scholarly journals Reduced foraging investment as an adaptation to patchy food sources: a phasic army ant simulation

2017 ◽  
Author(s):  
Serafino Teseo ◽  
Francesco Delloro
Keyword(s):  
Computational Approach ◽  
The Other ◽  
Food Sources ◽  
Army Ants ◽  
Phasic Activity ◽  
Ant Colonies ◽  
Eusocial Insects ◽  
Army Ant ◽  
Mixed Populations ◽  
Colony Level

AbstractColonies of several ant species within the subfamily Dorylinae alternate stereotypical discrete phases of foraging and reproduction. Such phasic cycles are thought to be adaptive because they minimize the amount of foraging and the related costs, and at the same time enhance the colony-level ability to rely on patchily distributed food sources. In order to investigate these hypotheses, we use here a simple computational approach to study the population dynamics of two species of virtual ant colonies that differ quantitatively in their foraging investment. One species, which we refer to as “phasic”, forages only half of the time, mirroring the phasic activity of some army ants; the other “non-phasic” species forages instead all the time. We show that, when foraging costs are relatively high, populations of phasic colonies grow on average faster than non-phasic populations, outcompeting them in mixed populations. Interestingly, such tendency becomes more consistent as food becomes more difficult to find but locally abundant. According to our results, reducing the foraging investment, for example by adopting a phasic lifestyle, can result in a reproductive advantage, but only in specific conditions. We thus suggest phasic colony cycles to have emerged together with the doryline specialization in feeding on the brood of other eusocial insects, a resource that is hard to obtain but highly abundant if available.

scholarly journals Pattern Formation and Optimization in Army Ant Raids

2000 ◽  
Vol 6 (3) ◽  
pp. 219-226 ◽  
Author(s):  
Ricard V. Solé ◽  
Eric Bonabeau ◽  
Jordi Delgado ◽  
Pau Fernández ◽  
Jesus Marín
Keyword(s):  
Return On Investment ◽  
Search Algorithm ◽  
Food Sources ◽  
Ant Colonies ◽  
Individual Level ◽  
Army Ant ◽  
Behavioral Rules ◽  
The Individual ◽  
Simple Search ◽  
Colony Level

Army ant colonies display complex foraging raid patterns involving thousands of individuals communicating through chemical trails. In this article we explore, by means of a simple search algorithm, the properties of these trails in order to test the hypothesis that their structure reflects an optimized mechanism for exploring and exploiting food resources. The raid patterns of three army ant species, Eciton hamatum, Eciton burchelli, and Eciton rapax, are analyzed. The respective diets of these species involve large but rare, small but common, and a combination of large but rare and small but common food sources. Using a model proposed by Deneubourg et al. [4], we simulate the formation of raid patterns in response to different food distributions. Our results indicate that the empirically observed raid patterns maximize return on investment, that is, the amount of food brought back to the nest per unit of energy expended, for each of the diets. Moreover, the values of the parameters that characterize the three optimal pattern-generating mechanisms are strikingly similar. Therefore the same behavioral rules at the individual level can produce optimal colony-level patterns. The evolutionary implications of these findings are discussed.

scholarly journals Bivouac Checking, A Novel Behavior Distinguishing Obligate from Opportunistic Species of Army-Ant-Following Birds

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 629-633 ◽  
Author(s):  
Monica Beth Swartz
Keyword(s):  
Food Supply ◽  
New Method ◽  
Army Ants ◽  
Ant Colonies ◽  
Opportunistic Species ◽  
Army Ant ◽  
Checking Behavior ◽  
Novel Behavior ◽  
Forest Floors ◽  
The Many

