1
|
Schapheer C, Pellens R, Scherson R. Arthropod-Microbiota Integration: Its Importance for Ecosystem Conservation. Front Microbiol 2021; 12:702763. [PMID: 34408733 PMCID: PMC8365148 DOI: 10.3389/fmicb.2021.702763] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/02/2021] [Indexed: 01/10/2023] Open
Abstract
Recent reports indicate that the health of our planet is getting worse and that genuine transformative changes are pressing. So far, efforts to ameliorate Earth's ecosystem crises have been insufficient, as these often depart from current knowledge of the underlying ecological processes. Nowadays, biodiversity loss and the alterations in biogeochemical cycles are reaching thresholds that put the survival of our species at risk. Biological interactions are fundamental for achieving biological conservation and restoration of ecological processes, especially those that contribute to nutrient cycles. Microorganism are recognized as key players in ecological interactions and nutrient cycling, both free-living and in symbiotic associations with multicellular organisms. This latter assemblage work as a functional ecological unit called "holobiont." Here, we review the emergent ecosystem properties derived from holobionts, with special emphasis on detritivorous terrestrial arthropods and their symbiotic microorganisms. We revisit their relevance in the cycling of recalcitrant organic compounds (e.g., lignin and cellulose). Finally, based on the interconnection between biodiversity and nutrient cycling, we propose that a multicellular organism and its associates constitute an Ecosystem Holobiont (EH). This EH is the functional unit characterized by carrying out key ecosystem processes. We emphasize that in order to meet the challenge to restore the health of our planet it is critical to reduce anthropic pressures that may threaten not only individual entities (known as "bionts") but also the stability of the associations that give rise to EH and their ecological functions.
Collapse
Affiliation(s)
- Constanza Schapheer
- Programa de Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Campus Sur Universidad de Chile, Santiago, Chile
- Laboratorio de Sistemática y Evolución, Departamento de Silvicultura y Conservación de la Naturaleza, Universidad de Chile, Santiago, Chile
| | - Roseli Pellens
- UMR 7205, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Ecole Pratique de Hautes Etudes, Institut de Systématique, Évolution, Biodiversité, Sorbonne Université, Université des Antilles, Paris, France
| | - Rosa Scherson
- Laboratorio de Sistemática y Evolución, Departamento de Silvicultura y Conservación de la Naturaleza, Universidad de Chile, Santiago, Chile
| |
Collapse
|
2
|
Comparative Antennal Morphometry and Sensilla Organization in the Reproductive and Non-Reproductive Castes of the Formosan Subterranean Termite. INSECTS 2021; 12:insects12070576. [PMID: 34202744 PMCID: PMC8307099 DOI: 10.3390/insects12070576] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 12/02/2022]
Abstract
Simple Summary Insects use antennae to perceive the chemical environment, and olfaction (the sense of smell) is essential for a variety of behavioral responses. Termites are social insects that display a division of labor based on an elaborate caste system consisting of reproductive (queen and king) and non-reproductive individuals (workers and soldiers). Whether these castes have different senses of smell is poorly understood. In this study, we characterized the morphology of antennae in alates (winged reproductives), workers, and soldiers in the Formosan subterranean termite, Coptotermes formosanus, and further analyzed the diversity and abundance of the antennal sensilla (sensory receptors) in each caste. We found that both female and male alates had longer antennae and greater numbers of sensilla than workers and soldiers, but all castes possessed the same nine types of antennal sensilla. Each type of sensilla had a specific spatial distribution along the antenna. The quantitative composition of sensilla differed between the reproductive and non-reproductive castes, but few differences were found between female and male alates or between worker and soldier castes. These results suggest that the olfactory morphology is associated with the reproductive division of labor in subterranean termites. Abstract Antennae are the primary sensory organs in insects, where a variety of sensilla are distributed for the perception of the chemical environment. In eusocial insects, colony function is maintained by a division of labor between reproductive and non-reproductive castes, and chemosensation is essential for regulating their specialized social activities. Several social species in Hymenoptera display caste-specific characteristics in antennal morphology and diversity of sensilla, reflecting their differential tasks. In termites, however, little is known about how the division of labor is associated with chemosensory morphology among castes. Using light and scanning electron microscopy, we performed antennal morphometry and characterized the organization of sensilla in reproductive (female and male alates) and non-reproductive (worker and soldier) castes in the Formosan subterranean termite, Coptotermes formosanus Shiraki. Here, we show that the antennal sensilla in alates are twice as abundant as in workers and soldiers, along with the greater number of antennal segments and antennal length in alates. However, all castes exhibit the same types of antennal sensilla, including basiconicum, campaniformium, capitulum, chaeticum I, chaeticum II, chaeticum III, marginal, trichodeum I, and trichodeum I. The quantitative composition of sensilla diverges between reproductive and non-reproductive castes, but not between female and male alates or between worker and soldier castes. The sensilla display spatial-specific distribution, with basiconicum exclusively and capitulum predominantly found on the ventral side of antennae. In addition, the abundance of chemosensilla increases toward the distal end of antennae in each caste. This research provides morphological signatures of chemosensation and their implications for the division of labor, and suggests future neurophysiological and molecular studies to address the mechanisms of chemical communication in termites.
Collapse
|
3
|
Oberst S, Martin R, Halkon BJ, Lai JCS, Evans TA, Saadatfar M. Submillimetre mechanistic designs of termite-built structures. J R Soc Interface 2021; 18:20200957. [PMID: 33947222 DOI: 10.1098/rsif.2020.0957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Termites inhabit complex underground mounds of intricate stigmergic labyrinthine designs with multiple functions as nursery, food storage and refuge, while maintaining a homeostatic microclimate. Past research studied termite building activities rather than the actual material structure. Yet, prior to understanding how multi-functionality shaped termite building, a thorough grasp of submillimetre mechanistic architecture of mounds is required. Here, we identify for Nasutitermes exitiosus via granulometry and Fourier transform infrared spectroscopy analysis, preferential particle sizes related to coarse silts and unknown mixtures of organic/inorganic components. High-resolution micro-computed X-ray tomography and microindentation tests reveal wall patterns of filigree laminated layers and sub-millimetre porosity wrapped around a coarse-grained inner scaffold. The scaffold geometry, which is designed of a lignin-based composite and densely biocementitious stercoral mortar, resembles that of trabecula cancellous bones. Fractal dimension estimates indicate multi-scaled porosity, important for enhanced evaporative cooling and structural stability. The indentation moduli increase from the outer to the inner wall parts to values higher than those found in loose clays and which exceed locally the properties of anthropogenic cementitious materials. Termites engineer intricately layered biocementitious composites of high elasticity. The multiple-scales and porosity of the structure indicate a potential to pioneer bio-architected lightweight and high-strength materials.
Collapse
Affiliation(s)
- Sebastian Oberst
- Centre for Audio, Acoustics and Vibrations, Faculty of Engineering and IT, University of Technology Sydney, Sydney, New South Wales 2040, Australia.,School of Engineering and Information Technology, University of New South Wales, Canberra, Australian Capital Territory 2600, Australia
| | - Richard Martin
- Centre for Audio, Acoustics and Vibrations, Faculty of Engineering and IT, University of Technology Sydney, Sydney, New South Wales 2040, Australia
| | - Benjamin J Halkon
- Centre for Audio, Acoustics and Vibrations, Faculty of Engineering and IT, University of Technology Sydney, Sydney, New South Wales 2040, Australia
| | - Joseph C S Lai
- School of Engineering and Information Technology, University of New South Wales, Canberra, Australian Capital Territory 2600, Australia
| | - Theodore A Evans
- School of Animal Biology, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Mohammed Saadatfar
- School of Civil Engineering, The University of Sydney, 2006, Sydney, Australia.,Department of Applied Mathematics, The Australian National University, Canberra, 2601, Australia
| |
Collapse
|
4
|
Vikram S, Arneodo JD, Calcagno J, Ortiz M, Mon ML, Etcheverry C, Cowan DA, Talia P. Diversity structure of the microbial communities in the guts of four neotropical termite species. PeerJ 2021; 9:e10959. [PMID: 33868801 PMCID: PMC8035897 DOI: 10.7717/peerj.10959] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 01/27/2021] [Indexed: 01/04/2023] Open
Abstract
The termite gut microbiome is dominated by lignocellulose degrading microorganisms. This study describes the intestinal microbiota of four Argentinian higher termite species with different feeding habits: Microcerotermes strunckii (hardwood), Nasutitermes corniger (softwood), Termes riograndensis (soil organic matter/grass) and Cornitermes cumulans (grass) by deep sequencing of amplified 16S rRNA and ITS genes. In addition, we have performed a taxonomic and gut community structure comparison incorporating into the analysis the previously reported microbiomes of additional termite species with varied diets. The bacterial phylum Spirochaetes was dominant in the guts of M. strunckii, N. corniger and C. cumulans, whereas Firmicutes predominated in the T. riograndensis gut microbiome. A single bacterial genus, Treponema (Spirochaetes), was dominant in all termite species, except for T. riograndensis. Both in our own sequenced samples and in the broader comparison, prokaryotic α-diversity was higher in the soil/grass feeders than in the wood feeders. Meanwhile, the β-diversity of prokaryotes and fungi was highly dissimilar among strict wood-feeders, whereas that of soil- and grass-feeders grouped more closely. Ascomycota and Basidiomycota were the only fungal phyla that could be identified in all gut samples, because of the lack of reference sequences in public databases. In summary, higher microbial diversity was recorded in termites with more versatile feeding sources, providing further evidence that diet, along with other factors (e.g., host taxonomy), influences the microbial community assembly in the termite gut.
Collapse
Affiliation(s)
- Surendra Vikram
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Joel D Arneodo
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Buenos Aires, Argentina
| | - Javier Calcagno
- Centro de Ciencias Naturales, Ambientales y Antropológicas, Universidad Maimonides (CCNAA), CABA, Argentina
| | - Maximiliano Ortiz
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Maria Laura Mon
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Buenos Aires, Argentina
| | - Clara Etcheverry
- Biología de los Invertebrados, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Corrientes, Argentina
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Paola Talia
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Buenos Aires, Argentina
| |
Collapse
|
5
|
A 37-amino acid loop in the Yarrowia lipolytica hexokinase impacts its activity and affinity and modulates gene expression. Sci Rep 2021; 11:6412. [PMID: 33742083 PMCID: PMC7979807 DOI: 10.1038/s41598-021-85837-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 03/04/2021] [Indexed: 01/31/2023] Open
Abstract
The oleaginous yeast Yarrowia lipolytica is a potent cell factory as it is able to use a wide variety of carbon sources to convert waste materials into value-added products. Nonetheless, there are still gaps in our understanding of its central carbon metabolism. Here we present an in-depth study of Y. lipolytica hexokinase (YlHxk1), a structurally unique protein. The greatest peculiarity of YlHxk1 is a 37-amino acid loop region, a structure not found in any other known hexokinases. By combining bioinformatic and experimental methods we showed that the loop in YlHxk1 is essential for activity of this protein and through that on growth of Y. lipolytica on glucose and fructose. We further proved that the loop in YlHxk1 hinders binding with trehalose 6-phosphate (T6P), a glycolysis inhibitor, as hexokinase with partial deletion of this region is 4.7-fold less sensitive to this molecule. We also found that YlHxk1 devoid of the loop causes strong repressive effect on lipase-encoding genes LIP2 and LIP8 and that the hexokinase overexpression in Y. lipolytica changes glycerol over glucose preference when cultivated in media containing both substrates.
Collapse
|
6
|
Stiblik P, Akama PD, Šobotník J. Complete mitochondrial genome of the drywood termite Cryptotermes havilandi (Isoptera: Kalotermitidae). Mitochondrial DNA B Resour 2021; 6:533-535. [PMID: 33628917 PMCID: PMC7889119 DOI: 10.1080/23802359.2021.1873710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We report the first complete mitochondrial genome of an important pest of timber, the drywood termite Cryptotermes havilandi. The gene content and synteny of the mitochondrial genome of C. havilandi is identical to that of other termite species reported to date. It is composed 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes. Our phylogenetic tree, that includes the mitochondrial genomes of 14 species of Kalotermitidae, including C. havilandi, resolves the phylogenetic position of C. havilandi within Kalotermitidae.
