DOCSLIB.ORG

Causes and Consequences of Genetic Caste-Bias in the Eusocial Hymenoptera

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Causes and Consequences of Genetic Caste-Bias in the Eusocial Hymenoptera Causes and consequences of genetic caste-bias in the eusocial Hymenoptera Rowena Elisabeth Mitchell Submitted in accordance with the requirements for the degree of Doctor of Philosophy The University of Leeds School of Biology September 2013 ii The candidate confirms that the work submitted is her own, except where work which has formed part of jointly-authored publications has been included. The contribution of the candidate and the other authors to this work has been explicitly indicated below. The candidate confirms that appropriate credit has been given within the thesis where reference has been made to the work of others. Chapter 6 contains work from a jointly authored publication: Mitchell, R. E., Frost, C. L., Hughes, W. O. H. (2012). Size and asymmetry: are there costs to winning the royalty race? Journal of Evolutionary Biology 25: 522– 531. Author contributions are as follows: REM designed the experiments, carried out the experimental work, analysed the data and wrote the manuscript. CLF assisted with the genotyping of ants. WOHH supervised the work, assisted with the design of the experiments, the data analysis and drafting of the manuscript. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. © 2013 The University of Leeds and Rowena Mitchell The right of Rowena Mitchell to be identified as Author of this work has been asserted by her in accordance with the Copyright, Designs and Patents Act 1988. iii Acknowledgements Firstly, I would like to thank Bill Hughes for giving me the opportunity to undertake this work and for all your help, encouragement and advice; I have learnt a lot. Thank you to Terry Crawford for nudging me down this road and for telling me I’d have what it takes. Thank you to Bill Cadmore for looking after our bees and then letting me use yours, and thank you to Koos Boomsma for letting me raid the Copenhagen Acro. colonies right at the start. Thank you to Paula Chappell for help in the lab, it would have been so much harder without you. Thank you to all the friends I have made throughout this journey. Thank you to Chris Tranter, Jasmine Parkinson and Victoria Norman for making me so welcome in Brighton and making sure I had everything I needed. Thanks to Crystal Frost, and Katherine Roberts help, advice, fun and good food, you made the lab such a great place to work. Thank you to Peter Graystock for making me chuckle, for being an adequate tea-maid and a great scientist, it rubs off on us all. Thanks to Kirsten Foley and Claire Asher for travelling this road with me, we all made it in the end. Thanks to Liz Elliot for supporting me through the good and the not-so-good, for preventing otherwise inevitable obesity, and for being such a wonderful friend. A really special thank you goes to Sophie Evison; I could not have done this without your help, you have been an absolute inspiration to me as well as a great friend. Thank you to my whole family for their love and support. Thanks to Lucy and Alex for being the best sibs ever, I hope you are as proud of me as I am of you. Thank you to Mum and Dad for giving us every opportunity we could have wished for and more, it is through a lifetime of encouragement that I have been able to get to where I am today and do so many great things along the way. Finally, thank you to Alan for your unerring belief that I can achieve anything I set my mind to, for making me laugh and for being a constant reminder that life outside the lab is so much better than a life spent in it. iv Abstract The eusocial Hymenoptera is one of the most successful groups to ever colonise the planet. They are defined by reproductive division of labour, whereby reproduction in a colony is dominated by one or a few queens, whilst all other individuals are more- or-less sterile. There has been much interest in understanding the mechanistic basis of caste determination, and particular interest in the evidence for genotypic variation in the propensity of individuals to become queens. However, the mechanisms underlying such genotypic variation in caste fate are as yet unknown. In this thesis, I examine potential causes and consequences of genetic caste-bias using the honey bee, Apis mellifera, and Acromyrmex leaf-cutting ants. In A. mellifera, individuals with queen-biased genotypes were shown to have a higher growth rate than those from genotypes with no caste-bias or a worker-bias. The variable response, in terms of growth rate, of genotypes to treatment with a juvenile hormone analogue suggested that variation in caste propensity could potentially arise from differential responses to environmentally induced physiological cues. In addition, an immune challenge by the fungal parasite Ascosphaera apis was found to affect the growth rate of A. mellifera larvae and caste determination at the colony level, suggesting that resistance to parasites may also be important in determining caste fate. In many species, workers have some control over caste determination, and I show that Ac. octospinosus workers were able to discriminate between nestmate and non-nestmate brood, even after larvae had been in contact with the fungus garden. That workers were able to discriminate between larvae within the nest suggests that they may be able to differentiate closely related kin during caste determination, despite homogenisation of fine scale cues. Finally, a positive relationship between patriline queen-worker skew and fluctuating asymmetry, an indicator of developmental stress, was found