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Fungal colonisation of the keelson and associated structures of a nineteenth century wooden frigate: Concepts of community structure and development
1994 - IRG/WP 94-10072
The early stages of microbial colonization and succession of wooden surfaces exposed to the sea have been extensively studied as have the community structures of archaeological timbers subjected to submergence and then retrieval from the sea. The frigate UNICORN, a largely intact 19th century wooden ship based in Dundee, Scotland, provides the microbial ecologist with a unique opportunity to study the microbial community structures of untreated and treated (with brine) English oak timbers of a vessel which apart from the occasional dry-docking, has remained afloat since 1824. The spatial structure of the keelson and sister keelson areas will be described as will the decay abilities of isolates and the decay status of core samples. The results will be discussed in terms of the development of community structures under different moisture content regimes.
N A White, J W Palfreyman, G M Smith

Fouling assemblage development on copper-chromium-arsenic-treated timber submerged in European waters
2002 - IRG/WP 02-50181
The effect of the anti-marine-borer timber preservative CCA on community development of non-target marine fouling animals was investigated. Panels of Scots pine treated to target retentions of 12, 24 and 48 kg CCA per m3 of wood, plus untreated controls were submerged at seven coastal sites (Portsmouth, UK; La Tremblade (2 sites), France; Ria Formosa, Portugal; Sagres, Portugal; Kristineberg, Sweden; Athens, Greece). Inspections were made after 6, 12 and 18 months exposure and the fouling community on the surface of the panels was assessed both qualitatively and quantitatively. Multivariate statistical methods were used to compare community structure between panel treatments. Results showed that panels treated to the three CCA loadings supported very similar fouling assemblages which, in most cases, had higher numbers of taxa and individuals compared to assemblages on untreated panels. There were no detectable detrimental effects on epibiota community development caused by the presence of CCA preservatives within the matrix of the wood at any of the treatment levels. Similar trends were found at all seven exposure sites. This indicates that the range of environmental conditions at the sites had no bearing on preservative impact on fouling biota. Differences in community structure between CCA-treated and untreated panels may be due to enhanced larval settlement on CCA-treated timber by some species as a result of modifications to the surface properties of the timber by the CCA preservative. Possible reasons for the higher numbers of certain species on the surface of CCA-treated panels are discussed.
C Brown, R J Eaton, S M Cragg, P Goulletquer, A Nicolaidou, M J Bebianno, J Icely, G F Daniel, T Nilsson, A J Pitman, G Sawyer

Effect of Preservative Treatment on Fungal Colonization of Teak, Redwood, and Western Red Cedar
2009 - IRG/WP 09-20404
Fungal flora present in preservative treated samples or non-treated samples from sapwood and heartwood of teak, western red cedar, redwood, and southern yellow pine was assessed after 6 to 18 months of exposure near Hilo, Hawaii. The objectives were to compare fungal composition and diversity between treated and non-treated samples, and to examine the use of molecular techniques for assessing fungal community structure in a ground-proximity-test located in Hilo, Hawaii. Fungi were recovered in culture after 6, 12, or 18 months, yielding 178 unique DNA sequences that represented 85 taxa. Sequence data from the nuclear ribosomal internal transcriber spacer (ITS) region showed the taxa represented 56 ascomycetes, 17 basidiomycetes, 1 zygomycete and 10 unknowns. Basidiomycetes were mainly found in samples treated to the lowest biocide concentrations or non-treated samples, while there were no consistent isolation patterns with ascomycetes. Overall, treatment did not appear to affect community structure. Our results highlight (i) the need for caution in designating taxonomic units (species) based on culture or ITS BLAST matches, (ii) the utility of fungal culturing followed by molecular identification but the limitation of the sampling process, (iii) the remarkably high diversity of fungi colonizing wood in a ground proximity test under these tropical conditions.
Y Cabrera, C Freitag, J J Morrell

