The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Anne-geneviève Bagnères - One of the best experts on this subject based on the ideXlab platform.
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Invasion Dynamics of A Termite, Reticulitermes flavipes, at Different Spatial Scales in France
Insects, 2019Co-Authors: Elfie Perdereau, Guillaume Baudouin, Stephanie Bankhead-dronnet, Zoé Chevalier, Marie Zimmermann, Simon Dupont, Franck Dedeine, Anne-geneviève BagnèresAbstract:Termites are social insects that can also be major pests. A well-known problem species is the subterranean termite, Reticulitermes flavipes. It is invasive in France and is thought to have arrived from Louisiana during the 18th century. While the putative source of French populations has been identified, little is known about how the termite spread following its establishment. Here, we examined expansion patterns at different spatial scales in urban areas to clarify how R. flavipes spread in France. Based on our analyses of phylogeography and population genetics, results suggest a scenario of successive introductions into the Charente-Maritime region, on the Atlantic Coast. Two major expansion fronts formed: one that spread toward the northeast and the other toward the southeast. At the regional scale, different spatial and genetic distribution patterns were observed: there was heterogeneity in ile-de-France and aggregation in Centre-Val de Loire. At the local scale, we found that our three focal urban sites each formed a single large colony that contained several secondary reproductives. Our findings represent a second step in efforts to reconstruct termite's invasion dynamics. They also highlight the role that may have been played by the French railway network in transporting Termites over long distances.
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potential spread of the invasive north american termite reticulitermes flavipes and the impact of climate warming
Biological Invasions, 2018Co-Authors: Christelle Suppo, Anne-geneviève Bagnères, Elfie Perdereau, Christelle Robinet, Dominique AndrieuAbstract:Reticulitermes flavipes is an invasive termite from North America that is found in several European countries, including France from north to south. It feeds on several timber species and can cause major damage when it infests lumber. Termites are urban pests: they are often found in and around towns and their expansion is closely linked to human activity. Although, by law, termite infestations must be reported and treated, R. flavipes continues to spread. To better identify areas that may soon be colonized, it is crucial to understand the mechanisms underlying the termite’s spread at a fine spatial scale. However, the complexity of the species’ dispersal dynamics (i.e., via swarming, budding, or human-mediated transport of infested material) and social organization render this process difficult. The goal of our study was to determine R. flavipes’ potential to expand its current range within a region of France: Centre-Val de Loire. We focused on one administrative department within the region—Indre and Loire—where infestations are common and data on termite presence date back to the 1980s. We developed a spatiotemporal model to study the growth and dispersal of termite colonies within favorable habitat. Habitat favorability was defined based on the density of urbanization and annual mean minimum temperature. First, we modeled temporal population dynamics, using biological parameters describing the transitions between life stages/castes within colonies; we could thus estimate alates production. Then, using this information, we modeled termite dispersal within favorable habitat, and determined the termite’s potential spread. We validated the results by comparing the model’s output with actual data on the termite’s range expansion between 1985 (when the termite was first observed in the region) and 2013. Finally, the model was used to predict the termite’s future spread given climate warming for the period from 2013 to 2030. The results show that an increase in temperature should increase the amount of favorable habitat and, as a consequence, Termites could continue to spread within this region. In addition to continuing current control efforts, it will be necessary to enact preventative strategies in newly favorable habitat. In these areas, monitoring efforts should therefore be intensified, as they might be able to slow down the termite’s spread and limit its impact.
Theodore A. Evans - One of the best experts on this subject based on the ideXlab platform.
