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Helmut König - One of the best experts on this subject based on the ideXlab platform.

  • Identification of the ectosymbiotic bacteria of Mixotricha paradoxa involved in movement symbiosis
    European Journal of Protistology, 2020
    Co-Authors: Marika Wenzel, Renate Radek, Guy Brugerolle, Helmut König
    Abstract:

    Mixotricha paradoxa, a trichomonad from the hindgut of the Australian termite Mastotermes Darwiniensis Froggatt, is a rare example of a movement symbiosis between eukaryotic and prokaryotic microorganisms. The surface of Mixotricha paradoxa is covered with spirochaetes and a rod-shaped bacterium. The four flagella at the anterior end seem only to alter the direction of movement, while the ectosymbiotic spirochaetes propel the flagellate cells. Based on a 16S rDNA sequence analysis after a semi-specific PCR, and subsequent fluorescence in situ hybridization applying helper oligonucleotides and a denaturing step of the 16S rRNA, three different spirochaete clones could be clearly identified on the surface of the protozoal cells. They belonged to the Treponema cluster. The rod shaped bacterium showed highest 16S rDNA sequence similarity to species related to Bacteroides. Due to its low phylogenetic relationship to its nearest relatives in the database, it should represent a so far undescribed species.

  • sugiyamaella mastotermitis sp nov and papiliotrema odontotermitis f a sp nov from the gut of the termites Mastotermes Darwiniensis and odontotermes obesus
    International Journal of Systematic and Evolutionary Microbiology, 2016
    Co-Authors: Steffen Handel, Tengfei Wang, Andrey Yurkov, Helmut König
    Abstract:

    Two novel yeast species were isolated from the guts of two different termite species. A new member of the genus Sugiyamaella was isolated from the hindgut and nest material of the lower Australian termite Mastotermes Darwiniensis. The second novel yeast species, isolated from the higher termite Odontotermes obesus, was identified as a member of the genus Papiliotrema. Both yeast species were able to hydrolyse xylan, methylumbelliferyl β-xylobiose and methylumbelliferyl β-xylotriose. The ability to debranch different hemicellulose side chains and growth without the addition of external vitamins was observed. A symbiotic role of the novel yeast species is indicated, especially in respect to xylan degradation and the production of vitamins. Here, we describe these species as Sugiyamaella mastotermitis sp. nov., MycoBank 816574 (type strain MD39VT=DSM 100793T=CBS 14182T), and Papiliotrema odontotermitis f.a., sp. nov., MycoBank 816575 (type strain OO5T=DSM 100791T=CBS 14181T). Additionally, we transfer Candida qingdaonensis to the genus Sugiyamaella and propose the following combination: Sugiyamaella qingdaonensis f.a., comb. nov., MycoBank 816576.

  • Isolation of methanotrophic bacteria from termite gut
    Microbiological Research, 2015
    Co-Authors: Julia Reuß, Peter Kämpfer, Stefan Droge, Reinhard Rachel, Andreas Rabenstein, Jan Dr. Küver, Helmut König
    Abstract:

    The guts of termites feature suitable conditions for methane oxidizing bacteria (MOB) with their permanent production of CH4 and constant supply of O2via tracheae. In this study, we have isolated MOB from the gut contents of the termites Incisitermes marginipennis, Mastotermes Darwiniensis, and Neotermes castaneus for the first time. The existence of MOB was indicated by detecting pmoA, the gene for the particulate methane monooxygenase, in the DNA of gut contents. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction supported those findings. The MOB cell titer was determined to be 102–103 per gut. Analyses of the 16S rDNA from isolates indicated close similarity to the genus Methylocystis. After various physiological tests and fingerprinting methods, no exact match to a known species was obtained, indicating the isolation of new MOB species. However, MALDI-TOF MS analyses revealed a close relationship to Methylocystis bryophila and Methylocystis parvus.

  • production of methyl mercury in the gut of the australian termite Mastotermes Darwiniensis
    Journal of Applied Entomology, 2008
    Co-Authors: U Limper, B Knopf, Helmut König
    Abstract:

    Animals are often exposed to or can ingest heavy metals along with their food. Therefore, we tested whether the hindgut microbiota of Mastotermes Darwiniensis possesses the capability to form methyl mercury. The termite M. Darwiniensis (Isoptera) was fed with saw dust containing different concentrations of inorganic mercury. Methyl mercury was determined by purge-and-trap capillary gas chromatography-atom fluorescence spectrometry (CGC-AFS) using ethyl mercury chloride as the internal standard. Total mercury concentrations were determined in the termite tissue by inductive coupled plasma-isotope dilution mass spectrometry (ICP-IDMS) after microwave-assisted digestion. The obtained results showed in vivo methyl mercury production in terrestrial insects for the first time. Desulfovibrio intestinalis isolated from M. Darwiniensis was identified as a biomethylating species of the intestinal microbiota.

