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Boudinot BE, van de Kamp T, Peters P, Knöllinger K. Male genitalia, hierarchical homology, and the anatomy of the bullet ant (Paraponera clavata; Hymenoptera, Formicidae). J Morphol 2024; 285:e21757. [PMID: 39192511 DOI: 10.1002/jmor.21757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 07/19/2024] [Accepted: 07/23/2024] [Indexed: 08/29/2024]
Abstract
The male genitalia of insects are among the most variable, complex, and informative character systems for evolutionary analysis and taxonomic purposes. Because of these general properties, many generations of systematists have struggled to develop a theory of homology and alignment of parts. This struggle continues to the present day, where fundamentally different models and nomenclatures for the male genitalia of Hymenoptera, for example, are applied. Here, we take a multimodal approach to digitalize and comprehensively document the genital skeletomuscular anatomy of the bullet ant (Paraponera clavata; Hymenoptera: Formicidae), including hand dissection, synchrotron radiation microcomputed tomography, microphotography, scanning electron microscopy, confocal laser scanning microscopy, and 3D-printing. Through this work, we generate several new concepts for the structure and form of the male genitalia of Hymenoptera, such as for the endophallic sclerite (=fibula ducti), which we were able to evaluate in detail for the first time for any species. Based on this phenomic anatomical study and comparison with other Holometabola and Hexapoda, we reconsider the homologies of insect genitalia more broadly, and propose a series of clarifications in support of the penis-gonopod theory of male genital identity. Specifically, we use the male genitalia of Paraponera and insects more broadly as an empirical case for hierarchical homology by applying and refining the 5-category classification of serial homologs from DiFrisco et al. (2023) (DLW23) to all of our formalized concepts. Through this, we find that: (1) geometry is a critical attribute to account for in ontology, especially as all individually identifiable attributes are positionally indexed hence can be recognized as homomorphic; (2) the definition of "structure" proposed by DLW23 is difficult to apply, and likely heterogeneous; and (3) formative elements, or spatially defined foldings or in- or evaginations of the epidermis and cuticle, are an important yet overlooked class of homomorphs. We propose a morphogenetic model for male and female insect genitalia, and a model analogous to gene-tree species-tree mappings for the hierarchical homology of male genitalia specifically. For all of the structures evaluated in the present study, we provide 3D-printable models - with and without musculature, and in various states of digital dissection - to facilitate the development of a tactile understanding. Our treatment of the male genitalia of P. clavata serves as a basic template for future phenomic studies of male insect genitalia, which will be substantially improved with the development of automation and collections-based data processing pipelines, that is, collectomics. The Hymenoptera Anatomy Ontology will be a critical resource to include in this effort, and in best practice concepts should be linked.
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Affiliation(s)
- Brendon E Boudinot
- Department of Terrestrial Zoology, Entomology II, Senckenberg Research Institute and Natural History Museum, Frankfurt am Main, Germany
| | - Thomas van de Kamp
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Patricia Peters
- Department of Terrestrial Zoology, Entomology II, Senckenberg Research Institute and Natural History Museum, Frankfurt am Main, Germany
| | - Katja Knöllinger
- Department of Terrestrial Zoology, Entomology II, Senckenberg Research Institute and Natural History Museum, Frankfurt am Main, Germany
- Zurich University of the Arts, Zurich, Switzerland
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2
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Imirzian N, Püffel F, Roces F, Labonte D. Large deformation diffeomorphic mapping of 3D shape variation reveals two distinct mandible and head capsule morphs in Atta vollenweideri leaf-cutter worker ants. Ecol Evol 2024; 14:e11236. [PMID: 38633523 PMCID: PMC11021802 DOI: 10.1002/ece3.11236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 02/21/2024] [Accepted: 03/15/2024] [Indexed: 04/19/2024] Open
Abstract
Ants are crucial ecosystem engineers, and their ecological success is facilitated by a division of labour among sterile "workers". In some ant lineages, workers have undergone further morphological differentiation, resulting in differences in body size, shape, or both. Distinguishing between changes in size and shape is not trivial. Traditional approaches based on allometry reduce complex 3D shapes into simple linear, areal, or volume metrics; modern approaches using geometric morphometrics typically rely on landmarks, introducing observer bias and a trade-off between effort and accuracy. Here, we use a landmark-free method based on large deformation diffeomorphic metric mapping (LDDMM) to assess the co-variation of size and 3D shape in the mandibles and head capsules of Atta vollenweideri leaf-cutter ants, a species exhibiting extreme worker size-variation. Body mass varied by more than two orders of magnitude, but a shape atlas created via LDDMM on μ-CT-derived 3D mesh files revealed only two distinct head capsule and mandibles shapes-one for the minims (body mass < 1 mg) and one for all other workers. We discuss the functional significance of the identified 3D shape variation, and its implications for the evolution of extreme polymorphism in Atta.
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Affiliation(s)
| | | | - Flavio Roces
- Department of Behavioural Physiology and SociobiologyBiocenter, University of WürzburgWürzburgGermany
| | - David Labonte
- Department of BioengineeringImperial College LondonLondonUK
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3
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Richter A, Economo EP. The feeding apparatus of ants: an overview of structure and function. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220556. [PMID: 37839452 PMCID: PMC10577024 DOI: 10.1098/rstb.2022.0556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/25/2023] [Indexed: 10/17/2023] Open
Abstract
Ants are a dominant family of eusocial terrestrial insects with a diversity of ecologies, lifestyles and morphologies. Ant diet preferences range from strict carnivory through omnivory to almost complete herbivory in species feeding on seeds or exudates of plant-sucking insects. While several studies have investigated ant feeding performance on different substrates, comparatively little is known about the functional morphology of the structures involved in food uptake or their diversification across the ants. To take stock of our current knowledge, we give an overview of how adult ants ingest food, followed by a morphological description of the mouthparts, preoral space and cephalic sucking pump. The mandibles are the most prominent mouthparts and have received considerable attention in the literature, so we focus on the maxillae and labium here. We present current hypotheses for the movement patterns of these parts and discuss morphological differences among ants that may be related to their ecological diversity. Finally, we give short comparisons of the ant condition with some other insects and vertebrates, as well as an outlook summarizing gaps in our knowledge. This sets the stage for future studies elucidating the connections between ant feeding mechanisms and mouthpart evolution. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.
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Affiliation(s)
- Adrian Richter
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1, Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Evan P Economo
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1, Tancha, Onna-son, Okinawa 904-0495, Japan
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4
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Klunk CL, Argenta MA, Rosumek FB, Schmelzle S, van de Kamp T, Hammel JU, Pie MR, Heethoff M. Simulated biomechanical performance of morphologically disparate ant mandibles under bite loading. Sci Rep 2023; 13:16833. [PMID: 37803099 PMCID: PMC10558566 DOI: 10.1038/s41598-023-43944-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/30/2023] [Indexed: 10/08/2023] Open
Abstract
Insects evolved various modifications to their mouthparts, allowing for a broad exploration of feeding modes. In ants, workers perform non-reproductive tasks like excavation, food processing, and juvenile care, relying heavily on their mandibles. Given the importance of biting for ant workers and the significant mandible morphological diversity across species, it is essential to understand how mandible shape influences its mechanical responses to bite loading. We employed Finite Element Analysis to simulate biting scenarios on mandible volumetric models from 25 ant species classified in different feeding habits. We hypothesize that mandibles of predatory ants, especially trap-jaw ants, would perform better than mandibles of omnivorous species due to their necessity to subdue living prey. We defined simulations to allow only variation in mandible morphology between specimens. Our results demonstrated interspecific differences in mandible mechanical responses to biting loading. However, we found no evident differences in biting performance between the predatory and the remaining ants, and trap-jaw mandibles did not show lower stress levels than other mandibles under bite loading. These results suggest that ant feeding habit is not a robust predictor of mandible biting performance, a possible consequence of mandibles being employed as versatile tools to perform several tasks.
