DOCSLIB.ORG

Genetic Evidence for Landscape Effects on Dispersal in the Army Ant Eciton Burchellii

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Genetic Evidence for Landscape Effects on Dispersal in the Army Ant Eciton Burchellii Molecular Ecology (2014) 23, 96–109 doi: 10.1111/mec.12573 Genetic evidence for landscape effects on dispersal in the army ant Eciton burchellii THOMAS W. SOARE,* ANJALI KUMAR,*† KERRY A. NAISH‡ and SEAN O’DONNELL*§ *Animal Behavior Program, Department of Psychology, University of Washington, Seattle, WA 98195, USA, †Massachusetts Institute of Technology, Cambridge, MA 02139, USA, ‡School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, USA, §Department of Biology, Drexel University, Philadelphia, PA 19104, USA Abstract Inhibited dispersal, leading to reduced gene flow, threatens populations with inbreed- ing depression and local extinction. Fragmentation may be especially detrimental to social insects because inhibited gene flow has important consequences for cooperation and competition within and among colonies. Army ants have winged males and per- manently wingless queens; these traits imply male-biased dispersal. However, army ant colonies are obligately nomadic and have the potential to traverse landscapes. Eciton burchellii, the most regularly nomadic army ant, is a forest interior species: col- ony raiding activities are limited in the absence of forest cover. To examine whether nomadism and landscape (forest clearing and elevation) affect population genetic structure in a montane E. burchellii population, we reconstructed queen and male genotypes from 25 colonies at seven polymorphic microsatellite loci. Pairwise genetic distances among individuals were compared to pairwise geographical and resistance distances using regressions with permutations, partial Mantel tests and random forests analyses. Although there was no significant spatial genetic structure in queens or males in montane forest, dispersal may be male-biased. We found significant isolation by landscape resistance for queens based on land cover (forest clearing), but not on elevation. Summed colony emigrations over the lifetime of the queen may contribute to gene flow in this species and forest clearing impedes these movements and subse- quent gene dispersal. Further forest cover removal may increasingly inhibit Eciton bur- chellii colony dispersal. We recommend maintaining habitat connectivity in tropical forests to promote population persistence for this keystone species. Keywords: deforestation, habitat fragmentation, isolation by distance, landscape genetics, sex-biased dispersal Received 21 November 2012; revision received 30 September 2013; accepted 15 October 2013 fragmentation can inhibit gene flow by isolating popu- Introduction lations, create inbreeding depression within subpopula- Dispersal has profound evolutionary consequences for tions, result in local extinction (Saccheri et al. 1998; many levels of biological organization (Broquet & Petit Segelbacher et al. 2010) and change species biology 2009). In continuous populations, the interaction (Fischer & Lindenmayer 2007). In tropical forest ecosys- between dispersal and genetic drift may lead to isola- tems, habitat fragmentation has altered species richness, tion by distance (Slatkin & Maddison 1990; Hardy & abundances and interactions, and affected ecosystem Vekemans 1999) and the balance between dispersal and processes such as nutrient cycling (Bierregaard et al. selection can influence adaptive evolution and specia- 1992; Laurance et al. 2002). tion (Turelli et al. 2001). Dispersal restricted by habitat Fragmentation may have significant effects on Hyme- noptera, which are haplodiploid and generally have a Correspondence: Thomas W. Soare, Fax: +1 206 685 3157; lower effective population size and less molecular vari- E-mail: [email protected] ation than diploids (Hedrick & Parker 1997). Gene flow © 2013 John Wiley & Sons Ltd LANDSCAPE AFFECTS DISPERSAL IN ARMY ANTS 97 in social insects may have important consequences for colonies at high elevations are probably living at the cooperation and competition within colonies, among lower limit of their thermal tolerance (O’Donnell & colonies and among populations (Pamilo et al. 1997; Kumar 2006; O’Donnell et al. 2011; Soare et al. 2011), Ross 2001). Evolutionary processes are of particular high elevations may inhibit dispersal uniformly. Alter- interest in nomadic army ants (Eciton burchellii) because natively, colonies may be locally adapted to and may they are top predators