Abstract As swarms of the army ant Eciton burchelli forage across forest floors of the lowland Neotropics, birds gather to eat arthropods flushed by the advancing ants. Past efforts to distinguish members of the obligate ant-following bird guild from the many species that forage opportunistically with army ants have been inadequate. Obligate ant-followers track the locations of multiple nomadic ant colonies in order to maintain a consistent food supply. Each morning, they visit the bivouac site of each colony they are monitoring to assess the ants' activity. Only species dependent upon foraging with army ants exhibit this specialized bivouac checking behavior. This paper proposes a new method for distinguishing between obligate and opportunistic ant-following birds by observing which species check bivouacs. Verificación de Vivaques, un Comportamiento Nuevo que Distingue a Especies Obligatorias de Especies Oportunistas Rastreadores de Hormigas-Ejército Resumen. Cuando enjambres de la hormiga ejército Eciton burchelli forrajean en los suelos de los bosques bajos Neotropicales, algunas aves se aglomeran para ingerir artrópodos espantados por las hormigas que avanzan. Esfuerzos pasados para distinguir entre aquellos miembros del gremio de aves que rastrean las hormigas obligatoriamente de las muchas especies que forrajean de manera oportunista con hormigas ejército han sido inadecuados. Seguidores obligatorios de las hormigas rastrean los sitios de varias colonias nómadas de hormigas a fin de mantener un suministro consistente de alimentos. Cada mañana, estas aves visitan el sitio de vivaque de cada una de las colonias que controlan con fin de evaluar las actividades de las hormigas. Sólo aquellas especies que dependen del forrajeo de las hormigas ejército manifiestan este comportamiento especializado de verificar los vivaques. Este artículo propone un nuevo método para distinguir entre las aves oportunistas y las aves obligatorias rastreadoras de hormigas mediante la observación de aquellas especies que verifican los vivaques.

scholarly journals The bacterial endosymbiontWolbachiaincreases reproductive investment and accelerates the life cycle of ant colonies

2019 ◽  
Author(s):  
Rohini Singh ◽  
Timothy A. Linksvayer
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Life History Strategy ◽  
Reproductive Investment ◽  
Ant Colonies ◽  
Eusocial Insects ◽  
History Of ◽  
Young Life ◽  
Colony Level

AbstractWolbachiais a widespread group of maternally-transmitted endosymbiotic bacteria that often manipulates the reproductive strategy and life history of its solitary hosts to enhance its own transmission.Wolbachiaalso commonly infects eusocial insects such as ants, although the effects of infection on social organisms remain largely unknown. We tested the effects of infection on colony-level reproduction and life history traits in the invasive pharaoh ant,Monomorium pharaonis. First we compared the reproductive investment of infected and uninfected colonies with queens of three discrete ages, and we found that infected colonies had increased reproductive investment. Next, we compared the long-term growth and reproduction of infected and uninfected colonies across their life cycle, and we found that infected colonies had increased colony-level growth and early colony reproduction. These colony-level effects ofWolbachiainfection seem to result because of a ‘live fast, die young’ life history strategy of infected queens. Such accelerated colony life cycle is likely beneficial for both the host and the symbiont and may have contributed to success of the highly invasive pharaoh ant.

scholarly journals The persistence of ant-following birds in small amazonian forest fragments

1989 ◽  
Vol 19 (0) ◽  
pp. 249-263 ◽  
Author(s):  
Lee H. Harper
Keyword(s):  
Forest Fragments ◽  
Ant Colonies ◽  
Amazonian Forest ◽  
Army Ant ◽  
Continuous Forest ◽  
Introduced Birds ◽  
Small Forest

SUMMARYMist-net captures of army ant-following bird were monitored during the isolation of central Amazonian forest fragments of 1 ha (n = 5), 10 ha (n = 4) and 100 ha (n = 1). Post-isolation captures of the three obligate ant-following birds Dendrocinela merula, Pithys albifrons, and Gymnopithys rufigula decreased significantly in all fragments. post-isolation captures of four facultative ant-following species were not significantly different in forest fragments of 1 ha and 10 ha, although two species decreased significantly in the 100 ha fragment. Experimental introductions of obligate species into small forest fragments in the absence and presence of introduced Eciton burchelli army ant colonies resulted in significantly greater recaptures of introduced birds when active army ant colonies were present. Of the 105 birds introduced, 58 ' 55%) crossed 100-320 m od dedorested area an were recaptured in continuous forest.

scholarly journals Comparison of Twelve Ant Species and Their Susceptibility to Fungal Infection

Insects ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 271 ◽  
Author(s):  
Nick Bos ◽  
Viljami Kankaanpää-Kukkonen ◽  
Dalial Freitak ◽  
Dimitri Stucki ◽  
Liselotte Sundström
Keyword(s):  
Entomopathogenic Fungi ◽  
Behavioral Response ◽  
Complex Disease ◽  
Experimental Conditions ◽  
Metapleural Gland ◽  
Eusocial Insects ◽  
Fungal Exposure ◽  
The Individual ◽  
Study Species ◽  
Colony Level