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Affiliation(s)
- C L Klunk
- Graduate Program in Ecology and Conservation, Universidade Federal do Paraná, Centro Politécnico, Av. Cel. Francisco H. dos Santos, 100 - Jardim das Américas, Curitiba, PR, 81531-980, Brazil.
- Animal Evolutionary Ecology, Technische Universität Darmstadt, Schnittspahnstr. 3, 64287, Darmstadt, Germany.
| | - M A Argenta
- Department of Civil Construction, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - F B Rosumek
- Department of Ecology and Zoology, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - S Schmelzle
- Animal Evolutionary Ecology, Technische Universität Darmstadt, Schnittspahnstr. 3, 64287, Darmstadt, Germany
| | - T van de Kamp
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
- Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - J U Hammel
- Institute of Materials Physics, Helmholtz-Zentrum Hereon, Geesthacht, Germany
| | - M R Pie
- Biology Department, Edge Hill University, Ormskirk, Lancashire, UK
| | - M Heethoff
- Animal Evolutionary Ecology, Technische Universität Darmstadt, Schnittspahnstr. 3, 64287, Darmstadt, Germany.
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5
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Klunk CL, Argenta MA, Casadei‐Ferreira A, Pie MR. Mechanical demands of bite in plane head shapes of ant (Hymenoptera: Formicidae) workers. Ecol Evol 2023; 13:e10162. [PMID: 37293120 PMCID: PMC10244895 DOI: 10.1002/ece3.10162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/16/2023] [Accepted: 05/24/2023] [Indexed: 06/10/2023] Open
Abstract
Food processing can exert significant evolutionary pressures on the morphological evolution of animal appendages. The ant genus Pheidole displays a remarkable degree of morphological differentiation and task specialization among its workers. Notably, there is considerable variation in head shape within worker subcastes of Pheidole, which could affect the stress patterns generated by bite-related muscle contraction. In this study, we use finite element analysis (FEA) to investigate the effect of the variation in head plane shape in stress patterns, while exploring the morphospace of Pheidole worker head shapes. We hypothesize that the plane head shapes of majors are optimized for dealing with stronger bites. Furthermore, we expect that plane head shapes at the edges of each morphospace would exhibit mechanical limitations that prevent further expansion of the occupied morphospace. We vectorized five head shapes for each Pheidole worker type located at the center and edges of the corresponding morphospaces. We conducted linear static FEA to analyze the stresses generated by mandibular closing muscle contraction. Our findings indicate that plane head shapes of majors exhibit signs of optimization to deal with stronger bites. Stresses are distinctly directed along the lateral margins of the head, following the direction of muscle contraction, whereas the stresses on the plane head shapes of minors tend to concentrate around the mandibular articulations. However, the comparatively higher stress levels observed on majors' plane head shapes suggest a demand for cuticular reinforcement, like increased cuticle thickness or sculpturing pattern. Our results align with the expectations regarding the main colony tasks performed by each worker subcaste, and we find evidence of biomechanical limitations on extreme plane head shapes for majors and minors.
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Affiliation(s)
- Cristian L. Klunk
- Graduate Program in Ecology and ConservationUniversidade Federal do ParanáCuritibaBrazil
| | - Marco A. Argenta
- Department of Civil ConstructionUniversidade Federal do ParanáCuritibaBrazil
| | - Alexandre Casadei‐Ferreira
- Biodiversity and Biocomplexity UnitOkinawa Institute of Science and Technology Graduate UniversityOnnaJapan
| | - Marcio R. Pie
- Department of BiologyEdge Hill UniversityOrmskirkUK
- Department of ZoologyUniversidade Federal do ParanáCuritibaBrazil
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6
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Püffel F, Johnston R, Labonte D. A biomechanical model for the relation between bite force and mandibular opening angle in arthropods. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221066. [PMID: 36816849 PMCID: PMC9929505 DOI: 10.1098/rsos.221066] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
Bite forces play a key role in animal ecology: they affect mating behaviour, fighting success, and the ability to feed. Although feeding habits of arthropods have a significant ecological and economical impact, we lack fundamental knowledge on how the morphology and physiology of their bite apparatus controls bite performance, and its variation with mandible gape. To address this gap, we derived a biomechanical model that characterizes the relationship between bite force and mandibular opening angle from first principles. We validate this model by comparing its geometric predictions with morphological measurements on the muscoloskeletal bite apparatus of Atta cephalotes leaf-cutter ants, using computed tomography (CT) scans obtained at different mandible opening angles. We then demonstrate its deductive and inductive utility with three examplary use cases: Firstly, we extract the physiological properties of the leaf-cutter ant mandible closer muscle from in vivo bite force measurements. Secondly, we show that leaf-cutter ants are specialized to generate extraordinarily large bite forces, equivalent to about 2600 times their body weight. Thirdly, we discuss the relative importance of morphology and physiology in determining the magnitude and variation of bite force. We hope that a more detailed quantitative understanding of the link between morphology, physiology, and bite performance will facilitate future comparative studies on the insect bite apparatus, and help to advance our knowledge of the behaviour, ecology and evolution of arthropods.
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Affiliation(s)
- Frederik Püffel
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Richard Johnston
- School of Engineering, Materials Research Centre, Swansea University, Swansea SA2 8PP, UK
| | - David Labonte
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
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7
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Cantone S, Di Giulio A. A new Neotropical ant species of genus Linepithema Mayr (Hymenoptera, Formicidae, Dolichoderinae) with partial revision of the L.fuscum group based on males. Zookeys 2023; 1160:125-144. [PMID: 37206885 PMCID: PMC10189538 DOI: 10.3897/zookeys.1160.95694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 03/30/2023] [Indexed: 05/21/2023] Open
Abstract
The genus Linepithema was erected by Mayr (1866) for his male-based species L.fuscum. In this study a new species is described also based on male morphology, L.paulistanasp. nov., collected in the city of São Paulo, Brazil, which is attributed to the fuscum group (Formicidae: Dolichoderinae). Linepithemapaulistanasp. nov. is the only species of fuscum group present in the eastern part of South America. It is easily distinguishable from the other species of the group because of the presence of a triangular volsellar tooth, which is distally situated between the digitus and the basivolsellar process. By using SEM and optical microscopy, the external genitalia of L.paulistanasp. nov. were analyzed and illustrated and some characters and previous interpretations have been re-evaluated in the Linepithemafuscum group. The male external genitalia are also comparatively analyzed in three species representative of the three Linepithema species groups, those of fuscum, humile, and neotropicum. The present work confirms that the morphological characters of male ants, especially those of male external genitalia, are effective for the identification of genera or species. Given the discrete morphological differences between the external genitalia of the fuscum group and the other species of this genus, a re-evaluation of the generic status of Linepithema is suggested.