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the evolutionary history of Termites as inferred from 66 mitochondrial genomes
Molecular Biology and Evolution, 2015Co-Authors: Thomas Bourguignon, Yves Roisin, Jan Šobotník, Stephen L. Cameron, Yoshinobu Hayashi, Shuji Shigenobu, Dai Watanabe, Toru Miura, Theodore A. EvansAbstract:Termites have colonized many habitats and are among the most abundant animals in tropical ecosystems, which they modify considerably through their actions. The timing of their rise in abundance and of the dispersal events that gave rise to modern termite lineages is not well understood. To shed light on termite origins and diversification, we sequenced the mitochondrial genome of 48 termite species and combined them with 18 previously sequenced termite mitochondrial genomes for phylogenetic and molecular clock analyses using multiple fossil calibrations. The 66 genomes represent most major clades of Termites. Unlike previous phylogenetic studies based on fewer molecular data, our phylogenetic tree is fully resolved for the lower Termites. The phylogenetic positions of Macrotermitinae and Apicotermitinae are also resolved as the basal groups in the higher Termites, but in the crown termitid groups, including Termitinae + Syntermitinae + Nasutitermitinae + Cubitermitinae, the position of some nodes remains uncertain. Our molecular clock tree indicates that the lineages leading to Termites and Cryptocercus roaches diverged 170 Ma (153-196 Ma 95% confidence interval [CI]), that modern Termitidae arose 54 Ma (46-66 Ma 95% CI), and that the crown termitid group arose 40 Ma (35-49 Ma 95% CI). This indicates that the distribution of basal termite clades was influenced by the final stages of the breakup of Pangaea. Our inference of ancestral geographic ranges shows that the Termitidae, which includes more than 75% of extant termite species, most likely originated in Africa or Asia, and acquired their pantropical distribution after a series of dispersal and subsequent diversification events.
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A mitochondrial genome phylogeny of Termites (Blattodea Termitoidae): Robust support for interfamilial relationships and molecular synapomorphies define major clades
Molecular Phylogenetics and Evolution, 2012Co-Authors: Stephen L. Cameron, Thomas Bourguignon, Nathan Lo, Gavin J. Svenson, Theodore A. EvansAbstract:Despite their ecological significance as decomposers and their evolutionary significance as the most speciose eusocial insect group outside the Hymenoptera, termite (Blattodea: Termitoidae or Isoptera) evolutionary relationships have yet to be well resolved. Previous morphological and molecular analyses strongly conflict at the family level and are marked by poor support for backbone nodes. A mitochondrial (mt) genome phylogeny of Termites was produced to test relationships between the recognised termite families, improve nodal support and test the phylogenetic utility of rare genomic changes found in the termite mt genome. Complete mt genomes were sequenced for 7 of the 9 extant termite families with additional representatives of each of the two most speciose families Rhinotermitidae (3 of 7 subfamilies) and Termitidae (3 of 8 subfamilies). The mt genome of the well supported sister-group of Termites, the subsocial cockroach Cryptocercus, was also sequenced. A highly supported tree of termite relationships was produced by all analytical methods and data treatment approaches, however the relationship of the Termites + Cryptocercus clade to other cockroach lineages was highly affected by the strong nucleotide compositional bias found in Termites relative to other dictyopterans. The phylogeny supports previously proposed suprafamilial termite lineages, the Euisoptera and Neoisoptera, a later derived Kalotermitidae as sister group of the Neoisoptera and a monophyletic clade of dampwood (Stolotermitidae, Archotermopsidae) and harvester Termites (Hodotermitidae). In contrast to previous termite phylogenetic studies, nodal supports were very high for family-level relationships within Termites. Two rare genomic changes in the mt genome control region were found to be molecular synapomorphies for major clades. An elongated stem-loop structure defined the clade Polyphagidae + (Cryptocercus + Termites), and a further series of compensatory base changes in this stem-loop is synapomorphic for the Neoisoptera. The complicated repeat structures first identified in Reticulitermes, composed of short (A-type) and long (B-type repeats) defines the clade Heterotermitinae + Termitidae, while the secondary loss of A-type repeats is synapomorphic for the non-macrotermitine Termitidae.
