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Robert Hanus - One of the best experts on this subject based on the ideXlab platform.
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Not only soldiers have weapons: Evolution of the frontal gland in imagoes of the termite families Rhinotermitidae and Serritermitidae
2016Co-Authors: Thomas Bourguignon, Robert Hanus, Yves RoisinAbstract:Background: The frontal gland is a unique adaptation of advanced termite families. It has been intensively studied in soldiers with respect to its anatomy and chemistry, with numerous novel compounds being discovered within the tremendous richness of identified products. At the same time, the presence of the frontal gland in non-soldier castes received only negligible attention in the past. Principal Findings: Here, we report on the development of the frontal gland in alate imagoes of 10 genera and 13 species of Rhinotermitidae and Serritermitidae, in order to shed light on the evolution and function of this gland in imagoes. All investigated species possess a frontal gland. In most cases, it is well-developed and equipped with a sac-like reservoir, located in the postero-dorsal part of cranium, but reaching as far as the seventh abdominal segment in some Rhinotermitinae. The only exception is the genus Psammotermes, in which the gland is very small and devoid of the reservoir. Conclusions: Our direct observations and comparisons with soldiers suggest a defensive role of the gland in imagoes of all studied species. This functional analogy, along with the anatomic homology between the frontal gland in soldiers and imagoes, make it likely that the gland appeared once during the early evolution of rhinotermitid ancestors, and remained a
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Chemical alarm in the termite Termitogeton planus (Rhinotermitidae)
Journal of Chemical Ecology, 2014Co-Authors: Klára Dolejšová, Jana Krasulová, Kateřina Kutalová, Robert HanusAbstract:Effective defense is a common characteristic of insect societies. Indeed, the occurrence of specialized defenders, soldiers, has been the first step toward eusociality in several independent lineages, including termites. Among the multitude of defensive strategies used by termite soldiers, defense by chemicals plays a crucial role. It has evolved with complexity in advanced isopteran lineages, whose soldiers are equipped with a unique defensive organ, the frontal gland. Besides direct defense against predators, competitors, and pathogens, the chemicals emitted by soldiers from the frontal gland are used as signals of alarm. In this study, we investigated the chemical composition of the defensive secretion produced by soldiers of the termite Termitogeton planus (Isoptera: Rhinotermitidae), from West Papua, and the effects of this secretion on the behavior of termite groups. Detailed two-dimensional gas chromatography/mass spectrometry analyses of the soldier defensive secretion revealed the presence of four linear and nine monoterpene hydrocarbons. Soldier head extracts, as well as synthetic mixtures of the monoterpenes found in these extracts, elicited alarm behavior in both soldiers and pseudergates. Our results suggest that the alarm is not triggered by a single monoterpene from the defensive blend, but by a multi-component signal combining quantitatively major and minor compounds.
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Chemical alarm in the termite Termitogeton planus (Rhinotermitidae).
Journal of chemical ecology, 2014Co-Authors: Klára Dolejšová, Jana Krasulová, Kateřina Kutalová, Robert HanusAbstract:Effective defense is a common characteristic of insect societies. Indeed, the occurrence of specialized defenders, soldiers, has been the first step toward eusociality in several independent lineages, including termites. Among the multitude of defensive strategies used by termite soldiers, defense by chemicals plays a crucial role. It has evolved with complexity in advanced isopteran lineages, whose soldiers are equipped with a unique defensive organ, the frontal gland. Besides direct defense against predators, competitors, and pathogens, the chemicals emitted by soldiers from the frontal gland are used as signals of alarm. In this study, we investigated the chemical composition of the defensive secretion produced by soldiers of the termite Termitogeton planus (Isoptera: Rhinotermitidae), from West Papua, and the effects of this secretion on the behavior of termite groups. Detailed two-dimensional gas chromatography/mass spectrometry analyses of the soldier defensive secretion revealed the presence of four linear and nine monoterpene hydrocarbons. Soldier head extracts, as well as synthetic mixtures of the monoterpenes found in these extracts, elicited alarm behavior in both soldiers and pseudergates. Our results suggest that the alarm is not triggered by a single monoterpene from the defensive blend, but by a multi-component signal combining quantitatively major and minor compounds.