and ecological keystones in Neo- preferentially disperse within their natal elevation band; tropical forests (Franks 1982; Franks & Bossert 1983; elevation bands are coarsely correlated with Holdridge Kaspari et al. 2011). life zones (Holdridge 1967; Haber 2000). In undisturbed ant populations, dispersal is primarily The specific aim of this study was to determine determined by the mode of colony founding: indepen- whether landscape variables (forest fragmentation and dent founding by flying queens or dependent founding elevation) affect recent gene flow in army ants. To where queens are accompanied by flightless workers achieve this aim, we determined whether colony emi- (Pamilo et al. 1997; Peeters & Ito 2001; Ross 2001). Dis- grations contributed to gene dispersion by comparing persal of dependent foundresses is determined by the spatial genetic structure (SGS) across castes (workers, distance over which they can walk and therefore is queens and males) sampled after dispersal. We then more limited than that of independent foundresses compared relatedness patterns among queens with (Pamilo et al. 1997; Peeters & Ito 2001; Sundstrom€ et al. competing isolation by landscape resistance models to 2005). Male ants are winged in most species (Holldobler€ examine the effects of forest clearing and elevation on & Wilson 1990); therefore, male-biased dispersal is more colony dispersal. We used a landscape genetics strongly associated with dependent colony founding in approach and sampled at the level of individuals with- ants (Pamilo et al. 1997; Sundstrom€ et al. 2005). out identifying populations in advance, enabling detec- Regular colony emigrations have the potential to con- tion of SGS (e.g. isolation-by-distance patterns: Rousset tribute to gene flow in nomadic army ants. Eciton burch- 2000; Hazlitt et al. 2004; Hardy et al. 2008; Banks & ellii army ant colonies are monogynous and reproduce Peakall 2012; Ivens et al. 2012) and comparison of rela- by fission. Two giant wingless queens each walk away tive influence of landscape variables on contemporary with half of the worker force (Schneirla 1971; Gotwald gene flow (Manel et al. 2003; Segelbacher et al. 2010; 1995; Kronauer 2009). Virgin queens mate immediately Storfer et al. 2010; Short Bull et al. 2011). with multiple males and store this sperm for the rest of their lives (Kronauer et al. 2006; Kronauer & Boomsma Methods 2007). Because army ants reproduce by colony fission but males are winged, dispersal may be male-biased. We sampled 25 Eciton burchellii colonies in Neotropical Previous genetic studies of army ants have detected montane forest around Monteverde, Costa Rica, from 15 high rates of polyandry (Kronauer et al. 2006) and evi- Jul 2006 to 16 Sep 2006 over 4.6 km E-W and 9.3 km N- dence for male-biased dispersal (Berghoff et al. 2008; S and across 600 m of elevation. We located colonies Perez-Espona et al. 2012a). However, army ant colonies through systematic trail walks and opportunistic have a regular two week nomadic period tied to their encounters (Vidal-Riggs & Chaves-Campos 2008; five-week reproductive cycle while the larvae are grow- Kumar & O’Donnell 2009; Soare et al. 2011), thus ing (Schneirla 1971; Franks & Fletcher 1983) and cover assuming a continuously distributed population and hundreds of metres during this time (Franks & Fletcher independence of observations (Storfer et al. 2007). Addi- 1983; Willson et al. 2011). tional details regarding the study site, sample collection Landscape variables may primarily affect queen dis- and genotyping can be found in the Supporting infor- persal by restricting colony emigrations. Despite regular mation (Data S1, Tables S1, S2). obligate nomadism and a wide geographical range, the army ant Eciton burchellii is a forest interior species Genetic analysis (Schneirla 1971; Meisel 2006) and populations are vul- nerable to local extinction in forest fragments (Partridge We reconstructed queen and male genotypes from 13– et al. 1996; Boswell et al. 1998; Meisel 2004) and agroeco- 20 worker genotypes from each of 25 colonies (Table systems (Roberts et al. 2000). In lowland rainforest, Eci- S1) in the program COLONY 2.0 (Jones & Wang 2010). ton burchellii avoids entering open areas (Meisel 2006) To test the effects of genotyping error and to confirm and deforestation might inhibit dispersal (Perez-Espona reliability, we repeated COLONY analyses with error et al. 2012a). Colonies increasingly forage in open areas rates ranging from 0 to 5% and multiple random num- at high elevations (Kumar & O’Donnell 2009), and thus ber seeds. We calculated overall and within locus fragmentation in montane forest may or may not inbreeding among queen genotypes (FIq) in SPAGeDi impede gene flow. Furthermore, because Eciton burchellii 1.3 (Hardy & Vekemans 2002) and tested for linkage © 2013 John Wiley & Sons Ltd 98 T. W. SOARE ET AL. disequilibrium among all pairs of loci in queen geno- In order to further evaluate the power of our types using FSTAT 2.9.3.2 (Goudet 2002) with 420 per- approach, we compared our data to a recent landscape mutations (Bonferroni adjusted nominal P = 0.0024). genetics study of a population of Eciton burchellii foreli The effective mating frequency
Load more

Recommended publications
  • Hybridization in East African Swarm-Raiding Army Ants Kronauer Et Al
    Hybridization in East African swarm-raiding army ants Kronauer et al. Kronauer et al. Frontiers in Zoology 2011, 8:20 http://www.frontiersinzoology.com/content/8/1/20 (22 August 2011) Kronauer et al. Frontiers in Zoology 2011, 8:20 http://www.frontiersinzoology.com/content/8/1/20 RESEARCH Open Access Hybridization in East African swarm-raiding army ants Daniel JC Kronauer1,2*†, Marcell K Peters3,4†, Caspar Schöning1,5 and Jacobus J Boomsma1 Abstract Background: Hybridization can have complex effects on evolutionary dynamics in ants because of the combination of haplodiploid sex-determination and eusociality. While hybrid non-reproductive workers have been found in a range of species, examples of gene-flow via hybrid queens and males are rare. We studied hybridization in East African army ants (Dorylus subgenus Anomma) using morphology, mitochondrial DNA sequences, and nuclear microsatellites. Results: While the mitochondrial phylogeny had a strong geographic signal, different species were not recovered as monophyletic. At our main study site at Kakamega Forest, a mitochondrial haplotype was shared between a “Dorylus molestus-like” and a “Dorylus wilverthi-like” form. This pattern is best explained by introgression following hybridization between D. molestus and D. wilverthi. Microsatellite data from workers showed that the two morphological forms correspond to two distinct genetic clusters, with a significant proportion of individuals being classified as hybrids. Conclusions: We conclude that hybridization and gene-flow between the two army ant species D. molestus and D. wilverthi has occurred, and that mating between the two forms continues to regularly produce hybrid workers. Hybridization is particularly surprising in army ants because workers have control over which males are allowed to mate with a young virgin queen inside the colony.
    [Show full text]
  • Hybridization in Ants
    Rockefeller University Digital Commons @ RU Student Theses and Dissertations 2020 Hybridization in Ants Ian Butler Follow this and additional works at: https://digitalcommons.rockefeller.edu/ student_theses_and_dissertations Part of the Life Sciences Commons HYBRIDIZATION IN ANTS A Thesis Presented to the Faculty of The Rockefeller University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Ian Butler June 2020 © Copyright by Ian Butler 2020 HYBRIDIZATION IN ANTS Ian Butler, Ph.D. The Rockefeller University 2020 Interspecific hybridization is a relatively common occurrence within all animal groups. Two main factors make hybridization act differently in ants than in other species: eusociality and haplodiploidy. These factors serve to reduce the costs of interspecific hybridization in ants while simultaneously allowing them to take advantage of certain benefits. Eusociality may mitigate the effects of hybridization by allowing hybrids to be shunted into the worker caste, potentially reducing the effects of hybrid sterility. In haplodiploid species, males do not have a father. They instead develop from unfertilized eggs as haploid clones of their mother. This means that interspecifically mated queens do not completely sacrifice reproductive potential even if all hybrids are sterile because they can still produce fertile males. These factors in turn suggest that hybridization should be more common among the social Hymenoptera than other animal groups. Nevertheless, current data suggest that ants hybridize at rates similar to other animal groups, although these data are limited. Furthermore, there is a large amount of overlap between cases of interspecific hybridization and cases of genetic caste determination. A majority of the cases in ants where caste is determined primarily by genotype are associated with hybridization.