in Ac. echinatior, suggesting that subtle costs to caste-biasing strategies could explain the rarity of queen-biased genotypes. Overall this work shows that genotypic differences in the physiological response to environmental cues may underlie genetic caste-bias in the social insects. However, understanding the interaction between physiology, environment and genotype is essential if we are to understand the ultimate determinants of individual caste fate. v Contents Acknowledgements ................................................................................................... iii Abstract ...................................................................................................................... iv List of Figures ............................................................................................................ ix List of Tables ............................................................................................................. xi 1. General introduction ........................................................................................ 1 1.1 The eusocial Hymenoptera .......................................................................... 1 1.2 Conditions for the evolution of eusociality in the Hymenoptera ................. 2 1.3 Polyandry in the eusocial Hymenoptera ...................................................... 4 1.4 Altruism under conditions of low relatedness ............................................. 5 1.5 Caste determination mechanisms ................................................................ 7 1.5.1 Environmental caste determination .................................................. 7 1.5.2 Genetic caste determination ............................................................. 8 1.5.3 Gene by environment interactions.................................................. 10 1.5.4 Worker caste ................................................................................... 11 1.5.5 Social species without a queen caste .............................................. 13 1.5.6 The molecular basis of caste determination ................................... 14 1.6 Conflict over caste determination .............................................................. 15 1.7 Caste determination in the honey bee, Apis mellifera ............................... 18 1.8 ‘Royal cheats’ in leaf-cutting ants ............................................................. 19 1.9 Nepotism in the eusocial Hymenoptera ...................................................... 21 1.10 Causes and consequences of genetic caste-bias in the eusocial Hymenoptera..................................................................................................... 23 2. Raising royalty: genotypic variation in larval growth rate affects royal destiny in honey bees ...................................................................................... 25 Abstract ............................................................................................................. 25 2.1 Introduction................................................................................................ 26 vi 2.2 Methods ..................................................................................................... 28 2.2.1 Growth rate quantification ............................................................. 28 2.2.2 Royal propensity ............................................................................ 29 2.2.3 Genotyping ..................................................................................... 29 2.2.4 Statistical analysis .......................................................................... 31 2.3 Results ....................................................................................................... 32 2.3.1 Genetic variation in growth rate ..................................................... 32 2.3 2 Growth rate and royal propensity ..................................................
Load more

Recommended publications
  • Reproductive Conflict Among Workers of the Ant Species Pseudomyrmex Gracilis (Hymenoptera: Formicidae)
    Reproductive conflict among workers of the ant species Pseudomyrmex gracilis (Hymenoptera: Formicidae) DISSERTATION ZUR ERLANGUNG DES DOKTORGRADES DER NATURWISSENSCHAFTEN (DR. RER. NAT.) DER FAKULTÄT FÜR BIOLOGIE UND VORKLINISCHE MEDIZIN DER UNIVERSITÄT REGENSBURG vorgelegt von Volker Schmid aus Wolfschlugen im Jahr 2012 Das Promotionsgesuch wurde eingereicht am: 20.06.2012 Die Arbeit wurde angeleitet von: Prof. Dr. Jürgen Heinze Unterschrift: Für Simone “Under carefully controlled experimental conditions, an animal will behave as it damned well pleases.” Harvard Law of Animal Behaviour Volker Schmid – Reproductive conflict in Pseudomyrmex gracilis (Dissertation 2012) Contents 1. Introduction .......................................................................................................................... 2 1.1 Inter- and intraspecific conflicts ...................................................................................... 2 1.2 Eusociality – cooperation and conflict ............................................................................. 3 1.3 Conflicts over reproduction in social Hymenoptera ........................................................ 4 1.4 Aims of the present study .................................................................................................. 6 2. Material and Methods .......................................................................................................... 7 2.1 Microsatellite primer establishment ................................................................................