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Developmental pathways of Psammotermes hybostoma (Isoptera: Rhinotermitidae): old pseudergates make up a new sterile caste.
PloS one, 2012Co-Authors: Thomas Bourguignon, David Sillam-dussès, Yves Roisin, Jan Šobotník, Robert Hanus, Pavel Jiroš, Toru MiuraAbstract:Background: Ergonomic efficiency is in termites maximized by task partitioning among specialized castes. The isopteran caste systems can be classified as either (i) linear, when tasks are performed by pluripotent immatures (pseudergates), retaining the ability to develop into winged imagoes or (ii) bifurcated, with the presence of a true worker caste, which diverges early and permanently from the sexual (nymph/alate) line. Principal Findings: Here, we report on the ontogenetic potentialities of the highly polymorphic sand termite Psammotermes hybostoma. Beside numerous pluripotent pseudergates, constituting the main work force, some larger non-feeding apterous immatures, also occur. These individuals are unable to proceed to the winged imago stage, but store large amounts of fat and also give rise to large soldiers. Soldiers therefore originate from a wide range of apterous instars, consequently being highly polymorphic. Conclusions: The caste system of P. hybostoma is essentially linear, as in other basal Rhinotermitidae, but is distinguished by the late bifurcation leading to large apterous immatures. Because these large worker-like individuals deviate late and do not perform worker tasks, they cannot be considered homologous to the true workers of Termitidae and advanced Rhinotermitidae, but they provide a novel example of the evolution of sterile immatures in termites. © 2012 Bourguignon et al.
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Identification by GC-EAD of the two-component trail-following pheromone of Prorhinotermes simplex (Isoptera, Rhinotermitidae, Prorhinotermitinae)
Journal of insect physiology, 2009Co-Authors: David Sillam-dussès, Christian Bordereau, Jan Šobotník, Robert Hanus, Pavel Jiroš, Blanka Kalinová, Anna Brezinová, Josef Cvačka, Irena ValterováAbstract:GC/MS analysis confirmed that neocembrene is the major component of the trail pheromone in the three species of the termite genus Prorhinotermes (P. simplex, P. canalifrons, P. inopinatus). In addition, EAG and GC-EAD experiments with P. simplex strongly suggest that dodecatrienol is a quantitatively minor component but a qualitatively important component of this trail pheromone. Trail-following bioassays confirmed the two-component nature of the trail pheromone. This is the first report of the use of the GC-EAD for the identification of trail pheromone in termites. These original results underline once again the special phylogenetic status of the Prorhinotermitinae among Rhinotermitidae.
Yves Roisin - One of the best experts on this subject based on the ideXlab platform.
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historical biogeography of the termite clade rhinotermitinae blattodea isoptera
Molecular Phylogenetics and Evolution, 2019Co-Authors: Menglin Wang, Nathan Lo, Ales Bucek, Yves Roisin, David Sillamdusses, Theodore A. Evans, Jan Šobotník, Thomas BourguignonAbstract:Abstract Termites are the principal decomposers in tropical and subtropical ecosystems around the world. Time-calibrated molecular phylogenies show that some lineages of Neoisoptera diversified during the Oligocene and Miocene, and acquired their pantropical distribution through transoceanic dispersal events, probably by rafting in wood. In this paper, we intend to resolve the historical biogeography of one of the earliest branching lineages of Neoisoptera, the Rhinotermitinae. We used the mitochondrial genomes of 27 species of Rhinotermitinae to build two robust time-calibrated phylogenetic trees that we used to reconstruct the ancestral distribution of the group. Our analyses support the monophyly of Rhinotermitinae and all genera of Rhinotermitinae. Our molecular clock trees provided time estimations that diverged by up to 15.6 million years depending on whether or not 3rd codon positions were included. Rhinotermitinae arose 50.4–64.6 Ma (41.7–74.5 Ma 95% HPD). We detected four disjunctions among biogeographic realms, the earliest of which occurred 41.0–56.6 Ma (33.0–65.8 Ma 95% HPD), and the latest of which occurred 20.3–34.2 Ma (15.9–40.4 Ma 95% HPD). These results show that the Rhinotermitinae acquired their distribution through a combination of transoceanic dispersals and dispersals across land bridges.
