Your search resulted in 33 documents. Displaying 25 entries per page.
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
Estimation of service life of durable timber species by accelerated decay test and fungal cellar test
2002 - IRG/WP 02-20249
Many kinds of durable wood species for outdoor uses has been imported from all over the world to Japan. However information on the natural durability of these species is not sufficient to estimate the service life of them in the climate of Japan. Highly durable species such as Jarrh, Teak, Ipe, Ekki, Selangan batu, Red wood, Western red cedar showed no significant percent mass losses by accelerated decay test according to the JIS Z2101, but some of them are degraded during fungal cellar test for 4 years . The decay rating (0:sound to 5:totally decayed) of them after 4 years exposure was 1.0, 2.0, 0.0, 1.0, 0.0, 2.3, 5.0 respectively. This results indicated that the conventional accelerated decay test could not evaluate the natural durability of these highly durable species at all. Solid wood specimens treated with boiling water at 120? for one hour are subjected to the same JIS test, and the obtained percent mass losses of these species are 1.2, 2.9, 1.9, 3.8, 4.7, 17.5, 0.0 % by a brown rot fungus, Fomitopsis palustris, and 17.5, 14.3, 3.3, 8.2, 4.2, 0.0, 18.3 % by a white rot fungus, Trametes versicolor respectively. Pre-treatment of solid wood specimens for removal of heartwood extractives before a accelerated decay test would be an effective way to evaluate the natural durability of highly durable species in a laboratory.
K Yamamoto, I Momohara
Three dimensional computer representations of growth of microbial populations in wood
1984 - IRG/WP 1243
Creosoted distribution poles inoculated with either Lentinus lepideus, biological control organisms including Triochoderma or combinations of both were extensively sampled to monitor the spread of organisms. A computer program which enabled the results to be portrayed in a three dimensional graphic form was developed and is illustrated. Results showed that computer mapping of this type usefully enabled microbial interactions in wood to be evaluated.
A Bruce, B King, C Bruce, G M Smith
Estimation of effective diffusion path lengths in wood by swelling studies
1989 - IRG/WP 3524
The effective average distance that a solute must diffuse to penetrate the cell wall matrix following pressure treatment is estimated from the rate of swelling of wood, vacuum treated with water. It is assumed that the diffusion paths are similar for water and a solute such as a wood preservative component. Since bound water diffusion coefficients for water in wood have been estimated by others, the effective path lengths (Le) can be estimated. Effective average path lengths are estimated for red pine (Pinus resinosa), Southern yellow pine (Pinus sp), trembling aspen (Populus tremuloides) and soft maple (Acer rubra) sapwood and red oak (Quercus rubra) heartwood samples. The estimated path lengths are shortest for the softwoods, and longest for the ring porous oak. The results reflect the different patterns of cell penetration and different densities of the wood species.
P A Cooper, R Churma
The proposal for optimalization of the agar-block method for wood preservatives fungitoxic evaluation
1995 - IRG/WP 95-20065
On the base of own research and other scientists results the proposal for optimalization of agar-block method was presented by: - selection of test fungal species and strains and central distribution of their pure cultures, - change of the treatment and control samples exposure procedure, - application of mathematical estimation of toxic value results, - shortening the duration of fungitoxic test by miniaturization of wood samples.
Termite physical barriers: Update on retrofitting Granitgard around 'mock-up' buildings after three years
1995 - IRG/WP 95-10118
This field experiment was installed three years ago (March 1992) to evaluate the effectiveness of Granitgard, the commercial name of a grade of crushed granite aggregate or "screenings", as a physical termite barrier when retrofitted around 'mock-up' buildings. The field site is located at Walpeup in the semi-arid mallee region of north-west Victoria (360 km from Melbourne), and there are at least eight common indigenous subterranean termite species at the site. This paper describes the results of the field evaluation after three years in test using Granitgard as a retrofitted termite physical barrier. We discuss these findings and their implications in the protection of timber structures in areas in which there are naturally foraging populations of subterranean termites.
