DOCSLIB.ORG

Mandible Movements in Ants ଝ

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Mandible Movements in Ants ଝ Comparative Biochemistry and Physiology Part A 131Ž. 2001 7᎐20 Review Mandible movements in ants ଝ Jurgen¨ PaulU Uni¨ersitat¨¨ Wurzburg, Theodor-Bo¨eri-Institut() Biozentrum , Lehrstuhl fur¨ Verhaltensphysiologie und Soziobiologie, Am Hubland, D-97074 Wurzburg,¨ Germany Received 13 January 2001; received in revised form 30 March 2001; accepted 3 April 2001 Abstract Ants use their mandibles for almost any task, including prey-catching, fighting, leaf-cutting, brood care and communication. The key to the versatility of mandible functions is the mandible closer muscle. In ants, this muscle is generally composed of distinct muscle fiber types that differ in morphology and contractile properties. Fast contracting fibers have short sarcomeresŽ. 2᎐3 ␮m and attach directly to the closer apodeme, that conveys the muscle power to the mandible joint. Slow but forceful contracting fibers have long sarcomeresŽ. 5᎐6 ␮m and attach to the apodeme either directly or via thin thread-like filaments. Volume proportions of the fiber types are species-specific and correlate with feeding habits. Two biomechanical models explain why species that rely on fast mandible strikes, such as predatory ants, have elongated head capsules that accommodate long muscle fibers directly attached to the apodeme at small angles, whereas species that depend on forceful movements, like leaf-cutting ants, have broader heads and many filament- attached fibers. Trap-jaw ants feature highly specialized catapult mechanisms. Their mandible closing is known as one of the fastest movements in the animal kingdom. The relatively large number of motor neurons that control the mandible closer reflects the importance of this muscle for the behavior of ants as well as other insects. ᮊ 2001 Elsevier Science Inc. All rights reserved. Keywords: Adaptation; Biomechanics; Force; Insects; Morphology; Motor control; Muscle fiber types; Trap-jaw mechanisms; Velocity 1. Introduction brood care, carrying nestmates, transporting liq- uids and communicationŽ Holldobler¨ and Wilson, For the majority of insects, the mouthparts are 1990. Accordingly, ant mandibles have to per- the most important tools for almost any task. This form many different kinds of movements in terms is particularly true for the mandibles of ants. Ants of velocity, force output and precision. While employ their mandibles for fast or powerful ac- some tasks are common among ant speciesŽ e.g. tions like prey-catching, fighting, digging, leaf-cut- brood care. , others represent specific adaptations. ting, and also for delicate tasks such as grooming, Predators often have long jaws equipped with piercing teeth and sharp edges, whereas herbivo- rous ants have more compact mandibles suited ଝ This paper was originally presented as part of the ESCPB for the special task of processing plant material Congress symposium ‘Learning about the Comparative Ž.Gronenberg et al., 1997 . In many ant species, Biomechanics of Locomotion and Feeding’, Liege` July 26᎐27, 2000. however, the mandibles resemble a general type U Tel.: q49-931-888-4303; fax: q49-931-888-4309. found in many other insect groups: they are sturdy, E-mail address: [email protected]Ž J. shovel-like, non-segmented limbs. But mandible Paul. specialization is not only based on shape but also 1095-6433r01r$ - see front matter ᮊ 2001 Elsevier Science Inc. All rights reserved. PII: S 1 0 9 5 - 6 4 3 3Ž. 0 1 00458-5 8 J. Paul rComparati¨e Biochemistry and Physiology Part A 131() 2001 7᎐20 depends on the speed of movement and on the closer muscle is much larger than the opener force the jaws can generate. Catching elusive prey muscle. In large species or in large individuals of obviously requires different movement character- polymorphic speciesŽ Holldobler¨ and Wilson, istics and tactics than cracking seeds. 