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Affiliation(s)
- Stefano Cantone
- Department of Science, University ‘Roma Tre’, Viale G. Marconi, 446, 00146 Rome, ItalyUniversity ‘Roma Tre’RomaItaly
- NBFC, National Biodiversity Future Center, Palermo 90133, ItalyNBFC, National Biodiversity Future CenterPalermoItaly
| | - Andrea Di Giulio
- Department of Science, University ‘Roma Tre’, Viale G. Marconi, 446, 00146 Rome, ItalyUniversity ‘Roma Tre’RomaItaly
- NBFC, National Biodiversity Future Center, Palermo 90133, ItalyNBFC, National Biodiversity Future CenterPalermoItaly
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8
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Zhuang Y, Xu W, Zhang G, Mai H, Li X, He H, Ran H, Liu Y. Unparalleled details of soft tissues in a Cretaceous ant. BMC Ecol Evol 2022; 22:146. [PMID: 36526958 PMCID: PMC9756460 DOI: 10.1186/s12862-022-02099-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
For social insects such as ants, the internal organs are likely important in understanding their eusocial behavior and evolution. Such organs, however, are rarely preserved on fossils. In each of the few cases reporting exceptionally fossilized soft tissues in arthropods, the nervous, muscular and cardiovascular systems have been described individually, but never in combination. Here, we report a female specimen (gyne) of the extinct ant group-†Zigrasimecia-included in a Cretaceous amber piece from Kachin, Myanmar, with an almost complete system formed by various internal organs. These include the brain, the main exocrine system, part of the digestive tract, and several muscle clusters. This research expands our knowledge of internal anatomy in stem group ants. As the gyne bears a morphologically unique labrum, our specimen's internal and external features support the notion that the early ant may have special ecological habits during the Cretaceous period.
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Affiliation(s)
- Yuhui Zhuang
- Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, South Waihuan Road, Chenggong District, Kunming, 650500, China
- MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, 650500, China
| | - Wenjing Xu
- Key Laboratory of National Forestry and Grassland Administration On Management of Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Guojie Zhang
- Evolutionary & Organismal Biology Research Center, Zhejiang University School of Medicine, Hangzhou, 310058, China
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
- Villum Center for Biodiversity Genomics, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Huijuan Mai
- Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, South Waihuan Road, Chenggong District, Kunming, 650500, China
- MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, 650500, China
| | - Xiaoqin Li
- Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, South Waihuan Road, Chenggong District, Kunming, 650500, China
- MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, 650500, China
| | - Hong He
- Key Laboratory of National Forestry and Grassland Administration On Management of Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Hao Ran
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China.
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, Guilin, 541004, China.
- Biological Education and Research Laboratory, Mancheng High School of Hebei Province, Baoding, 072150, China.
| | - Yu Liu
- Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, South Waihuan Road, Chenggong District, Kunming, 650500, China.
- MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, 650500, China.
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9
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Xu W, Zhang G, Zhang L, Wang X, Billen J, He H. Morphology and ultrastructure of the prepharyngeal and pharyngeal glands in the ant Camponotus japonicus. ARTHROPOD STRUCTURE & DEVELOPMENT 2022; 71:101212. [PMID: 36270167 DOI: 10.1016/j.asd.2022.101212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
The prepharyngeal gland (prePG) and pharyngeal gland (PG) make up the largest exocrine structures in the head of the ant Camponotus japonicus. We used microscopy to study the histological and ultrastructural features of both glands in different castes. The number of secretory units in the prePG is considerably higher than in other ant species and shows a complex duct system which is made up by duct cells, secondary ducts and a main duct. These lead the secretions of hundreds to thousands of secretory cells into the prepharynx through a modified sieve plate at each side. The glove-shaped PG shows clear caste differences in tubule number. The ultrastructure of both the prePG and PG shows abundant mitochondria and secretion vesicles. Moreover, the prePG is loaded with rough endoplasmic reticulum (RER) which means its main secretions are proteinaceous compounds, while the PG is dominated by smooth endoplasmic reticulum (SER) which means the main secretions are lipids. The morphological differences like cell number of the prePG and tubule number of the PG indicate different secretory abilities of each caste. We for the first time introduce histology-based relative size to indicate secretory activity. The proportionally high development of the prePG in minor workers supports a role in trophallaxis.
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Affiliation(s)
- Wenjing Xu
- Key Laboratory of National Forestry and Grassland Administration on Management of Forest Bio-Disaster, College of Forestry, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Guoyun Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Liangliang Zhang
- Key Laboratory of National Forestry and Grassland Administration on Management of Forest Bio-Disaster, College of Forestry, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Xiaolei Wang
- Key Laboratory of National Forestry and Grassland Administration on Management of Forest Bio-Disaster, College of Forestry, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Johan Billen
- Zoological Institute, KU Leuven, Naamsestraat 59, Box 2466, 3000, Leuven, Belgium.
| | - Hong He
- Key Laboratory of National Forestry and Grassland Administration on Management of Forest Bio-Disaster, College of Forestry, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China.
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10
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Wong MKL, Lee RH, Leong CM, Lewis OT, Guénard B. Trait-mediated competition drives an ant invasion and alters functional diversity. Proc Biol Sci 2022; 289:20220504. [PMID: 35765840 PMCID: PMC9240689 DOI: 10.1098/rspb.2022.0504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 06/01/2022] [Indexed: 11/12/2022] Open
Abstract
The assumption that differences in species' traits reflect their different niches has long influenced how ecologists infer processes from assemblage patterns. For instance, many assess the importance of environmental filtering versus classical limiting-similarity competition in driving biological invasions by examining whether invaders' traits are similar or dissimilar to those of residents, respectively. However, mounting evidence suggests that hierarchical differences between species' trait values can distinguish their competitive abilities (e.g. for the same resource) instead of their niches. Whether such trait-mediated hierarchical competition explains invasions and structures assemblages is less explored. We integrate morphological, dietary, physiological and behavioural trait analyses to test whether environmental filtering, limiting-similarity competition or hierarchical competition explain invasions by fire ants on ant assemblages. We detect both competition mechanisms; invasion success is not only explained by limiting similarity in body size and thermal tolerance (presumably allowing the invader to exploit different niches from residents), but also by the invader's superior position in trait hierarchies reflecting competition for common trophic resources. We find that the two mechanisms generate complex assemblage-level functional diversity patterns-overdispersion in some traits, clustering in others-suggesting their effects are likely missed by analyses restricted to a few traits and composite trait diversity measures.
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Affiliation(s)
- Mark K. L. Wong
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
- School of Biological Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Roger H. Lee
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pok Fu Lam Road, Hong Kong SAR, People's Republic of China
| | - Chi-Man Leong
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pok Fu Lam Road, Hong Kong SAR, People's Republic of China
| | - Owen T. Lewis
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - Benoit Guénard
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pok Fu Lam Road, Hong Kong SAR, People's Republic of China
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11
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Lieberman ZE, Billen J, Kamp T, Boudinot BE. The ant abdomen: the skeletomuscular and soft tissue anatomy of
Amblyopone australis
workers (Hymenoptera: Formicidae). J Morphol 2022; 283:693-770. [DOI: 10.1002/jmor.21471] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/28/2022] [Accepted: 03/09/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Ziv Ellis Lieberman
- Department of Entomology and Nematology University of California Davis, One Shields Ave, Davis, CA, U. S. A. 95616
| | - Johan Billen
- Zoological Institute, University of Leuven, Naamsestraat 59, Box 2466, B‐3000 Leuven Belgium
| | - Thomas Kamp
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Hermann‐von‐Helmholtz‐Platz 1, 76344 Eggenstein‐Leopoldshafen Germany
- Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Kaiserstraße 12 Karlsruhe Germany
| | - Brendon Elias Boudinot
- Friedrich‐Schiller‐Universität Jena, Institut für Spezielle Zoologie und Evolutionsforschung, Entomologie Gruppe, Erbertstraße 1 07743 Jena Germany
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12
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Boudinot BE, Richter A, Katzke J, Chaul JCM, Keller RA, Economo EP, Beutel RG, Yamamoto S. Evidence for the evolution of eusociality in stem ants and a systematic revision of †Gerontoformica (Hymenoptera: Formicidae). Zool J Linn Soc 2022. [DOI: 10.1093/zoolinnean/zlab097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
It is generally assumed that Cretaceous stem ants were obligately eusocial, because of the presence of wingless adult females, yet the available evidence is ambiguous. Here, we report the syninclusion of a pupa and adult of a stem ant species from Mid-Cretaceous amber. As brood are immobile, the pupa was likely to have been transported by an adult. Therefore, the fossil substantiates the hypothesis that wingless females were cooperators, thus these were true ‘workers’. Re-examination of all described Cretaceous ant species reveals that winged–wingless diphenism – hence a variable dispersal capacity – may have been ancestral to the total clade of the ants, and that highly specialized worker-specific phenotypes evolved in parallel between the stem and crown groups. The soft-tissue preservation of the fossil is exceptional, demonstrating the possibility of analysing the development of the internal anatomy in stem ants. Based on the highest-resolution µ-CT scans of stem ants to date, we describe †Gerontoformica sternorhabda sp. nov., redescribe †G. gracilis, redefine the species group classification of †Gerontoformica, and provide a key to the species of the genus. Our work clarifies the species boundaries of †Gerontoformica and renders fossils relevant to the discussion of eusocial evolution in a way that has heretofore been intractable.