Collapse
Affiliation(s)
- Petr Stiblik
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Pierre Dieudonné Akama
- Département des sciences biologiques, Ecole normale supérieure, Université de Yaoundé I, Yaoundé, Cameroon
| | - Jan Šobotník
- Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| |
Collapse
|
7
|
Ye C, Song Z, Wu T, Zhang W, Saba NU, Xing L, Su X. Endocuticle is involved in caste differentiation of the lower termite. Curr Zool 2021; 67:489-499. [PMID: 34616947 PMCID: PMC8489109 DOI: 10.1093/cz/zoab005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/19/2021] [Indexed: 12/30/2022] Open
Abstract
Caste differentiation in termites is one of the most conspicuous examples of facultative polyphenism in animals. It is clear that specific cuticular formation occurs in hard exocuticles during caste differentiation. However, the developmental pattern of the soft endocuticle in the differentiation pathways of castes is unknown. To reveal whether the endocuticle is involved in caste differentiation, we compared the exocuticle and endocuticle thickness of individuals in 2 pathways (nymph line and worker line) of caste differentiation in the termite Reticulitermes aculabialis. The endocuticle protein genes were identified by transcriptome analysis and the expression patterns of these genes were confirmed in caste differentiation. We found that the endocuticle structure showed dynamic changes in 2 pathways, and the first difference in endocuticle structure occurred after larvae differentiation bifurcated into workers and nymphs. The thinning of the endocuticle was a significant event from nymphs developing into alates with the thickest exocuticle and thinnest endocuticle. The thickest endocuticle layers were found in the heads of the workers and the ultrastructure of the endocuticle in the heads was more complex than that in the thorax–abdomens. Six endocuticle protein genes were identified and annotated as endocuticle structural glycoproteins SgAbd-2, SgAbd-9, and Abd-5. The expression levels of endocuticle protein genes changed dramatically during caste development and the expression levels in neotenic reproductives (secondary reproductives) were significantly higher than those in alates (primary reproductives). These results reveal the roles of endocuticles in caste differentiation and adaptation to the environment.
Collapse
Affiliation(s)
- Chenxu Ye
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an 710069, China.,College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Zhuanzhuan Song
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Taoyu Wu
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Wenxiu Zhang
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Noor Us Saba
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an 710069, China.,College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Lianxi Xing
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an 710069, China.,College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Xiaohong Su
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an 710069, China.,College of Life Sciences, Northwest University, Xi'an 710069, China
| |
Collapse
|
8
|
Reproductive Soldier Development Is Controlled by Direct Physical Interactions with Reproductive and Soldier Termites. INSECTS 2021; 12:insects12010076. [PMID: 33467647 PMCID: PMC7830014 DOI: 10.3390/insects12010076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary Generally, in termites, the soldier caste is sterile, and their reproductive organ formation is suppressed. However, in some primitive taxa, neotenic reproductives with soldier-like mandibles, called reproductive soldiers, occasionally appear in the incipient colony. Our first step in understanding the developmental mechanism of this unique caste was to establish efficient conditions to induce reproductive soldiers in Zootermopsis nevadensis. Removing both the king and soldiers from an incipient colony strongly stimulated the formation of male reproductive soldiers, which possessed soldier-like mandibles and developed testes. Similarly, high differentiation rates of male reproductive soldiers were observed after king-and-soldier separation treatment using wire mesh. However, no male reproductive soldiers were produced without direct interaction with the queen. These results suggest that reproductive soldier development might be initiated and controlled by direct physical interactions with both reproductives (the king and queen) and soldiers. Abstract In eusocial insects (e.g., ants, bees, and termites), the roles of different castes are assigned to different individuals. These castes possess unique phenotypes that are specialized for specific tasks. The acquisition of sterile individuals with specific roles is considered a requirement for social evolution. In termites, the soldier is a sterile caste. In primitive taxa (family Archotermopsidae and Stolotermitidae), however, secondary reproductives (neotenic reproductives) with their mandibles developed into weapons (so-called reproductive soldiers, also termed as soldier-headed reproductives or soldier neotenics) have been reported. To understand the developmental mechanism of this unique caste, it is necessary to understand the environmental cues and developmental processes of reproductive soldiers under natural conditions. Here, we established efficient conditions to induce reproductive soldiers in Zootermopsis nevadensis. Male reproductive soldiers frequently developed after the removal of both the king and soldiers from an incipient colony. Similarly, high differentiation rates of male reproductive soldiers were observed after king-and-soldier separation treatment using wire mesh. However, no male reproductive soldiers were produced without direct interaction with the queen. These results suggest that male reproductive soldier development is repressed by direct physical interactions with both the king and soldiers and facilitated by direct physical interaction with the queen.
Collapse
|
9
|
First record of gregarine protists (Apicomplexa: Sporozoa) in Asian fungus-growing termite Macrotermes barneyi (Blattaria: Termitidae). Sci Rep 2021; 11:989. [PMID: 33441676 PMCID: PMC7806973 DOI: 10.1038/s41598-020-79671-7] [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: 09/15/2020] [Accepted: 12/08/2020] [Indexed: 11/29/2022] Open
Abstract
Macrotermes barneyi, widely distributed in southern China, is the major fungus-growing termite in the subfamily Macrotermitinae. It has no flagellated protists in the guts. Here, we report occurrence of gregarine, a protozoan parasite in the digestive tract of M. barneyi. The general morphology and ultrastructure of the gregarine gamonts and syzygies by light micrograph and scanning electron micrograph are presented. SSU rDNA sequence analysis showed that the termite gregarine has the highest identity (90.10%) to that of Gregarina blattarum from cockroaches. Phylogenetic analysis based on the SSU rDNA sequences from diverse insect eugregarines indicated that the gregarine from M. barneyi is phylogenetically close to G. blattarus, L. erratica and G. tropica from Gregarinidae and Leidyanidae families, and may represent a novel species. This study expands our knowledge about the diversity of terrestrial eugregarines parasitizing in termites.
Collapse
|
10
|
Anti-Termitic Activity of Three Plant Extracts, Chlorpyrifos, and a Bioagent Compound (Protecto) against Termite Microcerotermes eugnathus Silvestri (Blattodea: Termitidae) in Egypt. INSECTS 2020; 11:insects11110756. [PMID: 33158029 PMCID: PMC7692362 DOI: 10.3390/insects11110756] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/31/2020] [Accepted: 11/02/2020] [Indexed: 11/16/2022]
Abstract
Simple Summary The termite Microcerotermes eugnathus Silvestri (Blattodea, Termitidae) showed structural damage in Bir al-Shaghala cemeteries located in the oasis of Dakhla, Egypt. The mud tubes of this termite spread inside and over the mural painted floors of the tombs. Extracts from Lavandula latifolia, Origanum vulgare, and Syzygium aromaticum were tested for their anti-termitic activity and compared with the bio-insecticide, Bacillus thuringiensis var. kurstaki (Protecto 9.4% WP) and Dursban (Chlorpyrifos 48%). The bioassay experimental showed that the extracts have low activity against M. eugnathus compared to Protecto and Dursban, but the extract from O. vulgare showed promising natural termiticides. Abstract A trend towards environmentally friendly chemicals for use in termite management has been occurring globally. This study examined three naturally occurring plant extracts from Lavandula latifolia (Spike lavender), Origanum vulgare (Marjorum), and Syzygium aromaticum (Clove) against the termite Microcerotermes eugnathus. Plant extract results were compared to two commercially used termite pesticides, the bio-insecticide, Bacillus thuringiensis var. kurstaki (Protecto 9.4% WP) and Dursban (Chlorpyrifos 48%). Gas chromatography–mass spectrometry (GC-MS) analysis was used to identify the main compounds in the three plant extracts. The main compounds in Lavandula Latifolia were linalool (21.49%), lavandulol (12.77%), β-terpinyl acetate (10.49%), and camphor (9.30%). Origanum vulgare extract contained thymol (14.64%), m-cymene (10.63%), linalool (6.75%), and terpinen-4-ol (6.92%) as main compounds. Syzygium aromaticum contained eugenol (99.16%) as the most abundant identified compound. The extract of O. vulgare caused the highest termite death rate, with an LC50 of 770.67 mg/L. Exposure to lavender extract showed a high death rate with an LC50 of 1086.39 mg/L. Clove extract did not show significant insecticidal activity with an LC50 > 2000 mg/L. Significant termiticide effects were found, with LC50 values of 84.09 and 269.98 mg/L for soldiers and workers under the application of Dursban and Protecto, respectively. The LC50 values reported for nymphs were <120, <164.5, and 627.87 mg/L after exposure to Dursban, Protecto, and O. vulgare extract, respectively. The results of the study show that some of the extracts have low toxicity compared to the bioagent and Dursban, and may show promise as natural termiticides, particularly as extracts from O. vulgare.
Collapse
|
11
|
Maák I, Tóth E, Lenda M, Lőrinczi G, Kiss A, Juhász O, Czechowski W, Torma A. Behaviours indicating cannibalistic necrophagy in ants are modulated by the perception of pathogen infection level. Sci Rep 2020; 10:17906. [PMID: 33087857 PMCID: PMC7578781 DOI: 10.1038/s41598-020-74870-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 09/21/2020] [Indexed: 12/25/2022] Open
Abstract
Cannibalistic necrophagy is rarely observed in social hymenopterans, although a lack of food could easily favour such behaviour. One of the main supposed reasons for the rarity of necrophagy is that eating of nestmate corpses carries the risk of rapid spread of pathogens or parasites. Here we present an experimental laboratory study on behaviour indicating consumption of nestmate corpses in the ant Formica polyctena. We examined whether starvation and the fungal infection level of the corpses affects the occurrence of cannibalistic necrophagy. Our results showed that the ants distinguished between corpses of different types and with different levels of infection risk, adjusting their behaviour accordingly. The frequency of behaviours indicating cannibalistic necrophagy increased during starvation, although these behaviours seem to be fairly common in F. polyctena even in the presence of other food sources. The occurrence and significance of cannibalistic necrophagy deserve further research because, in addition to providing additional food, it may be part of the hygienic behaviour repertoire. The ability to detect infections and handle pathogens are important behavioural adaptations for social insects, crucial for the fitness of both individual workers and the entire colony.
Collapse
Affiliation(s)
- István Maák
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679, Warsaw, Poland.
- Department of Ecology, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary.
| | - Eszter Tóth
- Department of Microbiology, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary
- Fungal Pathogenicity Mechanisms Research Group, Hungarian Academy of Sciences, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary
| | - Magdalena Lenda
- Australian Research Council Centre of Excellence for Environmental Decisions, School of Biological Sciences, University of Queensland, St. Lucia, QLD, 4072, Australia
- Institute of Nature Conservation, Polish Academy of Sciences, Mickiewicza 33, 31-120, Kraków, Poland
| | - Gábor Lőrinczi
- Department of Ecology, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary
| | - Anett Kiss
- Department of Ecology, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary
| | - Orsolya Juhász
- Department of Ecology, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary
- Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary
| | - Wojciech Czechowski
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679, Warsaw, Poland
| | - Attila Torma
- Department of Ecology, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary
- Center for Ecological Research, Institute of Ecology and Botany, 'Lendület' Landscape and Conservation Ecology, Alkotmány Utca 2-4, Vácrátót, 2163, Hungary
| |
Collapse
|
12
|
Revisiting stigmergy in light of multi-functional, biogenic, termite structures as communication channel. Comput Struct Biotechnol J 2020; 18:2522-2534. [PMID: 33005314 PMCID: PMC7516209 DOI: 10.1016/j.csbj.2020.08.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 12/22/2022] Open
Abstract
Termite mounds are fascinating because of their intriguing composition of numerous geometric shapes and materials. However, little is known about these structures, or of their functionalities. Most research has been on the basic composition of mounds compared with surrounding soils. There has been some targeted research on the thermoregulation and ventilation of the mounds of a few species of fungi-growing termites, which has generated considerable interest from human architecture. Otherwise, research on termite mounds has been scattered, with little work on their explicit properties. This review is focused on how termites design and build functional structures as nest, nursery and food storage; for thermoregulation and climatisation; as defence, shelter and refuge; as a foraging tool or building material; and for colony communication, either as in indirect communication (stigmergy) or as an information channel essential for direct communication through vibrations (biotremology). Our analysis shows that systematic research is required to study the properties of these structures such as porosity and material composition. High resolution computer tomography in combination with nonlinear dynamics and methods from computational intelligence may provide breakthroughs in unveiling the secrets of termite behaviour and their mounds. In particular, the examination of dynamic and wave propagation properties of termite-built structures in combination with a detailed signal analysis of termite activities is required to better understand the interplay between termites and their nest as superorganism. How termite structures serve as defence in the form of disguising acoustic and vibration signals from detection by predators, and what role local and global vibration synchronisation plays for building are open questions that need to be addressed to provide insights into how termites utilise materials to thrive in a world of predators and competitors.