1990. , the mandible closer occupies up to two- Force and velocity of a limb movement depend thirds of the entire head capsule volumeŽ. Fig. 1a . on the muscles and the accessory structures that The proportion of the mandible closer muscle control the particular limb. In ants, the mandible volume in relation to the head capsule volume design is simple. It conforms to the common decreases with decreasing size of the antŽ. Fig. 1a . mandible organization of other hymenopterans In small species or small individuals, the mandible Ž.Snodgrass, 1935, 1956 : the mandibles are con- closer muscle only fills approximately 25% of the nected to the head capsule by a hinge joint, head capsuleŽ. Fig. 1a . The reason for this allo- movable only in a single planeŽ inwardsrout- metric correlation is that other organs and struc- wards. , operated by only a single closer and tures within the head take up relatively more opener muscle on each side of the head. Even space when the head capsule volume decreases ᎐ though opener closer muscle co-contraction may Že.g. antennal, labial, and maxillary muscles; Fig. occur, the mandible closer muscle is much larger 1b; Paul and Roces, 1999. Most notably, the and the key to the versatility of mandible func- brain is relatively larger in small antsŽ Jaffe and Ž. tions Gronenberg et al., 1998a . All the fast, Perez, 1989. However, the mandible closer is the forceful, or delicate mandible movements are largest muscle in any ant worker, even in very generated by the mandible closer muscle. small species or individuals. Because of its relative simplicity and its great In almost all ants, the mandible closer muscle behavioral relevance, this movement system is is composed of two morphologically distinct types very well suited for studying adaptive muscle mor- of muscle fibersŽ Gronenberg et al., 1997; Paul phology, biomechanics, and motor control. This and Gronenberg, 1999. : fibers with short sar- review gives an overview of the diversity of ant comeresŽ. sarcomere length 2᎐3 ␮m and fibers mandible movements and the underlying mecha- with long sarcomeresŽ. 5᎐6 ␮m . As a general nisms considering an evolutionary context by rule, in long sarcomeres, more myosin᎐actin comparing species adapted to different lifestyles. cross-bridges act in parallelŽ Huxley, 1974; Tregear and Marston, 1979; Cooke, 1997. There- 2. Muscle fiber types and general morphology of fore, fibers with long sarcomeres generate larger the mandible closer muscle forces. In muscle fibers with short sarcomeres many units simultaneously shorten in series, re- In ants, as in most other animals, the mandible sulting in a high contraction velocityŽ Jahromi Fig. 1. Allometric correlations between mouthpart muscle and head capsule volumes in ants. Data points represent single individuals of various ant species, respectively Ž Atta sexdens, Camponotus rufipes, ns4; Diacamma sp., Ectatomma ruidum, Harpegnathos saltator, Leptothorax sordidulus, ns3; Pachycondyla ¨illosa, Myrmecia sp., ns2.Ž. a The relative volume of the mandible closer muscle increases with increasing head capsule volume Ž.rs0.76315; P-0.0001 .Ž b. The relative volumes of the labial adductor, abductor, maxillary adductor, and abductor decrease with increasing head capsule volume Ž.rsy0.75849; P-0.0001 . J. Paul rComparati¨e Biochemistry and Physiology Part A 131() 2001 7᎐20 9 and Atwood, 1969, 1971; Lang et al., 1977. This 1999. The main body of the apodeme is a mas- correlation between sarcomere length and con- sive sclerotized structure, which funnels the forces tractile properties of a muscle fiber has been of all closer muscle fibers into the mandible. The shown in many different studiesŽ O’Connor et al., apodeme base gives rise to apodeme collaterals. 