    [Show full text]
  • Masondentinger Umn 0130E 1
    The Nature of Defense: Coevolutionary Studies, Ecological Interaction, and the Evolution of 'Natural Insecticides,' 1959-1983 A DISSERTATION SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL OF THE UNIVERSITY OF MINNESOTA BY Rachel Natalie Mason Dentinger IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Mark Borrello December 2009 © Rachel Natalie Mason Dentinger 2009 Acknowledgements My first thanks must go to my advisor, Mark Borrello. Mark was hired during my first year of graduate school, and it has been my pleasure and privilege to be his first graduate student. He long granted me a measure of credit and respect that has helped me to develop confidence in myself as a scholar, while, at the same time, providing incisive criticism and invaluable suggestions that improved the quality of my work and helped me to greatly expand its scope. My committee members, Sally Gregory Kohlstedt, Susan Jones, Ken Waters, and George Weiblen all provided valuable insights into my dissertation, which will help me to further develop my own work in the future. Susan has given me useful advice on teaching and grant applications at pivotal points in my graduate career. Sally served as my advisor when I first entered graduate school and has continued as my mentor, reading nearly as much of my work as my own advisor. She never fails to be responsive, thoughtful, and generous with her attention and assistance. My fellow graduate students at Minnesota, both past and present, have been a huge source of encouragement, academic support, and fun. Even after I moved away from Minneapolis, I continued to feel a part of this lively and cohesive group of colleagues.
    [Show full text]
  • Reconstruction and Functional Annotation of Ascosphaera Apis Full
    bioRxiv preprint doi: https://doi.org/10.1101/770040; this version posted September 16, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 1 Reconstruction and functional annotation of 2 Ascosphaera apis full-length transcriptome via PacBio 3 single-molecule long-read sequencing 4 Dafu Chen 1,†, Yu Du 1,†, Xiaoxue Fan 1, Zhiwei Zhu 1, Haibin Jiang 1, Jie Wang 1, 5 Yuanchan Fan 1, Huazhi Chen 1, Dingding Zhou 1, Cuiling Xiong 1, Yanzhen Zheng 1, 6 Xijian Xu 2, Qun Luo 2, Rui Guo 1,* 7 1 College of Bee Science, Fujian Agriculture and Forestry University, Fuzhou 8 350002, China 9 2 Jiangxi Province Institute of Apiculture, Nanchang, Jiangxi 330201, China 10 † These authors contributed equally to this work. 11 * Correspondence author: 12 E-mail address: [email protected]; 13 Tel: +86-0591-87640197; Fax: +86-0591-87640197 14 15 16 17 18 19 20 21 22 23 24 25 26 1 bioRxiv preprint doi: https://doi.org/10.1101/770040; this version posted September 16, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 27 Abstract: 28 Ascosphaera apis is a widespread fungal pathogen of honeybee larvae that results 29 in chalkbrood disease, leading to heavy losses for the beekeeping industry in China and 30 many other countries.