  • the flagellates of the australian termite Mastotermes Darwiniensis identification of their symbiotic bacteria and cellulases
    Symbiosis, 2007
    Co-Authors: Helmut König, Marika Wenzel, Manfred Berchtold, Stefan Droge, Jurgen Frohlich, Li Li, Alfred Breunig, Peter Pfeiffer, Renate Radek, Guy Brugerolle
    Abstract:

    Termites are among the most important wood- and litter-feeding insects. The gut microbiota plays an indispensable role in the digestion of food. They can include Bacteria, Archaea, flagellates, yeasts, and fungi. The unique flagellates of the termite gut belong to the Preaxostyla (Oxymonadida) and Parabasalia (Cristamonadida, Spirotrichonymphida, Trichomonadida, Trichonymphida), which have branched off very early in the evolution of the eukaryotes. The termite Mastotermes Darwiniensis is the only species of the most primitive termite family Mastotermitidae. It harbors four large flagellate species in the hindgut: the cristamonads Koruga bonita, Deltotrichonympha nana, Deltotrichonympha operculata and Mixotricha paradoxa. Two small flagellate species also thrive in the intestine: the cristamonad Metadevescovina extranea and the trichomonad Pentatrichomonoides scroa. The flagellates themselves harbor extracellular and intracellular prokaryotes. From cell extracts of the not yet culturable symbiotic flagellates two endoglucanases with a similar apparent molecular mass of approximately 36 kD have been isolated. They exhibited significant homology to cellulases of termite origin. The corresponding genes were detected not in the mRNA pool of the flagellates, but in the salivary glands of Mastotermes Darwiniensis. These results indicated that the intestinal flagellates of Mastotermes Darwiniensis also use the termite's cellulases for cellulose hydrolysis. In total extracts of the intestine of wild termites also three cellulases were detected, which should originate from flagellates.

Manfred Berchtold - One of the best experts on this subject based on the ideXlab platform.

  • the flagellates of the australian termite Mastotermes Darwiniensis identification of their symbiotic bacteria and cellulases
    Symbiosis, 2007
    Co-Authors: Helmut König, Marika Wenzel, Manfred Berchtold, Stefan Droge, Jurgen Frohlich, Li Li, Alfred Breunig, Peter Pfeiffer, Renate Radek, Guy Brugerolle
    Abstract:

    Termites are among the most important wood- and litter-feeding insects. The gut microbiota plays an indispensable role in the digestion of food. They can include Bacteria, Archaea, flagellates, yeasts, and fungi. The unique flagellates of the termite gut belong to the Preaxostyla (Oxymonadida) and Parabasalia (Cristamonadida, Spirotrichonymphida, Trichomonadida, Trichonymphida), which have branched off very early in the evolution of the eukaryotes. The termite Mastotermes Darwiniensis is the only species of the most primitive termite family Mastotermitidae. It harbors four large flagellate species in the hindgut: the cristamonads Koruga bonita, Deltotrichonympha nana, Deltotrichonympha operculata and Mixotricha paradoxa. Two small flagellate species also thrive in the intestine: the cristamonad Metadevescovina extranea and the trichomonad Pentatrichomonoides scroa. The flagellates themselves harbor extracellular and intracellular prokaryotes. From cell extracts of the not yet culturable symbiotic flagellates two endoglucanases with a similar apparent molecular mass of approximately 36 kD have been isolated. They exhibited significant homology to cellulases of termite origin. The corresponding genes were detected not in the mRNA pool of the flagellates, but in the salivary glands of Mastotermes Darwiniensis. These results indicated that the intestinal flagellates of Mastotermes Darwiniensis also use the termite's cellulases for cellulose hydrolysis. In total extracts of the intestine of wild termites also three cellulases were detected, which should originate from flagellates.

  • Cellulosimicrobium variabile sp. nov., a cellulolytic bacterium from the hindgut of the termite Mastotermes Darwiniensis
    International Journal of Systematic and Evolutionary Microbiology, 2002
    Co-Authors: Agapia Bakalidou, Thomas Kuhnigk, Marika Wenzel, Manfred Berchtold, Peter Kämpfer, Helmut König
    Abstract:

    A novel cellulolytic and xylanolytic bacterium, strain MX5T, was isolated from the hindgut contents of the Australian termite Mastotermes Darwiniensis (Froggatt). The isolate was a facultative anaerobe and had a Gram-positive cell-wall profile. The rod-shaped bacterium formed irregular coryneform and coccoid cells during growth. Phylogenetic analysis of the 16S rDNA provided evidence that the organism was closely related to the as-yet undescribed cellulolytic strain SR272 and the non-validly described species 'Cellulomonas pachnodae' as well as Promicromonospora citrea and Promicromonospora sukumoe. Strain MX5T was assigned to the genus Cellulosimicrobium on the basis of phylogenetic and chemotaxonomic criteria. The murein of strain MX5T contained the diamino acid lysine. N-Glycolylmuramic acid, mycolic acids and hydroxy fatty acids were absent. The major neutral sugar in the cell wall was galactose and the major quinone was menaquinone MK-9(H4). The predominant fatty acids were ai-C15:0, i-C15:0, i-C16:0 and C16:0. The G+C content of the DNA was in a range 70-72 mol%. On the basis of 16S rDNA sequence similarities and chemotaxonomic features, MX5T was clearly different from Cellulosimicrobium cellulans and other validly described species within this phylogenetic group. For this reason, a novel species is described, for which the name Cellulosimicrobium variabile sp. nov. is proposed.

  • differential enumeration and in situ localization of microorganisms in the hindgut of the lower termite Mastotermes Darwiniensis by hybridization with rrna targeted probes
    Archives of Microbiology, 1999
    Co-Authors: Manfred Berchtold, Antonis Chatzinotas, Wilhelm Schonhuber, Andreas Brune, Rudolf Amann, D Hahn, Helmut König
    Abstract:

    We examined the abundance and spatial distribution of major phylogenetic groups of the domain Bacteria in hindguts of the Australian lower termite Mastotermes Darwiniensis by using in situ hybridization with group-specific, fluorescently labeled, rRNA-targeted oligonucleotide probes. Between 32.0 ± 7.2% and 52.3 ± 8.2% of the DAPI-stained cells in different hindgut fractions were detected with probe EUB338, specific for members of the domain Bacteria. About 85% of the prokaryotic cells were associated with the flagellates of the thin-walled anterior region (P3a) and the thick wall of the posterior region (P3b/P4) of the hindgut, as shown by DAPI staining. At most, half of the EUB338-detected cells hybridized with one of the other probes that targeted a smaller assemblage within the bacterial domain. In most fractions, cells were found in varying numbers with probe ALF1b, which targeted members of the α-Proteobacteria, whereas substantial amounts of sulfate-reducing bacteria, gram-positive bacteria with a high DNA G+C content and members of the Cytophaga-Flavobacterium cluster of the Cytophaga-Flavobacterium-Bacteroides (CFB) phylum could be detected only in the wall fraction of P3b/P4. This clearly indicates that the hindgut microhabitats differ in the composition of their microbial community. In situ hybridization of cryosections through the hindgut showed only low numbers of bacteria attached to the P3a wall. In contrast, the wall of P3b was densely colonized by rod- and coccus-shaped bacteria, which could be assigned to the Cytophaga-Flavobacterium cluster of the CFB phylum and to the group of gram-positive bacteria with a high DNA G+C content, respectively. Oxygen concentration profiles determined with microelectrodes revealed steep oxygen gradients both in P3a and P3b. Oxygen was consumed within 100 μm below the gut surface, and anoxic conditions prevailed in the central portions of both gut regions, indicating that oxygen consumption in the hindgut does not depend on the presence of a biofilm on the hindgut wall.

  • phylogenetic analysis and in situ identification of uncultivated spirochetes from the hindgut of the termite Mastotermes Darwiniensis
    Systematic and Applied Microbiology, 1996
    Co-Authors: Manfred Berchtold, Helmut König
    Abstract:

    Summary Different small subunit ribosomal DNA (SSU rDNA) sequences of uncultivated spirochetes from the hindgut of the termite Mastotermes Darwiniensis were determined and phylogenetically analysed. Starting with DNA isolated from hindgut contents we amplified SSU rDNA coding regions by PCR using bacteria- and spirochete-specific primers, respectively. Cloning and sequencing of the amplification products re-sulted in 11 different spirochetal SSU rDNA sequences with similarity values of 81.8% to 99.0% to each other. Phylogenetic trees showed that the obtained sequences are related to the genus Treponema with 84.0% to 91.1% similarity to Treponema spec. H1 and Spirochaeta stenostrepta as their nearest relatives among the cultivated spirochetes. Using fluorescence in situ hybridisation one of the SSU rDNA sequences could be assigned to a large spirochete. So at least one of the large hindgut spirochetes unique in termite hindguts and assigned to the genera Hollandina , Pillotina , Clevelandina or Diplocalyx phylogenetically belongs to the treponeme cluster of spirochetes.