1982; Stephens et al., 1984; Gunzel¨ et al., 1993; Typically, three branches project from the Taylor, 2000. Hence, muscle fibers with short apodeme base posteriorly into the closer muscle: sarcomeres are fast contracting fibers, whereas a central principal branch and two accessory long sarcomeres indicate slow but forceful muscle branches, a median and a lateral one. The most fibers. Ultrastructural observations and consider- significant alteration of the basic design is the ations support this classification of muscle fiber introduction of apodeme filaments. Bundles of types in antsŽ proportion and density of myofila- such filaments, each of which connects exclusively ments, mitochondria, sarcoplasmatic reticulum, to a single muscle fiber, may replace the acces- and thickness of z-discs; van Leeuwen, 1991; sory branches entirely although the basic organi- Gronenberg et al., 1997. However, absolute val- zation can still be discerned. ues of sarcomere lengths and other structural The muscle fiber types of the ant mandible properties do not always accurately predict physi- closerŽ fast directly attached, slow directly and ological performance of muscle fibers in filament-attached fibers. are arranged in bundles arthropodsŽ Costello and Govind, 1983; Silverman of like fibersŽ Gronenberg et al., 1997; Paul and et al., 1987; Gunzel¨ et al., 1993. A causal rela- Gronenberg, 1999. In all ants studied, the tionship between the characteristics of the mandible closer muscle is thus composed of sub- mandible movement and the electrical activity of units that each comprises only a single muscle particular muscle fiber types has been established fiber type and occupies characteristic positions Ž.Paul and Gronenberg, submitted . In conclusion, within the head capsuleŽ. Fig. 2 . While the rela- the mandible closer muscle of ants is composed tive and absolute size of each muscle fiber group of two different sets of fibers: slow but forceful differs across species and in some cases between muscle fibersŽ. sarcomere length 5᎐6 ␮m and individuals of different body size, the relative probably less forceful but fast onesŽ sarcomere position of the different muscle fiber bundles is length 2᎐3 ␮m.. very similar in different speciesŽ. Fig. 2 . These In arthropods, muscle fibers attach to the ex- typical positions of the muscle fiber types possess oskeletonŽ. e.g. the thorax or head capsule di- functional significanceŽ see below; Paul and Gro- rectly via a deeply serrated area of adhesion nenberg, 1999. between the muscle fiber and the cuticleŽ Neville, In contrast to the mandible closer of ants, 1975a,b.
Load more

Recommended publications
  • What Can the Bacterial Community of Atta Sexdens (Linnaeus, 1758) Tell Us About the Habitats in Which This Ant Species Evolves?
    insects Article What Can the Bacterial Community of Atta sexdens (Linnaeus, 1758) Tell Us about the Habitats in Which This Ant Species Evolves? Manuela de Oliveira Ramalho 1,2,*, Cintia Martins 3, Maria Santina Castro Morini 4 and Odair Correa Bueno 1 1 Centro de Estudos de Insetos Sociais—CEIS, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro 13506-900, SP, Brazil; [email protected] 2 Department of Entomology, Cornell University, 129 Garden Ave, Ithaca, NY 14850, USA 3 Campus Ministro Reis Velloso, Universidade Federal do Piauí, Av. São Sebastião, 2819, Parnaíba, Piauí 64202-020, Brazil; [email protected] 4 Núcleo de Ciências Ambientais, Universidade de Mogi das Cruzes, Av. Dr. Cândido Xavier de Almeida e Souza, 200, Centro Cívico, Mogi das Cruzes 08780-911, SP, Brazil; [email protected] * Correspondence: [email protected] Received: 5 March 2020; Accepted: 22 May 2020; Published: 28 May 2020 Abstract: Studies of bacterial communities can reveal the evolutionary significance of symbiotic interactions between hosts and their associated bacteria, as well as identify environmental factors that may influence host biology. Atta sexdens is an ant species native to Brazil that can act as an agricultural pest due to its intense behavior of cutting plants. Despite being extensively studied, certain aspects of the general biology of this species remain unclear, such as the evolutionary implications of the symbiotic relationships it forms with bacteria. Using high-throughput amplicon sequencing of 16S rRNA genes, we compared for the first time the bacterial community of A.
