasion on resources and habitat structure that influence bird abundances and behaviours. This invasive ant, whose high densities are sustained through mutualism with introduced scale insects, rapidly decreases fruit handling by endemic island birds and may erode a key ecological function, seed dispersal. Because most other invasive ant species form expansive, high-density supercolonies that depend in part on association with hemipteran mutualists, the effects that we report here on avian frugivore-plant associations may emerge across their introduced ranges. PMID:1