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Termites assess wood size by using vibration signals
Proceedings of the National Academy of Sciences of the United States of America, 2005Co-Authors: Theodore A. Evans, Joseph C. S. Lai, Emilie Toledano, Lee Mcdowall, Sandrine T. Rakotonarivo, Michael LenzAbstract:Contrary to the common perception that Termites are indiscrimi-nant eaters, Termites choose their food carefully; however, the methods by which they choose food are not well understood. Using choice experiments and recordings of Termites feeding on wooden blocks of different sizes, we show that worker drywood Termites (Cryptotermes domesticus) use the resonant frequency of a block of wood to assess its size. Drywood Termites showed differences in their response to vibration recordings of Termites compared with artificially generated signals, suggesting that they can discriminate the source of vibration. Furthermore, fewer workers matured into neotenic reproductives when recorded termite signals were played, suggesting that vibration signals play an important role in termite communication.
Thomas Bourguignon - One of the best experts on this subject based on the ideXlab platform.
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Termite evolution: mutualistic associations, key innovations, and the rise of Termitidae
Cellular and Molecular Life Sciences, 2021Co-Authors: Thomas Chouvenc, Jan Šobotník, Thomas BourguignonAbstract:Termites are a clade of eusocial wood-feeding roaches with > 3000 described species. Eusociality emerged ~ 150 million years ago in the ancestor of modern Termites, which, since then, have acquired and sometimes lost a series of adaptive traits defining of their evolution. Termites primarily feed on wood, and digest cellulose in association with their obligatory nutritional mutualistic gut microbes. Recent advances in our understanding of termite phylogenetic relationships have served to provide a tentative timeline for the emergence of innovative traits and their consequences on the ecological success of Termites. While all “lower” Termites rely on cellulolytic protists to digest wood, “higher” Termites (Termitidae), which comprise ~ 70% of termite species, do not rely on protists for digestion. The loss of protists in Termitidae was a critical evolutionary step that fostered the emergence of novel traits, resulting in a diversification of morphology, diets, and niches to an extent unattained by “lower” Termites. However, the mechanisms that led to the initial loss of protists and the succession of events that took place in the termite gut remain speculative. In this review, we provide an overview of the key innovative traits acquired by Termites during their evolution, which ultimately set the stage for the emergence of “higher” Termites. We then discuss two hypotheses concerning the loss of protists in Termitidae, either through an externalization of the digestion or a dietary transition. Finally, we argue that many aspects of termite evolution remain speculative, as most termite biological diversity and evolutionary trajectories have yet to be explored.
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The trail-following pheromone of the termite Serritermes serrifer
Chemoecology, 2020Co-Authors: David Sillam-dussès, Thomas Bourguignon, Jaromír Hradecký, Petr Stiblik, Hélida Ferreira Cunha, Tiago F. Carrijo, Michael J. Lacey, Jan ŠobotníkAbstract:The Neotropical family Serritermitidae is a monophyletic group of Termites including two genera, Serritermes and Glossotermes , with different way-of-life, the former being the sole obligatory inquiline among “lower” Termites, while the latter is a single-site nester feeding on dry rotten red wood. Like the most advanced termite’s family, the Termitidae, the Serritermitidae is an inner group of the paraphyletic family “Rhinotermitidae”, but unlike the Termitidae, it has been poorly studied so far. In this study, we bring new insights into the chemical ecology of this key taxon. We studied the trail-following pheromone of Serritermes serrifer and we identified (10 Z ,13 Z )-nonadeca-10,13-dien-2-one as the only component of the trail-following pheromone of this termite species, as it is the case in Glossotermes , the other genus belonging to Serritermitidae. This result makes the family Serritermitidae clearly distinct from other Rhinotermitidae, such as the Termites Psammotermes and Prorhinotermes , that use (3 Z ,6 Z ,8 E )-dodeca-3,6,8-trien-1-ol and/or neocembrene as trail-following pheromones.