Eusocial insects, such as ants, have access to complex disease defenses both at the individual, and at the colony level. However, different species may be exposed to different diseases, and/or deploy different methods of coping with disease. Here, we studied and compared survival after fungal exposure in 12 species of ants, all of which inhabit similar habitats. We exposed the ants to two entomopathogenic fungi (Beauveria bassiana and Metarhizium brunneum), and measured how exposure to these fungi influenced survival. We furthermore recorded hygienic behaviors, such as autogrooming, allogrooming and trophallaxis, during the days after exposure. We found strong differences in autogrooming behavior between the species, but none of the study species performed extensive allogrooming or trophallaxis under the experimental conditions. Furthermore, we discuss the possible importance of the metapleural gland, and how the secondary loss of this gland in the genus Camponotus could favor a stronger behavioral response against pathogen threats.

Niche opportunity and ant invasion: the case of Wasmannia auropunctata in a New Caledonian rain forest

2005 ◽  
Vol 21 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Julien Le Breton ◽  
Hervé Jourdan ◽  
Jean Chazeau ◽  
Jérôme Orivel ◽  
Alain Dejean
Keyword(s):  
Resource Use ◽  
Rain Forest ◽  
Biotic Resistance ◽  
Fire Ant ◽  
Food Sources ◽  
Ant Colonies ◽  
Wasmannia Auropunctata ◽  
Nesting Sites ◽  
Island Communities ◽  
Little Fire Ant

Due to the unbalanced distribution of their fauna and flora, which leads to the creation of a niche opportunities, it is generally accepted that island communities offer weak biotic resistance to biological invasion. In order to empirically test this statement, we compared resource use by ants in the understorey of an undisturbed New Caledonian rain forest recently invaded by the little fire ant, Wasmannia auropunctata. We tested the exploitation of: (1) food sources by placing baits on all trees with trunks greater than 5 cm in diameter; and (2) nesting sites on two tree species likely to shelter ant colonies. In non-invaded areas, the native ants occupied only 44.6% of the baits after 2 h of exposure, while in invaded areas all the baits were occupied by numerous W. auropunctata workers. Similarly, in non-invaded areas only 48.9% of Meryta coriacea (Araliaceae) trees and 64.5% of Basselinia pancheri (Arecaceae) sheltered ants, while in invaded areas W. auropunctata nested in 92.6–98.3% of these trees. Also, workers attended native Margarodidae (Hemiptera) for which they promoted the development of populations significantly larger than those attended by native ants. Thus native ants appear unable to efficiently exploit and defend several of the available food sources and nesting sites, providing a niche opportunity for an invader like W. auropunctata.

scholarly journals Observations on two commercial flower mixtures as food sources for beneficial insects in the UK

1997 ◽  
Vol 128 (4) ◽  
pp. 397-403 ◽  
Author(s):  
N. L. CARRECK ◽  
I. H. WILLIAMS
Keyword(s):  
Plant Species ◽  
Dominant Species ◽  
Flowering Phenology ◽  
Flowering Plants ◽  
The Other ◽  
Food Sources ◽  
Beneficial Insects ◽  
Flower Density ◽  
The Uk ◽  
Made In

Observations were made in 1994 and 1995 in Hertfordshire of the flowering phenology and attractiveness to beneficial insects of two commercial mixtures of flowering plants intended for set-aside land. These were the Tübingen Mixture from Germany and Ascot Linde SN from the Netherlands. The mixtures were visited by 14 species of Hymenoptera, 14 species of syrphid Diptera and six species of Lepidoptera. Although the mixtures contained 12 and five plant species respectively, Phacelia tanacetifolia was the dominant species to establish, flower and attract insects in both mixtures. The other plants contributed little to flower density or insect diversity. These mixtures are therefore not suitable for UK needs using the present proportions of plant species.

scholarly journals Towards a general life-history model of the superorganism: predicting the survival, growth and reproduction of ant societies