    [Show full text]
  • Swollen-Thorn Acacias of Central America
    SMITHSONIAN CONTRIBUTIONS TO BOTANY NUMBER 13 Swollen-Thorn Acacias of Central America Daniel H. Janzen SMITHSONIAN INSTITUTION PRESS City of Washington 1974 ABSTRACT Janzen, Daniel H. Swollen-Thorn Acacias of Central America. Smithsonian Contributions to Botany, number 13, 131 pages, 119 figures, 1974.-This nomen- clatural, taxonomic, and ecological treatment of 11 Central American obligate ant-acacias (Acacia allenii, A. chiapensis, A. collinsii, A. cookii, A. cornigera, A. gentlei, A. globulifera, A hindsii, A nzayana, A. melanoceras, and A. sphaero- cephala) and one quasi-obligate ant-acacia (Acacia ruddiae) is based on ex- tensive field study from 1963 to 1972 and on herbarium specimens where of use. 7 he population boundaries of all species are mapped and described with respect to ecological parameters. Morphological variation, details of the interaction with the ants, and acacia reproductive biology are presented for most species. OFFICIALPUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution‘s annual report, Srnithsonian Year. SI PRESSNUMBER 4817. SERIESCOVER DESIGN: Leaf clearing from the Katsura tree Cercidiphyllurn japonicum Siebold and Zuccarini. Library of Congress Cataloging in Publication Data Janzen, Daniel H: Swollen-thorn acacias of Central America. (Smithsonian contributions to botany, no. 13) Bibliography: p. 1. Acacia. 2. Ants-Central America. 3. Botany-Central America-Ecology. I. Title. 11. Series: Smithsonian Institution. Smithsonian contributions to botany, no. 13. QKl.S27 no. 13. [QK495.L52] 581’.08s [583’.321] 73-4401 For sale by the Superintendent of Documents, US. Government Printing O5ce Washington, D.C. 20402 . Price $2.35 (paper cover) Contents Page Introduction ..................................................
    [Show full text]
  • Selection of Larvae for Queen Rearing by Workers in the Honey Bee (Apis
    Humboldt-Universität zu Berlin Dissertation Selection of Larvae for Queen Rearing by Workers in the Honey Bee (Apis mellifera L.) − Nepotism or Different Maternal Supply? zur Erlangung des akademischen Grades doctor rerum agriculturarum (Dr. rer. agr.) Eingereicht an der Landwirtschaftlich-Gärtnerischen Fakultät der HumboldtUniversität zu Berlin von AL-Kahtani, Saad Naser Saad Präsident der Humboldt-Universität zu Berlin Prof. Dr. Jan-Hendrik Olbertz Dekan der Landwirtschaftlich-Gärtnerischen Fakultät Prof. Dr. Dr. h. c. Frank Ellmer Gutachter: 1. Prof. Dr. agr. habil. Kaspar Bienefeld 2. Prof. Dr. agr. Kurt-Johannes Peters 3. PD Dr. Ricarda Scheiner Datum der Promotion: 27.07.2011 II Abstract Natural selection favours an efficient cooperation within eusocial colonies. However, in polyandrous species, queen rearing may provide some conflict. Worker bees are assumed to play a nepotistic role during the queen-rearing phase by preferring more closely related larvae. Honeybee workers were found to be able to discriminate between different related individuals, but published data are inconsistent. Here in my study I show that larvae reared on a standardized basis were not significantly preferred by related worker bees, but that a higher egg weight – from which the larvae originated – significantly increased the chance to receive a royalty treatment and showed a tendency to correlate positively with fitness traits of the resulting queen. Queen rearing results from a colony decision, and this involves many workers. Consequently any lack of a nepotism which is proved may be due to the fact that relatedness-driven kin preference of individuals cannot be applied to a colony decision. In view of this, using DNA fingerprinting, I also tested the relatedness of larvae to be reared as queens and those nursing worker bees which initiated the queen−rearing process.