Seasonal shifts of fungal community structure at the interface of treated or untreated wood and soil
2010 - IRG/WP 10-10721
Many wood species are degraded rapidly in soil by the fungal community. In order to preserve wood and structures in which it is used, chemical preservatives are used. Little is known about the interaction of treated wood and the surrounding soil fungal community. For this work, presented at IRG 41, wooden specimens (Pinus sylvestris sapwood, sizes 25 mm x 50 mm x 500 mm (longitudinal)) were treated with a formulation of chromium-copper-arsenic-(CCA) at two concentrations. Untreated wood of the same dimensions was used as controls. After drying and an appropriate fixation period, the specimens were buried in soi1 up to half of their length at the BAM test site in North East Germany. The interface of the wooden specimens and soil were sampled in spring, summer and autumn 2008 and the nucleic acids were extracted. The structure of fungal community was assessed by T-RFLP analyses (terminal-restriction fragment-length polymorphism) of the fungal ITS (internal transcribed spacer) region. In addition, samples were sequenced to identify fungal community members. Significant differences in the fungal community composition were detected in response to the presence (and concentration) of wood preservatives and to the season. The species identified were predominated by ascomycete fungi, and only at the actual interface of the non-preserved wood and the soil were basidiomyecte fungi detected. The interface to CCA preserved wood was composed of sequences affiliated to the genera Phoma, Peziza and Cladosporium. Patterns of the fungal communities were highly reproducible and the spatial sampling at the test site had only a minor effect on their composition.
M Noll, I Stephan

The effect of certain wood extractives on the growth of marine micro-organisms
1977 - IRG/WP 438
S E J Furtado, E B G Jones, J D Bultman

The restricted distribution of Serpula lacrymans in Australian buildings
1989 - IRG/WP 1382
Temperature data has been gathered over a number of years, not only for flooring regions of various buildings in Melbourne, but also within roof spaces and external to the buildings. Findings are discussed in relation to the distribution of Serpula lacrymans within Australia, its restriction to certain types of building construction and its restriction to flooring regions. The subfloor spaces of badly-ventilated, masonry buildings are highlighted as being better suited than are the subfloor spaces of, for example, Japanese buildings for the activity of this fungus. Hence Serpula lacrymans is very restricted in its distribution in Australia, yet where it is active it does grow rapidly and causes rapid flooring failures.
J D Thornton

Basidiosporogenesis by the white-rot basidiomycetes in vitr
1994 - IRG/WP 94-10081
Basidiospores of all forest-inhabiting basidiomycetes are a primary source of infection causing wood decay. However, most studies evaluating wood preservatives have used mycelia or basidiospores obtained from wild mushrooms. The objective of this study was to demonstrate in vitro methods that promote carpogenesis and basidiosporogenesis by the white-rot basidiomycetes, Schizophyllum commune and Trametes versicolor. After preincubation in the dark at 27°C for three to fifteen days, basidiospores were produced in four to sixteen weeks in basidiomes exposed to light at 12°C. Adequate light exposure, aeration, and low temperature treatment after preincubation are essential for fruiting body of these white-rotting basidiomycetes. Carpogenesis and basidiosporogenesis of Schizophyllum commune is controlled by nitrogen and carbon limitation. However, fruiting body formation in Trametes versicolor was induced by nitrogen limitation. Walset cellulose was found to be the best carboun source for carpogenesis and subsequent basidiosporogenesis. These results demonstrate the feasibility of using various potential inhibitors on basidiospore germination rather than relying on mycelial growth.
S C Croan

European standardization for wood preservation
1989 - IRG/WP 2335
G Castan

What can DNA fingerprinting, aggression tests and morphometry contribute to the identification of colonies of the Formosan subterranean termite
2000 - IRG/WP 00-10371
Multilocus DNA fingerprinting, aggression tests and morphometry were compared to evaluate their potential for the identification of colonies of the Formosan subterranean termite, Coptotermes formosanus (Isoptera: Rhinotermitidae) in Hawaii. DNA fingerprinting separates the termites from all studied collection sites. Since the genetic similarity between termites from different collection sites lies in the range of the genetic background similarity in the population, collection sites in this study represent independent colonies. No significant differences could be found in the intra- and intercolonial aggression levels. While aggression tests do not support colony identification, morphometric measurements do show differentiations between colonies. However, classification of individuals to their original colony does not reach the 100% success provided by genetic analyses. No correlation between genetic similarities and aggression levels or morphometric distances could be found. This suggests that neither aggression levels nor morphometric parameters are significantly influenced by genetic factors in this species. Genetic studies appear to be the most useful approach to the identification of colonies and the analysis of small scale population structures in C. formosanus.
C Husseneder, J K Grace