    [Show full text]
  • Hymenoptera: Formicidae) in Brazilian Forest Plantations
    Forests 2014, 5, 439-454; doi:10.3390/f5030439 OPEN ACCESS forests ISSN 1999-4907 www.mdpi.com/journal/forests Review An Overview of Integrated Management of Leaf-Cutting Ants (Hymenoptera: Formicidae) in Brazilian Forest Plantations Ronald Zanetti 1, José Cola Zanuncio 2,*, Juliana Cristina Santos 1, Willian Lucas Paiva da Silva 1, Genésio Tamara Ribeiro 3 and Pedro Guilherme Lemes 2 1 Laboratório de Entomologia Florestal, Universidade Federal de Lavras, 37200-000, Lavras, Minas Gerais, Brazil; E-Mails: [email protected] (R.Z.); [email protected] (J.C.S.); [email protected] (W.L.P.S.) 2 Departamento de Entomologia, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil; E-Mail: [email protected] 3 Departamento de Ciências Florestais, Universidade Federal de Sergipe, 49100-000, São Cristóvão, Sergipe State, Brazil; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +55-31-389-925-34; Fax: +55-31-389-929-24. Received: 18 December 2013; in revised form: 19 February 2014 / Accepted: 19 February 2014 / Published: 20 March 2014 Abstract: Brazilian forest producers have developed integrated management programs to increase the effectiveness of the control of leaf-cutting ants of the genera Atta and Acromyrmex. These measures reduced the costs and quantity of insecticides used in the plantations. Such integrated management programs are based on monitoring the ant nests, as well as the need and timing of the control methods. Chemical control employing baits is the most commonly used method, however, biological, mechanical and cultural control methods, besides plant resistance, can reduce the quantity of chemicals applied in the plantations.
    [Show full text]
  • Ant–Fungus Species Combinations Engineer Physiological Activity Of
    © 2014. Published by The Company of Biologists Ltd | The Journal of Experimental Biology (2014) 217, 2540-2547 doi:10.1242/jeb.098483 RESEARCH ARTICLE Ant–fungus species combinations engineer physiological activity of fungus gardens J. N. Seal1,2,*, M. Schiøtt3 and U. G. Mueller2 ABSTRACT such complexity, the fungus-gardening insects have evolved obligate Fungus-gardening insects are among the most complex organisms macro-symbioses with specific clades of fungi, and use fungal because of their extensive co-evolutionary histories with obligate symbionts essentially as an external digestive organ that allows the fungal symbionts and other microbes. Some fungus-gardening insect insect to thrive on otherwise non-digestible substrates, such as lineages share fungal symbionts with other members of their lineage structural carbohydrates of plants (e.g. cellulose) (Aanen et al., and thus exhibit diffuse co-evolutionary relationships, while others 2002; Aylward et al., 2012a; Aylward et al., 2012b; Bacci et al., exhibit little or no symbiont sharing, resulting in host–fungus fidelity. 1995; Farrell et al., 2001; De Fine Licht and Biedermann, 2012; The mechanisms that maintain this symbiont fidelity are currently Martin, 1987a; Mueller et al., 2005). One of the most striking unknown. Prior work suggested that derived leaf-cutting ants in the attributes of these symbioses is the degree of physiological genus Atta interact synergistically with leaf-cutter fungi (Attamyces) integration: the insect host functions as a distributor of fungal by exhibiting higher fungal growth rates and enzymatic activities than enzymes, which digest plant fibers external to the insect’s body when growing a fungus from the sister-clade to Attamyces (so-called (Aanen and Eggleton, 2005; Aylward et al., 2012b; De Fine Licht ‘Trachymyces’), grown primarily by the non-leaf cutting and Biedermann, 2012; De Fine Licht et al., 2013; Martin, 1987b; Trachymyrmex ants that form, correspondingly, the sister-clade to Schiøtt et al., 2010).