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Not only soldiers have weapons: Evolution of the frontal gland in imagoes of the termite families Rhinotermitidae and Serritermitidae
2016Co-Authors: Thomas Bourguignon, Robert Hanus, Yves RoisinAbstract:Background: The frontal gland is a unique adaptation of advanced termite families. It has been intensively studied in soldiers with respect to its anatomy and chemistry, with numerous novel compounds being discovered within the tremendous richness of identified products. At the same time, the presence of the frontal gland in non-soldier castes received only negligible attention in the past. Principal Findings: Here, we report on the development of the frontal gland in alate imagoes of 10 genera and 13 species of Rhinotermitidae and Serritermitidae, in order to shed light on the evolution and function of this gland in imagoes. All investigated species possess a frontal gland. In most cases, it is well-developed and equipped with a sac-like reservoir, located in the postero-dorsal part of cranium, but reaching as far as the seventh abdominal segment in some Rhinotermitinae. The only exception is the genus Psammotermes, in which the gland is very small and devoid of the reservoir. Conclusions: Our direct observations and comparisons with soldiers suggest a defensive role of the gland in imagoes of all studied species. This functional analogy, along with the anatomic homology between the frontal gland in soldiers and imagoes, make it likely that the gland appeared once during the early evolution of rhinotermitid ancestors, and remained a
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Developmental pathways of Psammotermes hybostoma (Isoptera: Rhinotermitidae): old pseudergates make up a new sterile caste.
PloS one, 2012Co-Authors: Thomas Bourguignon, David Sillam-dussès, Yves Roisin, Jan Šobotník, Robert Hanus, Pavel Jiroš, Toru MiuraAbstract:Background: Ergonomic efficiency is in termites maximized by task partitioning among specialized castes. The isopteran caste systems can be classified as either (i) linear, when tasks are performed by pluripotent immatures (pseudergates), retaining the ability to develop into winged imagoes or (ii) bifurcated, with the presence of a true worker caste, which diverges early and permanently from the sexual (nymph/alate) line. Principal Findings: Here, we report on the ontogenetic potentialities of the highly polymorphic sand termite Psammotermes hybostoma. Beside numerous pluripotent pseudergates, constituting the main work force, some larger non-feeding apterous immatures, also occur. These individuals are unable to proceed to the winged imago stage, but store large amounts of fat and also give rise to large soldiers. Soldiers therefore originate from a wide range of apterous instars, consequently being highly polymorphic. Conclusions: The caste system of P. hybostoma is essentially linear, as in other basal Rhinotermitidae, but is distinguished by the late bifurcation leading to large apterous immatures. Because these large worker-like individuals deviate late and do not perform worker tasks, they cannot be considered homologous to the true workers of Termitidae and advanced Rhinotermitidae, but they provide a novel example of the evolution of sterile immatures in termites. © 2012 Bourguignon et al.
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Coming out of the woods: do termites need a specialized worker caste to search for new food sources?
Naturwissenschaften, 2008Co-Authors: Thomas Rupf, Yves RoisinAbstract:Most small-colony termites live confined within a single piece of wood on which they feed and do not possess permanent workers: Tasks are done by developmentally flexible immatures (pseudergates). By contrast, large-colony termites possess a specialized (true) worker caste and forage outside their nest for food. To shed light on possible transitional steps between these contrasting patterns of social organization, we studied an atypical Rhinotermitidae, Prorhinotermes inopinatus . In this species, despite the absence of a true worker caste, soldiers, pseudergates, and neotenic reproductives may leave the nest and explore their surroundings. Although evidence presented in this study indicates that termites recognize unknown areas, there is no directional recruitment toward them. The discovery of a food source, i.e., a piece of wood, is followed by the establishment of a long-lasting trail between the nest and the food source. A large fraction of the colony, including neotenic reproductives, ultimately migrates into the piece of wood. Our results thus demonstrate that multiple features of external foraging behavior can evolve independently of the existence of a true worker caste in termites. We suggest that large colonies with true workers, like those of most Rhinotermitidae, may easily have evolved from a Prorhinotermes -like pattern if submitted to increasing selective pressures for worker efficiency in a stable environment.