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Affiliation(s)
- Brendon E Boudinot
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Erberstraße 1, 07743 Jena, Germany
| | - Adrian Richter
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Erberstraße 1, 07743 Jena, Germany
| | - Julian Katzke
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Júlio C M Chaul
- Pós-Graduação em Ecologia, Departamento de Biologia Geral, Universidade Federal do Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil
| | - Roberto A Keller
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
- Museu Nacional de História Natural e da Ciência & cE3c, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal
| | - Evan P Economo
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Rolf Georg Beutel
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Erberstraße 1, 07743 Jena, Germany
| | - Shûhei Yamamoto
- Hokkaido University Museum, Hokkaido University, Kita 8, Nishi 5, Kita-ku, Sapporo 060-0808, Japan
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13
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Katzke J, Puchenkov P, Stark H, Economo EP. A Roadmap to Reconstructing Muscle Architecture from CT Data. INTEGRATIVE ORGANISMAL BIOLOGY (OXFORD, ENGLAND) 2022; 4:obac001. [PMID: 35211665 PMCID: PMC8857456 DOI: 10.1093/iob/obac001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Indexed: 02/02/2023]
Abstract
Skeletal muscle is responsible for voluntary force generation across animals, and muscle architecture largely determines the parameters of mechanical output. The ability to analyze muscle performance through muscle architecture is thus a key step towards better understanding the ecology and evolution of movements and morphologies. In pennate skeletal muscle, volume, fiber lengths, and attachment angles to force transmitting structures comprise the most relevant parameters of muscle architecture. Measuring these features through tomographic techniques offers an alternative to tedious and destructive dissections, particularly as the availability of tomographic data is rapidly increasing. However, there is a need for streamlined computational methods to access this information efficiently. Here, we establish and compare workflows using partially automated image analysis for fast and accurate estimation of animal muscle architecture. After isolating a target muscle through segmentation, we evaluate freely available and proprietary fiber tracing algorithms to reconstruct muscle fibers. We then present a script using the Blender Python API to estimate attachment angles, fiber lengths, muscle volume, and physiological cross-sectional area. We apply these methods to insect and vertebrate muscle and provide guided workflows. Results from fiber tracing are consistent compared to manual measurements but much less time-consuming. Lastly, we emphasize the capabilities of the open-source three-dimensional software Blender as both a tool for visualization and a scriptable analytic tool to process digitized anatomical data. Across organisms, it is feasible to extract, analyze, and visualize muscle architecture from tomography data by exploiting the spatial features of scans and the geometric properties of muscle fibers. As digital libraries of anatomies continue to grow, the workflows and approach presented here can be part of the open-source future of digital comparative analysis.
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Affiliation(s)
| | - Pavel Puchenkov
- Scientific Computing and Data Analysis Section, Research Support Division, Okinawa Institute of Science and Technology Graduate University, Onna, 904-0495 Okinawa, Japan
| | - Heiko Stark
- Institute of Zoology and Evolutionary Research, Friedrich Schiller University Jena, Fürstengraben 1,07743 Jena, Germany
| | - Evan P Economo
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, 904-0495 Okinawa, Japan
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Zheng Z, Zhao M, Zhang Z, Hu X, Xu Y, Wei C, He H. Lactic Acid Bacteria Are Prevalent in the Infrabuccal Pockets and Crops of Ants That Prefer Aphid Honeydew. Front Microbiol 2022; 12:785016. [PMID: 35126329 PMCID: PMC8814368 DOI: 10.3389/fmicb.2021.785016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/09/2021] [Indexed: 01/04/2023] Open
Abstract
Ants are evolutionarily successful species and occupy diverse trophic and habitat niches on the earth. To fulfill dietary requirements, ants have established commensalism with both sap-feeding insects and bacteria. In this study, we used high-throughput sequencing of the bacterial 16S rRNA gene to characterize the bacterial composition and structure of the digestive tracts in three species of Formica ants and Lasius niger (Linnaeus)—species that predominantly feed on honeydew secreted by aphids. We found that bacterial communities displayed species- and colony-level signatures, and that bacterial communities in the infrabuccal pockets and crops were different from those in the midguts and hindguts. Lactobacillus and Wolbachia were dominant in the infrabuccal pockets and crops of workers, whereas Wolbachia was dominant in the midguts, hindguts and brood (larvae, pupae and cocoons). To learn more about the dominant Lactobacillus in ants, we assessed its prevalence in a wide range of aphid-tending ants using diagnostic PCR. We found that Lactobacillus was more prevalent in Formicinae than in Myrmicinae species. We also isolated four strains of lactic acid bacteria (Lactobacillus sanfranciscensis, Lactobacillus lindneri, Weissella cibaria and Fructobacillus sp.) from the infrabuccal pockets and crops of aphid-tending ants using a culture-dependent method. Two predominant lactic acid bacterial isolates, Lactobacillus sanfranciscensis (La2) and Weissella cibaria (La3), exhibited abilities in catabolizing sugars (sucrose, trehalose, melezitose and raffinose) known to be constituents of hemipteran honeydew. These findings contribute to further understanding the association between ants, aphids and bacteria, and provide additional information on the function of lactic acid bacteria in ants.