    [Show full text]
  • Chimpanzee (Pan Troglodytes Ellioti)
    CHIMPANZEE (PAN TROGLODYTES ELLIOTI) ECOLOGY IN A NIGERIAN MONTANE FOREST A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy in Ecology in the University of Canterbury by P. E. Dutton University of Canterbury 2012 Acknowledgements Firstly, I would like to thank Dr. Hazel Chapman as supervisor and the director of the Nigerian Montane Forest Project (NMFP) as without her support this research would not have been possible. Furthermore, I would like to thank the NMFP staff for their dedication towards this research, without them my time at Ngel Nyaki would have been very difficult. I would also like to thank Dr. Elena Moltchanova for providing statistical support for this research. I would like to thank Primate Conservation Inc. (PCI) for its financial support as well as the North of England Zoological Society (NEZS), Nexen Nigeria and A. G. Leventis Foundation for their contributions towards the project. Lastly, I would like to thank Annelies Vranken for her tolerance and understanding during my university studies. TABLE OF CONTENTS TABLE OF CONTENTS .................................................................................................... III LIST OF FIGURES ......................................................................................................... VIII LIST OF TABLES ............................................................................................................ XIV ABSTRACT ......................................................................................................................
    [Show full text]
  • Mechanisms for the Evolution of Superorganismality in Ants
    Rockefeller University Digital Commons @ RU Student Theses and Dissertations 2021 Mechanisms for the Evolution of Superorganismality in Ants Vikram Chandra Follow this and additional works at: https://digitalcommons.rockefeller.edu/ student_theses_and_dissertations Part of the Life Sciences Commons MECHANISMS FOR THE EVOLUTION OF SUPERORGANISMALITY IN ANTS A Thesis Presented to the Faculty of The Rockefeller University in Partial Fulfillment of the Requirements for the degree of Doctor of Philosophy by Vikram Chandra June 2021 © Copyright by Vikram Chandra 2021 MECHANISMS FOR THE EVOLUTION OF SUPERORGANISMALITY IN ANTS Vikram Chandra, Ph.D. The Rockefeller University 2021 Ant colonies appear to behave as superorganisms; they exhibit very high levels of within-colony cooperation, and very low levels of within-colony conflict. The evolution of such superorganismality has occurred multiple times across the animal phylogeny, and indeed, origins of multicellularity represent the same evolutionary process. Understanding the origin and elaboration of superorganismality is a major focus of research in evolutionary biology. Although much is known about the ultimate factors that permit the evolution and persistence of superorganisms, we know relatively little about how they evolve. One limiting factor to the study of superorganismality is the difficulty of conducting manipulative experiments in social insect colonies. Recent work on establishing the clonal raider ant, Ooceraea biroi, as a tractable laboratory model, has helped alleviate this difficulty. In this dissertation, I study the proximate evolution of superorganismality in ants. Using focussed mechanistic experiments in O. biroi, in combination with comparative work from other ant species, I study three major aspects of ant social behaviour that provide insight into the origin, maintenance, and elaboration of superorganismality.
    [Show full text]
  • DIVERSITY of HONEY BEE Apis Mellifera SUBSPECIES (HYMENOPTERA: APIDAE) and THEIR ASSOCIATED ARTHROPOD PESTS in CAMEROON
    DIVERSITY OF HONEY BEE Apis mellifera SUBSPECIES (HYMENOPTERA: APIDAE) AND THEIR ASSOCIATED ARTHROPOD PESTS IN CAMEROON BY DAVID TEMBONG CHAM (I80/92221/2013) (B.Sc. UNIVERSITY OF BUEA-CAMEROON, M.PHIL. UNIVERSITY OF GHANA-LEGON) A THESIS SUBMITTED IN FULFILLMENT OF REQUIREMENTS FOR THE AWARD OF THE DEGREE OF DOCTOR OF PHILOSOPHY IN ENTOMOLOGY SCHOOL OF BIOLOGICAL SCIENCES UNIVERSITY OF NAIROBI 2017 i DECLARATION Candidate I, DAVID TEMBONG CHAM, Registration Number I80/92221/2013, declare that this thesis is my original work and has not been submitted for award of a degree in any other University. Signature__________________________ Date ____________________________ Supervisors This thesis has been submitted with our approval Prof. Paul N. Ndegwa School of Biological Sciences, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya Signature __________________________ Date ____________________________ Prof. Lucy W. Irungu School of Biological Sciences, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya Signature __________________________ Date ____________________________ Dr. Ayuka T. Fombong International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772-00100, Nairobi, Kenya Signature __________________________ Date ____________________________ Prof. Suresh Raina International Centre of Insect Physiology and Ecology (ICIPE), PO. BOX 30772-00100, Nairobi, Kenya Signature __________________________ Date ____________________________ ii DEDICATION This thesis is dedicated to the Cham’s family iii ACKNOWLEDGEMENTS My sincere gratitude to my supervisors Prof. Paul N. Ndegwa, and Prof. Lucy W. Irungu of the University of Nairobi, and Dr. Ayuka T. Fombong and Prof. Suresh K. Raina of ICIPE for their guidance, invaluable suggestions, support, and reviews that led to the successful completion of this thesis and associated manuscripts.