    [Show full text]
  • Landscape Composition and Fungicide Exposure Influence Host
    Environmental Entomology, XX(XX), 2020, 1–10 doi: 10.1093/ee/nvaa138 Insect-Microbial Interaction Research Landscape Composition and Fungicide Exposure Downloaded from https://academic.oup.com/ee/advance-article/doi/10.1093/ee/nvaa138/6008150 by Cornell University Library user on 05 December 2020 Influence Host–Pathogen Dynamics in a Solitary Bee Erin Krichilsky,1,4 Mary Centrella,2 Brian Eitzer,3 Bryan Danforth,1 Katja Poveda,1 and Heather Grab1, 1Department of Entomology, Cornell University, 2130 Comstock Hall, Ithaca, 14853, NY, 2Pesticide Management Education Program, Cornell University, 525 Tower Road, Ithaca 14853, NY, 3The Connecticut Agricultural Experiment Station, Department of Analytical Chemistry, Johnson-Horsfall Laboratory, 123 Huntington Street, P.O. Box 1106, New Haven 06504-1106, CT, and 4Corresponding author, e-mail: [email protected] Subject Editor: Gloria DeGrandi-Hoffman Received 25 May 2020; Editorial decision 13 October 2020 Abstract Both ecosystem function and agricultural productivity depend on services provided by bees; these services are at risk from bee declines which have been linked to land use change, pesticide exposure, and pathogens. Although these stressors often co-occur in agroecosystems, a majority of pollinator health studies have focused on these factors in isolation, therefore limiting our ability to make informed policy and management decisions. Here, we investigate the combined impact of altered landscape composition and fungicide exposure on the prevalence of chalkbrood disease, caused by fungi in the genus Ascosphaera Olive and Spiltoir 1955 (Ascosphaeraceae: Onygenales), in the introduced solitary bee, Osmia cornifrons (Radoszkowski 1887) (Megachilidae: Hymenoptera). We used both field studies and laboratory assays to evaluate the potential for interactions between altered landscape composition, fungicide exposure, and Ascosphaera on O.
    [Show full text]
  • Control of Chalkbrood Disease with Natural Products
    Control of chalkbrood disease with natural products A report for the Rural Industries Research and Development Corporation by Dr Craig Davis and Wendy Ward December 2003 RIRDC Publication No 03/107 RIRDC Project No DAQ-269A © 2003 Rural Industries Research and Development Corporation. All rights reserved. ISBN 0 642 58672 X ISSN 1440-6845 The control of chalkbrood disease with natural products Publication No. 03/107 Project No. DAQ-269A The views expressed and the conclusions reached in this publication are those of the author and not necessarily those of persons consulted. RIRDC shall not be responsible in any way whatsoever to any person who relies in whole or in part on the contents of this report. This publication is copyright. However, RIRDC encourages wide dissemination of its research, providing the Corporation is clearly acknowledged. For any other enquiries concerning reproduction, contact the Publications Manager on phone (02) 6272 3186. Researcher Contact Details: Dr Craig Davis Wendy Ward Centre for Food Technology Animal Research Institute 19 Hercules Street, Hamilton 4007 665 Fairfield Road, Yeerongpilly 4105 Phone: (07) 3406 8611 Phone: (07) 3362 9446 Fax: (07) 3406 8677 Fax: (07) 3362 9440 Email: [email protected] Email: [email protected] In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form. RIRDC Contact Details Rural Industries Research and Development Corporation Level 1, AMA House 42 Macquarie Street BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: 02 6272 4819 Fax: 02 6272 5877 Email: [email protected] Website: http://www.rirdc.gov.au Published in December 2003 Printed on environmentally friendly paper by Canprint ii Foreword Chalkbrood of honeybees (Apis mellifera) is caused by the fungus Ascosphaera apis.