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Affiliation(s)
- Zhou Zheng
- Key Laboratory of National Forestry and Grassland Administration for Control of Forest Biological Disasters in Western China, College of Forestry, Northwest A&F University, Yangling, China
| | - Mengqin Zhao
- Key Laboratory of National Forestry and Grassland Administration for Control of Forest Biological Disasters in Western China, College of Forestry, Northwest A&F University, Yangling, China
| | - Zhijun Zhang
- Key Laboratory of National Forestry and Grassland Administration for Control of Forest Biological Disasters in Western China, College of Forestry, Northwest A&F University, Yangling, China
| | - Xin Hu
- Key Laboratory of National Forestry and Grassland Administration for Control of Forest Biological Disasters in Western China, College of Forestry, Northwest A&F University, Yangling, China
| | - Yang Xu
- Key Laboratory of National Forestry and Grassland Administration for Control of Forest Biological Disasters in Western China, College of Forestry, Northwest A&F University, Yangling, China
| | - Cong Wei
- Key Laboratory of Plant Protection Resources and Pest Management, College of Plant Protection, Northwest A&F University, Yangling, China
- *Correspondence: Cong Wei,
| | - Hong He
- Key Laboratory of National Forestry and Grassland Administration for Control of Forest Biological Disasters in Western China, College of Forestry, Northwest A&F University, Yangling, China
- Hong He,
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15
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Boudinot BE, Moosdorf OTD, Beutel RG, Richter A. Anatomy and evolution of the head of Dorylus helvolus (Formicidae: Dorylinae): Patterns of sex- and caste-limited traits in the sausagefly and the driver ant. J Morphol 2021; 282:1616-1658. [PMID: 34427942 DOI: 10.1002/jmor.21410] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 12/21/2022]
Abstract
Ants are highly polyphenic Hymenoptera, with at least three distinct adult forms in the vast majority of species. Their sexual dimorphism, however, is overlooked to the point of being a nearly forgotten phenomenon. Using a multimodal approach, we interrogate the near total head microanatomy of the male of Dorylus helvolus, the "sausagefly," and compare it with the conspecific or near-conspecific female castes, the "driver ants." We found that no specific features were shared uniquely between the workers and males to the exclusion of the queens, indicating independence of male and worker development; males and queens, however, uniquely shared several features. Certain previous generalizations about ant sexual dimorphism are confirmed, while we also discover discrete muscular presences and absences, for which reason we provide a coarse characterization of functional morphology. Based on the unexpected retention of a medial carinate line on the structurally simplified mandible of the male, we postulate a series of developmental processes to explain the patterning of ant mandibles. We invoke functional and anatomical principles to classify sensilla. Critically, we observe an inversion of the expected pattern of male-queen mandible development: male Dorylus mandibles are extremely large while queen mandibles are poorly developed. To explain this, we posit that the reproductive-limited mandible phenotype is canalized in Dorylus, thus partially decoupling the queen and worker castes. We discuss alternative hypotheses and provide further comparisons to understand mandibular evolution in army ants. Furthermore, we hypothesize that the expression of the falcate phenotype in the queen is coincidental, that is, a "spandrel," and that the form of male mandibles is also generally coincidental across the ants. We conclude that the theory of ant development and evolution is incomplete without consideration of the male system, and we call for focused study of male anatomy and morphogenesis, and of trait limitation across all castes.
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Affiliation(s)
- Brendon Elias Boudinot
- Friedrich-Schiller-Universität Jena, Institut für Spezielle Zoologie und Evolutionsforschung, Entomology Group, Erbertstraße, Jena, Germany
| | - Olivia Tikuma Diana Moosdorf
- Friedrich-Schiller-Universität Jena, Institut für Spezielle Zoologie und Evolutionsforschung, Entomology Group, Erbertstraße, Jena, Germany
| | - Rolf Georg Beutel
- Friedrich-Schiller-Universität Jena, Institut für Spezielle Zoologie und Evolutionsforschung, Entomology Group, Erbertstraße, Jena, Germany
| | - Adrian Richter
- Friedrich-Schiller-Universität Jena, Institut für Spezielle Zoologie und Evolutionsforschung, Entomology Group, Erbertstraße, Jena, Germany
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16
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Zhang W, Wu Z, Wang Z, Wang Z, Li C, Rajabi H, Wu J. Double-rowed teeth: design specialization of the H. venatorants for enhanced tribological stability. BIOINSPIRATION & BIOMIMETICS 2021; 16:055003. [PMID: 34233306 DOI: 10.1088/1748-3190/ac124a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
The antH. venatorcan engage in various labors using a pair of elongated mandibles with the ability to rotate about two orthogonal axes. This biaxial rotation enables the ant to gently handle their small, fragile eggs with enhanced contact area and smaller work space. However, how this biaxial rotation influences the ant's predation ability and how the ant responds to this influence remain elusive. We quantitatively investigate the tribological performance of the ant's mandibles during interactions with prey by taking morphology and kinematics into consideration. We find that each ant mandible features unique, double-rows of dorsal teeth (DT) and ventral teeth (VT), which are employed to firmly clamp prey over a wide range of sizes by biting their different body parts, demonstrating the ant's predation ability. We hypothesize the mechanism underlying such an ability may rely on the two, non-parallel rows of teeth which potentially eliminate effects of biaxial rotation. To test this hypothesis, we systematically change the distribution and orientation of teeth on bio-inspired robotic mandibles and investigate the mandible tribological performance of different teeth configurations. We find that the friction coefficient varies prominently between the DT and VT resulting from biaxial rotation, with the variations showing an inverse pattern. This explains the observed phenomenon that mandibles equipped with DT and VT provide the most stable friction coefficient when clamping objects of different sizes using different mandible regions. The specialized distribution of teeth facilitates enhanced tribological stability in capturing prey, and demonstrates an intrinsic link between the form, motion, and function in the insect appendages. Our research sheds lights on the current understanding of the predation behaviors of ants, and can inspire future design of multifunctional robotic grippers.
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Affiliation(s)
- Wei Zhang
- School of Aeronautics and Astronautics, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
| | - Zhigang Wu
- School of Aeronautics and Astronautics, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
| | - Zixin Wang
- School of Engineering and Technology, China University of Geosciences, Beijing, 100083, People's Republic of China
| | - Zhe Wang
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan, 250031, People's Republic of China
| | - Chuchu Li
- Functional Morphology & Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
| | - Hamed Rajabi
- Functional Morphology & Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
- Division of Mechanical Engineering and Design, School of Engineering, London South Bank University, London, United Kingdom
| | - Jianing Wu
- School of Aeronautics and Astronautics, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
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17
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Beutel RG, Friedrich F, Economo EP. Patterns of morphological simplification and innovation in the megadiverse Holometabola (Insecta). Cladistics 2021; 38:227-245. [DOI: 10.1111/cla.12483] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2021] [Indexed: 12/22/2022] Open
Affiliation(s)
- Rolf Georg Beutel
- Entomology Group Institut für Zoologie und Evolutionsforschung Friedrich‐Schiller‐Universität Jena Erbertstrasse 1 Jena D‐07743 Germany
- Biodiversity and Biocomplexity Unit Okinawa Institute of Science and Technology Graduate University 1919‐1 Tancha, Onna‐son Kunigami‐gun Okinawa 904‐0495 Japan
| | - Frank Friedrich
- Institut für Zoologie Universität Hamburg Martin‐Luther‐King‐Platz 3 Hamburg D‐20146 Germany
| | - Evan P. Economo
- Biodiversity and Biocomplexity Unit Okinawa Institute of Science and Technology Graduate University 1919‐1 Tancha, Onna‐son Kunigami‐gun Okinawa 904‐0495 Japan
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18
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Klunk CL, Argenta MA, Casadei-Ferreira A, Economo EP, Pie MR. Mandibular morphology, task specialization and bite mechanics in Pheidole ants (Hymenoptera: Formicidae). J R Soc Interface 2021; 18:20210318. [PMID: 34102082 PMCID: PMC8187013 DOI: 10.1098/rsif.2021.0318] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 05/17/2021] [Indexed: 11/12/2022] Open
Abstract
Ants show remarkable ecological and evolutionary success due to their social life history and division of labour among colony members. In some lineages, the worker force became subdivided into morphologically distinct individuals (i.e. minor versus major workers), allowing for the differential performance of particular roles in the colony. However, the functional and ecological significance of these morphological differences are not well understood. Here, we applied finite element analysis (FEA) to explore the biomechanical differences between major and minor ant worker mandibles. Analyses were carried out on mandibles of two Pheidole species, a dimorphic ant genus. We tested whether major mandibles evolved to minimize stress when compared to minors using combinations of the apical tooth and masticatory margin bites under strike and pressure conditions. Majors performed better in pressure conditions yet, contrary to our expectations, minors performed better in strike bite scenarios. Moreover, we demonstrated that even small morphological differences in ant mandibles might lead to substantial differences in biomechanical responses to bite loading. These results also underscore the potential of FEA to uncover biomechanical consequences of morphological differences within and between ant workers.