    [Show full text]
  • The Evolution of Extreme Polyandry in Social Insects: Insights from Army Ants
    The Evolution of Extreme Polyandry in Social Insects: Insights from Army Ants Matthias Benjamin Barth1,2*, Robin Frederik Alexander Moritz1,3, Frank Bernhard Kraus1,4 1 Institute of Biology, Department of Zoology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany, 2 DNA-Laboratory, Museum of Zoology, Senckenberg Natural History Collections Dresden, Dresden, Germany, 3 Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa, 4 Department of Laboratory Medicine, University Hospital Halle, Halle (Saale), Germany Abstract The unique nomadic life-history pattern of army ants (army ant adaptive syndrome), including obligate colony fission and strongly male-biased sex-ratios, makes army ants prone to heavily reduced effective population sizes (Ne). Excessive multiple mating by queens (polyandry) has been suggested to compensate these negative effects by increasing genetic variance in colonies and populations. However, the combined effects and evolutionary consequences of polyandry and army ant life history on genetic colony and population structure have only been studied in a few selected species. Here we provide new genetic data on paternity frequencies, colony structure and paternity skew for the five Neotropical army ants Eciton mexicanum, E. vagans, Labidus coecus, L. praedator and Nomamyrmex esenbeckii; and compare those data among a total of nine army ant species (including literature data). The number of effective matings per queen ranged from about 6 up to 25 in our tested species, and we show that such extreme polyandry is in two ways highly adaptive. First, given the detected low intracolonial relatedness and population differentiation extreme polyandry may counteract inbreeding and low Ne. Second, as indicated by a negative correlation of paternity frequency and paternity skew, queens maximize intracolonial genotypic variance by increasingly equalizing paternity shares with higher numbers of sires.
    [Show full text]
  • Colony Expansions Underlie the Evolution of Army Ant Mass Raiding
    Colony expansions underlie the evolution of army ant mass raiding Vikram Chandraa,1,2, Asaf Gala,1, and Daniel J. C. Kronauera,1 aLaboratory of Social Evolution and Behavior, The Rockefeller University, New York, NY 10065 Edited by Joan E. Strassmann, Washington University in St. Louis, St. Louis, MO, and approved April 8, 2021 (received for review January 7, 2021) The mass raids of army ants are an iconic collective phenomenon, in much smaller colonies of only hundreds of workers. They are which many thousands of ants spontaneously leave their nest to hunt rarely encountered in the field, and little is known about their for food, mostly other arthropods. While the structure and ecology of behavior. Sporadic and usually partial observations suggest that these raids have been relatively well studied, how army ants evolved many non-army ant dorylines display a different form of foraging such complex cooperative behavior is not understood. Here, we show called group raiding (SI Appendix, Supplementary Note 1 and that army ant mass raiding has evolved from a different form of Table S1), in which scouts find prey before recruiting a raiding cooperative hunting called group raiding, in which a scout directs a party from the nest (4, 11). W. M. Wheeler, who first observed small group of ants to a specific target through chemical communi- these group raids in 1918, noted similarities in diet and foraging cation. We describe the structure of group raids in the clonal raider behavior with army ants and suggested that this had evolutionary ant, a close relative of army ants in the subfamily Dorylinae.