Effect of methylene bisthiocyanate on morphology and ultra-structure of a sapstain fungus, Ophiostoma floccosum
2003 - IRG/WP 03-10471
In vitro effects of methylene bisthiocyanate (MBT) on hyphal morphology and ultrastructure of Ophiostoma floccosum were examined using differential interference contrast, epifluorescence and transmission electron microscopy (TEM). Differential interference contrast microscopy suggested that MBT caused rapid changes to the morphology of O. floccosum resulting in excessive formation of vacuoles and granules within the cytoplasm. Epifluorescence microscopy indicated that damage to the plasma membrane occurred in the MBT treated, but not the control, hyphae. TEM showed that in MBT treated hyphae, the plasma membrane had retracted from the cell wall. Cytoplasmic aggregation and increased vacuolation were also observed. Furthermore, complete disintegration of the cytoplasmic organelles was seen in more advanced stages of MBT induced damage. In contrast, plasma membrane of untreated hyphae closely adhered to the cell wall showing cytoplasma with typical cell organelles. Based on the results from this study we suggest that the primary site of mode of action of MBT occurred at the plasma membrane, which then triggered subsequent changes within the cytoplasm of the test fungus.
T Singh, B Kreber, R N Wakeling, A Stewart

Termiticidal chemicals derived from tropical tree resins
1991 - IRG/WP 1477
To test the hypothesis that defensive chemicals protect tropical primary forest trees against biological attack, a bioassay and fractionation program was conducted in Indonesia. Fresh dipterocarp resins were fed in no-choice tests to Neotermes dalbergiae termites on 4.5 cm filter papers, or tested for inhibition of fungal growth. Fractionation of biologically active resins via flash column chromatography, followed by subsequent bioassay and analytical chemical studies, revealed that several sesquiterpene compounds inhibited fungal growth and killed 50% of test termites in 3-7 days. Toxic fractions contained caryophyllene, caryophyllene oxide, alloaromadendrene, and other compounds. From the relatively non-toxic a-gurjunene, novel termiticidal compounds were synthesized, indicating the potential for manufacture of insecticides from natural products.
A Messer, K McCormick, D Richardson, Sunjaya, H Hagedorn, J Meinwald

Sex pheromone of the male house longhorn beetle Hylotrupes bajulus (L.) (Coleoptera: Cerambycidae)
1995 - IRG/WP 95-10100
Since 1990 studies have been conducted with respect to the chemical communication of the house longhorn beetle Hylotrupes bajulus (L.) (Coleoptera: Cerambycidae). The structure of glands located in the prothorax of the beetles was examined with light and scanning electron microscopy. The analyses of different extracts from beetles resulted in the finding and identification (GC-, GC/MS-, and HR-GC/MS-studies) of specific substances derived from the prothoracal glands: (3R)-3-hydroxy-2-hexanone, (2R,3S)-2,3-hexanediol and (2R,3R)-2,3hexanediol. In wind tunnel experiments, unmated female beetles were attracted over a distance of 1m by males, headspace extracts of males, the 3 major components of the glands as well as by the synthetic blends of the components. Thus, the bioassays revealed the initiation of premating behaviour by emission of a long-range sex pheromone from the male prothoracal glands. The pheromone functions as activator, attractant and possibly aphrodisiac for unmated females. Further studies are conducted with respect to disturbance and prevention of mating behaviour of Hylotrupes bajulus in the attics of houses by using pheromone traps.
U Noldt, R Fettköther, F Schröder, H Meyer, K Dettner, W Francke, W A König