Collapse
|
13
|
Wisselink M, Aanen DK, van ’t Padje A. The Longevity of Colonies of Fungus-Growing Termites and the Stability of the Symbiosis. INSECTS 2020; 11:E527. [PMID: 32823564 PMCID: PMC7469218 DOI: 10.3390/insects11080527] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/08/2020] [Accepted: 08/10/2020] [Indexed: 01/10/2023]
Abstract
The agricultural mutualistic symbiosis between macrotermitine termites and Termitomyces fungi is obligate for both partners. The termites provide a protective growth environment for the fungus by cultivating it inside their colony and providing it with foraged plant material. The termites use the fungus for plant substrate degradation, and the production of asexual fruiting bodies for nourishment and re-inoculation of the fungus garden. The termite colony can reach an age of up to several decades, during which time it is believed that a single fungal monoculture is asexually propagated by the offspring of a single founding royal pair. The termite-fungus mutualism has a long evolutionary history dating back more than 30 million years. Both on the time-scale of a termite colony lifespan and that of the mutualistic symbiosis, questions arise about stability. We address the physical stability of the mound, the termite colony and the monoculture fungal garden during a colony's lifetime. On the long-term evolutionary scale, we address the stability of the symbiosis, where horizontal transmission of the symbiotic fungus raises the question of how the mutualistic interaction between host and symbiont persists over generations.
Collapse
Affiliation(s)
| | - Duur K. Aanen
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands; (M.W.); (A.v.P.)
| | | |
Collapse
|
14
|
Anyango JJ, Bautze D, Fiaboe KKM, Lagat ZO, Muriuki AW, Stöckli S, Riedel J, Onyambu GK, Musyoka MW, Karanja EN, Adamtey N. The impact of conventional and organic farming on soil biodiversity conservation: a case study on termites in the long-term farming systems comparison trials in Kenya. BMC Ecol 2020; 20:13. [PMID: 32103743 PMCID: PMC7045444 DOI: 10.1186/s12898-020-00282-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 02/20/2020] [Indexed: 11/18/2022] Open
Abstract
Background A long-term experiment at two trial sites in Kenya has been on-going since 2007 to assess the effect of organic and conventional farming systems on productivity, profitability and sustainability. During these trials the presence of significant numbers of termites (Isoptera) was observed. Termites are major soil macrofauna and within literature they are either depict as ‘pests’ or as important indicator for environmental sustainability. The extent by which termites may be managed to avoid crop damage, but improve sustainability of farming systems is worthwhile to understand. Therefore, a study on termites was added to the long-term experiments in Kenya. The objectives of the study were to quantify the effect of organic (Org) and conventional (Conv) farming systems at two input levels (low and high) on the abundance, incidence, diversity and foraging activities of termites. Results The results showed higher termite abundance, incidence, activity and diversity in Org-High compared to Conv-High, Conv-Low and Org-Low. However, the termite presence in each system was also dependent on soil depth, trial site and cropping season. During the experiment, nine different termite genera were identified, that belong to three subfamilies: (i) Macrotermitinae (genera: Allodontotermes, Ancistrotermes, Macrotermes, Microtermes, Odontotermes and Pseudocanthotermes), (ii) Termitinae (Amitermes and Cubitermes) and (iii) Nasutitiermitinae (Trinervitermes). Conclusions We hypothesize that the presence of termites within the different farming systems might be influenced by the types of input applied, the soil moisture content and the occurrence of natural enemies. Our findings further demonstrate that the organic high input system attracts termites, which are an important, and often beneficial, component of soil fauna. This further increases the potential of such systems in enhancing sustainable agricultural production in Kenya.
Collapse
Affiliation(s)
- John J Anyango
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya.,Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - David Bautze
- Department of International Cooperation, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, P.O. Box 219, 5070, Frick, Switzerland.
| | - Komi K M Fiaboe
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Zipporah O Lagat
- Zoology Department, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Anne W Muriuki
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - Sibylle Stöckli
- Department of Plant Science, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, P.O. Box 219, 5070, Frick, Switzerland
| | - Judith Riedel
- Department of International Cooperation, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, P.O. Box 219, 5070, Frick, Switzerland
| | - Gladys K Onyambu
- Zoology Department, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Martha W Musyoka
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Edward N Karanja
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Noah Adamtey
- Department of International Cooperation, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, P.O. Box 219, 5070, Frick, Switzerland
| |
Collapse
|
15
|
Caste-specific nutritional differences define carbon and nitrogen fluxes within symbiotic food webs in African termite mounds. Sci Rep 2019; 9:16698. [PMID: 31723187 PMCID: PMC6853943 DOI: 10.1038/s41598-019-53153-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/28/2019] [Indexed: 11/30/2022] Open
Abstract
Fungus-growing termites of the genus Macrotermes cultivate symbiotic fungi (Termitomyces) in their underground nest chambers to degrade plant matter collected from the environment. Although the general mechanism of food processing is relatively well-known, it has remained unclear whether the termites get their nutrition primarily from the fungal mycelium or from plant tissues partly decomposed by the fungus. To elucidate the flows of carbon and nitrogen in the complicated food-chains within the nests of fungus-growing termites, we determined the stable isotope signatures of different materials sampled from four Macrotermes colonies in southern Kenya. Stable isotopes of carbon revealed that the termite queen and the young larvae are largely sustained by the fungal mycelium. Conversely, all adult workers and soldiers seem to feed predominantly on plant and/or fungus comb material, demonstrating that the fungal symbiont plays a different nutritional role for different termite castes. Nitrogen stable isotopes indicated additional differences between castes and revealed intriguing patterns in colony nitrogen cycling. Nitrogen is effectively recycled within the colonies, but also a presently unspecified nitrogen source, most likely symbiotic nitrogen-fixing bacteria, seems to contribute to nitrogen supply. Our results indicate that the gut microbiota of the termite queen might be largely responsible for the proposed nitrogen fixation.
Collapse
|
16
|
Sun P, Li G, Jian J, Liu L, Chen J, Yu S, Xu H, Lei C, Zhou X, Huang Q. Transcriptomic and Functional Analyses of Phenotypic Plasticity in a Higher Termite, Macrotermes barneyi Light. Front Genet 2019; 10:964. [PMID: 31681415 PMCID: PMC6797822 DOI: 10.3389/fgene.2019.00964] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 09/10/2019] [Indexed: 12/04/2022] Open
Abstract
Eusocial termites have a complex caste system, which leads to the division of labor. Previous studies offered some insight into the caste differentiation in lower termites; however, few studies were focusing on the molecular mechanisms of higher termites with sophisticated societies. Comparative transcriptomic analyses of five immature castes of a higher termite, Macrotermes barneyi Light, suggest that phenotypic plasticity is modulated by an array of transcriptional changes, including differentially expressed genes (e.g., caste-biased genes Vtg and TnC), co-expression networks (e.g., genes associated with nymph reproduction), and alternative splicing (e.g., events related to muscle development in presoldiers). Transcriptional (RT-PCR and RT-qPCR) and functional (in vivo RNAi) validation studies reveal multiple molecular mechanisms contributing to the phenotypic plasticity in eusocial termites. Molecular mechanisms governing the phenotypic plasticity in M. barneyi could be a rule rather than an exception in the evolution of sociality.
Collapse
Affiliation(s)
- Pengdong Sun
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Ganghua Li
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jianbo Jian
- Marine Biology Institute, Shantou University, Shantou, China
| | - Long Liu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Junhui Chen
- School of Bioscience and Bioengineering, Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, China
| | - Shuxin Yu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Huan Xu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Chaoliang Lei
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xuguo Zhou
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Qiuying Huang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
17
|
Rasheed H, Ye C, Meng Y, Ran Y, Li J, Su X. Comparative transcriptomic analysis and endocuticular protein gene expression of alate adults, workers and soldiers of the termite Reticulitermes aculabialis. BMC Genomics 2019; 20:742. [PMID: 31615402 PMCID: PMC6794787 DOI: 10.1186/s12864-019-6149-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/29/2019] [Indexed: 12/11/2022] Open
Abstract
Background The insect cuticle is mainly composed of exocuticle and endocuticle layers that consist of a large number of structural proteins. The thickness and synthesis of the exocuticle depend on different castes that perform various functions in alates, workers and soldiers. However, it is not clear whether the soft endocuticle is involved in the division of labour in termite colonies. To reveal the structural characteristics of the endocuticle in different castes, we investigated the thickness of endocuticle layers in alates, workers and soldiers of the termite Reticulitermes aculabialis, and then we sequenced their transcriptome and detected the endocuticle protein genes. The differential expression levels of the endocuticular protein genes were confirmed in the three castes. Results We found that there was a great difference in the thickness of the endocuticle among the alates, soldiers and workers. The thickest endocuticle layers were found in the heads of the workers 7.88 ± 1.67 μm. The endocuticle layer in the head of the workers was approximately three-fold and nine-fold thicker than that in the heads of soldiers and alates, respectively. The thinnest endocuticle layers occurred in the head, thorax and abdomen of alates, which were 0.86 ± 0.15, 0.76 ± 0.24 and 0.52 ± 0.17 μm thick, respectively, and had no significant differences. A total of 43,531,650 clean sequencing reads was obtained, and 89,475 unigenes were assembled. Of the 70 identified cuticular protein genes, 10 endocuticular genes that belong to the RR-1 family were selected. qRT-PCR analysis of the five endocuticular genes (SgAbd-2, SgAbd-9, Abd-5, SgAbd-2-like and Abd-4-like) revealed that the endocuticle genes were more highly expressed in workers than in soldiers and alates. Conclusion These results suggest that SgAbd and Abd are the key components of the endocuticle. We infer that the thicker endocuticle in workers is helpful for them to perform their functions against environmental stress.
Collapse
Affiliation(s)
- Humaira Rasheed
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an, China.,College of Life Sciences, Northwest University, Xi'an, China
| | - Chenxu Ye
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an, China.,College of Life Sciences, Northwest University, Xi'an, China
| | - Yufeng Meng
- College of Life Sciences, Northwest University, Xi'an, China
| | - Yuehua Ran
- College of Life Sciences, Northwest University, Xi'an, China
| | - Jing Li
- College of Life Sciences, Northwest University, Xi'an, China
| | - Xiaohong Su
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an, China. .,College of Life Sciences, Northwest University, Xi'an, China.
| |
Collapse
|
18
|
Cesar CS, Giacometti D, Costa-Leonardo AM, Casarin FE. Drywood Pest Termite Cryptotermes brevis (Blattaria: Isoptera: Kalotermitidae): a Detailed Morphological Study of Pseudergates. NEOTROPICAL ENTOMOLOGY 2019; 48:822-833. [PMID: 31197677 DOI: 10.1007/s13744-019-00687-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 04/11/2019] [Indexed: 06/09/2023]
Abstract
The Kalotermitidae Cryptotermes brevis (Walker) presents colonies that lack a true worker caste. They have totipotent worker-like individuals named pseudergates. Few studies have characterized the morphology of immature instars, including pseudergates. In order to identify these instars and characterize the pseudergates, we conducted a comparison between morphometric and morphological variations among immature individuals of C. brevis colonies. Juvenile hormone analog (JHA) was used in the first instar nymphs to induce regressive molts and compare morphological differences between nymphs and pseudergates. Results showed the existence of three larval instars and four nymphal instars. These immatures were morphologically characterized. Individuals classified as third instar larvae presented white body, 10 to 12 antennal articles, absent or small non-pigmented compound eyes, and absence of wing buds. Pseudergates presented pigmented abdomen and sclerotized cuticle, 10 to 12 antennal articles, and absent or small compound eyes, and few specimens had large pigmented compound eyes and absence of wing buds. First instar nymphs had pigmented abdomen and sclerotized cuticle, 10 to 12 antennal articles, both large non-pigmented and pigmented compound eyes, the presence of wing buds. Bioassays using JHA on first instar nymphs resulted in a large percentage of nymph-soldier intercastes. We concluded that abdomen pigmentation and sclerotized cuticle are good characters to differentiate pseudergates from larvae and the absence of wing buds is a good character to differentiate pseudergates from nymphs. Our findings not only contribute to the basic biological and morphological information of this species but also help to identify correctly pseudergates in further studies that involve applied bioassays.