2012 ◽  
Vol 8 (6) ◽  
pp. 1059-1062 ◽  
Author(s):  
Jonathan Z. Shik ◽  
Chen Hou ◽  
Adam Kay ◽  
Michael Kaspari ◽  
James F. Gillooly
Keyword(s):  
Life History ◽  
Terrestrial Ecosystems ◽  
The Body ◽  
Ant Colonies ◽  
Insect Societies ◽  
Model Predictions ◽  
Body Sizes ◽  
Survival And Reproduction ◽  
Growth And Reproduction ◽  
Colony Level

Social insect societies dominate many terrestrial ecosystems across the planet. Colony members cooperate to capture and use resources to maximize survival and reproduction. Yet, when compared with solitary organisms, we understand relatively little about the factors responsible for differences in the rates of survival, growth and reproduction among colonies. To explain these differences, we present a mathematical model that predicts these three rates for ant colonies based on the body sizes and metabolic rates of colony members. Specifically, the model predicts that smaller colonies tend to use more energy per gram of biomass, live faster and die younger. Model predictions are supported with data from whole colonies for a diversity of species, with much of the variation in colony-level life history explained based on physiological traits of individual ants. The theory and data presented here provide a first step towards a more general theory of colony life history that applies across species and environments.

A Numerical Simulation Capability for Analysis of Aircraft Inlet-Engine Compatibility

2004 ◽  
Vol 128 (3) ◽  
pp. 473-481 ◽  
Author(s):  
Alan Hale ◽  
Milt Davis ◽  
Jim Sirbaugh
Keyword(s):  
Numerical Simulation ◽  
Computational Approach ◽  
The Other ◽  
Computational Tool ◽  
Additional Insight ◽  
Turbine Engine ◽  
Inlet Distortion ◽  
Full Knowledge ◽  
Engine System ◽  
Isolated Systems

Two primary aircraft propulsion subsystems are the inlet and the engine. Traditionally these subsystems have been designed, analyzed, and tested as isolated systems. The interaction between the subsystems is modeled primarily through evaluating inlet distortion in an inlet test and then simulating this distortion in engine tests via screens or similar devices. Recently, it has been recognized that significant improvements in both performance and operability can be realized when both the inlet and the engine are designed with full knowledge of the other. In this paper, a computational tool called Turbine Engine Analysis Compressor Code is used to evaluate the effect of inlet distortion on a three-stage military fan. This three-stage military fan is further connected to an F-16 inlet and forebody operating at an angle of attack and sideslip to demonstrate the effect of inlet distortion generated by flight maneuvers. The computational approach of simulating an integrated inlet-engine system is expected to provide additional insight over evaluating the components separately.

scholarly journals Deep-time parallel evolution of myrmecoid syndrome in rove beetle symbionts of army ants

2016 ◽  
Author(s):  
Munetoshi Maruyama ◽  
Joseph Parker
Keyword(s):  
Parallel Evolution ◽  
Army Ants ◽  
Deep Time ◽  
Rove Beetles ◽  
Army Ant ◽  
Rove Beetle ◽  
Arthropod Predators ◽  
Adaptive Radiations ◽  
Ecological Dominance ◽  
Temporary Nest

Recent adaptive radiations provide striking examples of convergence, but the predictability of evolution over much deeper timescales is controversial, due to a scarcity of ancient clades exhibiting repetitive patterns of phenotypic evolution. Army ants are ecologically dominant arthropod predators of the world's tropics, with large nomadic colonies housing diverse communities of socially parasitic myrmecophiles. Remarkable among these are many species of rove beetle (Staphylinidae) that exhibit ant-mimicking “myrmecoid” body forms and are behaviorally accepted into their aggressive hosts' societies: emigrating with colonies and inhabiting temporary nest bivouacs, grooming and feeding with workers, but also consuming the brood. Here we demonstrate that myrmecoid rove beetles are strongly polyphyletic, with this novel adaptive morphological and behavioral syndrome having evolved at least twelve times during the evolution of a single staphylinid subfamily, Aleocharinae. Each independent myrmecoid clade is restricted to one zoogeographic region and highly host-specific on a single army ant genus. Dating estimates reveal that myrmecoid clades are separated by substantial phylogenetic distances—as much as 105 million years (My). All such groups arose in parallel during the Cenozoic, as army ants are proposed to have risen to ecological dominance. This work uncovers a rare example of an ancient system of complex morphological and behavioral convergence, with replicate beetle lineages following a predictable phenotypic trajectory during their parasitic coevolution with army ants.

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