    [Show full text]
  • Lach Et Al 2009 Ant Ecology.Pdf
    Ant Ecology This page intentionally left blank Ant Ecology EDITED BY Lori Lach, Catherine L. Parr, and Kirsti L. Abbott 1 3 Great Clarendon Street, Oxford OX26DP Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide in Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur Madrid Melbourne Mexico City Nairobi New Delhi Shanghai Taipei Toronto With offices in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan Poland Portugal Singapore South Korea Switzerland Thailand Turkey Ukraine Vietnam Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries Published in the United States by Oxford University Press Inc., New York # Oxford University Press 2010 The moral rights of the author have been asserted Database right Oxford University Press (maker) First published 2010 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above You must not circulate this book in any other binding or cover and you must impose the same condition on any acquirer British Library Cataloguing in Publication Data Data available Library of Congress Cataloging in Publication Data Data available Typeset by SPI Publisher Services, Pondicherry, India Printed in Great Britain on acid-free paper by CPI Antony Rowe, Chippenham, Wiltshire ISBN 978–0–19–954463–9 13579108642 Contents Foreword, Edward O.
    [Show full text]
  • Mpthesis 12 Article3
    Université Libre de Bruxelles Faculté des sciences Service d'Eco-Ethologie Evolutive Stratégies reproductrices chez la fourmi Cataglyphis cursor Thèse présentée en vue de l'obtention du grade de Docteur en Sciences Biologiques par Morgan Pearcy Directeur de Thèse Serge Aron Université Libre de Bruxelles (Belgique) Rapporteurs Guy Josens Université Libre de Bruxelles (Belgique) Yves Roisin Université Libre de Bruxelles (Belgique) Michel Baguette Université Catholique de Louvain (Belgique) Alain Lenoir Université François-Rabelais, Tours (France) et Jacques M. Pasteels Université Libre de Bruxelles (Belgique) - Décembre 2005 - Remerciements Je tenais à remercier chaleureusement Serge Aron pour ses qualités certaines de chef d'équipe et son enthousiasme communicatif. Travailler sous son égide s'est révélée une expérience passionnante. Je saisirai toute opportunité future de travailler avec lui sans hésiter. Merci au Service d'Etho-Ecologie Evolutive, ses chercheurs, son personnel, ses étudiants, où il a toujours fait bon travailler dans une ambiance conviviale et humaine. Merci à Claudie Doums et au laboratoire d'Ecologie de Jussieu (Paris VI) pour leur accueil et leur encadrement si efficace. Merci à ma famille, ma belle-famille, à mes amis, pour la chance que vous représentez tous à mes yeux. Et enfin, merci à toi, Vanessa, pour ton soutien inconditionnel, pour qui tu es et pour qui tu seras. Résumé La sélection de la parentèle est le concept actuellement le plus fréquemment avancé pour justifier l’évolution et le maintien d'une caste ouvrière stérile chez les Hyménoptères sociaux. La fourmi méditerranéenne Cataglyphis cursor possède plusieurs traits biologiques qui font de cette espèce un modèle particulièrement intéressant pour tester les prédictions de la théorie de la sélection de la parentèle, le plus important d'entre eux étant la capacité des ouvrières, qui ne s'accouplent jamais, à produire une descendance mâle (haploïde) par parthénogenèse arrhénotoque, ou femelle (diploïde) par parthénogenèse thélytoque.
    [Show full text]
  • Incidental Interactions Among Neotropical Army-Ant Colonies Are Met with Self-Organized Walls of Ants (Hymeno­Ptera: Formicidae) Kaitlin M
    ISSN 1997-3500 Myrmecological News myrmecologicalnews.org Myrmecol. News 30: 251-258 doi: 10.25849/myrmecol.news_030:251 16 December 2020 Original Article Incidental interactions among Neotropical army-ant colonies are met with self-organized walls of ants (Hymeno ptera: Formicidae) Kaitlin M. Baudier & Theodore P. Pavlic Abstract Warfare between social groups has long been a popular topic of study among ethologists, but less well studied are the mechanisms by which interacting groups maintain peace. We report on the use of transient living walls as a mechanism by which avoidance is established between army-ant mass raids and non-prey ant species commonly encountered in the environment (other army ants and leafcutter ants). These transient walls are composed of a series of individuals performing stereotyped posturing displays at the border between interacting colonies. Unlike preemptive column guarding by soldiers, these walls are composed of a variety of worker sub-castes and can arise and disappear rapidly in response to the presence of local threats. Quantified videos of in-field artificial introductions revealed that walking ants switch to the task of posturing within a wall following multiple contacts with non-nestmates and that posturing ants return to walking as contacts with intruders decline and contacts with nestmates increase. The rapid shift of army ants to the task of forming transient walls at the instant when they are needed for traffic management provides a highly observable system in which to study the rules of individual-based living constructions, providing potential insight into similar processes across levels of biological organization. Key words: Eciton, emergent structures, Labidus, Nomamyrmex, self-assembly, walling.