Basidiosporogenesis by brown-rot basidiomycetes in vitro
1995 - IRG/WP 95-10126
Basidiospores of wood-rotting basidiomycetes are a primary sourse of infection causing wood biodeterioration, especially in wood above ground. Most studies evaluating wood preservatives have used mycelia or basidiospores obtained from wild mushrooms. The objective of this study was to demonstrate in vitro methods that promote carpogenesis and basidiosporogenesis by the brown-rot fungi Antrodia carbonisa, Neolentinus lepideus, and Postia placenta. After preincubation in the dark at 27°C for 3 to 11 days, basidiospores were easily prodused in 1 to 4 months by basidiomata exposed to light at 12°C. Adequate light exposure, aeration, and low temperature treatment after preincubation are essential for fruiting body formation of these brown-rot basidiomycetes. The morphology of the basidiomata differed according to the basidiomycetes and the medium used. These results demonstrate that an enormous quantity of basidiosporee can be easily and continuously prodused in 2 to 4 months in vitro.
S C Croan

Fungal degradation of wood treated with metal-based preservatives. Part 2: Redox states of chromium
1996 - IRG/WP 96-10164
Concerns have arisen about the leaching of heavy metals from wood treated with metal-based preservatives, such as chromated copper arsenate (CCA). Of particular concern is the toxic redox state of chromium and arsenic in aging and decayed CCA-treated wood. Generally, hexavalent chromium is more toxic than trivalent chromium and trivalent arsenic is more toxic than pentavalent arsenic. The desired outcome from treating wood with CCA is total change of Cr(VI) to Cr(III) and As(III) to As(V). As part of an on-going study to determine the fate of copper, chromium and arsenic during aging and decay of CCA-treated wood, we detected Cr(III) and Cr(VI) in situ in CCA-treated southern yellow pine lumber. The redox states of Cr were determined using synchrotron X-ray fluorescence spectroscopy (SXRF). An SXRF microprobe was used to to detect Cr redox states by measuring X-ray absorption near-edge structure (XANES). The ratio of Cr(III) to Cr(VI) was determined (1) on the surface and interior of lumber two years after CCA treatment and (2) in lumber during decay by a CCA-tolerant fungus, Meruliporia incrassata TFFH-294. The XANES spectrum for Cr(VI) has a strong pre-edge feature that is not present in the spectrum for Cr(III). Only the Cr(III) XANES spectrum was detected on the surface and in the interior of the wood, indicating total reduction of Cr(VI). The XANES spectrum for Cr(III) was detected in wood after 12 week decay by Meruliporia incrassata TFFH-294, indicating that the fungus does not oxidize Cr(III) to Cr(VI) during the decay process. We are currently using XANES spectroscopy to detect and map in situ redox states of As in CCA-treated wood.
B Illman, S Bajt, T L Highley

The permanence of permethrin in wood preservation
1984 - IRG/WP 3288
The permanence of the synthetic pyrethroid permethrin in treated wood has been assessed for double vacuum and immersion treated Scots pine sapwood and whitewood using a 0.5% m/m solution of the insecticide in a hydrocarbon solvent. It is concluded that for all but the outermost 0.5 mm of the treated battens the distribution of the permethrin is relatively permanent. The outermost 0.5 mm appears vulnerable to degradation rather than volatile loss, and this varies with timber species and the loading in that zone. Linking this information with published bioassay work allows speculation as to the strength of treating solutions needed for adequate long-term protection
R J Orsler, M W S Stone

Laboratory evaluation of organophosphates as termiticides
1985 - IRG/WP 3330
In accordance with Japan Wood Preserving Association Standard 11(1) laboratory evaluations of five organophosphate insecticides and chlordane were conducted. Superficially treated sapwood of Pinus densiflora Sieb. et Zucc. (10 x 10 x 20 mm³) was compulsorily exposed to the attacks of 150 workers and 15 soldiers of Coptotermes formosanus Shiraki for 21 days at 28±2°C in the dark. Percentage weight loss of the wood blocks was determined at the end of the test. Termite mortality was additionally calculated at regular intervals. Of five organophosphate insecticides evaluated, chlorpyrifos and phoxim were the most effective and were followed by acephate and tetrachlorvinphos. Required treating concentrations were < 0.1% for chlorpyrifos, phoxim and tetrachlorovinphos, 0.1-0.2% for acephate and 0.2-0.4% for fenitrothion. For chlordane 0.5-1.0% was desired. Results based on the percentage weight loss indicated that organophosphates were generally more effective than chlordane in controlling termites. It is, therefore, worthy to take up potential chemicals for further investigation.
K Tsunoda, K Nishimoto