    [Show full text]
  • Ant Muscle Fibre Attachment
    The Journal of Experimental Biology 202, 797–808 (1999) 797 Printed in Great Britain © The Company of Biologists Limited 1999 JEB1762 OPTIMIZING FORCE AND VELOCITY: MANDIBLE MUSCLE FIBRE ATTACHMENTS IN ANTS JÜRGEN PAUL* AND WULFILA GRONENBERG Theodor Boveri Institut der Universität, Lehrstuhl für Verhaltensphysiologie und Soziobiologie, Am Hubland, D-97074 Würzburg, Germany *e-mail: [email protected] Accepted 14 January; published on WWW 3 March 1999 Summary To be able to perform swift and powerful movements, attached fibres and they maximize speed of action at the ant mandible closer muscles are composed of two expense of force output. (2) Ants performing particularly subpopulations of muscle fibres: fast fibres for rapid forceful mandible movements, such as seed cracking, rely actions and slow fibres for forceful biting. All these fibres on many short parallel muscle fibres contained within a attach to a sturdy and complex apodeme which conveys broad head capsule. Their slower muscles incorporate a force into the mandible base. Fast muscle fibres attach large proportion of filament-attached fibres. Two simple directly to the apodeme. Slow fibres may attach directly or models explain how the attachment angles are optimized insert at individual thin filament processes of the apodeme with respect to force and velocity output and how filament- which vary in length. Comparisons of different ant species attached fibres help to generate the largest power output suggest two basic principles underlying the design of from the available head capsule volume. mandible muscles. (1) Ants specialized for fast mandible movements generally feature long heads which contain long fast muscle fibres that attach to the apodeme at small Key words: biomechanics, insect, apodeme, ant, feeding, muscle angles.
    [Show full text]
  • Microbial Communities in Different Tissues of Atta Sexdens Rubropilosa Leaf-Cutting Ants
    Curr Microbiol (2017) 74:1216–1225 DOI 10.1007/s00284-017-1307-x Microbial Communities in Different Tissues of Atta sexdens rubropilosa Leaf-cutting Ants 1 1 2 1 Alexsandro S. Vieira • Manuela O. Ramalho • Cintia Martins • Vanderlei G. Martins • Odair C. Bueno1 Received: 6 February 2017 / Accepted: 11 July 2017 / Published online: 18 July 2017 Ó Springer Science+Business Media, LLC 2017 Abstract Bacterial endosymbionts are common in all were Burkholderiales, Clostridiales, Syntrophobacterales, insects, and symbiosis has played an integral role in ant Lactobacillales, Bacillales, and Actinomycetales (midgut) evolution. Atta sexdens rubropilosa leaf-cutting ants cul- and Entomoplasmatales, unclassified c-proteobacteria, and tivate their symbiotic fungus using fresh leaves. They need Actinomycetales (postpharyngeal glands). The high abun- to defend themselves and their brood against diseases, but dance of Entomoplasmatales in the postpharyngeal glands they also need to defend their obligate fungus gardens, (77%) of the queens was an unprecedented finding. We their primary food source, from infection, parasitism, and discuss the role of microbial communities in different tis- usurpation by competitors. This study aimed to character- sues and castes. Bacteria are likely to play a role in ize the microbial communities in whole workers and dif- nutrition and immune defense as well as helping antimi- ferent tissues of A. sexdens rubropilosa queens using Ion crobial defense in this ant species. Torrent NGS. Our results showed that the microbial com- munity in the midgut differs in abundance and diversity Keywords Attini Á Endosymbiont Á Entomoplasmatales Á from the communities in the postpharyngeal gland of the Next-generation sequencing queen and in whole workers.