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A new genus and three new species of termitophilous staphylinids (Coleoptera: Staplylinidae) associated with Schedorhinotermes (Isoptera : Rhinotermitidae) in New Guinea
Sociobiology, 2006Co-Authors: Thomas Bourguignon, Yves RoisinAbstract:A new species of Myrmedonota (Myrmedonota termitophila, n. sp.) and a new genus of Coptotermoeciina with two new species (Schedotermoecia kaimanensis and S. papuana, n. spp.), all associated with termites of the genus Schedorhinotermes, are described. This is the first report of a species of Myrmedonota, a genus known to be myrmecophilous, associated with termites. The finding of Coptotermoeciina with Schedorhinotermes in New Guinea, while this subtribe is found with Coptotermes in Australia, suggests a change of host within the family Rhinotermitidae.
Klára Dolejšová - One of the best experts on this subject based on the ideXlab platform.
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Chemical alarm in the termite Termitogeton planus (Rhinotermitidae)
Journal of Chemical Ecology, 2014Co-Authors: Klára Dolejšová, Jana Krasulová, Kateřina Kutalová, Robert HanusAbstract:Effective defense is a common characteristic of insect societies. Indeed, the occurrence of specialized defenders, soldiers, has been the first step toward eusociality in several independent lineages, including termites. Among the multitude of defensive strategies used by termite soldiers, defense by chemicals plays a crucial role. It has evolved with complexity in advanced isopteran lineages, whose soldiers are equipped with a unique defensive organ, the frontal gland. Besides direct defense against predators, competitors, and pathogens, the chemicals emitted by soldiers from the frontal gland are used as signals of alarm. In this study, we investigated the chemical composition of the defensive secretion produced by soldiers of the termite Termitogeton planus (Isoptera: Rhinotermitidae), from West Papua, and the effects of this secretion on the behavior of termite groups. Detailed two-dimensional gas chromatography/mass spectrometry analyses of the soldier defensive secretion revealed the presence of four linear and nine monoterpene hydrocarbons. Soldier head extracts, as well as synthetic mixtures of the monoterpenes found in these extracts, elicited alarm behavior in both soldiers and pseudergates. Our results suggest that the alarm is not triggered by a single monoterpene from the defensive blend, but by a multi-component signal combining quantitatively major and minor compounds.
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Chemical alarm in the termite Termitogeton planus (Rhinotermitidae).
Journal of chemical ecology, 2014Co-Authors: Klára Dolejšová, Jana Krasulová, Kateřina Kutalová, Robert HanusAbstract:Effective defense is a common characteristic of insect societies. Indeed, the occurrence of specialized defenders, soldiers, has been the first step toward eusociality in several independent lineages, including termites. Among the multitude of defensive strategies used by termite soldiers, defense by chemicals plays a crucial role. It has evolved with complexity in advanced isopteran lineages, whose soldiers are equipped with a unique defensive organ, the frontal gland. Besides direct defense against predators, competitors, and pathogens, the chemicals emitted by soldiers from the frontal gland are used as signals of alarm. In this study, we investigated the chemical composition of the defensive secretion produced by soldiers of the termite Termitogeton planus (Isoptera: Rhinotermitidae), from West Papua, and the effects of this secretion on the behavior of termite groups. Detailed two-dimensional gas chromatography/mass spectrometry analyses of the soldier defensive secretion revealed the presence of four linear and nine monoterpene hydrocarbons. Soldier head extracts, as well as synthetic mixtures of the monoterpenes found in these extracts, elicited alarm behavior in both soldiers and pseudergates. Our results suggest that the alarm is not triggered by a single monoterpene from the defensive blend, but by a multi-component signal combining quantitatively major and minor compounds.
Christian Bordereau - One of the best experts on this subject based on the ideXlab platform.