    [Show full text]
  • Birds and the Ant X Acacia Interaction in Central America, with Notes on Birds and Other Myrmecophytes Author(S): Daniel H. Janzen Source: the Condor, Vol
    Birds and the Ant x Acacia Interaction in Central America, with Notes on Birds and Other Myrmecophytes Author(s): Daniel H. Janzen Source: The Condor, Vol. 71, No. 3 (Jul., 1969), pp. 240-256 Published by: University of California PressCooper Ornithological Society Stable URL: http://www.jstor.org/stable/1366301 Accessed: 28/08/2008 11:23 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=ucal. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact [email protected]. http://www.jstor.org BIRDS AND THE ANT X ACACIA INTERACTION IN CENTRAL AMERICA, WITH NOTES ON BIRDS AND OTHER MYRMECOPHYTES DANIEL H.
    [Show full text]
  • New and Little-Known Myrmecophytic Associations from Bornean Rain Forests
    Malayan Nature Journal 1989 43: 106-115 New and Little-known Myrmecophytic Associations from Bornean Rain Forests 1 2 3 ULRICH MASCHWITZ , BRIGITTE FlALA , YING FAH LEE , VUN KHEN CHEy3 AND FUI LIAN T AN4 Abstract: The woody climber Millettia niuewenhuisii (Fabaceae) and the shrub Myrmeconauclea strigosa (Rubiaceae) in Sabah, Borneo are associated with ants. The hollow stems of Millettia nieuwenhuisii are regularly inhabited by an aggressive Cladomyrma . sp., which keeps pseudococcids inside the stem. On Myrmeconauclea strigosa the ants live in hollow internodal swellings near the end of the branches. In this plant many different ant species use the nesting space in an opp(,rtuni.tic manner. INTRODUCTION During field study in Sabah (NE Borneo) in January 1989 we came across two plants which were inhabited by ants. One was a large woody climber, Millettia nieuwenhuisii (Fabaceae). The other was the shrub Myrme­ conauclea strigosa (Rubiaceae) (Fig. I), which Merrill (1920) mentioned to be associated with ants. Since little is known as yet about the ant-inhabitants of these myrmecophytes we studied the relationship in detail. Data charac­ teristic for the associations are presented. RESULTS Millettia nieuwenhuisii J .J. Smith (Leguminosae) We found a specimen of this large woody climber in lowland pri~ary forest at Poring in Kinabalu State Park (Figure 2). The leaves of this liana are pinnate, with 2-5 pairs of opposite leaflets and one terminal leaflet. The pink, papilionaceous flowers are arranged in paniculate inflorescences. The pith of all younger branches near the ground as well as in the crown region I Zoologisches Institut, J .W.-Goethe-Universitat, Siesmayerstr.
    [Show full text]
  • U N E P E M E R G I N G I S S U E S Global
    UNEP EMERGING ISSUES GLOBAL HONEY BEE COLONY DISORDERS AND OTHER THREATS For more information contact: Division of Early Warning Assessment TO INSECT United Nations Environment Programme P.O. Box 30552, Nairobi 00100, Kenya www.unep.org Tel: (+254) 20 7623450 United Nations Environment Programme P.O. Box 30552 - 00100 Nairobi, Kenya POLLINATORS Fax: (+254) 20 7624315 Tel.: +254 20 762 1234 Fax: +254 20 762 3927 e-mail: [email protected] e-mail: [email protected] Web: www.unep.org www.unep.org © UNEP 2010 - UNEP Emerging Issues: Global Honey Bee Colony Disorder and Other Threats to Insect Pollinators. This publication may be reproduced in whole or in part and in any form for educational or non-profit purposes without special permission from the copyright holder, provided acknowledgement of the source is made. United Nations Environment Programme (UNEP) would appreciate receiving a copy of any publication that uses this report as a source. No use of this publication may be made for resale or for any other commercial purpose whatsoever without prior permission in writing of the United Nations Environment Programme. Disclaimers The views expressed in this publication are not necessarily those of the agencies cooperating in this project. The designations employed and the presentations do not imply the expression of any opinion whatsoever on the part of UNEP or cooperating agencies concerning the legal status of any country, territory, city, or area of its authorities, or of the delineation of its frontiers or boundaries. Mention of a commercial company or product in this report does not imply endorsement by the United Nations Environment Programme.