    [Show full text]
  • Paleodistributions and Comparative Molecular Phylogeography of Leafcutter Ants (Atta Spp.) Provide New Insight Into the Origins of Amazonian Diversity
    Paleodistributions and Comparative Molecular Phylogeography of Leafcutter Ants (Atta spp.) Provide New Insight into the Origins of Amazonian Diversity Scott E. Solomon1,2,3*, Mauricio Bacci, Jr.3, Joaquim Martins, Jr.3, Giovanna Gonc¸alves Vinha3, Ulrich G. Mueller1 1 Section of Integrative Biology, The University of Texas at Austin, Austin, Texas, United States of America, 2 Department of Entomology, Smithsonian Institution, Washington, D. C., United States of America, 3 Center for the Study of Social Insects, Sa˜o Paulo State University, Rio Claro, Sa˜o Paulo, Brazil Abstract The evolutionary basis for high species diversity in tropical regions of the world remains unresolved. Much research has focused on the biogeography of speciation in the Amazon Basin, which harbors the greatest diversity of terrestrial life. The leading hypotheses on allopatric diversification of Amazonian taxa are the Pleistocene refugia, marine incursion, and riverine barrier hypotheses. Recent advances in the fields of phylogeography and species-distribution modeling permit a modern re-evaluation of these hypotheses. Our approach combines comparative, molecular phylogeographic analyses using mitochondrial DNA sequence data with paleodistribution modeling of species ranges at the last glacial maximum (LGM) to test these hypotheses for three co-distributed species of leafcutter ants (Atta spp.). The cumulative results of all tests reject every prediction of the riverine barrier hypothesis, but are unable to reject several predictions of the Pleistocene refugia and marine incursion hypotheses. Coalescent dating analyses suggest that population structure formed recently (Pleistocene-Pliocene), but are unable to reject the possibility that Miocene events may be responsible for structuring populations in two of the three species examined.
    [Show full text]
  • DISTRIBUTION and FORAGING by the LEAF-CUTTING ANT, Atta
    DISTRIBUTION AND FORAGING BY THE LEAF-CUTTING ANT, Atta cephalotes L., IN COFFEE PLANTATIONS WITH DIFFERENT TYPES OF MANAGEMENT AND LANDSCAPE CONTEXTS, AND ALTERNATIVES TO INSECTICIDES FOR ITS CONTROL A Dissertation Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy with a Major in Entomology in the College of Graduate Studies University of Idaho and with an Emphasis in Tropical Agriculture In the Graduate School Centro Agronómico Tropical de Investigación y Enseñanza by Edgar Herney Varón Devia June 2006 Major Professor: Sanford D. Eigenbrode, Ph.D. iii ABSTRACT Atta cephalotes L., the predominant leaf-cutting ant species found in coffee farms in the Turrialba region of Costa Rica, is considered a pest of the crop because it removes coffee foliage. I applied agroecosystem and landscape level perspectives to study A. cephalotes foraging, colony distribution and dynamics in coffee agroecosystems in the Turrialba region. I also conducted field assays to assess effects of control methods on colonies of different sizes and to examine the efficacy of alternatives to insecticides. Colony density (number of colonies/ha) and foraging of A. cephalotes were studied in different coffee agroecosystems, ranging from monoculture to highly diversified systems, and with either conventional or organic inputs. A. cephalotes colony density was higher in monocultures compared to more diversified coffee systems. The percentage of shade within the farm was directly related to A. cephalotes colony density. The proportion of coffee plant tissue being collected by A. cephalotes was highest in monocultures and lowest in farms with complex shade (more than three shade tree species present).
    [Show full text]
  • Impact of the Texas Leaf-Cutting Ant (Atta Texana (Buckley) (Order Hymenoptera, Family Formicidae) on a Forested Landscape
    Stephen F. Austin State University SFA ScholarWorks Faculty Publications Forestry 2001 Impact of the Texas Leaf-Cutting Ant (Atta texana (Buckley) (Order Hymenoptera, Family Formicidae) on a Forested Landscape David Kulhavy Arthur Temple College of Forestry and Agriculture, Stephen F. Austin State University, [email protected] L. A. Smith Arthur Temple College of Forestry and Agriculture, Stephen F. Austin State University W. G. Ross Department of Forestry, Oklahoma State University, Stillwater, Oklahoma Follow this and additional works at: https://scholarworks.sfasu.edu/forestry Part of the Forest Sciences Commons Tell us how this article helped you. Repository Citation Kulhavy, David; Smith, L. A.; and Ross, W. G., "Impact of the Texas Leaf-Cutting Ant (Atta texana (Buckley) (Order Hymenoptera, Family Formicidae) on a Forested Landscape" (2001). Faculty Publications. 416. https://scholarworks.sfasu.edu/forestry/416 This Conference Proceeding is brought to you for free and open access by the Forestry at SFA ScholarWorks. It has been accepted for inclusion in Faculty Publications by an authorized administrator of SFA ScholarWorks. For more information, please contact [email protected]. Impact of the Texas Leaf-Cutting Ant (Atta texana (Buckley)) (Order Hymenoptera, Family Formicidae) on a Forested Landscape D.L. KULHAVY1, L.A. SMITH1 AND W.G. ROSS2 1Arthur Temple College of Forestry, Stephen F. Austin State University, Nacogdoches, Texas 75962 USA 2 Department of Forestry, Oklahoma State University, Stillwater, Oklahoma USA ABSTRACT Atta texana (Buckley), the Texas leaf-cutting ant, rapidly expanded in a harvested forested landscape on sandhills characterized by droughty soils, causing mortality of planted loblolly pine (Pinus taeda (L.)).