Collapse
Affiliation(s)
- C S Cesar
- Dept of Ecology and Evolutionary Biology, Lab de Termitologia, Federal Univ of São Paulo (UNIFESP), Diadema, SP, Brasil.
- Dept of Ecology, Univ of São Paulo, São Paulo, SP, Brasil.
| | - D Giacometti
- Dept of Ecology and Evolutionary Biology, Lab de Termitologia, Federal Univ of São Paulo (UNIFESP), Diadema, SP, Brasil
| | - A M Costa-Leonardo
- Dept of Biological Sciences, Instituto de Biociências, São Paulo State Univ (UNESP), Rio Claro, SP, Brasil
| | - F E Casarin
- Dept of Ecology and Evolutionary Biology, Lab de Termitologia, Federal Univ of São Paulo (UNIFESP), Diadema, SP, Brasil
| |
Collapse
|
19
|
Tasanathai K, Noisripoom W, Chaitika T, Khonsanit A, Hasin S, Luangsa-Ard J. Phylogenetic and morphological classification of Ophiocordyceps species on termites from Thailand. MycoKeys 2019; 56:101-129. [PMID: 31402842 PMCID: PMC6684523 DOI: 10.3897/mycokeys.56.37636] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 07/22/2019] [Indexed: 11/14/2022] Open
Abstract
Seven new species occurring on termites are added to Ophiocordyceps – O.asiatica, O.brunneirubra, O.khokpasiensis, O.mosingtoensis, O.pseudocommunis, O.pseudorhizoidea and O.termiticola, based on morphological and molecular phylogenetic evidence. O.brunneirubra possesses orange to reddish-brown immersed perithecia on cylindrical to clavate stromata. O.khokpasiensis, O.mosingtoensis and O.termiticola have pseudo-immersed perithecia while O.asiatica, O.pseudocommunis and O.pseudorhizoidea all possess superficial perithecia, reminiscent of O.communis and O.rhizoidea. Phylogenetic analyses based on a combined dataset comprising the internal transcribed spacer regions (ITS) and the largest subunit (LSU) of the ribosomal DNA, partial regions of the elongation factor 1-α (TEF) and the largest and second largest subunits for the RNA polymerase genes (RPB1, RPB2) strongly support the placement of these seven new species in Ophiocordyceps.
Collapse
Affiliation(s)
- Kanoksri Tasanathai
- Plant Microbe Interaction Research Team, Bioscience and Biotechnology for Agriculture, BIOTEC, NSTDA, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand Bioscience and Biotechnology for Agriculture Pathum Thani Thailand
| | - Wasana Noisripoom
- Plant Microbe Interaction Research Team, Bioscience and Biotechnology for Agriculture, BIOTEC, NSTDA, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand Bioscience and Biotechnology for Agriculture Pathum Thani Thailand
| | - Thanyarat Chaitika
- Plant Microbe Interaction Research Team, Bioscience and Biotechnology for Agriculture, BIOTEC, NSTDA, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand Bioscience and Biotechnology for Agriculture Pathum Thani Thailand
| | - Artit Khonsanit
- Plant Microbe Interaction Research Team, Bioscience and Biotechnology for Agriculture, BIOTEC, NSTDA, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand Bioscience and Biotechnology for Agriculture Pathum Thani Thailand
| | - Sasitorn Hasin
- Innovation of Environmental Management, College of Innovative Management, Valaya Alongkorn Rajabhat University under the Royal Patronage, Khlong Luang, Pathum Thani 12120, Thailand Valaya Alongkorn Rajabhat University under the Royal Patronage Pathum Thani Thailand
| | - Jennifer Luangsa-Ard
- Plant Microbe Interaction Research Team, Bioscience and Biotechnology for Agriculture, BIOTEC, NSTDA, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand Bioscience and Biotechnology for Agriculture Pathum Thani Thailand
| |
Collapse
|
20
|
Hellemans S, Dolejšová K, Křivánek J, Fournier D, Hanus R, Roisin Y. Widespread occurrence of asexual reproduction in higher termites of the Termes group (Termitidae: Termitinae). BMC Evol Biol 2019; 19:131. [PMID: 31226928 PMCID: PMC6588926 DOI: 10.1186/s12862-019-1459-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 06/13/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A decade ago, the mixed reproductive strategy Asexual Queen Succession (AQS) was first described in termites. In AQS species, the workers, soldiers and dispersing reproductives are produced through sexual reproduction, while non-dispersing (neotenic) queens arise through automictic thelytokous parthenogenesis, replace the founding queen and mate with the founding king. As yet, AQS has been documented in six species from three lineages of lower (Rhinotermitidae) and higher (Termitinae: Termes group and Syntermitinae) termites. Independent evolution of the capacity of thelytoky as a preadaptation to AQS is supported by different mechanisms of automixis in each of the three clades. These pioneering discoveries prompt the question on the extent of thelytoky and AQS in the diversified family of higher termites. RESULTS Here, we investigated the capacity of thelytoky and occurrence of AQS in three species from the phylogenetic proximity of the neotropical AQS species Cavitermes tuberosus (Termitinae: Termes group): Palmitermes impostor, Spinitermes trispinosus, and Inquilinitermes inquilinus. We show that queens of all three species are able to lay unfertilized eggs, which undergo thelytokous parthenogenesis (via gamete duplication as in C. tuberosus) and develop through the transitional stage of aspirants into replacement neotenic queens. CONCLUSIONS The breeding system in P. impostor is very reminiscent of that described in C. tuberosus and can be characterized as AQS. In the remaining two species, our limited data do not allow classifying the breeding system as AQS; yet, also in these species the thelytokous production of neotenic females appears to be a systematic element of reproductive strategies. It appears likely that the capacity of thelytokous parthenogenesis evolved once in the Termes group, and may ultimately be found more widely, well beyond these Neotropical species.
Collapse
Affiliation(s)
- Simon Hellemans
- Evolutionary Biology & Ecology, Université Libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 160/12, B-1050, Brussels, Belgium.
| | - Klára Dolejšová
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, CZ-166 10, Prague 6, Czech Republic
| | - Jan Křivánek
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, CZ-166 10, Prague 6, Czech Republic
| | - Denis Fournier
- Evolutionary Biology & Ecology, Université Libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 160/12, B-1050, Brussels, Belgium
| | - Robert Hanus
- Chemistry of Social Insects, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, CZ-166 10, Prague 6, Czech Republic.
| | - Yves Roisin
- Evolutionary Biology & Ecology, Université Libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 160/12, B-1050, Brussels, Belgium
| |
Collapse
|
21
|
Funaro CF, Schal C, Vargo EL. Queen and king recognition in the subterranean termite, Reticulitermes flavipes: Evidence for royal recognition pheromones. PLoS One 2019; 14:e0209810. [PMID: 31145770 PMCID: PMC6542537 DOI: 10.1371/journal.pone.0209810] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 05/17/2019] [Indexed: 01/03/2023] Open
Abstract
Royal recognition is a central feature of insect societies, allowing them to maintain the reproductive division of labor and regulate colony demography. Queen recognition has been broadly demonstrated and queen recognition pheromones have been identified in social hymenopterans, and in one termite species. Here we describe behaviors that are elicited in workers and soldiers by neotenic queens and kings of the subterranean termite, Reticulitermes flavipes, and demonstrate the chemical basis for the behavior. Workers and soldiers readily perform a lateral or longitudinal shaking behavior upon antennal contact with queens and kings. When royal cuticular chemicals are transferred to live workers or inert glass dummies, they elicit antennation and shaking in a dose-dependent manner. The striking response to reproductives and their cuticular extracts suggests that royal-specific cuticular compounds act as recognition pheromones and that shaking behavior is a clear and measurable queen and king recognition response in this termite species.
Collapse
Affiliation(s)
- Colin F. Funaro
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States of America
- * E-mail:
| | - Coby Schal
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States of America
| | - Edward L. Vargo
- Department of Entomology, Texas A&M University, College Station, TX, United States of America
| |
Collapse
|
22
|
Nii R, Oguchi K, Shinji J, Koshikawa S, Miura T. Reduction of a nymphal instar in a dampwood termite: heterochronic shift in the caste differentiation pathways. EvoDevo 2019; 10:10. [PMID: 31123582 PMCID: PMC6521406 DOI: 10.1186/s13227-019-0123-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 04/16/2019] [Indexed: 11/10/2022] Open
Abstract
Background Generally in termites, alates differentiate through multiple nymphal instars which gradually develop wing buds. However, in a dampwood termite, Hodotermopsis sjostedti, alates molt directly from a single nymphal instar with short wing buds. In this study, to examine the mechanism underlying the wing formation during the alate differentiation in H. sjostedti, histological and morphological observations were carried out on the developmental process of wing formation during the nymphal instar, in comparison with those in Zootermopsis nevadensis, which has two nymphal instars. Furthermore, the expression patterns of genes that are thought to be responsible for wing formation, i.e., wing-patterning genes and genes encoding hormone-related factors, were quantified during alate differentiation and compared between the two species. Results The results showed that, in H. sjostedti, wings were formed in a complicatedly folded shape, not only inside the wing buds as seen in Z. nevadensis, but also under the dorsal thoracic cuticle, where the wing tips shifted toward the median thoracic part. Accordingly, the wing expansion pattern also differed from that in Z. nevadensis. Furthermore, the results of real-time qRT-PCR on overall expression profiles of wing-patterning genes and hormone-related genes suggest that the single nymphal instar in H. sjostedti well resembles to the second nymphal instar in Z. nevadensis. In particular, significant upregulation of vestigial (vg) and downregulation of Krüppel homolog 1 (Kr-h1) that were observed at the second nymphal instar in Z. nevadensis apparently occurred during the single nymphal instar in H. sjostedti. Conclusion The developmental events for wing formation are compacted into a single nymphal instar in H. sjostedti, and as a result, the unique wing formation is seen to compensate for the spatial restriction inside small wing buds, leading to the completion of functional wings.
Collapse
Affiliation(s)
- Ryotaro Nii
- 1Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810 Japan
| | - Kohei Oguchi
- 2Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Kanagawa 238-0225 Japan
| | - Junpei Shinji
- 2Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Kanagawa 238-0225 Japan
| | - Shigeyuki Koshikawa
- 3Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido 060-0810 Japan
| | - Toru Miura
- 2Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Kanagawa 238-0225 Japan
| |
Collapse
|
23
|
da Costa RR, Hu H, Li H, Poulsen M. Symbiotic Plant Biomass Decomposition in Fungus-Growing Termites. INSECTS 2019; 10:insects10040087. [PMID: 30925664 PMCID: PMC6523192 DOI: 10.3390/insects10040087] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/05/2019] [Accepted: 03/06/2019] [Indexed: 01/25/2023]
Abstract
Termites are among the most successful animal groups, accomplishing nutrient acquisition through long-term associations and enzyme provisioning from microbial symbionts. Fungus farming has evolved only once in a single termite sub-family: Macrotermitinae. This sub-family has become a dominant decomposer in the Old World; through enzymatic contributions from insects, fungi, and bacteria, managed in an intricate decomposition pathway, the termites obtain near-complete utilisation of essentially any plant substrate. Here we review recent insights into our understanding of the process of plant biomass decomposition in fungus-growing termites. To this end, we outline research avenues that we believe can help shed light on how evolution has shaped the optimisation of plant-biomass decomposition in this complex multipartite symbiosis.
Collapse
Affiliation(s)
- Rafael R da Costa
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen East, Denmark.
| | - Haofu Hu
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen East, Denmark.
| | - Hongjie Li
- Department of Bacteriology, University of Wisconsin⁻Madison, Madison, WI 53706, USA.
| | - Michael Poulsen
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen East, Denmark.
| |
Collapse
|
24
|
Termite Ecology in the First Two Decades of the 21st Century: A Review of Reviews. INSECTS 2019; 10:insects10030060. [PMID: 30813518 PMCID: PMC6468683 DOI: 10.3390/insects10030060] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/19/2019] [Accepted: 02/21/2019] [Indexed: 11/17/2022]
Abstract
Termite ecology came of age in 1978 with the seminal review of Wood and Sands which by considering the quantitative contributions made by termites to the carbon cycle at the landscape level concluded that they were major players in tropical ecosystems. Subsequent field work in the succeeding two decades was summarised in 2000 by Bignell and Eggleton, the most recent review which attempted to cover the entire topic in detail, which included 188 listed references and has been extensively cited for almost 20 years. Subsequent summaries more narrowly defined or in some cases more superficial are listed in the bibliography. In this overview, the main and subsidiary headings in Bignell and Eggleton are revisited and reclassified in the light of 186 selected articles added to the relevant literature since 2000, and some earlier work. While the literature on termite ecology remains buoyant, it has declined relative to publications on other aspects of termite biology. Overall, the thesis that termites have a major impact on, and are major indicators of soil health and landscape integrity in the tropics and sub-tropics is maintained, but the drivers of local diversity, abundance and biomass remain complex, with many biographical, edaphic and optimum sampling issues not completely resolved. The large increase in diversity and abundance data from Neotropical biomes can also be noted.