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Affiliation(s)
- Cristian L. Klunk
- Graduate Program in Ecology and Conservation, Federal University of Paraná, Curitiba-PR, Brazil
| | - Marco A. Argenta
- Department of Civil Construction, Federal University of Paraná, Curitiba-PR, Brazil
| | - Alexandre Casadei-Ferreira
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Evan P. Economo
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Marcio R. Pie
- Graduate Program in Ecology and Conservation, Federal University of Paraná, Curitiba-PR, Brazil
- Department of Zoology, Federal University of Paraná, Curitiba-PR, Brazil
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Casadei‐Ferreira A, Friedman NR, Economo EP, Pie MR, Feitosa RM. Head and mandible shapes are highly integrated yet represent two distinct modules within and among worker subcastes of the ant genus Pheidole. Ecol Evol 2021; 11:6104-6118. [PMID: 34141206 PMCID: PMC8207162 DOI: 10.1002/ece3.7422] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 02/14/2021] [Accepted: 02/23/2021] [Indexed: 11/10/2022] Open
Abstract
Ants use their mandibles for a wide variety of tasks related to substrate manipulation, brood transport, food processing, and colony defense. Due to constraints involved in colony upkeep, ants evolved a remarkable diversity of mandibular forms, often related to specific roles such as specialized hunting and seed milling. Considering these varied functional demands, we focused on understanding how the mandible and head shape vary within and between Pheidole subcastes. Using x-ray microtomography and 3D geometric morphometrics, we tested whether these structures are integrated and modular, and how ecological predictors influenced these features. Our results showed that mandible and head shape of majors and minor workers tend to vary from robust to slender, with some more complex changes related to the mandibular base. Additionally, we found that head and mandible shapes are characterized by a high degree of integration, but with little correlation with feeding and nesting habits. Our results suggest that a combination of structural (allometric) constraints and the behavioral flexibility conferred by subcaste dimorphism might largely buffer selective pressures that would otherwise lead to a fine-tuning between ecological conditions and morphological adaptation.
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Affiliation(s)
- Alexandre Casadei‐Ferreira
- Departamento de ZoologiaUniversidade Federal do ParanáCuritibaBrazil
- Biodiversity and Biocomplexity UnitOkinawa Institute of Science and Technology Graduate UniversityOnnaJapan
| | - Nicholas R. Friedman
- Biodiversity and Biocomplexity UnitOkinawa Institute of Science and Technology Graduate UniversityOnnaJapan
| | - Evan P. Economo
- Biodiversity and Biocomplexity UnitOkinawa Institute of Science and Technology Graduate UniversityOnnaJapan
| | - Marcio R. Pie
- Departamento de ZoologiaUniversidade Federal do ParanáCuritibaBrazil
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20
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Booher DB, Hoenle PO. A new species group of Strumigenys (Hymenoptera, Formicidae) from Ecuador, with a description of its mandible morphology. Zookeys 2021; 1036:1-19. [PMID: 34017211 PMCID: PMC8116322 DOI: 10.3897/zookeys.1036.62034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/05/2021] [Indexed: 11/19/2022] Open
Abstract
Strumigenys is one of the most diverse ant genera in the world and arguably the most morphologically diverse, exhibiting an exceptional range of mandible shape and function. A new species, Strumigenysayerstheysp. nov., discovered in the Chocó region of Ecuador is described. With two morphological characters, this species is shown to be a morphologically unique outlier among Strumigenys globally, having predominately smooth and shining cuticle surface sculpturing and long trap-jaw mandibles. Using µCT scans, we produced 3D images of the worker ant and static images to examine and compare mandible articular morphologies with most morphologically similar members of the mandibularis species group. Cuticular, pilosity, and articular mandible morphological differences supports placing the new species in its own new species group.
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Affiliation(s)
- Douglas B Booher
- Yale Center for Biodiversity and Global Change, 165 Prospect Street, New Haven, CT 06520-8106, USA Yale Center for Biodiversity and Global Change New Haven United States of America.,Georgia Museum of Natural History, 101 Cedar Street, Athens, GA 30602, USA Georgia Museum of Natural History Athens United States of America
| | - Philipp O Hoenle
- Ecological Networks, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany Ecological Networks, Department of Biology, Technical University of Darmstadt Darmstadt Germany
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21
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Richter A, Schoeters E, Billen J. Morphology and closing mechanism of the mandibular gland orifice in ants (Hymenoptera: Formicidae). J Morphol 2021; 282:1127-1140. [PMID: 33835596 DOI: 10.1002/jmor.21358] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 11/09/2022]
Abstract
The mandibular gland of ants releases chemical compounds with functions ranging from nestmate alarm and recognition to antimicrobial defense. While the morphology of this ethologically important gland is well investigated in several species, the mechanism of secretion release in ants was not explicitly addressed so far. To clarify this question, we examined the anatomy of the gland orifice in ant species from 14 different subfamilies employing different techniques. The orifice close to the mandibular base is located on an area called mandalus. Our investigations revealed variation in mandalar shape, with clear trends in different subfamilies. By contrast, the internal organization is remarkably congruent across all investigated species. The thin external mandalar cuticle is always connected to the mandibular gland duct by a cuticular lamella, visible as a characteristic anchor-shaped structure in cross section. The slit-like gland orifice at the distal end of the mandalus is usually crescent-shaped. In some ant species with specialized mandibles such as trap-jaws, the organization of the orifice area is adapted to the mandibular shape, but always retains the general internal organization. No muscles were found in association with the orifice, nor with any other part of the mandibular gland. However, the base of the mandalus is connected to the prepharyngeal sucking pump by a cuticular ligament. Additionally, it is continuous with the conjunctiva connecting the mandible to the head capsule. We propose that retraction of the sucking pump by the muscle M. tentoriobuccalis, potentially in concert with opening of the mandible, stretches out the ligament and thus pulls on the mandalus and mandalar lamella to open the gland orifice and allow for secretion release. This hypothesis is congruent with findings on other aculeate Hymenoptera and expands our knowledge on the function of an important gland of ants.
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Affiliation(s)
- Adrian Richter
- Institute for Zoology und Evolutionary Research, University of Jena, Jena, Germany
| | - Eric Schoeters
- Zoological Institute, University of Leuven, Leuven, Belgium
| | - Johan Billen
- Zoological Institute, University of Leuven, Leuven, Belgium
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22
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Csősz S, Seifert B, Mikó I, Boudinot BE, Borowiec ML, Fisher BL, Prebus M, Puniamoorthy J, Rakotonirina J, Rasoamanana N, Schultz R, Trietsch C, Ulmer JM, Elek Z. Insect morphometry is reproducible under average investigation standards. Ecol Evol 2021; 11:547-559. [PMID: 33437450 PMCID: PMC7790639 DOI: 10.1002/ece3.7075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/27/2020] [Accepted: 11/03/2020] [Indexed: 11/11/2022] Open
Abstract
Morphometric research is being applied to a growing number and variety of organisms. Discoveries achieved via morphometric approaches are often considered highly transferable, in contrast to the tacit and idiosyncratic interpretation of discrete character states. The reliability of morphometric workflows in insect systematics has never been a subject of focused research, but such studies are sorely needed. In this paper, we assess the reproducibility of morphometric studies of ants where the mode of data collection is a shared routine.We compared datasets generated by eleven independent gaugers, that is, collaborators, who measured 21 continuous morphometric traits on the same pool of individuals according to the same protocol. The gaugers possessed a wide range of morphometric skills, had varying expertise among insect groups, and differed in their facility with measuring equipment. We used intraclass correlation coefficients (ICC) to calculate repeatability and reproducibility values (i.e., intra- and intergauger agreements), and we performed a multivariate permutational multivariate analysis of variance (PERMANOVA) using the Morosita index of dissimilarity with 9,999 iterations.The calculated average measure of intraclass correlation coefficients of different gaugers ranged from R = 0.784 to R = 0.9897 and a significant correlation was found between the repeatability and the morphometric skills of gaugers (p = 0.016). There was no significant association with the magnification of the equipment in the case of these rather small ants. The intergauger agreement, that is the reproducibility, varied between R = 0.872 and R = 0.471 (mean R = 0.690), but all gaugers arrived at the same two-species conclusion. A PERMANOVA test revealed no significant gauger effect on species identity (R 2 = 0.69, p = 0.58).Our findings show that morphometric studies are reproducible when observers follow the standard protocol; hence, morphometric findings are widely transferable and will remain a valuable data source for alpha taxonomy.