    [Show full text]
  • Foraging Ecology of the Desert Leaf-Cutting Ant, Acromyrmex Versicolor, in Arizona (Hymenoptera: Formicidae)
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/256979550 Foraging ecology of the desert leaf-cutting ant, Acromyrmex versicolor, in Arizona (Hymenoptera: Formicidae) Article in Sociobiology · January 2001 CITATIONS READS 13 590 3 authors, including: James K. Wetterer Florida Atlantic University 184 PUBLICATIONS 3,058 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Ant stuff View project Systematics and Evolution of the Tapinoma ants (Formicidae: Dolichoderinae) from the Neotropical region View project All content following this page was uploaded by James K. Wetterer on 17 May 2014. The user has requested enhancement of the downloaded file. 1 Foraging Ecology of the Desert Leaf-Cutting Ant, Acromyrmex versicolor, in Arizona (Hymenoptera: Formicidae) by James K. Wetterer1,2, Anna G. Himler1, & Matt M. Yospin1 ABSTRACT The desert would seem to be an inhospitable place for leaf-cutting ants (Acromyrmex spp. and Atta spp.), both because the leaves of desert perennials are notably well-defended, both chemically and physically, and because leaf-cutters grow a fungus that requires constant high humidity. We investigated strategies that leaf-cutters use to survive in arid environments by examining foraging activity, resource use, forager size, load size, and nesting ecology of the desert leaf-cutting ant, Acromyrmex versicolor, at 12 colonies from 6 sites in Arizona during June, August, and November 1997, and March 1998. The ants showed striking seasonal changes in materials harvested, apparently in response to changes in the availability of preferred resources. Acromyrmex versicolor foragers (n = 800) most commonly collected dry vegetation (54.3% of all loads), but also harvested ephem- eral resources, such as dry flowers (18.6%), fresh young leaves (18.5%), fruits and seeds (4.0%), and fresh flowers (3.5%), when seasonally available.
    [Show full text]
  • Fungus Garden Structure in the Leaf-Cutting Ant Atta Sexdens (Formicidae, Attini)
    Symbiosis, 21 (1996) 9-24 9 Balaban, Philadelphia/Rehovot Fungus Garden Structure in the Leaf-Cutting Ant Atta sexdens (Formicidae, Attini) M. BASS1* and J.M. CHERRETT2 lTrinity College, Carmarthen, Wales SA31 3EP, UK, Fax. +44-1267-230933; and 2School of Biological Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, UK Received February 14, 1996; Accepted April 14, 1996 Abstract Leaf-cutting ants have a mutualistic relationship with a fungus, which they cultivate on fresh plant material. For optimum efficiency, this 'fungus garden' must have a structure that combines a large area for the production of ant rewards ('staphylae'), with the smallest chamber volume in which it can be maintained, and with accessibility for workers. We investigated the structure of a fungus garden of Atta sexdens (L.) by sectioning. It contained many small cavities, most of which (74.7%) were only accessible to small 'minima' workers, excluding larger sizes. These cavities provided a large internal surface area, 74% of the total surface area of the garden examined. Internal surfaces had more staphylae per unit surface area than external surfaces, suggesting a heavy harvesting pressure from large workers on the latter. The problem of producing a garden structure capable of yielding large crops of staphylae may have been important in the evolution of the characteristically small minima workers, which have access to the smallest cavities. We also examined staphyla production in fungus gardens. Numbers of staphylae present increased with garden age, but few were lost with discarded substrate. This suggests that workers remove all staphylae before removing substrate, or that the oldest garden produces few staphylae anyway.