  • phylogenetic position of the two uncultivated trichomonads pentatrichomonoides scroa kirby and metadevescovina extranea kirby from the hindgut of the termite Mastotermes Darwiniensis froggatt
    Systematic and Applied Microbiology, 1995
    Co-Authors: Manfred Berchtold, Helmut König
    Abstract:

    Summary The phylogenetic position of the two uncultivated trichomonad flagellates Pentatrichomonoides scroa and Metadevescovina extranea symbiotic in the hindgut of the Australian termite Mastotermes Darwiniensis was determined by analysis of small subunit ribosomal DNA (SSU rDNA) sequences. After enrichment of the two trichmonads from crude hindgut contents and isolation of DNA the SSU rDNA was amplified by the polymerase chain reaction (PCR). The amplification products were cloned and sequenced resulting in two different sequences. Excluding the amplification primers the sequences were 1526 and 1500 nucleotides in length, respectively. The two sequences were assigned to the corresponding flagellate cells by whole cell hybridization using specific oligonucleotide probes. The SSU rDNA of Pentatrichomonoides scroa showed 87.3% similarity to Metadevescovina extranea and 87.2% and 93.0% to the other so far examined trichomonads Tritrichomonas foetus and Trichonrinrs trypanoides, respectively. Metadevescovina extranea was 89.0% and 88.1% similar to Tritrichomonas foetus and Trichomitus trypanoides , respectively. The sequences were phylogenetically analysed using distance matrix and character state methods. Within the trichomonads Pentatrichomonoides scroa and Trichomitus trypanoides clustered together in all analyses and Tritrichomonas foetus was the first branching trichomonad. Depending on the data set used, the trichomonad cluster consisting of four SSU rDNA sequences was one of the three deepest branching eukaryotic lineages.

Michael Lenz - One of the best experts on this subject based on the ideXlab platform.

  • Application of the natural phagostimulant hydroquinone in bait systems for termite management (Isoptera)
    Sociobiology, 2020
    Co-Authors: Judith Reinhard, Michael J. Lacey, Michael Lenz
    Abstract:

    Hydroquinone is a phagostimulating pheromone found in labial glands of most, if not all, termite species. In this study, we investigated whether hydroquinone enhances the effectiveness of bait systems for termite control. Laboratory feeding choice tests on filter paper with Mastotermes Darwiniensis Froggatt and Coptotermes acinaciformis (Froggatt) demonstrated that several compounds chemically related to hydroquinone had a phagostimulating effect, but none as strong as the natural pheromone. Hydroquinone also works as short-distance attractant: termites were lured towards a source of hydroquinone over a distance of several centimeters. In long-term laboratory choice feeding tests, M. darwintensis and C. acinaciformis consumed significantly more wood within three days and one week, respectively, if hydroquinone had been applied. The preference had diminished after four weeks. Addition of glucose or amino acids did not increase the phagostimulating effect of hydroquinone. In field tests, hydroquinone proved to be comparatively stable under natural conditions: after four weeks in the soil, ca. 30% of the original amount of hydroquinone was still left in the baits. In field baiting trials with colonies of M. Darwiniensis, C. acinaciformis, and C. lacteus in Australia, hydroquinone significantly increased feeding and the number of termites in treated baits compared to controls. Preliminary field trials with 10 further termite species in Australia and overseas confirmed these results.

  • ability of field populations of coptotermes spp reticulitermes flavipes and Mastotermes Darwiniensis isoptera rhinotermitidae mastotermitidae to damage plastic cable sheathings
    Journal of Economic Entomology, 2013
    Co-Authors: Michael Lenz, Theodore A Evans, B M Kard, James W Creffield, Kenneth S Brown, Edward D Freytag, Junhong Zhong, Boonhoi Yeoh, Tsuyoshi Yoshimura, Kunio Tsunoda
    Abstract:

    ABSTRACT A comparative field study was conducted to evaluate the ability of subterranean termites to damage a set of four different plastic materials (cable sheathings) exposed below- and above-ground. Eight pest species from six countries were included, viz., Coptotermes formosanus (Shiraki) in China, Japan, and the United States; Coptotermes gestroi (Wasmann) in Thailand and Malaysia; Coptotermes curvignathus (Holmgren) and Coptotermes kalshoveni (Kemner) in Malaysia; Coptotermes acinaciformis (Froggatt) with two forms of the species complex and Mastotermes Darwiniensis (Froggatt) in Australia; and Reticulitermes flavipes (Kollar) in the United States. Termite species were separated into four tiers relative to decreasing ability to damage plastics. The first tier, most damaging, included C. acinaciformis, mound-building form, and M. Darwiniensis, both from tropical Australia. The second tier included C. acinaciformis, tree-nesting form, from temperate Australia and C. kalshoveni from Southeast Asia. The...

