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Killiny N, Brodersen CR. Using X-ray Micro-Computed Tomography to Three-Dimensionally Visualize the Foregut of the Glassy-Winged Sharpshooter ( Homalodisca vitripennis). INSECTS 2022; 13:710. [PMID: 36005335 PMCID: PMC9409420 DOI: 10.3390/insects13080710] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
Dissecting the heads of small insects belonging to the order Hemiptera for detailed anatomical investigation with light or scanning electron microscopy is difficult, time-consuming, and destructive, often resulting in sample preparation artifacts. Nevertheless, the structural details of these insects often hold critical information regarding their interactions with bacterial pathogens. For example, the glassy-winged sharpshooter (GWSS) is an efficient vector of the bacterium Xylella fastidiosa, the causal agent of Pierce's disease in grape vines, but the foregut of this species is exceptionally difficult to dissect. Here, we describe a simple, non-destructive method to investigate the structure of the anterior gut of GWSS using high-resolution micro-computed X-ray tomography (microCT). The use of microCT eliminates the need for destructive dissection and reveals the morphology of small insects in three dimensions, allowing the user to virtually dissect the sample. The use of microCT imaging is a promising and powerful tool in the entomological sciences for studying the structures of vector insects, especially for difficult-to-dissect regions such as the foregut.
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Affiliation(s)
- Nabil Killiny
- Citrus Research and Education Center, IFAS, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, USA
| | - Craig R. Brodersen
- School of the Forestry and Environmental Studies, Yale University, 195 Prospect, New Haven, CT 06511, USA
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2
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Laussmann T, Urspruch P, Flocke V, Windfelder AG, Aberle H, Lunau K, Flögel U. Dynamic monitoring of vital functions and tissue re-organization in Saturnia pavonia (Lepidoptera, Saturniidae) during final metamorphosis by non-invasive MRI. Sci Rep 2022; 12:1105. [PMID: 35058520 PMCID: PMC8776771 DOI: 10.1038/s41598-022-05092-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 01/06/2022] [Indexed: 11/09/2022] Open
Abstract
Magnetic resonance imaging (MRI) is the key whole-body imaging technology for observing processes within a living object providing excellent resolution and contrast between soft tissues. In the present work, we exploited the non-destructive properties of MRI to track longitudinally the dynamic changes that take place in developing pupae of the Emperor Moth (Saturnia pavonia) during the last days before eclosion. While in diapause pupae, body fluid was almost homogeneously distributed over the internal compartments, as soon as wings, legs, flight muscles and the head region were fully developed, a significant redistribution of water levels occurred between thoracic and abdominal regions. During the last two days before eclosion, the developing moths transferred substantial amounts of liquid into the gut and the labial gland, and in case of females, into developing eggs. Concomitantly, the volume of the air sacs increased drastically and their expansion/compression became clearly visible in time-resolved MR images. Furthermore, besides ventilation of the tracheal system, air sacs are likely to serve as volume reservoir for liquid transfer during development of the moths inside their pupal case. In parallel, we were able to monitor noninvasively lipid consumption, cardiac activity and haemolymph circulation during final metamorphosis.
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Martín-Vega D, Clark B, Ferrer LM, López-Tamayo S, Panadero R, Cepeda-Palacios R, Colwell DD, Hall MJR. Major differences in the larval anatomy of the digestive and excretory systems of three Oestridae species revealed by micro-CT. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:106-120. [PMID: 32896916 DOI: 10.1111/mve.12476] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/21/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Oestrid flies (Diptera: Oestridae) do not feed during the adult stage, so they depend on an efficient assimilation and storage of nutrients during their parasitic larval stage. We describe the general morphology and provide volumetric data for the digestive and excretory organs of the three larval instars of the nasal bot fly Oestrus ovis L., using micro-computed tomography. The size of the digestive and excretory organs greatly increased across larval instars. In all instars, the two salivary glands were remarkably large and formed a 'glandular band' by coming together, but without lumina uniting, at their posterior ends. The distal region of the anterior Malpighian tubules was greatly enlarged and full of highly radio-opaque concretions. Moreover, the anatomy of O. ovis third-instar larva was compared to that of two species of, respectively, similar and different feeding habits: Cephenemyia stimulator (Clark) and Hypoderma actaeon Brauer. Whereas the general morphology and arrangement of the digestive and excretory systems of C. stimulator was similar to that of O. ovis, some differences were observed in H. actaeon: a swollen anterior region of the midgut, salivary glands shorter and not forming a 'band' and anterior Malpighian tubules narrowly uniform throughout their entire length.