Collapse
|
25
|
Abstract
Several species of millimetric-sized termites across Africa, Asia, Australia, and South America collectively construct large, meter-sized, porous mound structures that serve to regulate mound temperature, humidity, and gas concentrations. These mounds display varied yet distinctive morphologies that range widely in size and shape. To explain this morphological diversity, we introduce a mathematical model that couples environmental physics to insect behavior: The advection and diffusion of heat and pheromones through a porous medium are modified by the mound geometry and, in turn, modify that geometry through a minimal characterization of termite behavior. Our model captures the range of naturally observed mound shapes in terms of a minimal set of dimensionless parameters and makes testable hypotheses for the response of mound morphology to external temperature oscillations and internal odors. Our approach also suggests mechanisms by which evolutionary changes in odor production rate and construction behavior coupled to simple physical laws can alter the characteristic mound morphology of termites.
Collapse
Affiliation(s)
- Samuel A Ocko
- Department of Applied Physics, Stanford University, Stanford, CA 94305
| | - Alexander Heyde
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | - L Mahadevan
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138;
- Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
- Department of Physics, Harvard University, Cambridge, MA 02138
- Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, MA 02138
| |
Collapse
|
26
|
Vargo EL. Diversity of Termite Breeding Systems. INSECTS 2019; 10:insects10020052. [PMID: 30759735 PMCID: PMC6409762 DOI: 10.3390/insects10020052] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 12/05/2022]
Abstract
Termites are social insects that live in colonies headed by reproductive castes. The breeding system is defined by the number of reproductive individuals in a colony and the castes to which they belong. There is tremendous variation in the breeding system of termites both within and among species. The current state of our understanding of termite breeding systems is reviewed. Most termite colonies are founded by a primary (alate-derived) king and queen who mate and produce the other colony members. In some species, colonies continue throughout their life span as simple families headed by the original king and queen. In others, the primary king and queen are replaced by numerous neotenic (nymph- or worker-derived) reproductives, or less commonly primary reproductives, that are descendants of the original founding pair leading to inbreeding in the colony. In still others, colonies can have multiple unrelated reproductives due to either founding the colonies as groups or through colony fusion. More recently, parthenogenetic reproduction has shown to be important in some termite species and may be widespread. A major challenge in termite biology is to understand the ecological and evolutionary factors driving the variation in termite breeding systems.
Collapse
Affiliation(s)
- Edward L Vargo
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA.
| |
Collapse
|
27
|
Characterization of the 12S rRNA Gene Sequences of the Harvester Termite Anacanthotermes ochraceus (Blattodea: Hodotermitidae) and Its Role as A Bioindicator of Heavy Metal Accumulation Risks in Saudi Arabia. INSECTS 2019; 10:insects10020051. [PMID: 30744024 PMCID: PMC6409844 DOI: 10.3390/insects10020051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/27/2019] [Accepted: 02/03/2019] [Indexed: 12/07/2022]
Abstract
Termites are social insects of economic importance that have a worldwide distribution. Identifying termite species has traditionally relied on morphometric characters. Recently, several mitochondrial genes have been used as genetic markers to determine the correlation between different species. Heavy metal accumulation causes serious health problems in humans and animals. Being involved in the food chain, insects are used as bioindicators of heavy metals. In the present study, 100 termite individuals of Anacanthotermes ochraceus were collected from two Saudi Arabian localities with different geoclimatic conditions (Riyadh and Taif). These individuals were subjected to morphological identification followed by molecular analysis using mitochondrial 12S rRNA gene sequence, thus confirming the morphological identification of A. ochraceus. Furthermore, a phylogenetic analysis was conducted to determine the genetic relationship between the acquired species and other termite species with sequences previously submitted in the GenBank database. Several heavy metals including Ca, Al, Mg, Zn, Fe, Cu, Mn, Ba, Cr, Co, Be, Ni, V, Pb, Cd, and Mo were measured in both collected termites and soil samples from both study sites. All examined samples (termite and soil) showed high concentrations of metals with different concentrations and ratios. Generally, most measured metals had a significantly high concentration in soil and termites at Taif, except for Ca, Cd, Co, Cr, Cu, Mg, and Ni showing significantly high concentrations at Riyadh. Furthermore, termites accumulated higher amounts of heavy metals than the soil at both locations. The mean concentrations of the measured metals in soil samples were found to be in the descending order Ca ˃ Al ˃ Mg ˃ Zn ˃ Fe ˃ Cu ˃ Mn ˃ Ba ˃ Cr ˃ Co ˃ Be ˃ Ni ˃ V ˃ Pb ˃ Cd ˃ Mo, while it was Ca ˃ Mg ˃ Al ˃ Fe ˃ Zn ˃ Cu ˃ Mn ˃ Be ˃ Ba ˃ Pb ˃ Cr ˃ V ˃ Ni ˃ Cd ˃ Mo ˃ Co in termite specimens. The mean concentrations of the studied metals were determined in the soil and termite specimens at both locations. In addition, the contamination factor, pollution load index (PLI) and degree of contamination were calculated for all studied metals in different samples, indicating that both studied sites were polluted. However, Taif showed a significantly higher degree of pollution. Thus, the accurate identification of economically important insects, such as termites, is of crucial importance to plan for appropriate control strategies. In addition, termites are a good bioindicator to study land pollution.
Collapse
|
28
|
Miskelly J, Paiero SM. Mantodea, Blattodea, Orthoptera, Dermaptera, and Phasmida of Canada. Zookeys 2019; 819:255-269. [PMID: 30713444 PMCID: PMC6355752 DOI: 10.3897/zookeys.819.27241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/21/2018] [Indexed: 11/12/2022] Open
Abstract
In the last 40 years, the number of species in the orthopteroid orders has increased by ~10% from that known in 1979. The largest order, the Orthoptera, has increased from 205 to 235 species known in Canada. The number of Blattodea has increased from 14 to 18 species, while Dermaptera has increased from 5 to 6 species. The number of species of Mantodea (3) and Phasmida (1) known in Canada have remained unchanged. Most new species records reported in Canada since 1979 have resulted from new collections along the periphery of the range of more widespread species. Some species reported since 1979 are recent introductions to Canada, including species restricted to homes or other heated buildings. The taxonomy of these orders has also changed, with only the Dermaptera having maintained its order definition since the 1979 treatment. Additional orthopteroid species are likely to occur in Canada, particularly in the orders Orthoptera and Blattodea. DNA barcodes are available for more than 60% of the species known to occur in Canada.
Collapse
Affiliation(s)
- James Miskelly
- Royal British Columbia Museum, 675 Belleville St., Victoria, British Columbia, V8W 9W2, CanadaRoyal British Columbia MuseumVictoriaCanada
| | - Steven M. Paiero
- School of Environmental Sciences, 50 Stone Rd. East, University of Guelph, Guelph, Ontario, N1G 2W1, CanadaUniversity of GuelphGuelphCanada
| |
Collapse
|
29
|
Vesala R, Harjuntausta A, Hakkarainen A, Rönnholm P, Pellikka P, Rikkinen J. Termite mound architecture regulates nest temperature and correlates with species identities of symbiotic fungi. PeerJ 2019; 6:e6237. [PMID: 30671290 PMCID: PMC6339472 DOI: 10.7717/peerj.6237] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 12/07/2018] [Indexed: 11/20/2022] Open
Abstract
Background Large and complex mounds built by termites of the genus Macrotermes characterize many dry African landscapes, including the savannas, bushlands, and dry forests of the Tsavo Ecosystem in southern Kenya. The termites live in obligate symbiosis with filamentous fungi of the genus Termitomyces. The insects collect dead plant material from their environment and deposit it into their nests where indigestible cell wall compounds are effectively decomposed by the fungus. Above-ground mounds are built to enhance nest ventilation and to maintain nest interior microclimates favorable for fungal growth. Objectives In Tsavo Ecosystem two Macrotermes species associate with three different Termitomyces symbionts, always with a monoculture of one fungal species within each termite nest. As mound architecture differs considerably both between and within termite species we explored potential relationships between nest thermoregulatory strategies and species identity of fungal symbionts. Methods External dimensions were measured from 164 Macrotermes mounds and the cultivated Termitomyces species were identified by sequencing internal transcribed spacer (ITS) region of ribosomal DNA. We also recorded the annual temperature regimes of several termite mounds to determine relations between mound architecture and nest temperatures during different seasons. Results Mound architecture had a major effect on nest temperatures. Relatively cool temperatures were always recorded from large mounds with open ventilation systems, while the internal temperatures of mounds with closed ventilation systems and small mounds with open ventilation systems were consistently higher. The distribution of the three fungal symbionts in different mounds was not random, with one fungal species confined to “hot nests.” Conclusions Our results indicate that different Termitomyces species have different temperature requirements, and that one of the cultivated species is relatively intolerant of low temperatures. The dominant Macrotermes species in our study area can clearly modify its mound architecture to meet the thermal requirements of several different symbionts. However, a treacherous balance seems to exist between symbiont identity and mound architecture, as the maintenance of the thermophilic fungal species obviously requires reduced mound architecture that, in turn, leads to inadequate gas exchange. Hence, our study concludes that while the limited ventilation capacity of small mounds sets strict limits to insect colony growth, in this case, improving nest ventilation would invariable lead to excessively low nest temperatures, with negative consequences to the symbiotic fungus.
Collapse
Affiliation(s)
- Risto Vesala
- Finnish Museum of Natural History, Botany Unit, University of Helsinki, Helsinki, Finland.,Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Anni Harjuntausta
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Anu Hakkarainen
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Petri Rönnholm
- Department of Built Environment, Aalto University, Espoo, Finland
| | - Petri Pellikka
- College of Global Change and Earth System Science, Beijing Normal University, Beijing, China.,Earth Change Observation Laboratory, Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
| | - Jouko Rikkinen
- Finnish Museum of Natural History, Botany Unit, University of Helsinki, Helsinki, Finland.,Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| |
Collapse
|
30
|
Schyra J, Korb J. Termite Communities along A Disturbance Gradient in a West African Savanna. INSECTS 2019; 10:insects10010017. [PMID: 30626037 PMCID: PMC6358944 DOI: 10.3390/insects10010017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 12/28/2018] [Accepted: 12/30/2018] [Indexed: 11/23/2022]
Abstract
(1) Background: Termites are important ecosystem engineers, crucial for the maintenance of tropical biodiversity and ecosystem functioning. But they are also pests which cause billions of dollars in damage annually to humans. Currently, our understanding of the mechanisms influencing species occurrences is limited and we do not know what distinguishes pest from non-pest species. (2) Method: We analyzed how anthropogenic disturbance (agriculture) affects species occurrences. We tested the hypothesis that strong disturbance functions as a habitat filter and selects for a subset of species which are major pests of crop. Using a cross-sectional approach, we studied termite assemblage composition along a disturbance gradient from fields to 12-year-old fallows in a West African savanna. (3) Results: We reliably identified 19 species using genetic markers with a mean of about 10 species—many of them from the same feeding type—co-occurring locally. Supporting our hypothesis, disturbance was associated with environmental filtering of termites from the regional species pool, maybe via its effect on vegetation type. The most heavily disturbed sites were characterized by a subset of termite species which are well-known pests of crop. (4) Conclusion: These results are in line with the idea that strong anthropogenic disturbance selects for termite pest species.
Collapse
Affiliation(s)
- Janine Schyra
- Behavioral Biology, University of Osnabrueck, Barbarastr. 11, D-49076 Osnabrueck, Germany.
| | - Judith Korb
- Behavioral Biology, University of Osnabrueck, Barbarastr. 11, D-49076 Osnabrueck, Germany.