  • Trail-Following Pheromones in Basal Termites, with Special Reference to Mastotermes Darwiniensis
    Journal of Chemical Ecology, 2007
    Co-Authors: David Sillam-dussès, Michael Lenz, Etienne Sémon, Michael J. Lacey, Alain Robert, Christian Bordereau
    Abstract:

    In the framework of an evolutionary study, trail pheromones have been studied in the most basal extant termite, Mastotermes Darwiniensis (Mastotermitidae), and two other basal termites, the Termopsidae Porotermes adamsoni (Porotermitinae) and Stolotermes victoriensis (Stolotermitinae). Although workers of M. Darwiniensis do not walk in single file while exploring a new environment under experimental conditions and are unable to follow artificial trails in ‘open field’ experiments, they do secrete a trail-following pheromone from their sternal glands. This unique behavior might reflect a primitive function of communication of the sternal gland. The major component of the pheromone appears to be the same in the three basal species: the norsesquiterpene alcohol ( E )-2,6,10-trimethyl-5,9-undecadien-1-ol. This represents a new chemical category of trail-following pheromones for termites. The quantity of pheromone was estimated as 20 pg/individual in M. Darwiniensis , 700 pg/individual in P. adamsoni , and 4 pg/individual in S. victoriensis . The activity threshold was 1 ng/cm in M. Darwiniensis and 10 pg/cm in P. adamsoni . In M. Darwiniensis , the trail pheromone was secreted by sternal gland 4 and to a lesser degree by sternal gland 3, sternal gland 5 being almost inactive. This study highlighted phylogenetic relationships between the Mastotermitidae and two subfamilies of the Termopsidae, the Porotermitinae and the Stolotermitinae. Furthermore, it indicated a heterogeneity within the Termopsidae, with Porotermitinae and Stolotermitinae on one hand, and Termopsinae on the other. Finally, Mastotermitidae and Termopsidae, with C14 trail pheromones, are clearly separated from the Kalotermitidae, Rhinotermitidae, and Termitidae that secrete C12 or C20 trail pheromones.

  • Hydroquinone: A General Phagostimulating Pheromone in Termites
    Journal of Chemical Ecology, 2002
    Co-Authors: Judith Reinhard, Michael J. Lacey, Fernando Ibarra, Frank C. Schroeder, Manfred Kaib, Michael Lenz
    Abstract:

    The organization of termite societies depends predominantly on intraspecific chemical signals (pheromones) produced by exocrine glands, which induce and modulate individual behavioral responses. Here, the saliva-producing labial glands of termites were investigated with respect to their pheromonal role in communal food exploitation of termite colonies. From these glands, we identified for the first time hydroquinone (1,4-dihydroxybenzene) as a phagostimulating pheromone in the Australian termite species Mastotermes Darwiniensis . Hydroquinone is released from the labial glands of termite workers and applied onto the food. It stimulates nestmates to feed at the spot of application and is, thus, employed to mark feeding sites. No synergistic effect with other identified labial gland compounds, such as glucose, inositol, and arbutin, was evident. Significantly, we show that termite species from all over the world, irrespective of taxonomic position and biological traits, produce and employ hydroquinone as phagostimulating signal. The use of the same chemical signal throughout an order is a unique phenomenon, not reported before in animals. Its possible biosynthetic pathway, ecological significance, and evolution are discussed.

  • flight characteristics of Mastotermes Darwiniensis isoptera mastotermitidae
    Insectes Sociaux, 2001
    Co-Authors: Christine A Nalepa, L R Miller, Michael Lenz
    Abstract:

    Flight patterns of Mastotermes Darwiniensis in northern Australia were monitored using a light trap during the summer monsoons of 1975 and 1996. A major flight was detected in both years, with flights of smaller magnitude also occurring. Results indicate that flight behaviour is more closely correlated with ecology and life type than with phylogenetic position. Overall, sex ratios were slightly but significantly biased in favor of males. Head capsule widths of males and females did not differ, but the wet and dry weights of females significantly exceeded those of males. In both sexes, the hindgut comprised 2.9 % of the wet weight, and whole body dry weight was 44 % of wet weight.

J W Creffield - One of the best experts on this subject based on the ideXlab platform.

  • the development of a standard laboratory bio assay technique with Mastotermes Darwiniensis froggatt isoptera mastotermitidae
    Journal of Applied Entomology, 2009
    Co-Authors: C D Howick, J W Creffield
    Abstract:

    Because of the increasing significance of damage by Mastotermes Darwiniensis Froggatt in Australia, a laboratory bio-assay technique with the species has become necessary. This paper gives details of all materials and methods associated with such a technique and supplies reasons for their selection. Details are also given of variations which may be made when special assessments are required. Results are shown of laboratory studies in which the technique is used to determine the effectiveness of three wood preservatives and the comparative susceptibility of three wood species. Results of similar tests with another termite species are also shown, to demonstrate the feasibility of such a comparison on the basis of the recommended assessment criteria. Zusammenfassung Labormasige Entwicklung einer standardisierten Bio-Prufungstechnik fur Mastotermes Darwiniensis Froggatt (Isoptera: Mastotermitidae) Die zunehmende Bedeutung der durch Mastotermes Darwiniensis in Australien verursachten Schaden machte es notwendig, eine fur diese Art eigene labormasige Bio-Prufungstechnik zu entwickeln. Es werden einige mit dieser Technik verbundene Methoden erortert und deren Wahl begrundet. Die unter Anwendung dieser Technik gewonnenen Testresultate zeigen die Wirkungsweise von drei Holzschutzmitteln in Abhangigkeit vom Widerstand dreier Holzarten gegen Termitenfras. Uber ahnliche Untersuchungen an einer anderen Termitenart wird berichtet, um die breitere Anwendungsmoglichkeit der vorgeschlagenen Methode zu demonstrieren.