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identification of the trail following pheromone of the pest termite amitermes evuncifer isoptera termitidae
Sociobiology, 2010Co-Authors: Esse A Kotoklo, David Sillamdusses, Guillaume K Ketoh, Christian Bordereau, Alain Robert, Etienne Sémon, Isabelle Adole GlithoAbstract:Amitermes evuncifer (termitidae, termitinae) is a pest termite in several countries of Africa, damaging crops and buildings. The trail-following pheromone of this termite was isolated from worker sternal glands identified by GC-MS after solid phase microextraction (SPME). The pheromone is composed of (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol (dodecatrienol) and neocembrene acting in synergy, neocembrene being 5-10 times more abundant than dodecatrienol. Dodecatrienol alone is able to elicit trail-following in workers, whereas neocembrene alone is inactive. However, the association of both components induces a significantly higher trail-following activity. Multicomponent trail-following pheromones were only known, until now, in the termitidae Nasutitermitinae, and in the Rhinotermitidae Prorhinotermes.
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identification of the trail following pheromone of the pest termite amitermes evuncifer isoptera termitidae
Sociobiology, 2010Co-Authors: Esse A Kotoklo, David Sillamdusses, Guillaume K Ketoh, Christian Bordereau, Alain Robert, Etienne Sémon, Isabelle Adole GlithoAbstract:Amitermes evuncifer (termitidae, termitinae) is a pest termite in several countries of Africa, damaging crops and buildings. The trail-following pheromone of this termite was isolated from worker sternal glands identified by GC-MS after solid phase microextraction (SPME). The pheromone is composed of (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol (dodecatrienol) and neocembrene acting in synergy, neocembrene being 5-10 times more abundant than dodecatrienol. Dodecatrienol alone is able to elicit trail-following in workers, whereas neocembrene alone is inactive. However, the association of both components induces a significantly higher trail-following activity. Multicomponent trail-following pheromones were only known, until now, in the termitidae Nasutitermitinae, and in the Rhinotermitidae Prorhinotermes.
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(Z)-Dodec-3-en-1-ol, a common major component of the trail-following pheromone in the termites Kalotermitidae
Chemoecology, 2009Co-Authors: David Sillam-dussès, Alain Robert, Etienne Sémon, Christian BordereauAbstract:( Z )-Dodec-3-en-1-ol has been identified as the major component of the trail-following pheromone of nine species of Kalotermitidae belonging to six different genera, suggesting that this compound represents a common signal in this family of termites. The homogeneous nature of trail-following pheromones of Kalotermitidae well agrees with the monophyly of this family. It also supports the postulated position of this family as a sister group of the Rhinotermitidae and Termitidae, which also secrete C12-alcohols as trail-following pheromones. The significance of a trail pheromone in termites of the ‘one-piece’ life type, which spend their whole life within the same piece of wood, is discussed.
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Identification by GC-EAD of the two-component trail-following pheromone of Prorhinotermes simplex (Isoptera, Rhinotermitidae, Prorhinotermitinae)
Journal of insect physiology, 2009Co-Authors: David Sillam-dussès, Christian Bordereau, Jan Šobotník, Robert Hanus, Pavel Jiroš, Blanka Kalinová, Anna Brezinová, Josef Cvačka, Irena ValterováAbstract:GC/MS analysis confirmed that neocembrene is the major component of the trail pheromone in the three species of the termite genus Prorhinotermes (P. simplex, P. canalifrons, P. inopinatus). In addition, EAG and GC-EAD experiments with P. simplex strongly suggest that dodecatrienol is a quantitatively minor component but a qualitatively important component of this trail pheromone. Trail-following bioassays confirmed the two-component nature of the trail pheromone. This is the first report of the use of the GC-EAD for the identification of trail pheromone in termites. These original results underline once again the special phylogenetic status of the Prorhinotermitinae among Rhinotermitidae.