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Termites the neglected soil engineers of tropical soils
Soil Science, 2016Co-Authors: Pascal Jouquet, Thomas Bourguignon, Nicolas Bottinelli, Rashmi Ramesh Shanbhag, Saran Traore, S A AbbasiAbstract:Termites are undoubtedly key soil organisms in tropical and subtropical soils. They are soil engineers in influencing the physical, chemical, and biological properties of soils and, consequently, water dynamics in tropical and subtropical ecosystems. To appreciate the effect of Termites on soil, there is a need for a thorough understanding of the ecological needs and building strategies of Termites and the mechanisms regulating termite diversity at local and regional scales. Termite impacts on soil properties and water dynamics can be differentiated at four different scales: (i) at the landscape scale, where Termites act as heterogeneity drivers; (ii) at the soil profile scale, where Termites act as soil bioturbators; (iii) at the aggregate scale, where they act as aggregate reorganizers; (iv) and last, at the clay mineral scale, where they can act as weathering agents. Last, we discuss recent literature on termite engineering published in the last 10 years in the major journals of soil science and suggest new research topics that could contribute to improved knowledge of the impact of Termites on soil properties and water dynamics.
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the evolutionary history of Termites as inferred from 66 mitochondrial genomes
Molecular Biology and Evolution, 2015Co-Authors: Thomas Bourguignon, Yves Roisin, Jan Šobotník, Stephen L. Cameron, Yoshinobu Hayashi, Shuji Shigenobu, Dai Watanabe, Toru Miura, Theodore A. EvansAbstract:Termites have colonized many habitats and are among the most abundant animals in tropical ecosystems, which they modify considerably through their actions. The timing of their rise in abundance and of the dispersal events that gave rise to modern termite lineages is not well understood. To shed light on termite origins and diversification, we sequenced the mitochondrial genome of 48 termite species and combined them with 18 previously sequenced termite mitochondrial genomes for phylogenetic and molecular clock analyses using multiple fossil calibrations. The 66 genomes represent most major clades of Termites. Unlike previous phylogenetic studies based on fewer molecular data, our phylogenetic tree is fully resolved for the lower Termites. The phylogenetic positions of Macrotermitinae and Apicotermitinae are also resolved as the basal groups in the higher Termites, but in the crown termitid groups, including Termitinae + Syntermitinae + Nasutitermitinae + Cubitermitinae, the position of some nodes remains uncertain. Our molecular clock tree indicates that the lineages leading to Termites and Cryptocercus roaches diverged 170 Ma (153-196 Ma 95% confidence interval [CI]), that modern Termitidae arose 54 Ma (46-66 Ma 95% CI), and that the crown termitid group arose 40 Ma (35-49 Ma 95% CI). This indicates that the distribution of basal termite clades was influenced by the final stages of the breakup of Pangaea. Our inference of ancestral geographic ranges shows that the Termitidae, which includes more than 75% of extant termite species, most likely originated in Africa or Asia, and acquired their pantropical distribution after a series of dispersal and subsequent diversification events.
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A mitochondrial genome phylogeny of Termites (Blattodea Termitoidae): Robust support for interfamilial relationships and molecular synapomorphies define major clades
Molecular Phylogenetics and Evolution, 2012Co-Authors: Stephen L. Cameron, Thomas Bourguignon, Nathan Lo, Gavin J. Svenson, Theodore A. EvansAbstract:Despite their ecological significance as decomposers and their evolutionary significance as the most speciose eusocial insect group outside the Hymenoptera, termite (Blattodea: Termitoidae or Isoptera) evolutionary relationships have yet to be well resolved. Previous morphological and molecular analyses strongly conflict at the family level and are marked by poor support for backbone nodes. A mitochondrial (mt) genome phylogeny of Termites was produced to test relationships between the recognised termite families, improve nodal support and test the phylogenetic utility of rare genomic changes found in the termite mt genome. Complete mt genomes were sequenced for 7 of the 9 extant termite families with additional representatives of each of the two most speciose families Rhinotermitidae (3 of 7 subfamilies) and Termitidae (3 of 8 subfamilies). The mt genome of the well supported sister-group of Termites, the subsocial cockroach Cryptocercus, was also sequenced. A highly supported tree of termite relationships was produced by all analytical methods and data treatment approaches, however the relationship of the Termites + Cryptocercus clade to other cockroach lineages was highly affected by the strong nucleotide compositional bias found in Termites relative to other dictyopterans. The phylogeny supports previously proposed suprafamilial termite lineages, the Euisoptera and Neoisoptera, a later derived Kalotermitidae as sister group of the Neoisoptera and a monophyletic clade of dampwood (Stolotermitidae, Archotermopsidae) and harvester Termites (Hodotermitidae). In contrast to previous termite phylogenetic studies, nodal supports were very high for family-level relationships within Termites. Two rare genomic changes in the mt genome control region were found to be molecular synapomorphies for major clades. An elongated stem-loop structure defined the clade Polyphagidae + (Cryptocercus + Termites), and a further series of compensatory base changes in this stem-loop is synapomorphic for the Neoisoptera. The complicated repeat structures first identified in Reticulitermes, composed of short (A-type) and long (B-type repeats) defines the clade Heterotermitinae + Termitidae, while the secondary loss of A-type repeats is synapomorphic for the non-macrotermitine Termitidae.
