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Programme section 2, Test methodology and assessment
1997 - IRG/WP 97-20126
Confocal laser scanning microscopy of a novel decay in preservative treated radiata pine in wet acidic soils
1997 - IRG/WP 97-10215
Light microscopy of radiata pine (Pinus radiata D. Don) field test stakes (20x20x500mm3) exposed in wet acidic (pH 3-4) soil for 12 - 24 months showed predominance of an unusual type of decay characte-rised by tunnelling attack of wood cell walls. After two years decay was moderate to severe in wood treated to ground contact CCA specifications and also equivalent retentions of creosote, and a number of new generation preservatives. Relative to other New Zealand temperate test sites and also an Australian tropical site, the New Zealand acidic soil test site was very aggressive. Correlative scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to elucidate the micromorphology of this attack. Tunnels of diameter 0.2-5 µm were present throughout all layers of the cell wall, and their orientation was not related to cellulose microfibril orientation. They also showed no preference for particular cell wall layers, indicating a lignin degrading capability. CLSM images showed that living, connecting fungal hyphae were present in the cell lumina and tunnels. This type of attack was predominant in wood that was highly saturated with water whereas wood that was less moist was predominantly attacked by classical white rot. Ongoing isolation and incubation studies in conjunction with further microscopy should enable identification of the fungal species involved.
R N Wakeling, Ying Xiao, A P Singh
Evaluation of two populations of Reticulitermes santonensis De Feytaud (Isoptera) by triple mark-recapture procedure
1997 - IRG/WP 97-10237
The optimisation and use of biocides is linked to the improvement in our understanding of the target organism. With this in mind we have studied 2 populations of the termite Reticulitermes santonensis De Feytaud. The first inhabiting an urban territory, the trees lining Ave. Boutroux in Paris. The colony has been estimated at 1,200,000 +/- 130,000 insects by triple mark-recapture procedure, foraging a surface of 1080 m2. The area containing visible damages in the trees is of 2,100 m2. The greatest distance covered by an individual is 65 m in 18 days. The second is a field population at Fondette near Tours. The zone studied is of 2,500 m2, the colony being estimated at 230,000 +/- 14,000 insects, foraging a surface of 145 m2. The greatest distance covered by an individual is 40 m in 13 days. This study shows that a termite worker can cover a considerable distance in a short time and that the colonies themselves seem to move within a zone that they cannot totally exploit permanently.
I Paulmier, B Vauchot, A-M Pruvost, C Lohou, M Tussac, M Jéquel, J-L Leca, J-L Clément
Field performance of wood preservative systems in secondary timber species
1997 - IRG/WP 97-30152
The objective of this ongoing study is to evaluate the performance of new, potential, and standard wood preservative systems in secondary North American timber species. Eleven preservative systems were evaluated in this study - ACQ Type B, Copper Citrate 2: l, CDDC, chlorothalonil/chlorpyrifos, copper-8-quinolinolate, tebuconazole/chlorpyrifos, RH287, propiconazole/chlorpyrifos, copper naphthenate, CCA. and creosote. Field evaluations are being performed with ground contact field stakes and termite-specific testing in Hawaii, along with laboratory soil bed tests. The major wood species used with all the systems and evaluation methodologies are loblolly pine, northern red oak, tulip poplar, and cottonwood. More limited evaluations (field stakes only) are being conducted with eastern hemlock, red maple, and sweetgum. Information is presented from laboratory soil bed, field termite, and field stake evaluations. There is good correspondence between soil bed and field stake results. The more highly developed preservative systems and those in an AWPA P9 Type A oil carrier tend to perform better, and there can be a strong affect on performance from the wood species.
P E Laks, K W Gutting, R C De Groot
Programme section 3, Wood protecting chemicals
1997 - IRG/WP 97-30159
Programme section 5, Environmental aspects
1997 - IRG/WP 97-50099
IRG documents 1997
1997 - IRG/WP 97-60081
International Directory of Members and Sponsors 1997
1997 - IRG/WP 97-60076
Conditions of the Ron Cockcroft Award scheme
1997 - IRG/WP 97-60086
New technique for inoculation of wood wafers with fungi
1997 - IRG/WP 97-20113
A pilot study is described for determining the best possible method for inoculating fungi onto the surface of wood wafers for sapstain control studies. Direct inoculation and spray inoculation are compared on water soaked and malt extract broth soaked wood wafers. The best growth of fungal hyphae across the surface of the wood wafers was achieved following spray inoculation onto malt extract broth soaked wood wafers.