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Affiliation(s)
- Sándor Csősz
- MTA‐ELTE‐MTM Ecology Research GroupBudapestHungary
- Evolutionary Ecology Research GroupCentre for Ecological ResearchInstitute of Ecology and BotanyVácrátótHungary
| | | | - István Mikó
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
| | | | - Marek L. Borowiec
- Department of Entomology, Plant Pathology and NematologyUniversity of IdahoIDUSA
| | - Brian L. Fisher
- Department of EntomologyCalifornia Academy of SciencesSan FranciscoCAUSA
| | - Matthew Prebus
- Department of Entomology, Plant Pathology and NematologyUniversity of IdahoIDUSA
| | | | - Jean‐Claude Rakotonirina
- Madagascar Biodiversity CenterAntananarivoMadagascar
- Département d'EntomologieUniversité d'AntananarivoAntananarivoMadagascar
| | | | - Roland Schultz
- Senckenberg Museum of Natural History GörlitzGörlitzGermany
| | | | | | - Zoltán Elek
- MTA‐ELTE‐MTM Ecology Research GroupBudapestHungary
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23
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Boudinot BE, Perrichot V, Chaul JCM. † Camelosphecia gen. nov., lost ant-wasp intermediates from the mid-Cretaceous (Hymenoptera, Formicoidea). Zookeys 2020; 1005:21-55. [PMID: 33390754 PMCID: PMC7762752 DOI: 10.3897/zookeys.1005.57629] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 11/14/2020] [Indexed: 12/21/2022] Open
Abstract
Fossils provide primary material evidence for the pattern and timing of evolution. The newly discovered "beast ants" from mid-Cretaceous Burmite, †Camelosphecia gen. nov., display an exceptional combination of plesiomorphies, including absence of the metapleural gland, and a series of unique apomorphies. Females and males, represented by †C. fossor sp. nov. and †C. venator sp. nov., differ in a number of features which suggest distinct sexual biologies. Combined-evidence phylogenetic analysis recovers †Camelosphecia and †Camelomecia as a clade which forms the extinct sister group of the Formicidae. Notably, these genera are only known from alate males and females; workers, if present, have yet to be recovered. Based on ongoing study of the total Aculeata informed by the beast ant genera, we provide a brief diagnosis of the Formicoidea. We also provide the first comprehensive key to the major groupings of Mesozoic Formicoidea, alongside a synoptic classification in which †Zigrasimeciinaestat. nov. and †Myanmyrma maraudera comb. nov. are recognized. Finally, a brief diagnosis of the Formicoidea is outlined.
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Affiliation(s)
- Brendon E. Boudinot
- Department of Entomology & Nematology, University of California, Davis, One Shields Ave, Davis, CA 95616, USAUniversity of CaliforniaDavisUnited States of America
- Friedrich-Schiller-Universität Jena, Institut für Zoologie und Evolutionsforschung, 1 Erberstraße, 07743 Jena, Thüringen, GermanyFriedrich-Schiller-UniversitätJenaGermany
| | - Vincent Perrichot
- Univ. Rennes, CNRS, Géosciences – UMR 6118, F-35000, Rennes, FranceUniv. Rennes, CNRSRennesFrance
| | - Júlio C. M. Chaul
- Pós-Graduação em Ecologia, Departamento de Biologia Geral, Universidade Federal do Viçosa, 36570-900, Viçosa, MG, BrazilUniversidade Federal do ViçosaViçosaBrazil
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24
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Abstract
Abstract
The evolution of eusociality has led to considerable changes in the general hymenopteran body plan. In particular, the evolution of reproductive division of labour caused the worker caste to be largely freed from the demands involved in reproduction. As a consequence, workers were able to evolve highly specialized morphologies for foraging and colony maintenance, whereas the reproductive caste became specialized for reproduction. Despite these important changes, little is known about the general patterns of morphological evolution within the ant reproductive caste. Our goals here were to characterize morphological variation in the ant reproductive caste and to test whether different sexes display variation in their evolutionary rates. We obtained measurements of 897 specimens from a total of 678 ant species. The shapes of the size distributions were similar between sexes, with queens being larger than males in all traits except for eye length. Contrary to the expectation based on Rensch’s rule, although queens were larger, the degree of dimorphism increased with body size. Finally, there was strong evidence for an accelerated tempo of morphological evolution in queens in relation to males. These results represent the first comprehensive treatment of morphological variation in the ant reproductive caste and provide important new insights into their evolution.
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Affiliation(s)
- Raquel Divieso
- Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Thiago S R Silva
- Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Marcio R Pie
- Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
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25
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Casadei-Ferreira A, Fischer G, Economo EP. Evidence for a thoracic crop in the workers of some Neotropical Pheidole species (Formicidae: Myrmicinae). ARTHROPOD STRUCTURE & DEVELOPMENT 2020; 59:100977. [PMID: 32818807 DOI: 10.1016/j.asd.2020.100977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 06/11/2023]
Abstract
The ability of ant colonies to transport, store, and distribute food resources through trophallaxis is a key advantage of social life. Nonetheless, how the structure of the digestive system has adapted across the ant phylogeny to facilitate these abilities is still not well understood. The crop and proventriculus, structures in the ant foregut (stomodeum), have received most attention for their roles in trophallaxis. However, potential roles of the esophagus have not been as well studied. Here, we report for the first time the presence of an auxiliary thoracic crop in Pheidole aberrans and Pheidole deima using X-ray micro-computed tomography and 3D segmentation. Additionally, we describe morphological modifications involving the endo- and exoskeleton that are associated with the presence of the thoracic crop. Our results indicate that the presence of a thoracic crop in major workers suggests their potential role as repletes or live food reservoirs, expanding the possibilities of tasks assumed by these individuals in the colony. Our contribution emphasizes the utility of combining data from external and internal morphology to better understand functional and behavioral mechanisms.
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Affiliation(s)
- A Casadei-Ferreira
- Departamento de Zoologia, Universidade Federal do Paraná, Avenida Francisco Heráclito dos Santos, s/n, Centro Politécnico, Curitiba, Mailbox 19020, CEP 81531-980, Brazil.
| | - G Fischer
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Okinawa, 904-0495, Japan.
| | - E P Economo
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Okinawa, 904-0495, Japan.