Susumu Shimizu - One of the best experts on this subject based on the ideXlab platform.
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S: Odor aversion and pathogen-removal efficiency in grooming behavior of the termite Coptotermes formosanus
2016Co-Authors: Aya Yanagawa, Toshiharu Akino, Tsuyoshi Yoshimura, Takashi Yanagawa, Nao Fujiwara-tsujii, Susumu ShimizuAbstract:The results of biocontrol with entomopathogens in Termites have been discouraging because of the strong social hygiene behavior for removing pathogens from termite colonies. However, the mechanism of pathogen detection is still unclear. For the successful application of biopesticides to Termites in nature, it would be beneficial to identify substances that could disrupt the termite’s ability to perceive pathogens. We hypothesized that Termites can perceive pathogens and this ability plays an important role in effective hygiene behavior. In this study, pathogen-detection in the subterranean termite Coptotermes formosanus was investigated. We performed quantitative assays on conidia removal by grooming behavior using epifluoresence microscopy and Y-maze tests to examine the perception of fungal odor by Termites. Three species each of high- and low-virulence entomopathogenic fungi were used in each test. The results demonstrated that Termites removed conidia more effectively from a nestmate’s cuticle if its odor elicited stronger aversion. Highly virulent pathogens showed higher attachment rates to termite surfaces and their odors were more strongly avoided than those of low-virulence isolates in the same species. Moreover, Termites appeared to groom each other more persistently when they had more conidia on their bodies. In brief, insect perception of pathogen-related odor seems to play a role in the mechanism o
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odor aversion and pathogen removal efficiency in grooming behavior of the termite coptotermes formosanus
PLOS ONE, 2012Co-Authors: Aya Yanagawa, Toshiharu Akino, Nao Fujiwaratsujii, Tsuyoshi Yoshimura, Takashi Yanagawa, Susumu ShimizuAbstract:The results of biocontrol with entomopathogens in Termites have been discouraging because of the strong social hygiene behavior for removing pathogens from termite colonies. However, the mechanism of pathogen detection is still unclear. For the successful application of biopesticides to Termites in nature, it would be beneficial to identify substances that could disrupt the termite’s ability to perceive pathogens. We hypothesized that Termites can perceive pathogens and this ability plays an important role in effective hygiene behavior. In this study, pathogen-detection in the subterranean termite Coptotermes formosanus was investigated. We performed quantitative assays on conidia removal by grooming behavior using epifluoresence microscopy and Y-maze tests to examine the perception of fungal odor by Termites. Three species each of high- and low-virulence entomopathogenic fungi were used in each test. The results demonstrated that Termites removed conidia more effectively from a nestmate’s cuticle if its odor elicited stronger aversion. Highly virulent pathogens showed higher attachment rates to termite surfaces and their odors were more strongly avoided than those of low-virulence isolates in the same species. Moreover, Termites appeared to groom each other more persistently when they had more conidia on their bodies. In brief, insect perception of pathogen-related odor seems to play a role in the mechanism of their hygiene behavior.