  • The development of a standard laboratory bio‐assay technique with Mastotermes Darwiniensis Froggatt (Isoptera: Mastotermitidae)
    Journal of Applied Entomology, 2009
    Co-Authors: C D Howick, J W Creffield
    Abstract:

    Because of the increasing significance of damage by Mastotermes Darwiniensis Froggatt in Australia, a laboratory bio-assay technique with the species has become necessary. This paper gives details of all materials and methods associated with such a technique and supplies reasons for their selection. Details are also given of variations which may be made when special assessments are required. Results are shown of laboratory studies in which the technique is used to determine the effectiveness of three wood preservatives and the comparative susceptibility of three wood species. Results of similar tests with another termite species are also shown, to demonstrate the feasibility of such a comparison on the basis of the recommended assessment criteria. Zusammenfassung Labormasige Entwicklung einer standardisierten Bio-Prufungstechnik fur Mastotermes Darwiniensis Froggatt (Isoptera: Mastotermitidae) Die zunehmende Bedeutung der durch Mastotermes Darwiniensis in Australien verursachten Schaden machte es notwendig, eine fur diese Art eigene labormasige Bio-Prufungstechnik zu entwickeln. Es werden einige mit dieser Technik verbundene Methoden erortert und deren Wahl begrundet. Die unter Anwendung dieser Technik gewonnenen Testresultate zeigen die Wirkungsweise von drei Holzschutzmitteln in Abhangigkeit vom Widerstand dreier Holzarten gegen Termitenfras. Uber ahnliche Untersuchungen an einer anderen Termitenart wird berichtet, um die breitere Anwendungsmoglichkeit der vorgeschlagenen Methode zu demonstrieren.

  • effects of hydroprene on the feeding activity of Mastotermes Darwiniensis froggatt isoptera
    Journal of Applied Entomology, 2009
    Co-Authors: J R J French, J W Creffield, P J Robinson, C D Howick
    Abstract:

    The juvenile hormone analogue, hydroprene (ethyl 3,7,11-trimethyldodeca-2,4-dienoate) impregnated into Pinus radiata wood-blocks affected the feeding activity of Mastotermes Darwiniensis workers in two laboratory bioassays. There was a highly significant decrease in wood eaten per gram of termites with an increase in hydroprene concentration in the jar-colony bioassay whereas in the petri-dish bioassay the decrease in wood eaten was not as significant. The mean number of workers on the treated blocks were observed to have decreased significantly (5 % level) with an increase in hydroprene concentration. Termite fat contents decreased significantly with increase in days of feeding in the jar-colony bioassay, though there was no evidence that the concentration of hydroprene significantly affected fat content. In the jar-colony bioassay sequential samples of hindgut endosymbiont bacteria were isolated from the workers. The data indicated a pattern of bacterial colony-type decline in all treatments after 14 d. Zusammenfassung Wirkungen von Hydropren auf die Frasaktivitat von Mastotermes Darwiniensis Froggatt (Isoptera) Eine Impragnierung von Holzblocken von Pinus radiata mit dem Juvenilhormon-Analogen Hydropren (ethyl 3,7,11-trimethyldodeca-2,4-dienoate) veranderten die Frasaktivitat von in zwei Laborzuchten gehaltenen Mastotermes Darwiniensis-Arbeitern derart, das mit steigender Hydrop-ren-Konzentration die Menge des gefressenen Holzes hochsignifikant abnahm. Allerdings war dies nur bei der Gefaszucht, nicht bei der Petri-Schalen-Zucht der Fall. Die mittlere Zahl an Arbeitern nahm bei den behandelten Holzstucken mit steigender Hydropren-Konzentration signifikant ab (5 % Grenze). Der Korperfettgehalt der Termiten sank bei den Gefaszucht-Tieren signifikant mit der Frasdauer, obgleich keine Korrelation zwischen Hydropren-Konzentrationen und Fettgehalt bestand. In der Gefaszucht wurden regelmasig Proben der im Enddarm der Termiten symbiontisch lebenden Bakterien entnommen. Es zeigte sich, das die Bakterienflora bei allen Tieren, die behandeltes Holz frasen, binnen 14 Tagen reduziert wurde.