    [Show full text]
  • Directional Vibration Sensing in the Leafcutter Ant Atta Sexdens Felix A
    © 2017. Published by The Company of Biologists Ltd | Biology Open (2017) 6, 1949-1952 doi:10.1242/bio.029587 RESEARCH ARTICLE Directional vibration sensing in the leafcutter ant Atta sexdens Felix A. Hager1,2,*, Lea Kirchner1 and Wolfgang H. Kirchner1 ABSTRACT Ants should be confronted with a comparable selection pressure Leafcutter ants communicate with the substrate-borne component of on the extraction of directional information out of the vibrational the vibratory emission produced by stridulation. Stridulatory signals in signal. In this context, leafcutter ants of the genus Atta are the genus Atta have been described in different behavioural contexts, particularly interesting to study. The leafcutter ants can be reared in such as foraging, alarm signalling and collective nest building. the laboratory and forage in the open. Workers can easily be Stridulatory vibrations are employed to recruit nestmates, which can motivated to enter certain experimental set-ups, simply by offering localize the source of vibration, but there is little information about the forage. Atta sexdens is relatively well studied in terms of both underlying mechanisms. Our experiments reveal that time-of-arrival vibrational and chemical communication. For these and the delays of the vibrational signals are used for tropotactic orientation in following reasons, Atta sexdens is particularly suitable as a model Atta sexdens. The detected time delays are in the same range as the system to investigate directional vibration sensing as well as its time delays detected by termites. Chemical communication is also of interplay with chemical communication signals. Like many other great importance in foraging organization, and signals of different ant species, A.
    [Show full text]
  • Foundress Queen Mortality and Early Colony Growth of the Leafcutter Ant, Atta Texana (Formicidae, Hymenoptera)
    Insect. Soc. (2015) 62:357–363 DOI 10.1007/s00040-015-0413-7 Insectes Sociaux RESEARCH ARTICLE Foundress queen mortality and early colony growth of the leafcutter ant, Atta texana (Formicidae, Hymenoptera) 1 1 2 1 H. E. Marti • A. L. Carlson • B. V. Brown • U. G. Mueller Received: 26 September 2014 / Revised: 17 April 2015 / Accepted: 21 April 2015 / Published online: 8 May 2015 Ó International Union for the Study of Social Insects (IUSSI) 2015 Abstract Nest-founding queens of social insects typically Keywords Incipient colony Á Disease Á Parasite Á experience high mortality rates. Mortality is particularly Fusarium oxysporum Á Aspergillus flavus Á severe in leafcutter ants of the fungus-growing ant genus Megaselia scalaris Atta that face the challenge of cultivating a delicate fungus garden in addition to raising brood. We quantified foundress queen survivorship of Atta texana that were collected in Introduction northwest Texas and maintained in single-queen laboratory nests, and we tracked the rate of colony growth during the The nest-founding stage is a particularly critical stage in the first precarious months of the colony lifecycle. Ninety days life history of social insects (Oster and Wilson 1978). Nest- post-mating flight, only 16.3 % of 141 of the original founding queens typically experience low survivorship, queens had survived, and colony growth rates varied which creates a selective bottleneck where a very small markedly across the surviving colonies. Worker production proportion of surviving queens contribute to the next gen- was weakly correlated with fungus garden growth over the eration (Brian 1965; Wilson 1971; Cole 2009).
    [Show full text]