J Snow, P Vinden
Fungicidal activity of some organic solvents, copper carboxylates and their complexes with 2-aminoethanol
1997 - IRG/WP 97-30136
We evaluated the activity of eight organic solvents against wood - rotting fungus Trametes versicolor in order to choose the most appropriate one for rapid screening tests of some copper(II) carboxylates and their adducts with 2-aminoethanol. Their activity against the selected fungus was classified in the following order: chloroform > N,N-dimethylformamide > acetonitrile > methanol > dimethyl sulfoxide > ethanol > acetone. The non-polar white spirit did not dissolve in the growth medium and the results could not be directly compared with the results for other solvents. As an appropriate solvent for screening of the tested copper(II) carboxylates, dimethyl sulfoxide (DMSO) was chosen. Minimal inhibitory concentration against Trametes versicolor of the screened carboxylates was in the concentration range of 1x10-4 to 1x10-3 mol/l. Coordinated amine ligands slightly, and not significantly, decreased fungicidal properties of the tested carboxylates.
M Petric, F Pohleven
Termite resistance of pine wood treated with chromated copper arsenates
1997 - IRG/WP 97-30128
Two four-week, no-choice laboratory tests were performed with CCA-treated southern yellow pine and radiata pine against Formosan subterranean termites, Coptotermes formosanus. CCA retentions as low as 0.05 kg/m3 (0.03 pcf) provided protection from all but light termite attack (rating of 9 on a 10-point visual scale). Similar and consistent light attack on wafers containing retentions as high as 6.4 kg/m3 (0.4 pcf), coupled with complete termite mortality, demonstrates that the mode of action of CCA treatments relies upon toxicity rather than having any repellent effects against termites.
J K Grace
Durability of larch (Larix spp.) wood against brown-rot fungi
1997 - IRG/WP 97-10228
Durability of the heartwood of Larix decidua, L. sibirica, L. gmelinii, L. gmelinii var japonica, L. gmelinii var olgensis and L. sibirica x decidua against brown rot fungi Coniophora puteana, Poria placenta and Gloeophyllum trabeum was tested according to EN 113 test method. Parallel samples were used to study the amount and composition of wood extractives. The sample trees originated from the research forest of Punkaharju Research Station. The average age of the trees was 60 years. In addition, from L. sibirica also trees at 25 and 102 years were used. Results show that the durability of larch is depending on species, age of the tree, the wood part (inner or outer heartwood) and fungus. The average durability of larch heartwood was equal to class 3 or 4 (moderately or slightly durable, according to the standard EN350:2) and comparable with the durability of pine heartwood (Pinus sylvestris L). However, the durability of L. gmelinii var olgensis and L. sibirica (102 years old) was on the higher level than that of the other studied species but the durability varied even within the same board. Also the durability of wood from L. sibirica grown in the Russian side (Siberia) was studied. It was equal to that of the trees grown in Finland. The average amount of resin acids of larch heartwood was only about 0.1% (dry weight). In contrast, the heartwood of scots pine may contain up to 4.0% of resin acids. Resin acids are found to inhibit the linear growth of certain fungi. Interestingly, the largest amounts of resin acids (0.3%) were found in the heartwood of L. gmelinii which also showed high durability. The concentration of water soluble extracts (mainly arabinogalactan) of larch heartwood was quite large, varying between 3.2 - 20.5%. The concentration of water soluble extracts in the heartwood increased along the age of the trees. Lowest level of extractives were found in Larix decidua which was also the least decay resistant species. The durability of wood in different targets and the role of different chemical compounds of larch heartwood on decay resistance needs to be clarified.
H Viitanen, L Paajanen, P Saranpää, P Viitaniemi
Aspects of the biology of the wood-boring weevil Pselactus spadix herbst
1997 - IRG/WP 97-10221
The external morphology of the adult and larval digestive tract of the wood boring weevil Pselactus spadix has been reported for the first time. An examination of adult gut ultrastructure showed that the foregut was adapted for the wood boring habit with the presence of chitinous setae, grinding plates and sieve plates. The adult midgut bore eight caecae and numerous palpii. Spherical yeast-like micro-organisms were observed throughout the foregut and midgut. Adults demonstrated sexual dimorphism in body capsule and rostrum dimensions. The study also demonstrated this weevil to be incapable of flight.