  • Treatment of timber with permethrin in supercritical carbon dioxide to control termites
    Journal of Supercritical Fluids, 2009
    Co-Authors: L. J. Cookson, J W Creffield, Abdul Qader, D. K. Scown
    Abstract:

    Abstract The solubility of permethrin in supercritical carbon dioxide (scCO2) was determined, with optimal solubility for the timber impregnation trial and the specific operating conditions examined occurring at 50 °C. Methanol as co-solvent improved solubility, but was not needed for timber impregnation. Eucalyptus obliqua heartwood (a refractory timber), Pinus radiata sapwood and P. radiata LVL were impregnated in a treatment cylinder, and their resistance to attack by termites was compared to that of material protected with standard permethrin treatments using light organic solvent preservative (LOSP). Termite field tests were conducted against Coptotermes acinaciformis and Mastotermes Darwiniensis. The choice of solvent system did not affect permethrin efficacy in P. radiata sapwood against termites. P. radiata LVL specimens treated using scCO2 had slightly lower mean mass losses than those impregnated with LOSP, reflecting slightly higher permethrin uptakes in the former. E. obliqua heartwood was completely destroyed by M. Darwiniensis when impregnated with LOSP, but was mostly sound when scCO2 was used. These results show that scCO2 did not alter the effectiveness of the insecticide, while giving the added benefit of allowing the impregnation of timbers previously considered refractory to treatment.

  • Efficacy of chlorothalonil and chlorothalonil plus chlorpyrifos against termite attack
    Forest Products Journal, 1995
    Co-Authors: J W Creffield, N. Chew
    Abstract:

    Results of a laboratory bioassay on the efficacy of two preservative formulations (chlorothalonil in oil ; chlorothalonil plus chlorpyrifos in oil) to the Australian subterranean termite Mastotermes Darwiniensis Froggatt are given. Specimens of Pinus radiata D.Don sapwood were treated to three retentions of each formulation to achieve 3.2, 6.4, and 12,8 kg/m 3 of chlorothalonil a.i. (active ingredient) and 3.2 + 0,2, 6,4 + 0.4, and 12.8 + 0,8 kg/m 3 of chlorothalonil plus chlorpyrifos a.i. All specimens (including controls) were subjected to an artificial leaching/volatilization weathering schedule prior to the bioassay. Results showed that all three retentions of each formulation were successful in protecting specimens from significant attack by M.Darwiniensis. The results also indicated that the chlorothalonil in oil formulation appeared to have an antifeedant effect on M.Darwiniensis

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  • parallel and gradual genome erosion in the blattabacterium endosymbionts of Mastotermes Darwiniensis and cryptocercus wood roaches
    Genome Biology and Evolution, 2018
    Co-Authors: Yukihiro Kinjo, Christine A Nalepa, Thomas Bourguignon, Kwei Jun Tong, Hirokazu Kuwahara, Kwang Bae Yoon, Shuji Shigenobu, Yung Chul Park, Yuichi Hongoh
    Abstract:

    : Almost all examined cockroaches harbor an obligate intracellular endosymbiont, Blattabacterium cuenoti. On the basis of genome content, Blattabacterium has been inferred to recycle nitrogen wastes and provide amino acids and cofactors for its hosts. Most Blattabacterium strains sequenced to date harbor a genome of ∼630 kbp, with the exception of the termite Mastotermes Darwiniensis (∼590 kbp) and Cryptocercus punctulatus (∼614 kbp), a representative of the sister group of termites. Such genome reduction may have led to the ultimate loss of Blattabacterium in all termites other than Mastotermes. In this study, we sequenced 11 new Blattabacterium genomes from three species of Cryptocercus in order to shed light on the genomic evolution of Blattabacterium in termites and Cryptocercus. All genomes of Cryptocercus-derived Blattabacterium genomes were reduced (∼614 kbp), except for that associated with Cryptocercus kyebangensis, which comprised 637 kbp. Phylogenetic analysis of these genomes and their content indicates that Blattabacterium experienced parallel genome reduction in Mastotermes and Cryptocercus, possibly due to similar selective forces. We found evidence of ongoing genome reduction in Blattabacterium from three lineages of the C. punctulatus species complex, which independently lost one cysteine biosynthetic gene. We also sequenced the genome of the Blattabacterium associated with Salganea taiwanensis, a subsocial xylophagous cockroach that does not vertically transmit gut symbionts via proctodeal trophallaxis. This genome was 632 kbp, typical of that of nonsubsocial cockroaches. Overall, our results show that genome reduction occurred on multiple occasions in Blattabacterium, and is still ongoing, possibly because of new associations with gut symbionts in some lineages.