    [Show full text]
  • Mutualistic Acacia-Ants Show That Specialized Bacteria Are Not Required for the Evolution of Herbivory
    bioRxiv preprint doi: https://doi.org/10.1101/208215; this version posted October 26, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC 4.0 International license. Mutualistic acacia-ants show that specialized bacteria are not required for the evolution of herbivory Benjamin E.R. Rubin1,*,§, Stefanie Kautz2, Brian D. Wray3, Corrie S. Moreau1 1Department of Science and Education, Field Museum of Natural History, Chicago, IL, USA 2Department of Biology, Portland State University, Portland, OR, USA 3Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA *Corresponding author: [email protected] §Current address: Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA Abstract Acacia-ant mutualists in the genus Pseudomyrmex nest obligately in acacia plants and, through stable isotope analysis, we show that they are among the strictest of herbivores, feeding exclusively from their hosts. The diets of herbivorous insects such as these are often enriched by obligate bacterial endosymbionts through nitrogen recycling and even gaseous di-nitrogen fixation. We, therefore, examine the bacterial communities associated with mutualistic acacia- ants, comparing them with related non-mutualists in order to determine whether they host bacterial partners likely to contribute to the enrichment of their diets. However, despite their low trophic position, we find no evidence for bacteria-assisted nutrition in either adults or larvae. These acacia-ants do not host any species- or clade-specific bacteria, though several lineages of acetic acid bacteria present across social insects do differ in abundance between mutualists and non-mutualists, likely in response to the sugar-rich diets of their hosts.
    [Show full text]
  • Nuptial Flight of the Southeast Asian Plant-Ant Crematogaster Captiosa (Forel, 1911) and the Phenology of Colony Founding
    ASIAN MYRMECOLOGY Volume 9, e009013, 2017 ISSN 1985-1944 | eISSN: 2462-2362 © Brigitte Fiala, Rosli bin Hashim, DOI: 10.20362/am.009013 Klaus Dumpert and Ulrich Maschwitz Nuptial flight of the Southeast Asian plant-ant Crematogaster captiosa (Forel, 1911) and the phenology of colony founding Brigitte Fiala1*, Rosli bin Hashim2, Klaus Dumpert3 and Ulrich Maschwitz4 1University of Würzburg, Animal Ecology and Tropical Biology, Biocenter, Am Hubland, 97074 Würzburg, Germany 2Institute of Biological Sciences, Faculty of Science Building, University of Malaya, 50603 Kuala Lumpur, Malaysia 3Im Maierbrühl 59, 70112 Freiburg, Germany 4Fachbereich Biowissenschaften, Johann-Wolfgang-Goethe-Universität Frank- furt, present address: Anemonenweg 33, 63263 Neu-Isenburg, Germany. *Corresponding author: [email protected] ABSTRACT. Despite the great importance of nuptial flights for ants, little is known about the swarming processes from the highly diverse tropical regions, especially rainforests. This is particularly true for ants living in obligate sym- biosis with myrmecophytic plants. Here we present the first direct observations of the swarming event in the association between Crematogaster captiosa and the pioneer tree Macaranga bancana in Southeast Asia. Nuptial flights of C. captiosa on M. bancana took place during the night, and alate females were seen to copulate with alate males on the tree. Data on C. captiosa from the Malay Peninsula as well as Borneo indicate that sexual production and colony founding occurs throughout the year. Despite episodic fruiting seasons of the host plants, Macaranga saplings for colony founding can also become available outside peak seasons from seed banks after disturbance. Therefore, continuous swarming might be a good strategy to avoid strong competition for limited nest- ing sites while still securing permanent colonisation of saplings - a prerequisite for their survival.
    [Show full text]