B M Ahmed, J R J French
Estimation of the population of a sound colony of Coptotermes lacteus (Froggatt)
1988 - IRG/WP 1353
Selecting an area with a high termite hazard is deemed essential in locating field sites in order to screen potential termiticides and wood preservatives. Yet, quantifying termite populations in such sites remains imprecise. There are major problems associated with estimating populations of termites in mound colonies (either free-standing or in trees), and these are briefly discussed. In this paper we estimate the population of a mound colony of Coptotermes lacteus as 3.06 x 105. The estimate relates to foragers collected at baits that had been inserted into the mound. The technique adopted, "removal sampling", did not destroy the integrity of the mound nor incur unnecessary expense.
D M Ewart, J R J French
Estimation of oral toxicity of boron as a bait toxicant and the trophallactic effects between individual members of termite colonies.
2003 - IRG/WP 03-10495
In recent years, because of the favourable environmental characteristics of boron, researchers in the wood preservation industries have refocussed on the use of boron as a major wood preservative against wood-destroying insects. Currently the greatest use of boron compounds is in remedial treatments. Boron has been found to have slow-acting toxicity against subterranean termites. Because of this characteristic, boron compounds may also be used as termite bait toxicants. The effect of boric acid on an individual donor termite was investigated in laboratory bioassays Trophallactic transfer of boron by these individual termites to other orphaned group of termite workers was conducted and the effects on the recipient groups recorded. It was believed that, this sequence of tests would provide a greater understanding of the carrying ability of ‘bait toxicant’ by individual termites, and allow estimates of the threshold toxicity of boric acid and termite survival rates to be determined. The bait matrix was Eucalyptus regnans F. Muell sawdust impregnated with various formulations of boric acid solutions in the laboratory. The result suggests that the toxicity of boron is dose dependent and it critical for the termites to ingest sufficient amounts of boron. But the mode of toxicity of boron has not yet been fully explained.
B M Ahmed
Toxic value estimation of wood preservatives by using the probit analysis
1990 - IRG/WP 2348
As it was assumed from previous experiments, the probit analysis appears to be the most suitable method of all used to estimate the toxic value of wood preservatives. With the help of the classical agar-block method the probit analysis was tested for its suitability in: 1) fungitoxic value estimation of the WR-3 preservative (quaternary ammonium compound + borate), as compared to different test fungi (Coniophora puteana, Gloeophyllum sepiarium, Lentinus lepideus, Poria placenta, Serpula lacrymans), and 2) in leaching value estimation by the mycological method (Coniophora puteana)
J Wazny, K J Krajewski
NIR spectroscopy for rapid estimation of decay resistance
2004 - IRG/WP 04-20294
In Scandinavia Scots pine (Pinus sylvestris L.) is an important commercial tree species. Its heartwood has traditionally been used in constructions exposed to risk of decay. In a laboratory experiment Scots pine wood specimens sampled from inner heartwood, outer heartwood and sapwood were exposed to the brown rot fungus Poria placenta. In general outer heartwood was more resistant than inner heartwood, but there were variations even within the same wood zone. NIR spectra obtained on solid wood prior to decay testing were used in multivariate calibrations to predict decay resistance of heartwood. Results from segmented cross validated partial least squares (PLS1) regression modelling showed that resistance to decay in Scots pine heartwood could be predicted with satisfying precision using NIR spectroscopy. As NIR spectra were collected on solid wood, development of the method for industrial use is potentially possible.
P O Flæte, E Ystrøm Haartveit
Above-Ground Durability Estimation in Australia. Results after 16 years exposure
2005 - IRG/WP 05-20314
A program of research was established in 1987 to examine the above-ground durability of a selection of timbers that are commercially significant in Australia. Test samples were assembled in an L-Joint design and placed on exposure racks in a format to replicate joinery that is exposed to the weather above ground. Both painted and unpainted material has been exposed. Test samples have been evaluated regularly over the sixteen-year exposure period, and although the trial is not yet complete, the research has highlighted and provided data on the effect of painting, the source of timber and the influence of location. Biodeterioration models are now being developed and as the exposure approaches completion, the models will be further refined using results that emerge for the more durable softwoods and hardwoods that are incorporated into the project. As data is finalised for a particular species, it is to be submitted to the national standard for timber durability as well as design for durability programs currently underway in Australia.