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the role of antennae in removing entomopathogenic fungi from cuticle of the termite coptotermes formosanus
Journal of Insect Science, 2009Co-Authors: Fumio Yokohari, Aya Yanagawa, Susumu ShimizuAbstract:Our previous research has shown that the termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), protects itself from entomopathogenic fungi by mutual grooming behavior. The termite removes and discards foreign organisms, such as fungal conidia, from the body surface of its nestmates by mutual grooming behavior. The role of the antennae in detecting the condia was examind here. Three entomopathogenic fungi were used, Beauveria brongniartii 782 (Saccardo) (Hypocreales), Paecilomyces fumosoroseus K3 (Wize) (Hyphomycetes), and Metarhizium anisopliae 455 Sorokin (Hyphomycetes). Termites with antennae removed conidia more efficiently than Termites without antennae. There were differences between Termites with and without antennae in selection of sites to be groomed on nestmates, in the length of grooming and in occurrence of grooming. Electroantennogram (EAG) responses were recorded from termite antennae and the waveforms were rather specific to the kinds of fungi used as odor sources. Termites were able to distinguish between the tested fungi in feeding tests. These results show that the antennae play important roles in the mutual grooming behavior of the termite.
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pathogenicity of entomopathogenic fungi to the termite reticulitermes speratus
Japanese Journal of Applied Entomology and Zoology, 2002Co-Authors: Susumu Shimizu, Motoko YamajiAbstract:Twenty isolates of entomopathogenic fungi (Beauveria bassiana, Metarhizium anisopliae and Paecilomyces sp.) were bioassayed against groups (5 Termites in 90×15 mm petri dishes) of the termite, Reticulitermes speratus. Termites were susceptible to the various isolates. Effect of termite density on susceptibility to B. bassiana and M. anisopliae was also assayed. Reared individually, Termites were highly susceptible to B. bassiana and M. anisopliae. When groups of Termites (10 Termites in 90×15 mm petri dishes) were exposed to B. bassiana and M. anisopliae, they were highly resistant to infection.
J.k. Grace - One of the best experts on this subject based on the ideXlab platform.
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Prospects for the biological control of subterranean Termites (Isoptera: rhinotermitidae), with special reference to Coptotermes formosanus.
Bulletin of Entomological Research, 2000Co-Authors: Thomas W. Culliney, J.k. GraceAbstract:Costs associated with subterranean termite damage and control are estimated to approach $2 billion annually in the United States alone. The Formosan subterranean termite, Coptotermes formosanus Shiraki, is one of the more economically important subterranean species. In recent years, the shortcomings associated with conventional chemical control methods have prompted policymakers and scientists to evaluate the potential for biological control of subterranean Termites (C. formosanus in particular), that is, to determine the potential for natural enemies - predators, parasitoids and pathogens - to suppress termite populations. Ants are the greatest predators of Termites, and may have a considerable local impact on termite populations in some areas of the world. A few parasitoids of Termites are known, but their potential for regulating termite populations seems negligible. Characteristics of the colony, such as a protected, underground location (and, for the C. formosanus nest, its modular and dispersed nature), are likely to limit the impact predators and parasitoids have on subterranean Termites. Thus, there seems little potential for use of these agents for subterranean termite control. For various reasons, pathogenic organisms, such as viruses, bacteria, Protozoa, nematodes and most fungi, have shown little promise for use in biological termite control. However, research suggests that strains of two well-studied, endoparasitic fungi, Beauveria bassiana and Metarhizium anisopliae, when employed in baiting schemes, may offer the potential for at least some measure of subterranean termite control, although their successful use is compromised by a number of inherent biological limitations and logistical problems that have yet to be solved. Although not strictly in the realm of classical biological control, recent studies suggest that natural products, such as ant semiochemicals and fungal metabolites (siderophores), or their synthetic analogues, eventually might find a use in termite control programmes as repellents or insecticides in wood treatments or soil applications if stable formulations can be developed.