- Evolution and Ecology, Albert-Ludwigs-University Freiburg, Hauptstr. 1, D-79104 Freiburg im Breisgau, Germany.
| |
Collapse
|
31
|
Diversity of Bacterial Biota in Capnodis tenebrionis (Coleoptera: Buprestidae) Larvae. Pathogens 2019; 8:pathogens8010004. [PMID: 30621355 PMCID: PMC6470736 DOI: 10.3390/pathogens8010004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 01/01/2019] [Accepted: 01/04/2019] [Indexed: 11/17/2022] Open
Abstract
The bacterial biota in larvae of Capnodis tenebrionis, a serious pest of cultivated stone-fruit trees in the West Palearctic, was revealed for the first time using the MiSeq platform. The core bacterial community remained the same in neonates whether upon hatching or grown on peach plants or an artificial diet, suggesting that C. tenebrionis larvae acquire much of their bacterial biome from the parent adult. Reads affiliated with class levels Gammaproteobacteria and Alphaproteobacteria (phylum Proteobacteria ca. 86%), and Actinobacteria (ca. 14%) were highly abundant. Most diverse reads belong to the families Xanthomonadaceae (50%), Methylobacteriaceae (20%), Hyphomicrobiaceae (9%), Micrococcaceae (7%) and Geodermatophilaceae (4.5%). About two-thirds of the reads are affiliated with the genera Lysobacter, Microvirga, Methylobacterium, and Arthrobacter, which encompass species displaying cellulolytic and lipolytic activities. This study provides a foundation for future studies to elucidate the roles of bacterial biota in C. tenebrionis.
Collapse
|
32
|
Fiber-associated spirochetes are major agents of hemicellulose degradation in the hindgut of wood-feeding higher termites. Proc Natl Acad Sci U S A 2018; 115:E11996-E12004. [PMID: 30504145 DOI: 10.1073/pnas.1810550115] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Symbiotic digestion of lignocellulose in wood-feeding higher termites (family Termitidae) is a two-step process that involves endogenous host cellulases secreted in the midgut and a dense bacterial community in the hindgut compartment. The genomes of the bacterial gut microbiota encode diverse cellulolytic and hemicellulolytic enzymes, but the contributions of host and bacterial symbionts to lignocellulose degradation remain ambiguous. Our previous studies of Nasutitermes spp. documented that the wood fibers in the hindgut paunch are consistently colonized not only by uncultured members of Fibrobacteres, which have been implicated in cellulose degradation, but also by unique lineages of Spirochaetes. Here, we demonstrate that the degradation of xylan, the major component of hemicellulose, is restricted to the hindgut compartment, where it is preferentially hydrolyzed over cellulose. Metatranscriptomic analysis documented that the majority of glycoside hydrolase (GH) transcripts expressed by the fiber-associated bacterial community belong to family GH11, which consists exclusively of xylanases. The substrate specificity was further confirmed by heterologous expression of the gene encoding the predominant homolog. Although the most abundant transcripts of GH11 in Nasutitermes takasagoensis were phylogenetically placed among their homologs of Firmicutes, immunofluorescence microscopy, compositional binning of metagenomics contigs, and the genomic context of the homologs indicated that they are encoded by Spirochaetes and were most likely obtained by horizontal gene transfer among the intestinal microbiota. The major role of spirochetes in xylan degradation is unprecedented and assigns the fiber-associated Treponema clades in the hindgut of wood-feeding higher termites a prominent part in the breakdown of hemicelluloses.
Collapse
|
33
|
Downing PA, Griffin AS, Cornwallis CK. Sex differences in helping effort reveal the effect of future reproduction on cooperative behaviour in birds. Proc Biol Sci 2018; 285:20181164. [PMID: 30135160 PMCID: PMC6125912 DOI: 10.1098/rspb.2018.1164] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 07/25/2018] [Indexed: 01/06/2023] Open
Abstract
The evolution of helping behaviour in species that breed cooperatively in family groups is typically attributed to kin selection alone. However, in many species, helpers go on to inherit breeding positions in their natal groups, but the extent to which this contributes to selection for helping is unclear as the future reproductive success of helpers is often unknown. To quantify the role of future reproduction in the evolution of helping, we compared the helping effort of female and male retained offspring across cooperative birds. The kin selected benefits of helping are equivalent between female and male helpers-they are equally related to the younger siblings they help raise-but the future reproductive benefits of helping differ because of sex differences in the likelihood of breeding in the natal group. We found that the sex which is more likely to breed in its natal group invests more in helping, suggesting that in addition to kin selection, helping in family groups is shaped by future reproduction.
Collapse
|
34
|
Mhatre N, Robert D. The Drivers of Heuristic Optimization in Insect Object Manufacture and Use. Front Psychol 2018; 9:1015. [PMID: 29977216 PMCID: PMC6021527 DOI: 10.3389/fpsyg.2018.01015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/31/2018] [Indexed: 11/17/2022] Open
Abstract
Insects have small brains and heuristics or 'rules of thumb' are proposed here to be a good model for how insects optimize the objects they make and use. Generally, heuristics are thought to increase the speed of decision making by reducing the computational resources needed for making decisions. By corollary, heuristic decisions are also deemed to impose a compromise in decision accuracy. Using examples from object optimization behavior in insects, we will argue that heuristics do not inevitably imply a lower computational burden or lower decision accuracy. We also show that heuristic optimization may be driven by certain features of the optimization problem itself: the properties of the object being optimized, the biology of the insect, and the properties of the function being optimized. We also delineate the structural conditions under which heuristic optimization may achieve accuracy equivalent to or better than more fine-grained and onerous optimization methods.
Collapse
Affiliation(s)
- Natasha Mhatre
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada
| | - Daniel Robert
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
35
|
Zhang P, Yuan X, Du Y, Li JJ. Heterologous expression and biochemical characterization of a GHF9 endoglucanase from the termite Reticulitermes speratus in Pichia pastoris. BMC Biotechnol 2018; 18:35. [PMID: 29859082 PMCID: PMC5984754 DOI: 10.1186/s12896-018-0432-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/02/2018] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Cellulases are of great significance for full utilization of lignocellulosic biomass. Termites have an efficient ability to degrade cellulose. Heterologous production of the termite-origin cellulases is the first step to realize their industrial applications. The use of P. pastoris for the expression of recombinant proteins has become popular. The endoglucanase from Reticulitermes speratus (RsEG), belonging to glycoside hydrolase family 9 (GHF9), has not been produced in P. pastoris yet. RESULTS A mutant RsEGm (G91A/Y97W/K429A) was successfully overexpressed in P. pastoris. RsEGm, with optimum pH 5.0, was active over the pH range of 4.0 to 9.0, and exhibited superior pH stability over between pH 4.0 and pH 11.0. It displayed the highest activity and good stability at 40 °C, but lost activity quickly at 50 °C. The apparent kinetic parameters of RsEGm against Carboxymethyl Cellulose (CMC) were determined, with K m and V max of 7.6 mg/ml and 5.4 μmol/min•mg respectively. Co2+, Mn2+ and Fe2+ enhanced the activity of RsEGm by 32.0, 19.5 and 11.2% respectively, while Pb2+ and Cu2+ decreased its activity by 19.6 and 12.7% separately. CONCLUSIONS RsEGm could be overexpressed in P. pastoris. It was stable between pH 4.0 and pH 11.0, and exhibited higher stability at temperatures ≤ 40 °C. This endoglucanase may have potential to be used in the field of laundry, textile and lignocellulose-based biofuels and chemicals.
Collapse
Affiliation(s)
- Pengfei Zhang
- Sichuan Normal University, College of Life Science, Chengdu, 610101 China
| | - Xianghua Yuan
- Sichuan Normal University, College of Life Science, Chengdu, 610101 China
| | - Yuguang Du
- National Key Laboratory of Biochemical Engineering, National Engineering Research Center for Biotechnology (Beijing), Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 North 2nd Street, Beijing, 100190 China
| | - Jian-Jun Li
- National Key Laboratory of Biochemical Engineering, National Engineering Research Center for Biotechnology (Beijing), Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 North 2nd Street, Beijing, 100190 China
| |
Collapse
|
36
|
Dolejšová K, Křivánek J, Kalinová B, Hadravová R, Kyjaková P, Hanus R. Sex-Pairing Pheromones in Three Sympatric Neotropical Termite Species (Termitidae: Syntermitinae). J Chem Ecol 2018; 44:534-546. [PMID: 29752680 DOI: 10.1007/s10886-018-0965-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/06/2018] [Accepted: 04/30/2018] [Indexed: 11/25/2022]
Abstract
Termite colonies are almost always founded by a pair of winged dispersers, in spite of the high costs and low success rates inherent in independent colony foundation. The dispersal flights of imagoes from natal colonies are followed by mate search, mediated by sex-pairing pheromones. Here, we studied the chemistry of sex-pairing pheromones and the related aspects of mate search in winged imagoes of two facultatively parthenogenetic species, Embiratermes neotenicus and Silvestritermes minutus, and an additional species from the same subfamily, Silvestritermes heyeri. All three species are widespread in the Neotropics, including the rainforests of French Guiana. After the dispersal flight and spontaneous loss of wings, females expose their hypertrophied tergal glands situated under abdominal tergites VIII - X. The females are attractive to males and, upon direct contact, the two sexes form characteristic tandems. Chemical analyses indicated that the females secrete species-specific combinations of unbranched, unsaturated C12 primary alcohols from the tergal glands, (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol (approx. 200 pg per female) and (3Z)-dodec-3-enol (185 pg) in E. neotenicus, (3Z,6Z)-dodeca-3,6-dien-1-ol (3500 pg) in S. heyeri, and (3Z,6Z)-dodeca-3,6-dien-1-ol (300 pg) and (3Z)-dodec-3-enol (50 pg) in S. minutus. (3Z,6Z,8E)-Dodeca-3,6,8-trien-1-ol and (3Z,6Z)-dodeca-3,6-dien-1-ol act as major pheromone components in the respective species and mimic the function of female tergal gland extracts in electrophysiological and behavioral experiments. Biologically relevant amounts of the third compound, (3Z)-dodec-3-enol, elicited non-significant reactions in males of E. neotenicus and S. minutus, and slight synergistic effects in males of S. minutus when tested in combination with the major component.
Collapse
Affiliation(s)
- Klára Dolejšová
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jan Křivánek
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Blanka Kalinová
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Romana Hadravová
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Pavlína Kyjaková
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic.
| | - Robert Hanus
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| |
Collapse
|
37
|
Korb J. Chemical Fertility Signaling in Termites: Idiosyncrasies and Commonalities in Comparison with Ants. J Chem Ecol 2018; 44:818-826. [PMID: 29616376 DOI: 10.1007/s10886-018-0952-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/15/2018] [Accepted: 03/21/2018] [Indexed: 11/25/2022]
Abstract
Termites evolved eusociality independently from social Hymenoptera. As a common trait, reproductive monopoly is maintained through chemical communication. The queen (and in termites also a king) prevents workers from reproduction by conveying their reproductive status. In termites all soldiers are sterile, but workers' potential to reproduce differs between species. It ranges from totipotency in wood-dwelling lower termites where workers are a transient stage from which all other castes develop, to sterile workers in some higher termites. Intermediate are species in which workers can develop into replacement sexuals within the nest but not into winged sexuals. I summarize the patchy picture about fertility signaling that we currently have for termites, pointing also to potential conflicts over reproduction that differ from those in social Hymenoptera. Recent findings imply that, similar to many social Hymenoptera, wood-dwelling termites that live in confined nests use long-chain cuticular hydrocarbons (CHCs) as fertility signals. Yet other compounds are important as well, comprising proteinaceous secretions and especially volatiles. For a subterranean termite, two volatiles have been identified as primer pheromones that prevent reproductive differentiation of workers. It requires more data to test whether wood-dwelling termites use CHCs, while species with larger colonies and less confined nests use volatiles, or whether all species rely on multicomponent signals. Ultimately, we need more effort to model and test potential conflicts over reproduction between queens, kings and workers. Here results from social Hymenoptera cannot be transferred to termites as the latter are diploid and commonly inbred. This review illustrates promising future research avenues.