L P Francis, J Norton
Use of mixed populations of microflora to control sapstain on radiata pine
2002 - IRG/WP 02-10427
Most methods of biological control in the wood products field have focused on the use of single species of fungi or bacteria to control sapstain or decay. The approach taken in this study involved applying soil microorganisms, in combination with nutrients and various adjuvants that collectively form the biological control system. Radiata pine branch discs, autoclaved or fresh, were dipped in a forest soil suspension (FS) or FS plus a cocktail containing alkaline adjuvants (ammonia, ethanolamine and lime) and nitrogen rich (urea and DIFCO nutrient media) compounds (AC). Treated discs were pre-incubated for either 48 or 72 hours prior to spray application of challenge sapstain fungi and subsequently assessed at weekly intervals for sapstain. The effects of FS alone, adjuvant concentration, autoclaving the radiata pine discs, and the difference in time interval prior to challenge with staining fungi were determined. A commercial antisapstain product was included as a benchmark. After three weeks, fresh wood pre-incubated for 48 hours with FS plus 5.0 % w/w AC gave the best performance out of the experimental treatments. This treatment had a mean surface coverage of 31.5%, compared to 24.5% for the lower and 10.2% for the higher concentration of the commercial benchmark and 88% for the controls. However, for similarly treated discs incubated for 72 hours prior to spraying with the challenge fungi, mean surface coverage was reduced to 17.5%. In general, a 72 hour interval between treatment and challenge with staining fungi reduced surface coverage regardless of treatment. Overall, the experimental treatments on fresh wood discs were more effective than on autoclaved discs but a reversed trend was seen for the commercial benchmark product. These results are discussed within the context of fungal ecology.
C Chittenden, R Wakeling, B Kreber
Patterns of decay in CCA-treated horticultural post populations - A fungus cellar simulation
1986 - IRG/WP 1286
The distribution of decayed posts in 10-, 14-, and 18-year-old vineyards supported a hypothesis to explain variability in intensity of decay found among posts in New Zealand horticultural properties. The development of decay patterns between samples in a simulated vineyard plot established in the Forest Research Institute fungus cellar gave additional support to the hypothesis that decay within large blocks of posts emanates from discrete loci of infection and gradually, but at variable rates, infects all posts.
M E Hedley
Termite physical barriers: Update on retrofitting Granitgard around 'mock up' buildings after four years
1996 - IRG/WP 96-10140
This field experiment was installed four years ago (March 1992) to evaluate the effectiveness of graded crushed granite stone, commercially marketed under the name, Granitgard, as a physical termite barrier when retrofitted around 'mock-up' buildings. The field site is located at Walpeup in the semi-arid mallee region of north-west Victoria (360 km from Melbourne), and there are eight common indigenous subterranean termite species at the site. This paper describes the results of the field evaluation after four years in test using Granitgard as a retrofitted termite physical barrier. No termites penetrated the Granitgard barriers, with and without chlorpyrifos treatments. We discuss these findings and their implications in the protection of timber structures in areas in which there are naturally foraging populations of subterranean termites.
B M Ahmed, J R J French
Experiences with the OECD guideline proposals for the estimation of emissions from preservative-treated wood in the environment
2004 - IRG/WP 04-50209
The practicability of 2 CEN proposals for OECD guidelines on the estimation of emissions from preservative treated wood by laboratory methods for either wood held in storage after treatment and for wooden commodities that are not covered, and are not in contact with ground (guideline 1) or wooden commodities that are not covered and are in contact with ground, fresh water or seawater (guideline 2) was tested during a research project in Germany. The influence of several test parameters was investigated for different types of preservatives, i.e. duration of the dipping time for guideline 1 experiments as well as size and surface structure of the specimens, comparability with EN 84 experiments and the influence of the ratio of the water volume per emitting surface area in guideline 2 experiments. Parallel tests in two laboratories allow the assessment of the repeatability of the laboratory tests. The results of the experiments with a solvent based preservative containing propiconazole are presented and compared with experiences from field experiments. The emissions were lower if less water was available per surface area and time. Different specimens yielded similar losses per surface area and the results from leaching experiments according to EN 84 were similar to the results from guideline 2 experiments. Emission rates and total losses can be estimated according to the calculation model of the OECD ESD for Wood Preservatives. Calculated data fit the experimental data. Emission rates of propiconazole estimated in guideline 2 experiments were generally higher than losses by natural rain. Minimum emission rates in these experiments were similar to the maximum values estimated in the field experiment. Losses by guideline 1 experi¬ments were in the range of the field data.