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Neocembrene A, a major component of the trail-following pheromone in the genus Prorhinotermes (Insecta, Isoptera, Rhinotermitidae)
Chemoecology, 2005Co-Authors: David Sillam-dussès, Alain Robert, Jan Šobotník, Céline Moreau, Irena Valterová, Etienne Sémon, Christian BordereauAbstract:The diterpene neocembrene A or (1E,5E,9E,12R)-1,5,9-trimethyl-12-(1-methylethenyl)-1,5,9-cyclotetradecatriene, known as the trail-following pheromone of the advanced Termitidae Nasutitermitinae Nasutitermes exitiosus and Trinervitermes bettonianus, has been identified after SPME-GC/MS as the major component of the trail-following pheromone of the Rhinotermitidae Prorhinotermitinae, Prorhinotermes canalifrons and P. simplex. In all the other Rhinotermitidae studied until now, the major component of their trail pheromones is dodecatrienol ((3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol). This biochemical data further add to the anatomical and molecular characteristics that give a special status to the taxon Prorhinotermes among Rhinotermitidae. In Prorhinotermes canalifrons and P. simplex, neocembrene A was the only secretory compound specific to the sternal gland surface that could be detected after SPME. It elicited orientation as well as recruitment behavioral effects. However, the comparison of the respective biological activities triggered by neocembrene A and by sternal gland secretion suggests that minor components of the latter are acting in synergy with neocembrene A.
Brian T. Forschler - One of the best experts on this subject based on the ideXlab platform.
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Mermithid nematode parasites of eastern subterranean termites in North America
Nematology, 2020Co-Authors: George Poinar, A. Myer, Brian T. ForschlerAbstract:The subterranean termite Reticulitermes flavipes (Kollar, 1837) (Isoptera: Rhinotermitidae) occurs throughout the eastern USA and populations have been found as far west as Oregon. As with other termites, eastern subterranean termites live in colonies composed of workers, soldiers and reproductives. The blind, wingless workers, which are only between 3 and 4 mm long, feed on wood and can cause serious damage to wooden structures throughout their range (Edwards & Mill, 1986). Mermithid parasitism of termites is a rare occurrence and this report represents the first case of mermithid parasitism of termites in North and Central America.
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0252. A new species of Reticulitermes Holmgren, 1913 (Isoptera: Rhinotermitidae) from the southeastern United States
2012Co-Authors: Su Yee Lim, Brian T. ForschlerAbstract:Reticulitermes nelsonae, a new species of subterranean termite (Isoptera, Rhinotermitidae) is described from Sapelo Island, Georgia, United States of America, with specimens also found in North Carolina and Florida. The adult and soldier castes are described and illustrated to distinguish R. nelsonae from the four described Reticulitermes spp. known to occur in the southeastern United States.
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Reticulitermes nelsonae, a New Species of Subterranean Termite (Rhinotermitidae) from the Southeastern United States
Insects, 2012Co-Authors: Su Yee Lim, Brian T. ForschlerAbstract:Reticulitermes nelsonae, a new species of Rhinotermitidae (Isoptera) is described based on specimens from Sapelo Island, GA, Thomasville, GA, Havelock, NC, and Branford, FL. Adult (alate) and soldier forms are described. Diagnostic characters are provided and incorporated into a supplemental couplet of a dichotomous key to the known species of Reticulitermes found in Georgia, USA.
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New termite (Isoptera: Kalotermitidae, Rhinotermitidae) records from Georgia.
Journal of Entomological Science, 2001Co-Authors: Rudolf H Scheffrahn, James A. Chase, Brian T. ForschlerAbstract:Deliberate surveys and submitted samples have yielded five termite species not previously recorded from Georgia including Coptotermes formosanus Shiraki (Family Rhinotermitidae), and Calcaritermes nearcticus (Snyder), Cryptotermes brevis (Walker), Incisitermes minor (Hagen), and Kalotermes approximatus Snyder (Family Kalotermitidae) bringing the total number of termite species in Georgia to nine. Coptotermes formosanus, C. brevis, and I. minor are all non-endemic pest species in Georgia. The Georgia records for C. nearcticus are the first outside of Florida and represent new northern limits, while collections of K. approximatus bridge a former gap in its north-south distribution. Previous records for Reticulitermes flavipes (Kollar), R. hageni Banks, and R. virginicus (Banks) (Family Rhinotermitidae), and Incisitermes snyderi (Light) (Kalotermitidae) are confirmed, while the name R. malletei is relegated to nomen nudum status. The prospects for additional termite records and status of Reticulitermes taxon...