Collapse
Affiliation(s)
- Judith Korb
- Evolutionary Biology & Ecology, University of Freiburg, Hauptstrasse 1, D-79104, Freiburg, Germany.
| |
Collapse
|
38
|
Auer L, Lazuka A, Sillam-Dussès D, Miambi E, O'Donohue M, Hernandez-Raquet G. Uncovering the Potential of Termite Gut Microbiome for Lignocellulose Bioconversion in Anaerobic Batch Bioreactors. Front Microbiol 2017; 8:2623. [PMID: 29312279 PMCID: PMC5744482 DOI: 10.3389/fmicb.2017.02623] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 12/15/2017] [Indexed: 11/16/2022] Open
Abstract
Termites are xylophages, being able to digest a wide variety of lignocellulosic biomass including wood with high lignin content. This ability to feed on recalcitrant plant material is the result of complex symbiotic relationships, which involve termite-specific gut microbiomes. Therefore, these represent a potential source of microorganisms for the bioconversion of lignocellulose in bioprocesses targeting the production of carboxylates. In this study, gut microbiomes of four termite species were studied for their capacity to degrade wheat straw and produce carboxylates in controlled bioreactors. All of the gut microbiomes successfully degraded lignocellulose and up to 45% w/w of wheat straw degradation was observed, with the Nasutitermes ephratae gut-microbiome displaying the highest levels of wheat straw degradation, carboxylate production and enzymatic activity. Comparing the 16S rRNA gene diversity of the initial gut inocula to the bacterial communities in lignocellulose degradation bioreactors revealed important changes in community diversity. In particular, taxa such as Spirochaetes and Fibrobacteres that were highly abundant in the initial gut inocula were replaced by Firmicutes and Proteobacteria at the end of incubation in wheat straw bioreactors. Overall, this study demonstrates that termite-gut microbiomes constitute a reservoir of lignocellulose-degrading bacteria that can be harnessed in artificial conditions for biomass conversion processes that lead to the production of useful molecules.
Collapse
Affiliation(s)
- Lucas Auer
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, INSA, Toulouse, France
| | - Adèle Lazuka
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, INSA, Toulouse, France
| | - David Sillam-Dussès
- Laboratoire d'Éthologie Expérimentale et Comparée, Université Paris 13 - Sorbonne Paris Cité, Villetaneuse, France
- Institut d'Ecologie et des Sciences de l'Environnement de Paris, Institut de Recherche Pour le Développement – Sorbonne Universités, Bondy, France
| | - Edouard Miambi
- Institut d'Ecologie et des Sciences de l'Environnement de Paris, Université Paris-Est Créteil, Créteil, France
| | - Michael O'Donohue
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, INSA, Toulouse, France
| | - Guillermina Hernandez-Raquet
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, INSA, Toulouse, France
| |
Collapse
|
39
|
Nalepa CA. What Kills the Hindgut Flagellates of Lower Termites during the Host Molting Cycle? Microorganisms 2017; 5:E82. [PMID: 29258251 PMCID: PMC5748591 DOI: 10.3390/microorganisms5040082] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/07/2017] [Accepted: 12/09/2017] [Indexed: 11/17/2022] Open
Abstract
Subsocial wood feeding cockroaches in the genus Cryptocercus, the sister group of termites, retain their symbiotic gut flagellates during the host molting cycle, but in lower termites, closely related flagellates die prior to host ecdysis. Although the prevalent view is that termite flagellates die because of conditions of starvation and desiccation in the gut during the host molting cycle, the work of L.R. Cleveland in the 1930s through the 1960s provides a strong alternate hypothesis: it was the changed hormonal environment associated with the origin of eusociality and its concomitant shift in termite developmental ontogeny that instigates the death of the flagellates in termites. Although the research on termite gut microbial communities has exploded since the advent of modern molecular techniques, the role of the host hormonal environment on the life cycle of its gut flagellates has been neglected. Here Cleveland's studies are revisited to provide a basis for re-examination of the problem, and the results framed in the context of two alternate hypotheses: the flagellate symbionts are victims of the change in host social status, or the flagellates have become incorporated into the life cycle of the eusocial termite colony. Recent work on parasitic protists suggests clear paths for exploring these hypotheses and for resolving long standing issues regarding sexual-encystment cycles in flagellates of the Cryptocercus-termite lineage using molecular methodologies, bringing the problem into the modern era.
Collapse
Affiliation(s)
- Christine A Nalepa
- Department of Entomology, North Carolina State University, Raleigh, NC 27695-7613, USA.
| |
Collapse
|
40
|
Sex-specific inhibition and stimulation of worker-reproductive transition in a termite. Naturwissenschaften 2017; 104:79. [PMID: 28879477 DOI: 10.1007/s00114-017-1501-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/28/2017] [Accepted: 08/30/2017] [Indexed: 10/18/2022]
Abstract
In social insects, the postembryonic development of individuals exhibits strong phenotypic plasticity in response to the environment, thus generating the caste system. Different from eusocial Hymenoptera, in which queens dominate reproduction and inhibit worker fertility, the primary reproductive caste in termites (kings and queens) can be replaced by neotenic reproductives derived from functionally sterile individuals. Feedback regulation of nestmate differentiation into reproductives has been suggested, but the sex specificity remains inconclusive. In the eastern subterranean termite, Reticulitermes flavipes, we tested the hypothesis that neotenic reproductives regulate worker-reproductive transition in a sex-specific manner. With this R. flavipes system, we demonstrate a sex-specific regulatory mechanism with both inhibitory and stimulatory functions. Neotenics inhibit workers of the same sex from differentiating into additional reproductives but stimulate workers of the opposite sex to undergo this transition. Furthermore, this process is not affected by the presence of soldiers. Our results highlight the reproductive plasticity of termites in response to social cues and provide insights into the regulation of reproductive division of labor in a hemimetabolous social insect.
Collapse
|
41
|
Scheffrahn RH, Carrijo TF, Postle AC, Tonini F. Disjunctitermes insularis, a new soldierless termite genus and species (Isoptera, Termitidae, Apicotermitinae) from Guadeloupe and Peru. Zookeys 2017:71-84. [PMID: 28769627 PMCID: PMC5523167 DOI: 10.3897/zookeys.665.11599] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/16/2017] [Indexed: 12/02/2022] Open
Abstract
Disjunctitermesinsularisgen. n. & sp. n. is described from workers collected on Guadeloupe and in Peru and is the first soldierless termite found on a deep-water island. As with many soldierless and soil-feeding termite species, the enteric valve morphology is an essential diagnostic character of D.insularis. The D.insularis sequence cluster, derived from a barcode analysis with twelve other described genera of New World Apicotermitinae, is well resolved. Results of a stochastic dynamic spread model suggest that the occurrence of D.insularis on Guadeloupe may be the result of a pre-Colombian overwater dispersal event from mainland South America.
Collapse
Affiliation(s)
- Rudolf H Scheffrahn
- Fort Lauderdale Research and Education Center, Institute for Food and Agricultural Sciences, 3205 College Avenue, Davie, Florida 33314, USA
| | - Tiago F Carrijo
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Arcturus 03, Jardim Antares, 09606-070, São Bernardo do Campo, SP, Brazil
| | | | - Francesco Tonini
- Center for Systems Integration and Sustainability, Michigan State University, 115 Manly Miles Building, 1405 S. Harrison Rd., East Lansing, MI 48823, USA
| |
Collapse
|
42
|
Scheffrahn RH, Bourguignon T, Bordereau C, Hernandez-Aguilar RA, Oelze VM, Dieguez P, Šobotnik J, Pascual-Garrido A. White-gutted soldiers: simplification of the digestive tube for a non-particulate diet in higher Old World termites (Isoptera: Termitidae). INSECTES SOCIAUX 2017; 64:525-533. [PMID: 29081537 PMCID: PMC5643368 DOI: 10.1007/s00040-017-0572-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 06/26/2017] [Accepted: 06/30/2017] [Indexed: 06/07/2023]
Abstract
Previous observations have noted that in some species of higher termites the soldier caste lacks pigmented particles in its gut and, instead, is fed worker saliva that imparts a whitish coloration to the abdomen. In order to investigate the occurrence of this trait more thoroughly, we surveyed a broad diversity of termite specimens and taxonomic descriptions from the Old World subfamilies Apicotermitinae, Cubitermitinae, Foraminitermitinae, Macrotermitinae, and Termitinae. We identified 38 genera that have this "white-gutted" soldier (WGS) trait. No termite soldiers from the New World were found to possess a WGS caste. Externally, the WGS is characterized by a uniformly pale abdomen, hyaline gut, and proportionally smaller body-to-head volume ratio compared with their "dark-gutted" soldier (DGS) counterparts found in most termitid genera. The WGS is a fully formed soldier that, unlike soldiers in other higher termite taxa, has a small, narrow, and decompartmentalized digestive tube that lacks particulate food contents. The presumed saliva-nourished WGS have various forms of simplified gut morphologies that have evolved at least six times within the higher termites.
Collapse
Affiliation(s)
- R. H. Scheffrahn
- Fort Lauderdale Research and Education Center, University of Florida, 3205 College Avenue, Davie, FL 33314 USA
| | - T. Bourguignon
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495 Japan
| | - C. Bordereau
- UMR CNRS 5548, Communication Chimique, Université de Bourgogne Développement, 21000 Dijon, France
| | - R. A. Hernandez-Aguilar
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, P.O. Box 1066, Blindern, 0316 Oslo, Norway
| | - V. M. Oelze
- Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - P. Dieguez
- Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - J. Šobotnik
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - A. Pascual-Garrido
- Leverhulme Trust Early Career Fellow, School of Archaeology, University of Oxford, Oxford, OX1 3QY UK
| |
Collapse
|
43
|
The first report of gynandromorphy in termites (Isoptera; Kalotermitidae; Neotermes koshunensis). Naturwissenschaften 2017; 104:60. [PMID: 28676938 DOI: 10.1007/s00114-017-1478-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/22/2017] [Accepted: 06/09/2017] [Indexed: 10/19/2022]
Abstract
This is the first report of gynandromorphy in Isoptera. An Asian dry-wood termite, Neotermes koshunensis (Shiraki) [Kalotermitidae], possessing both male and female phenotypic characteristics, was found on Okinawa Island, Japan. This deformed individual showed morphological and anatomical hermaphroditism in the abdomen. The right side of the seventh sternite was the female form and contained an ovary, while the left side was the male form and contained a testis. Genotypic analysis revealed that this individual was a genotypic bilateral chimera. These results suggested that the termite was a bilateral gynandromorph with a male left side and a female right side. As reported previously in other insects, double fertilization (by two sperms, one with an X and one with a Y chromosome) of a binucleate egg is the most likely mechanism that generated this genotypic bilateral chimera. N. koshunensis has the ability to reproduce through parthenogenesis, in which the secondary polar body is likely to be used for nuclear phase recovery. If the second polar body in this mechanism has high fertility and healthy embryogenic potential, like an egg nucleus, some of gynandromorphs might be produced by a side effect of parthenogenetic ability.
Collapse
|
44
|
Mitaka Y, Kobayashi K, Matsuura K. Caste-, sex-, and age-dependent expression of immune-related genes in a Japanese subterranean termite, Reticulitermes speratus. PLoS One 2017; 12:e0175417. [PMID: 28410430 PMCID: PMC5391962 DOI: 10.1371/journal.pone.0175417] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/24/2017] [Indexed: 12/02/2022] Open
Abstract
Insects protect themselves from microbial infections through innate immune responses, including pathogen recognition, phagocytosis, the activation of proteolytic cascades, and the synthesis of antimicrobial peptides. Termites, eusocial insects inhabiting microbe-rich wood, live in closely-related family groups that are susceptible to shared pathogen infections. To resist pathogenic infection, termite families have evolved diverse immune adaptations at both individual and societal levels, and a strategy of trade-offs between reproduction and immunity has been suggested. Although termite immune-inducible genes have been identified, few studies have investigated the differential expression of these genes between reproductive and neuter castes, and between sexes in each caste. In this study, we compared the expression levels of immune-related genes among castes, sexes, and ages in a Japanese subterranean termite, Reticulitermes speratus. Using RNA-seq, we found 197 immune-related genes, including 40 pattern recognition proteins, 97 signalling proteins, 60 effectors. Among these genes, 174 showed differential expression among castes. Comparing expression levels between males and females in each caste, we found sexually dimorphic expression of immune-related genes not only in reproductive castes, but also in neuter castes. Moreover, we identified age-related differential expression of 162 genes in male and/or female reproductives. In addition, although R. speratus is known to use the antibacterial peptide C-type lysozyme as an egg recognition pheromone, we determined that R. speratus has not only C-type, but also P-type and I-type lysozymes, as well as other termite species. Our transcriptomic analyses revealed immune response plasticity among all castes, and sex-biased expression of immune genes even in neuter castes, suggesting a sexual division of labor in the immune system of R. speratus. This study heightens the understanding of the evolution of antimicrobial strategies in eusocial insects, and of sexual roles in insect societies as a whole.