U Schoknecht, R Wegner, E Melcher
Detection and estimation of Hylotrupes bajulus L. wood damages by ultrasonics
1990 - IRG/WP 2350
To evaluate the validity of the ultrasonic application in the detection and evaluation of wood damages produced by Hylotrupes bajulus L. larvae, some laboratory tests were made with small wood samples. The pulse through transmission method was used. The transit time of ultrasonic pulses in transversal sections, radial and tangential, of the samples was measured. The increment of the transit time of ultrasonic pulses with respect to clear wood gave to this method the way to estimate the damage grade.
Estimation of mycelial biomass by determination of the ergosterol content of wood decayed by Coniophora puteana and Fomes fomentarius
1989 - IRG/WP 1415
The mycelial biomass of fungi decomposing wood materials may be estimated by the use of an ergosterol assay technique.ln decay tests, essentially according to EN 113, estimates made by HPLC analyses on wood decayed by Coniophora puteana and Fomes fomentarius show the increase in biomass in the wood blocks. The ergosterol contents were correlated with dry weight loss determinations. Degradation of wood in relation to colonization is discussed.
K Nilsson, J Bjurman
Estimation of the impregnation degree of pine wood by the distribution analysis of active ions concentration in the cross-section
1999 - IRG/WP 99-20174
Samples in the form of pine wood rollers of diversified moisture content of ca. 50, 28 and 12% were impregnated with a water solution of the mixture type CCB with the use of the full-cell process. Moisture content was determined in individual layers from the girth to the pith. In the same way the concentrations of copper and chromium ions with the use of the spectrophotometric method and recalculated to the total dry mass of the preservative. Simultaneously, there was performed biological test according to EN 113 for the investigated mixture and different concentrations: 0,1; 0,16; 0,25; 0,4; 0,63; 1,0; 1,6; 2,5. The obtained fungicidal value let to determine the depth of biological resistance of impregnated wood within the impregnated zone.
K Lutomski, B Mazela
Comparison of various types of bait containers designed to aggregate large numbers of foraging subterranean termites from natural populations in below-ground mound colonies
1995 - IRG/WP 95-10116
At Walpeup in the semi-arid mallee country of north-west Victoria (350 km from Melbourne), there are several indigenous subterranean termite species, none of which build above-ground mound colonies but build their colonies below-ground and/or in trees. This paper describes a baiting experiment in which three types of bait containers were compared in their ability to aggregate large numbers of foraging subterranean termites of the Coptotermes species. These species were targeted as they are considered the most economically important termite "pests" of wood and wood products in Australia. The area was pre-baited with radiata pine timbers that were buried just below the surface of the soil and located around trees and vegetation that were infested with Coptotermes species. After foraging termites had located and attacked the pre-baits, the various types of bait containers were installed on top of the infested pre-bait material. Bait containers were removed after five weeks and each was replaced by fresh bait containers. This occurred three times. All bait containers were transported to our laboratory in Melbourne and the mass of aggregated termites in each container weighed and wood consumption estimated. Bait containers that were half buried in the ground and covered with large plastic sheets and soil proved the most "attractive" of the various containers used in this field experiment. Also, the wood consumption rates of the two Coptotermes species collected from the field were compared in laboratory bioassays.
J R J French, B M Ahmed
Determination of fungitoxic value of preservatives in laboratory wood-block tests. Part 2: Statistical estimation
1989 - IRG/WP 2327
Laboratory modified agar-block tests were made to determine the fungitoxic value of the wood preservative CCA against the test fungus Serpula lacrymans using statistical methods. With the aid of statistical computer programmes based on the least square method. the regression equation was found for the dependence between sample mass loss and preservative retention both in terms of percentage and following probit, decimal and natural logarithmic transformations. The fungitoxic value was found to be lying in the point of intersection between the lines calculated and that of a 3 per cent mass loss. The application of mathematical statistics seems to have increased the objectivity and repeatability of measurements of fungitoxic value in the case of this wood preservative.
J Wazny, J D Thornton, K J Krajewski
Nondestructive assessment of biodegradation in southern pine sapwood exposed to attack by natural populations of decay fungi and subterranean termites
1994 - IRG/WP 94-20042
Field methods for evaluating decay resistance of experimentally treated materials lack a means for quantitative measurement of residual strength. Quantitative relationships between speed of impact-induced waves travelling parallel to the grain and residual compressive strength have been demonstrated in softwood attacked by brown rot-decay fungi, but the effects of termites have not been documented. We tested southern pine sapwood stakes that were vertically inserted for one-half their length in soil in a southern pine forest in southern Mississippi. The results showed that measurement of both speed and attenuation of a reciprocating impact-induced wave will yield quantitative information on extent of total biodegradation in southern pine sapwood, independent of organism causing the damage.