The use of TCMTB in applications other than sapstain prevention: A review
1990 - IRG/WP 3606
The efficacy of TCMTB against staining fungi and surface moulds has been thoroughly investigated during the last decade. As a result, the chemical is used as an alternative to the chlorinated phenols in various parts of the world for the preservation of freshly sawn timber. Less known are the data obtained against brown rot, white rot and soft rot fungi. The termite repellent and bactericidal properties of the chemical widen the scope of application possibilities. The objective of this article is to report on the data actually available.
R Van der Eynde

Role of cell wall structure in soft rot decay of bamboo
1995 - IRG/WP 95-10133
Models of soft rot hyphal penetration of bamboo cell walls are proposed. Soft rot hyphae show an interesting capability of penetrating the bamboo cell wall in different forms; typical longitudinal penetrating hyphae and tangentially orientated penetrating hyphae. The second form of penetration was found to be different from that normally associated with wood cell walls. The differences can be attributed to the cell wall structure of bamboo. Soft rot hyphae normally follow the microfibrillar orientation in either the broad lamellae or the narrow lamellae in bamboo cell walls. Hyphae that grow in the broad lamellae normally penetrate in the longitudinal direction and follow the orientation of the microfibrils of this layer of the cell wall. This produces a &apos;typical&apos; longitudinal penetrating hyphae and cavity. Soft rot hyphae are also found penetrating in the tangential direction. These arise from radially orientated hyphae trying to penetrate across the lamellated cell wall neighbouring cells. When a radially orientated hyphae encounters the narrow lamellae, the hyphae can reorientate in the direction of the microfibrils in this lamellae. Thus, the hyphae penetrate in a tangential direction in the cell wall. These types of penetrations are not seen in wood cell walls.
O Sulaiman, R J Murphy

Work programme of CEN/TC 38 (April 1999) and European publications
1999 - IRG/WP 99-20165
Scope of the CEN/TC38: Standardization of the characteristics of natural or conferred durability of wood and its derived materials against biological agents, including the characteristics of protection products and associated processes to obtain this durability. This applies in particular to: - the identification of hazard classes-, - the test methods (wood preservatives and treated wood and wood based materials) and interpretation of the results; - the specification of wood preservatives and treated wood by classes of hazard including processes-, - quality control methods-, -terminology.
R Hüe

The dry rot fungus Serpula lacrymans, its growth and damaging of wood
2004 - IRG/WP 04-10511
The dry rot fungus (Serpula lacrymans) is one of the most dangerous wood rotting fungi, especially in the built environment. In our mycological laboratory more experiments with this fungus have been carried out aimed at:- its growth under stable and variable climatic conditions, - its possibility to attack either natural wood of different species and also modified wood primary pre-treated with some other fungi, aggressive chemicals and high temperatures, - its influence on the molecular and anatomical wood structure, - its influence on the acoustical, electric, strength and some other properties of decayed wood which can be applied for its identification.
L Reinprecht

Preliminary study on relation of wood structure to copper/chrome/arsenic (CCA) distribution in kempas (Koompassia malaccensis)
1995 - IRG/WP 95-40054
Kempas had been treated with copper/chrome/arsenic (CCA) preservative using full cell process. Analysis of preservative distribution at the micro level in relation to wood structure was carried out using scanning electron microscope (SEM) and energy dispersive X-ray (EDXA) analysis. The results showed that CCA elements were detected in all wood tissues at different ratios. Distribution of chemical elements appeared to be much greater in the tangential longitudinal section (TLS) than the transverse section (TS). Though the amount of chemical elements had not been quantified from the radial longitudinal section (RLS), the SEM observations showed a high distribution of chemical precipitate. In all the wood tissues observed, Cr appeared in highest amount. The precipitate analysed by EDXA, showed As in greater amount than Cr or Cu. Silica content was highest in fibres and rays as determined by EDXA but could not be detected in structural form under SEM or light microscope.
S Ani, S Salamah