Collapse
Affiliation(s)
- Yuki Mitaka
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- * E-mail:
| | - Kazuya Kobayashi
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kenji Matsuura
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| |
Collapse
|
45
|
Anderson TR, Pond DW, Mayor DJ. The Role of Microbes in the Nutrition of Detritivorous Invertebrates: A Stoichiometric Analysis. Front Microbiol 2017; 7:2113. [PMID: 28101083 PMCID: PMC5209341 DOI: 10.3389/fmicb.2016.02113] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 12/14/2016] [Indexed: 12/02/2022] Open
Abstract
Detritus represents an important pool in the global carbon cycle, providing a food source for detritivorous invertebrates that are conspicuous components of almost all ecosystems. Our knowledge of how these organisms meet their nutritional demands on a diet that is typically comprised of refractory, carbon-rich compounds nevertheless remains incomplete. "Trophic upgrading" of detritus by the attached microbial community (enhancement of zooplankton diet by the inclusion of heterotrophic protozoans) represents a potential source of nutrition for detritivores as both bacteria and their flagellated protistan predators are capable of biosynthesizing essential micronutrients such as polyunsaturated fatty acids (PUFAs). There is however a trade-off because although microbes enhance the substrate in terms of its micronutrient content, the quantity of organic carbon is diminished though metabolic losses as energy passes through the microbial food web. Here, we develop a simple stoichiometric model to examine this trade-off in the nutrition of detritivorous copepods inhabiting the mesopelagic zone of the ocean, focusing on their requirements for carbon and an essential PUFA, docosahexaenoic acid (DHA). Results indicate that feeding on microbes may be a highly favorable strategy for these invertebrates, although the potential for carbon to become limiting when consuming a microbial diet exists because of the inefficiencies of trophic transfer within the microbial food web. Our study highlights the need for improved knowledge at the detritus-microbe-metazoan interface, including interactions between the physiology and ecology of the associated organisms.
Collapse
Affiliation(s)
| | - David W. Pond
- Scottish Association for Marine Science, Natural Environment Research CouncilOban, UK
| | | |
Collapse
|
46
|
Sapountzis P, de Verges J, Rousk K, Cilliers M, Vorster BJ, Poulsen M. Potential for Nitrogen Fixation in the Fungus-Growing Termite Symbiosis. Front Microbiol 2016; 7:1993. [PMID: 28018322 PMCID: PMC5156715 DOI: 10.3389/fmicb.2016.01993] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 11/28/2016] [Indexed: 11/13/2022] Open
Abstract
Termites host a gut microbiota of diverse and essential symbionts that enable specialization on dead plant material; an abundant, but nutritionally imbalanced food source. To supplement the severe shortage of dietary nitrogen (N), some termite species make use of diazotrophic bacteria to fix atmospheric nitrogen (N2). Fungus-growing termites (subfamily Macrotermitinae) host a fungal exosymbiont (genus Termitomyces) that provides digestive services and the main food source for the termites. This has been thought to obviate the need for N2-fixation by bacterial symbionts. Here, we challenge this notion by performing acetylene reduction assays of live colony material to show that N2 fixation is present in two major genera (Macrotermes and Odontotermes) of fungus-growing termites. We compare and discuss fixation rates in relation to those obtained from other termites, and suggest avenues of research that may lead to a better understanding of N2 fixation in fungus-growing and other termites.
Collapse
Affiliation(s)
- Panagiotis Sapountzis
- Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of CopenhagenCopenhagen, Denmark
| | - Jane de Verges
- Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of CopenhagenCopenhagen, Denmark
| | - Kathrin Rousk
- Section for Terrestrial Ecology, Department of Biology, University of CopenhagenCopenhagen, Denmark
| | - Magdeleen Cilliers
- Department of Plant Production and Soil Science, Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | - Barend J. Vorster
- Department of Plant Production and Soil Science, Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | - Michael Poulsen
- Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of CopenhagenCopenhagen, Denmark
| |
Collapse
|
47
|
Coon KL, Brown MR, Strand MR. Mosquitoes host communities of bacteria that are essential for development but vary greatly between local habitats. Mol Ecol 2016; 25:5806-5826. [PMID: 27718295 PMCID: PMC5118126 DOI: 10.1111/mec.13877] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 09/14/2016] [Accepted: 09/26/2016] [Indexed: 12/31/2022]
Abstract
Mosquitoes are insects of interest because several species vector disease-causing pathogens to humans and other vertebrates. We previously reported that mosquitoes from long-term laboratory cultures require living bacteria in their gut to develop, but development does not depend on particular species of bacteria. Here, we focused on three distinct but interrelated areas of study to better understand the role of bacteria in mosquito development by studying field and laboratory populations of Aedes aegypti, Aedes albopictus and Culex quinquefasciatus from the southeastern United States. Sequence analysis of bacterial 16S rRNA gene amplicons showed that bacterial community composition differed substantially in larvae from different collection sites, whereas larvae from the same site shared similarities. Although previously unknown to be infected by Wolbachia, results also indicated that Ae. aegypti from one field site hosted a dual infection. Regardless of collection site or factors like Wolbachia infection, however, each mosquito species required living bacteria in their digestive tract to develop. Results also identified several concerns in using antibiotics to eliminate the bacterial community in larvae in order to study its developmental consequences. Altogether, our results indicate that several mosquito species require living bacteria for development. We also hypothesize these species do not rely on particular bacteria because larvae do not reliably encounter the same bacteria in the aquatic habitats they develop in.
Collapse
Affiliation(s)
- Kerri L Coon
- Department of Entomology, University of Georgia, 120 Cedar Street, 420 Biological Sciences, Athens, GA, 30602, USA
| | - Mark R Brown
- Department of Entomology, University of Georgia, 120 Cedar Street, 420 Biological Sciences, Athens, GA, 30602, USA
| | - Michael R Strand
- Department of Entomology, University of Georgia, 120 Cedar Street, 420 Biological Sciences, Athens, GA, 30602, USA
| |
Collapse
|
48
|
Casalla R, Scheffrahn R, Korb J. Cryptotermes colombianus a new drywood termite and distribution record of Cryptotermes in Colombia. Zookeys 2016:39-52. [PMID: 27408575 PMCID: PMC4926653 DOI: 10.3897/zookeys.596.9080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 05/23/2016] [Indexed: 11/24/2022] Open
Abstract
A new species of drywood termite (Kalotermitidae), Cryptotermescolombianus, is described and new records for Cryptotermescylindroceps and Cryptotermesmangoldi are presented from the Caribbean coast of Colombia. Cryptotermescolombianus is described from two soldiers and genetic sequences. This unusual species differs noticeably from other regional Cryptotermes species for its weak and inconspicuous definition of the frontal and genal horns and its acute angle of the frons with respect to the vertex. Cryptotermescolombianus clustered with species from the Ethiopian and Oriental region and it is closely related to Cryptotermeshavilandi. Cryptotermescylindroceps is widely distributed along the Colombian Caribbean coast, commonly associated with dead wood in mangrove habitats. It also is commonly found in wooden furniture, constituting an important household pest. Cryptotermesmangoldi is reported from the Caribbean mainland for the first time. With these new records, there are now five Cryptotermes species for Colombia, including the pest species Cryptotermesbrevis and Cryptotermesdudleyi. This new description raises the numbers of Neotropical Cryptotermes to a total of 34 species, of which 2 are fossils, 4 introduced, and 28 endemic.
Collapse
Affiliation(s)
- Robin Casalla
- Universität Freiburg. Evolutionary Biology & Ecology. Hauptstrasse 1. Freiburg 79104. Germany; Universidad del Norte. Departamento de Química y Biología. Kilómetro 5 Antigua vía Puerto Colombia. Barranquilla. Colombia
| | - Rudolf Scheffrahn
- University of Florida. Fort Lauderdale Research & Education Center 3205 College Avenue Davie. Florida 33314. United States
| | - Judith Korb
- Universität Freiburg. Evolutionary Biology & Ecology. Hauptstrasse 1. Freiburg 79104. Germany
| |
Collapse
|
49
|
Arinana A, Aldina R, Nandika D, Rauf A, Harahap IS, Sumertajaya IM, Bahtiar ET. Termite Diversity in Urban Landscape, South Jakarta, Indonesia. INSECTS 2016; 7:E20. [PMID: 27164147 PMCID: PMC4931432 DOI: 10.3390/insects7020020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 04/26/2016] [Accepted: 05/03/2016] [Indexed: 11/16/2022]
Abstract
The population of South Jakarta, a city within the Province of Jakarta Capital Region, is increasing annually, and the development of land into building causes termite diversity loss. The aim of this research was to determine the diversity of subterranean termite species and their distribution in South Jakarta and to evaluate the soil profile termite habitat. This study was conducted in South Jakarta and was carried out at four residential areas representing four randomly selected sub-districts. Specimens were collected with a baiting system. At each residence, as many as 25-30 stakes of pine wood (Pinus merkusii) sized 2 cm × 2 cm × 46 cm were placed for termite sampling. Soil samples were also collected from each residence for testing of their texture, pH, soil water content, and C-organic. Three species of subterranean termites were identified, including Coptotermes curvignathus, Microtermes insperatus, and Macrotermes gilvus, with area-specific variations in occurrence. The soil and weather conditions in the studied areas provided suitable habitat for termites, and M. insperatus was the most commonly found species.
Collapse
Affiliation(s)
- Arinana Arinana
- Faculty of Forestry, Bogor Agricultural University, Bogor 16680, West Java, Indonesia.
| | - Rifat Aldina
- Faculty of Forestry, Bogor Agricultural University, Bogor 16680, West Java, Indonesia.
| | - Dodi Nandika
- Faculty of Forestry, Bogor Agricultural University, Bogor 16680, West Java, Indonesia.
| | - Aunu Rauf
- Faculty of Agriculture, Bogor Agricultural University, Bogor 16680, West Java, Indonesia.
| | - Idham S Harahap
- Faculty of Agriculture, Bogor Agricultural University, Bogor 16680, West Java, Indonesia.
| | - I Made Sumertajaya
- Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Bogor 16680, West Java, Indonesia.
| | - Effendi Tri Bahtiar
- Faculty of Forestry, Bogor Agricultural University, Bogor 16680, West Java, Indonesia.
| |
Collapse
|
50
|
Bourguignon T, Lo N, Šobotník J, Sillam-Dussès D, Roisin Y, Evans TA. Oceanic dispersal, vicariance and human introduction shaped the modern distribution of the termites Reticulitermes, Heterotermes and Coptotermes. Proc Biol Sci 2016; 283:20160179. [PMID: 27030416 PMCID: PMC4822470 DOI: 10.1098/rspb.2016.0179] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/03/2016] [Indexed: 11/12/2022] Open
Abstract
Reticulitermes, Heterotermes and Coptotermes form a small termite clade with partly overlapping distributions. Although native species occur across all continents, the factors influencing their distribution are poorly known. Here, we reconstructed the historical biogeography of these termites using mitochondrial genomes of species collected on six continents. Our analyses showed that Reticulitermes split from Heterotermes + Coptotermesat 59.5 Ma (49.9-69.5 Ma 95% CI), yet the oldest split within Reticulitermes(Eurasia and North America) is 16.1 Ma (13.4-19.5 Ma) and the oldest split within Heterotermes + Coptotermesis 36.0 Ma (33.9-40.5 Ma). We detected 14 disjunctions between biogeographical realms, all of which occurred within the last 34 Ma, not only after the break-up of Pangaea, but also with the continents in similar to current positions. Land dispersal over land bridges explained four disjunctions, oceanic dispersal by wood rafting explained eight disjunctions, and human introduction was the source of two recent disjunctions. These wood-eating termites, therefore, appear to have acquired their modern worldwide distribution through multiple dispersal processes, with oceanic dispersal and human introduction favoured by the ecological traits of nesting in wood and producing replacement reproductives.
Collapse
Affiliation(s)
- Thomas Bourguignon
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic School of Biological Sciences, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Nathan Lo
- School of Biological Sciences, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jan Šobotník
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - David Sillam-Dussès
- Institut de Recherche pour le Développement, Sorbonne Universités, iEES-Paris, Bondy U 242, France Université Paris 13, Sorbonne Paris Cité, LEEC, Villetaneuse EA 4443, France
| | - Yves Roisin
- Evolutionary Biology and Ecology, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Theodore A Evans
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore School of Animal Biology, University of Western Australia, Perth, Western Australia 6009, Australia
| |
Collapse
|