  • Evidence for Cocladogenesis Between Diverse Dictyopteran Lineages and Their Intracellular Endosymbionts
    Molecular Biology and Evolution, 2003
    Co-Authors: Nathan Lo, Christine A Nalepa, Claudio Bandi, Hirofumi Watanabe, Tiziana Beninati
    Abstract:

    : Bacteria of the genus Blattabacterium are intracellular symbionts that reside in specialized cells of cockroaches and the termite Mastotermes Darwiniensis. They appear to be obligate mutualists, and are transmitted vertically in the eggs. Such characteristics are expected to lead to equivalent phylogenies for host and symbiont, and we tested this hypothesis using recently accumulated data on relationships among termites and cockroaches and their Blattabacterium spp. Host and symbiont topologies were found to be highly similar, and various tests indicated that they were not statistically different. A close relationship between endosymbionts from termites and members of the wood-feeding cockroach genus Cryptocercus was found, supporting the hypothesis that the former evolved from subsocial, wood-dwelling cockroaches. The majority of the Blattabacterium spp. sequences appear to have undergone similar rates of evolution since their divergence from a common ancestor, and an estimate of this rate was determined based on early Cretaceous host fossils. The results support the idea that the stem group of modern cockroaches radiated sometime between the late Jurassic and early Cretaceous-not the Carboniferous, as has been suggested on the basis of roach-like fossils from this epoch.

  • flight characteristics of Mastotermes Darwiniensis isoptera mastotermitidae
    Insectes Sociaux, 2001
    Co-Authors: Christine A Nalepa, L R Miller, Michael Lenz
    Abstract:

    Flight patterns of Mastotermes Darwiniensis in northern Australia were monitored using a light trap during the summer monsoons of 1975 and 1996. A major flight was detected in both years, with flights of smaller magnitude also occurring. Results indicate that flight behaviour is more closely correlated with ecology and life type than with phylogenetic position. Overall, sex ratios were slightly but significantly biased in favor of males. Head capsule widths of males and females did not differ, but the wet and dry weights of females significantly exceeded those of males. In both sexes, the hindgut comprised 2.9 % of the wet weight, and whole body dry weight was 44 % of wet weight.

  • transovarial transmission of symbiotic bacteria in Mastotermes Darwiniensis isoptera mastotermitidae ultrastructural aspects and phylogenetic implications
    Annals of The Entomological Society of America, 2000
    Co-Authors: L Sacchi, Christine A Nalepa, Michael Lenz, Claudio Bandi, S Corona, Aldo Grigolo, Elisa Bigliardi
    Abstract:

    Intracellular symbiotic bacteria in specialized cells (bacteriocytes) of the fat body are found in all cockroaches and in the termite Mastotermes Darwiniensis Froggatt. DNA sequence analysis of the bacteria in the two taxa shows them to be phylogenetically related; thus, it has been suggested that the bacteriocyte symbiosis was established in an ancestor common to cockroaches and termites, with a loss of the symbiosis in all other known termite lineages. The offspring of both cockroaches and Mastotermes acquire the symbiosis via transovarial transmission. However, transmission of the bacteria in Mastotermes has not been examined since the pioneering works carried out by Koch in the 1930s. Here we report on transovariole transmission in primary and neotenic reproductives, and show that the ovarioles of both harbor fat body, which contains bacteriocytes. The conspicuous number of ovarian bacteriocytes in neotenic queens corresponds to the pattern previously observed in female nymphs. Bacterial transmission to offspring during the life of the colony thus occurs through continuous provisioning of symbionts to the ovariole from bacteriocytes in ovarian fat body. This pattern parallels that of cockroaches as does the entire mechanism of transovarial transmission.

  • the ootheca of Mastotermes Darwiniensis froggatt isoptera mastotermitidae homology with cockroach oothecae
    Proceedings of The Royal Society B: Biological Sciences, 2000
    Co-Authors: Christine A Nalepa, Michael Lenz
    Abstract:

    The basal termite Mastotermes Darwiniensis produces an egg mass, the nature of which is controversial. The debate centres on whether it is homologous with the oothecae of mantids and cockroaches and, if so, whether its simple structure is plesiomorphic or apomorphic within the Dictyoptera. To help resolve these issues we observed primary reproductives of M. Darwiniensis during oviposition and examined the morphology of the reproductive product. Oviposition is cockroach-like in that the egg mass is assembled within the vestibulum and the eggs are issued externally in pairs. The reproductive product is an ootheca of the blattarian type. A distinct, tanned outer covering is stretched over the two parallel rows of eggs. No keel is present and no calcium oxalate crystals were apparent in the outer covering. We cannot rule out the possibility that the simple structure of the ootheca is plesiomorphic within Dictyoptera. However, based on (i) apomorphies shared by Mastotermes and Blattaria, and (ii) the life habits of Isoptera, a secondary reduction is the more plausible explanation.