Evaluation of chlorpyrifos as an insecticidal component of a wood preservative
1984 - IRG/WP 3301
After two years of laboratory and field testing, chlorpyrifos is showing excellent potential as an insecticidal treatment to wood. In laboratory termite tests, retentions as low as 1-2 parts-per-million or approximately 0.0008 kg/m³ (0.00005 lbs/ft³) are effective against the Coptotermes formosanus. Laboratory leaching tests have shown no significant effect on the concentration of the retained chlorpyrifos. Pressure treatments and dip treatments, as an aqueous emulsion or oil solution, have resulted in good penetration of effective concentrations. Combinations of chlorpyrifos and various fungicides are being evaluated.
K Rose, J Kozuma, P Sparrow

Evaluation of substituted isothiazolone as a potential new wood preservative
1984 - IRG/WP 3306
Laboratory decay tests were carried out with isothiazolone (4,5-dichloro-2-n-octyl-4-isothiazolone-3-one) treated wood. This compound was found to be extremely effective against three common wood decaying brown-rot fungi, exhibiting toxic threshold values in the range of 0.37 to 0.50 kg/m³. For the white-rot fungus, Coriolus versicolor, the toxic threshold values for treated pine and sweetgum were 0.42 and 2.3 kg/m³, respectively. In an unsterile soil test (soft-rot fungi), a toxic threshold value of 0.48 kg/m³ was obtained, which indicates a high degree of effectiveness against these fungi.
D D Nicholas, A F Preston, D E Greenley, S V Parikh

Case histories involving attempts at identifying infestations, determining the source and controlling the Formosan subterranean termite in Atlanta, Georgia USA
2000 - IRG/WP 00-10342
The University of Georgia Department of Entomology and the Georgia State Department of Agriculture have been involved in identifying and working with Pest Control Operators and homeowners dealing with Formosan subterranean termite infestations in the Atlanta, Georgia metropolitan area since 1993. Our involvement with seven separate infestations is outlined in this paper in the form of case histories to highlight the need for the development of community-based action plans to deal with the inevitable introduction of this economically important insect pest to other non-endemic areas.
B T Forschler, J Harron, T M Jenkins

Changes in pore structure and cell wall volume in wood decayed by brown- and white-rot fungi
1991 - IRG/WP 1501
Sweetgum (Liquidambar styraciflua L.) wood blocks were decayed by Postia (=Poria) placenta or Phanerochaete chrysosporium in soil-block cultures. Decay was terminated at various weight losses, and the pore volumes available to probes of various molecular weight and diameter were determined by the solute exclusion technique (Stone, J.E. and A.M. Scallan. 1968. Cellulose Chem. Technol. 2, 343-358.). The volume in sound (undecayed) wood that was accessible to the probes varied from 1.0 ml g-1 for the largest to 1.35 ml g-1 for water. Thus, the volume in sound wood attributable to cell wall was 0.35 ml g-1. In brown-rotted samples, the volume of pores in the cell wall increased steadily to 0.7 ml g-1at 35% weight loss. New cell wall volume was accessible to low molecular weight probes but not to molecules of Mr ³ 6,000. Within experimental error, no pores of > 20Å were observed in sound wood or >38Å in brown-rotted wood. Most of the new cell wall volume create by rermoval of components during decay was in the pore size range of 12Å to 38Å. Our results are consistent with the hypothesis that the initial depolymerization of cellulose, characteristic of brown rot, is caused by a diffusible agent. The molecular diameter of the agent is apparently in the range 12Å to 38Å and it causes erosion and thus enlargement of the pores to which it has access. In the white-rotted wood, cell wall volume increased to 0.6 ml g-1 at 40% weight loss and maximum pore diameter increased to 50Å. Most of the cell wall volume increase resulted from the creation of pore of 20-50Å diameter. Analysis of loss of major wood components as a function of weight loss revealed that lignin, cellulose, and hemicellulose were removed at approximately equal rates. Under our experimental conditions, ligninolytic enzymes have access to only a small portion of the new cell wall volume, even after extensive decay.
D S Flournoy

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