G Cooper, A J Pitman, G S Sawyer
Abstracts of some papers and posters promised for IRG 28. Part 2
1997 - IRG/WP 97-60082
Programme section 1, Biology
1997 - IRG/WP 97-10241
Report of Section 1 1997
1997 - IRG/WP 97-10243
Abstracts of some papers promised for IRG 28
1997 - IRG/WP 97-60077
Development of a Granitgard® particulate termite barrier for use in tropical Australia
1997 - IRG/WP 97-10190
Granitgard® is superficially simple technology; graded crushed aggregate, sieved to a size range impenetrable to subterranean termites. However, behind this apparent simplicity lies a large research effort. In this paper we describe the laboratory development of a grading of Granitgard suitable for use against the wide range of termites which attack timber in northern Australia, above the Tropic of Capricorn.
D M Ewart, E R Rawlinson, A D Tolsma, G C Irvin, P R Wiggins
Resistance of the wood of Eucalyptus saligna and Paulownia tomentosa against some wood rotting fungi
1997 - IRG/WP 97-10238
Paulownia tomentosa and Eucalyptus saligna are not autochthonous species in Slovenia and we determined the resistance of their wood against our most common wood rotting fungi. The resistance against Coniophora puteana, Gloeophyllum trabeum and Trametes versicolor was determined according to EN 113 and compared to the resistance of beech (Fagus sylvatica) wood. It was stated, that both paulownia and eucalypt wood samples are much more resistant than beech wood. Especially paulownia wood was outstanding by its natural resistance against tested basidiomycetes.
F Pohleven, M Petric
The resistance of painting materials and consolidants against wood-destroying insects
1997 - IRG/WP 97-10239
Natural and synthetic adhesives, varnishes, painting materials and consolidants were used in investigations of bioresistance against newly hatched larvae and beetles of Hylotrupes bajulus (L.). Animal glues, casein, drying oils and natural resins such as dammar resin and shellac, were not resistant to attack by these larvae. Similarly, semi- and all-synthetic polymers tested including hydroxypropylcellulose, acrylate and methacrylate compounds, are also subject to attack by newly hatched larvae of the House Longhorn Beetle. In contrast, addition of inorganic pigments provides a significant improvement in bioresistance. This effect is influenced by the thickness and the hardness of the paintlayer. The test with beetles of Hylotrupes bajulus show that the restoration materials which are not resistant against an attack by newly hatched larvae are preferred for the egg depositions by the females.
W Unger, H Fritsche, A Unger
Environmental impact of CCA poles in service
1997 - IRG/WP 97-50087
Soil samples from different depths and distances from CCA treated utility poles in Canada were analyzed for copper, chromium and arsenic content for a number of soil types, two wood species red pine (Pinus resinosa) and jack pine (P. banksiana) and different pole ages in service. A limited number of poles were equipped with water traps to collect rain water that dripped down the poles and where sufficient ground water was present, ground water samples from next to the pole were analyzed. The level of soil contamination dropped rapidly with distance from the pole, with soil levels approaching background levels within 0.25 from the pole. Generally, copper levels (above background) were highest, followed by arsenic and chromium, consistent with the known relative leaching tendencies of the three elements. Contaminant levels increased with age of the pole in service and were generally highest in wet organic soils, followed by sand loam soils and clay soils. Soil concentrations were highest at the ground line, adjacent to the poles. This suggested that a large source of the soil contamination was contaminated rain water that ran down the pole. Rain water trapped from the pole surfaces during rain events had significant concentrations of all three elements. There was no obvious drop in contaminant content in water that dripped down the poles with age of the poles. Ground water samples from next to the poles occasionally had detectable CCA components above aquatic and drinking water guidelines.
P A Cooper, Y T Ung, J-P Aucoin
Chemical investigation of 23-year-old CDDC treated southern yellow pine
1997 - IRG/WP 97-30141
The effect of 23 years exterior exposure on CDDC treated southern yellow pine was evaluated by the application of solid state analytical instrumentation. Analytical methods including environmental scanning electron microscopy (ESEM),energy dispersive X-ray analysis (EDXA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), inductively coupled plasma (ICP) and atomic absorption spectroscopy (AAS) were used to study CDDC treated wood. The results of this study support modification of CDDC in treated wood with time. Data from ICP and AAS analysis indicated that about 60% of copper and 81% of SDDC are removed from the 1/8"shell of the below ground portion of the stakes after 23 year field exposure. The molar ratio of SDDC to copper for freshly treated southern yellow pine is 2 while it is reduced to 1 after 23 years field exposure. ESEM micrographs and EDXA data confirm the presence of solids rich in copper and sulfur similar to that of CDDC in freshly treated samples. XRD patterns suggest some modifications in the CDDC solids remaining in wood after 23 years.
D P Kamdem, C R McIntyre
Reports from IRG Corresponding Members 1996
1997 - IRG/WP 97-60083
Annual Report 1996
1997 - IRG/WP 97-60078