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26
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Barden P, Perrichot V, Wang B. Specialized Predation Drives Aberrant Morphological Integration and Diversity in the Earliest Ants. Curr Biol 2020; 30:3818-3824.e4. [PMID: 32763171 DOI: 10.1016/j.cub.2020.06.106] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/25/2020] [Accepted: 06/30/2020] [Indexed: 02/06/2023]
Abstract
Extinct haidomyrmecine "hell ants" are among the earliest ants known [1, 2]. These eusocial Cretaceous taxa diverged from extant lineages prior to the most recent common ancestor of all living ants [3] and possessed bizarre scythe-like mouthparts along with a striking array of horn-like cephalic projections [4-6]. Despite the morphological breadth of the fifteen thousand known extant ant species, phenotypic syndromes found in the Cretaceous are without parallel and the evolutionary drivers of extinct diversity are unknown. Here, we provide a mechanistic explanation for aberrant hell ant morphology through phylogenetic reconstruction and comparative methods, as well as a newly reported specimen. We report a remarkable instance of fossilized predation that provides direct evidence for the function of dorsoventrally expanded mandibles and elaborate horns. Our findings confirm the hypothesis that hell ants captured other arthropods between mandible and horn in a manner that could only be achieved by articulating their mouthparts in an axial plane perpendicular to that of modern ants. We demonstrate that the head capsule and mandibles of haidomyrmecines are uniquely integrated as a consequence of this predatory mode and covary across species while finding no evidence of such modular integration in extant ant groups. We suggest that hell ant cephalic integration-analogous to the vertebrate skull-triggered a pathway for an ancient adaptive radiation and expansion into morphospace unoccupied by any living taxon.
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Affiliation(s)
- Phillip Barden
- Department of Biological Sciences, New Jersey Institute of Technology, Dr Martin Luther King Jr Boulevard, Newark, NJ 07102, USA; Division of Invertebrate Zoology, American Museum of Natural History, Central Park West, New York, NY 10024, USA.
| | - Vincent Perrichot
- Univ Rennes, CNRS, Géosciences Rennes - UMR 6118, 35000 Rennes, France.
| | - Bo Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, China.
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27
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Wong MKL, Guénard B, Lewis OT. The cryptic impacts of invasion: functional homogenization of tropical ant communities by invasive fire ants. OIKOS 2020. [DOI: 10.1111/oik.06870] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Mark K. L. Wong
- Dept of Zoology, Univ. of Oxford South Parks Road Oxford OX1 3PS UK
| | - Benoit Guénard
- School of Biological Sciences, The Univ. of Hong Kong Hong Kong SAR PR China
| | - Owen T. Lewis
- Dept of Zoology, Univ. of Oxford South Parks Road Oxford OX1 3PS UK
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28
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Alba-Alejandre I, Alba-Tercedor J, Vega FE. Anatomical study of the coffee berry borer (Hypothenemus hampei) using micro-computed tomography. Sci Rep 2019; 9:17150. [PMID: 31748574 PMCID: PMC6868283 DOI: 10.1038/s41598-019-53537-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 11/04/2019] [Indexed: 11/09/2022] Open
Abstract
Traditionally, the study of anatomy in insects has been based on dissection techniques. Micro-computed tomography (micro-CT) is an X-ray based technique that allows visualization of the internal anatomy of insects in situ and does not require dissections. We report on the use of micro-CT scans to study, in detail, the internal structures and organs of the coffee berry borer (Hypothenemus hampei), the most damaging insect pest of coffee worldwide. Detailed images and videos allowed us to make the first description of the aedeagus and the first report of differences between the sexes based on internal anatomy (flight musculature, midgut shape, hindgut convolutions, brain shape and size) and external morphology (lateral outline of the pronotum and number of abdominal tergites). This study is the first complete micro-CT reconstruction of the anatomy of an insect and is also the smallest insect to have been evaluated in this way. High quality rendered images, and additional supplementary videos and 3D models are suitable for use with mobile devices and are useful tools for future research and as teaching aids.
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Affiliation(s)
- Ignacio Alba-Alejandre
- Department of Zoology, Faculty of Sciences, University of Granada, Campus de Fuentenueva, 18071, Granada, Spain
| | - Javier Alba-Tercedor
- Department of Zoology, Faculty of Sciences, University of Granada, Campus de Fuentenueva, 18071, Granada, Spain.
| | - Fernando E Vega
- Sustainable Perennial Crops Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, 20705, USA.
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29
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Silva TSR, Feitosa RM. Using controlled vocabularies in anatomical terminology: A case study with Strumigenys (Hymenoptera: Formicidae). ARTHROPOD STRUCTURE & DEVELOPMENT 2019; 52:100877. [PMID: 31357032 DOI: 10.1016/j.asd.2019.100877] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/23/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
Morphological studies of insects can help us to understand the concomitant or sequential functionality of complex structures and may be used to hypothetize distinct levels of phylogenetic relationship among groups. Traditional morphological works, generally, have encompassed a set of elements, including descriptions of structures and their respective conditions, literature references and images, all combined in a single document. Fast forward to the digital era, it is now possible to release this information simultaneously but also independently as data sets linked to the original publication in an external environment. In order to link data from various fields of knowledge, disseminating morphological information in an open environment, it is important to use tools that enhance interoperability. For example, semantic annotations facilitate the dissemination and retrieval of phenotypic data in digital environments. The integration of semantic (i.e. web-based) components with anatomic treatments can be used to generate a traditional description in natural language along with a set of semantic annotations. The ant genus Strumigenys currently comprises about 840 described species distributed worldwide. In the Neotropical region, almost 200 species are currently known, but it is possible that much of the species' diversity there remains unexplored and undescribed. The morphological diversity in the genus is high, reflecting an extreme generic reclassification that occurred in the late 20th and early 21st centuries. Here we define the anatomical concepts in this highly diverse group of ants using semantic annotations to enrich the anatomical ontologies available online, focussing on the definition of terms through subjacent conceptualization.
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Affiliation(s)
- Thiago S R Silva
- Department of Zoology, Universidade Federal do Paraná, Francisco Heráclito dos Santos Ave., Curitiba, PR, Brazil.
| | - Rodrigo M Feitosa
- Department of Zoology, Universidade Federal do Paraná, Francisco Heráclito dos Santos Ave., Curitiba, PR, Brazil.
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30
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Richter A, Keller RA, Rosumek FB, Economo EP, Hita Garcia F, Beutel RG. The cephalic anatomy of workers of the ant species Wasmannia affinis (Formicidae, Hymenoptera, Insecta) and its evolutionary implications. ARTHROPOD STRUCTURE & DEVELOPMENT 2019; 49:26-49. [PMID: 30738181 DOI: 10.1016/j.asd.2019.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 06/09/2023]
Abstract
Despite the ecological significance of ants and the intensive research attention they have received, thorough treatments of the anatomy and functional morphology are still scarce. In this study we document the head morphology of workers of the myrmicine Wasmannia affinis with optical microscopy, μ-computed tomography, scanning electron microscopy, and 3D reconstruction, providing the first complete anatomical treatment of an ant head with a broad array of modern techniques. We discuss the potential of the applied methods to generate detailed and well-documented morphological data sets with increased efficiency. We also address homology problems, particularly in the context of the cephalic digestive tract. According to our analyses the "pharynx" of previous ant studies is homologous to the prepharynx of other insects. We also discuss the phylogenetic potential and functional significance of the observed characters, with internal features such as tentorium and musculature discussed for the first time. Our investigation underlines that detailed anatomical data for Formicidae are still very fragmentary, which in turn limits our understanding of the major design elements underlying the ant bauplan. We attempt to provide a template for further anatomical studies, which will help to understand the evolution of this fascinating group on the phenotypic level.
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Affiliation(s)
- Adrian Richter
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany.
| | - Roberto A Keller
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan; MUHNAC/cE3c -Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal
| | - Félix Baumgarten Rosumek
- Ecological Networks, Technische Universität Darmstadt, Darmstadt, Germany; Department of Ecology and Zoology, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Evan P Economo
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Francisco Hita Garcia
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Rolf G Beutel
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany
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