    [Show full text]
  • Effect of Varied Disturbance Types on Dorylus (Anomma) Molestus Defensive Behavior in the West Usumbara Mountains, Tanzania
    SIT Graduate Institute/SIT Study Abroad SIT Digital Collections Independent Study Project (ISP) Collection SIT Study Abroad Spring 2016 Effect of Varied Disturbance Types on Dorylus (Anomma) molestus Defensive Behavior in the West Usumbara Mountains, Tanzania. Ryan Mahar SIT Graduate Institute - Study Abroad Follow this and additional works at: https://digitalcollections.sit.edu/isp_collection Part of the Biosecurity Commons, Climate Commons, Ecology and Evolutionary Biology Commons, and the Entomology Commons Recommended Citation Mahar, Ryan, "Effect of Varied Disturbance Types on Dorylus (Anomma) molestus Defensive Behavior in the West Usumbara Mountains, Tanzania." (2016). Independent Study Project (ISP) Collection. 2349. https://digitalcollections.sit.edu/isp_collection/2349 This Unpublished Paper is brought to you for free and open access by the SIT Study Abroad at SIT Digital Collections. It has been accepted for inclusion in Independent Study Project (ISP) Collection by an authorized administrator of SIT Digital Collections. For more information, please contact [email protected]. Effect of Varied Disturbance Types on Dorylus (Anomma) molestus Defensive Behavior in the West Usumbara Mountains, Tanzania. Ryan Mahar Bates College Advisor: Reese Matthews SIT Wildlife Conservation and Political Ecology ii ACKNOWLEDGEMENTS First, I must thank Baba Jack and Oskar for helping me with ideas and possible ISP topics; I wouldn’t have enjoyed ISP as much without you pushing me to follow my passion. Also, thank you to Mr. Kiparu, Richard, and David for being so welcoming and hospitable at the Chalet. The food was incredible, and your kindness made all the difference. To Francis, my fearless guard, thank you for leading me through the farms, the tops of the forests, and along the roads in the most dismal of weather.
    [Show full text]
  • Exocrine Glands in the Legs of the Social Wasp Vespula Vulgaris Catherine Nijs & Johan Billen
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Lirias 1 Submitted to Arthropod Structure and Development 2 3 4 5 Exocrine glands in the legs of the social wasp Vespula vulgaris 6 7 8 Catherine Nijs & Johan Billen 9 Zoological Institute, University of Leuven, Naamsestraat 59, box 2466, B-3000 10 Leuven (Belgium) 11 Keywords: morphology, legs, exocrine glands, social wasps 12 Running title: Exocrine glands in the legs of Vespula vulgaris 13 Corresponding author: 14 Johan Billen, University of Leuven, Zoological Institute, Naamsestraat 59, box 2466, 15 B-3000 Leuven, Belgium 16 Tel: (32) 16 323975 17 Fax: (32) 16 324575 18 E-mail: [email protected] 19 1 20 Abstract 21 This study brings a survey of the exocrine glands in the legs of Vespula 22 vulgaris wasps. We studied workers, males, virgin queens as well as mated queens. 23 A variety of 17 glands is found in the different leg segments. Among these, five 24 glands are novel exocrine structures for social insects (trochanter-femur gland, 25 ventrodistal tibial gland, distal tibial sac gland, ventral tibial gland, and ventral 26 tarsomere gland). Most leg glands are present in the three leg pairs of all castes. 27 This may indicate a mechanical function. This is likely for the numerous glands that 28 occur near the articulation between the various leg segments, where lubricant 29 production may be expected. Other possible functions include antenna cleaning, 30 acting as a hydraulic system, or pheromonal. Further research including leg-related 31 behavioural observations and chemical analyses may help to clarify the functions of 32 these glandular structures in the legs.
    [Show full text]