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Affiliation(s)
- D Martín-Vega
- Department of Life Sciences, University of Alcalá, Alcalá de Henares, Spain
- Department of Life Sciences, Natural History Museum, London, U.K
| | - B Clark
- Imaging and Analysis Centre, Natural History Museum, London, U.K
| | - L M Ferrer
- Department of Animal Pathology, University of Zaragoza, Zaragoza, Spain
| | - S López-Tamayo
- Department of Animal Pathology, University of Zaragoza, Zaragoza, Spain
| | - R Panadero
- Department of Animal Pathology, University of Santiago de Compostela, Lugo, Spain
| | - R Cepeda-Palacios
- Department of Animal Science and Environment Preservation, Autonomous University of Baja California Sur, La Paz, Mexico
| | - D D Colwell
- Agriculture and Agri-Food Canada, Lethbridge, Canada
| | - M J R Hall
- Department of Life Sciences, Natural History Museum, London, U.K
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Martín-Vega D, Clark B, Ferrer LM, López-Tamayo S, Colwell DD, Hall MJR. Internal morphological changes during metamorphosis in the sheep nasal bot fly, Oestrus ovis. MEDICAL AND VETERINARY ENTOMOLOGY 2020; 34:476-487. [PMID: 32767606 DOI: 10.1111/mve.12465] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 05/11/2023]
Abstract
During the larval stage, oestrid flies (Diptera: Oestridae) are obligate parasites, whereas during the adult stage they are free-living and do not feed. Like other cyclorrhaphous flies, oestrids undergo metamorphosis inside an opaque puparium, formed by the contracted and hardened cuticle of the third-instar larva. The present study documents the internal morphological changes taking place during metamorphosis of the sheep nasal bot fly, Oestrus ovis L., using non-invasive, micro-CT-based virtual histology and provides quantitative data of volumetric changes in specific organs. Virtual histological sections allowed visualisation of the progression and completion of the apolyses, which delimit the different intra-puparial stages, and the connection to the tracheal system of a large gas bubble, which plays an essential role during early metamorphosis. Overall, our results show that the sequence of morphological and volumetric changes in tissues and organs is similar to those found in other cyclorrhaphous flies, but they also reveal developmental differences that result in an adult vestigial digestive tract. Future studies could develop non-invasive, reliable methods for aging the intra-puparial forms of different oestrid species of veterinary importance, based on both qualitative and quantitative markers, thus improving our knowledge of their development and the efficiency of control strategies.
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Affiliation(s)
- D Martín-Vega
- Department of Life Sciences, University of Alcalá, Alcalá de Henares, Spain
- Department of Life Sciences, Natural History Museum, London, U.K
| | - B Clark
- Imaging and Analysis Centre, Natural History Museum, London, U.K
| | - L M Ferrer
- Department of Animal Pathology, University of Zaragoza, Zaragoza, Spain
| | - S López-Tamayo
- Department of Animal Pathology, University of Zaragoza, Zaragoza, Spain
| | - D D Colwell
- Agriculture and Agri-Food Canada, Lethbridge, Canada
| | - M J R Hall
- Department of Life Sciences, Natural History Museum, London, U.K
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Alba-Alejandre I, Alba-Tercedor J, Hunter WB. Anatomical study of the female reproductive system and bacteriome of Diaphorina citri Kuwayama, (Insecta: Hemiptera, Liviidae) using micro-computed tomography. Sci Rep 2020; 10:7161. [PMID: 32346040 PMCID: PMC7189384 DOI: 10.1038/s41598-020-64132-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 04/03/2020] [Indexed: 12/11/2022] Open
Abstract
Huanglongbing (HLB) (citrus greening disease) is one of the most serious bacterial diseases of citrus. It is caused by (1) Candidatus Liberibacter africanus, transmitted by Trioza erytreae and (2) C.L. asiaticus and C.L. americanus, transmitted by Diaphorina citri. As part of a multidisciplinary project on D. citri (www.citrusgreening.org), we made a detailed study, using micro-computed tomography, of the female abdominal terminalia, reproductive system (ovaries, accessory glands, spermatheca, colleterial (= cement) gland, connecting ducts, and ovipositor) and bacteriome, which we present here. New terms and structures are introduced and described, particularly concerning the spermatheca, ovipositor and bacteriome. The quality of images and bacteriome reconstructions are comparable, or clearer, than those previously published using a synchrotron or fluorescence in situ hybridisation (FISH). This study: reviews knowledge of the female reproductive system and bacteriome organ in D. citri; represents the first detailed morphological study of D. citri to use micro-CT; and extensively revises existing morphological information relevant to psylloids, hemipterans and insects in general. High quality images and supplementary videos represent a significant advance in knowledge of psylloid anatomy and are useful tools for future research and as educational aids.
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Affiliation(s)
- Ignacio Alba-Alejandre
- Department of Zoology, Faculty of Sciences, University of Granada, Campus de Fuentenueva, Granada, Spain.
| | - Javier Alba-Tercedor
- Department of Zoology, Faculty of Sciences, University of Granada, Campus de Fuentenueva, Granada, Spain.
| | - Wayne B Hunter
- U.S. Department Agriculture, Agricultural Research Service, Fort Pierce, Florida, USA
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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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Hall MJR, Martín-Vega D. Visualization of insect metamorphosis. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190071. [PMID: 31438819 DOI: 10.1098/rstb.2019.0071] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Metamorphosis and, in particular, holometaboly, the development of organisms through a series of discrete stages (egg, larva, pupa, adult) that hardly resemble one another but are finely adapted to specific roles in the life cycle of the organism, has fascinated and mystified humans throughout history. However, it can be difficult to visualize the dramatic changes that occur during holometaboly without destructive sampling, traditionally through histology. However, advances in imaging technologies developed mainly for medical sciences have been applied to studies of insect metamorphosis over the past couple of decades. These include micro-computed tomography, magnetic resonance imaging and optical coherence tomography. A major advantage of these techniques is that they are rapid and non-destructive, enabling virtual dissection of an organism in any plane by anyone who has access to the image files and the necessary software. They can also be applied in some cases to visualize metamorphosis in vivo, including the periods of most rapid and dramatic morphological change. This review focusses on visualizing the intra-puparial holometabolous metamorphosis of cyclorraphous flies (Diptera), including the primary model organism for all genetic investigations, Drosophila melanogaster, and the blow flies of medical, veterinary and forensic importance, but also discusses similar studies on other insect orders. This article is part of the theme issue 'The evolution of complete metamorphosis'.
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Affiliation(s)
- Martin J R Hall
- Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Daniel Martín-Vega
- Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK.,Department of Life Sciences, University of Alcalá, Alcalá de Henares, Spain
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