R C De Groot, R J Ross, W Nelson
The role of toilet paper in studies of desert subterranean termites in Arizona, USA
2000 - IRG/WP 00-10375
Toilet paper rolls were used as a substrate for observing foraging activity of Heterotermes aureus (Snyder) and Gnathamitermes perplexus (Banks) in the Sonoran Desert of Arizona. Foraging was minimal during the winter months, increased in the spring, was high but erratic in the summer, and then was moderate again in the fall. H. aureus foraged within a temperature range of 7.6° to 47°C, G. perplexus foraged within a range of 9° to 49°C. Temperature had the greatest influence on the number of foragers appearing at the soil surface. Rainfall (and resulting soil moisture) greatly affected foraging in the summer. Density of H. aureus foragers was estimated to be 4.31 x 106, while the density of G. perplexus was about twice that of H. aureus. Density of H. aureus colonies was ca. 190.4 colonies/hectare with an average of 22,632 foragers/colony and an average foraging territory of 12.5m2. Together, these two species transported soil to the soil surface at a combined rate of 744.2kg/hectare/year. Both species brought up soil richer in clay and added significant quantities of organic carbon, nitrogen, PO4, Na, Mg, and soluable salts, while H. aureus alone increased soil K.
M I Haverty
Comparison of laboratory tests and field experiments for the estimation of emissions from treated wood
2005 - IRG/WP 05-50224-6
The authorisation procedure for biocidal products according to the European Biocides Direc¬tive in¬cludes the assessment of possible environmental risks by the emission of ac¬tive ingre¬dients. This needs an input of data on the expected emissions of biocides into environmental com¬part¬ments. The procedures for the estimation of these emissions should be harmonised. La¬boratory test proce¬dures as proposed by the CEN TC38 WG27 might be a suitable means to obtain emis¬¬sion data. However, laboratory data cannot directly represent variable service con¬ditions. Only a limited number of the en¬vi¬ron¬mental conditions that can influence the emis¬¬¬sion of bio¬cides are represented in the la¬bo¬ratory tests. Never¬theless, water contact is a crucial factor for the emission of sub¬stan¬ces into water that can be controlled under labo¬ra¬to¬ry conditions. Al¬though there are only few studies that directly compare biocide emissions in laboratory and field ex¬pe¬riments it is helpful to summarise literature data for active ingre¬dients that have been ex¬ten¬sively investigated. Emission data from different types of experi¬ments are summa¬rised. Limitations and benefits of laboratory tests and field experiments as well as the resulting con¬se¬quences for the assess¬ment of emission data are discussed. Finally, it will be necessary to com¬promise about the suitability and repeatability of the test pro¬cedures and the applicability of the test results to different environmental conditions.
Feeding response of field populations of Coptotermes species to softwood blocks treated with non-toxic water-proofing and anti-microbial products.
2003 - IRG/WP 03-10487
The feeding response of field populations of the subterranean termite, Coptotermes lacteus, to Pinus radiata wood blocks (50 x 40 x40 mm) treated with various combinations of non-toxic and odourless water-proofing materials based on natural high molecular weight esters (TimberTreatÒ) and a new water insoluble quaternary ammonium compound (‘anti-microbial’) is described. Treated wood blocks were inserted into tube containers (300 x 90 mm) and placed into active above-ground mound colonies of C. lacteus in the south east Queensland. A simple objective rating system of attack measured this response over a period of 28 days. During the periods of test, termites had ‘visited’ all the wood specimens in the containers. Specimens treated with 1.5% anti-microbial solution and one coat of the timber treatment (TimberTreat®) were not attacked or damaged. The termites completely encased these specimens in soil and faecal material but did not consume any of the blocks. Blocks treated with one coat of the timber treatment and blocks treated with 0.5 and 1.0% anti-microbial solutions were only slightly to moderately attacked. These results suggest a strong ‘anti-feeding’ reaction by the termites to these novel non-toxic and odourless products, and maybe a role for these products as potential termiticides and/or wood preservatives against Coptotermes species. Further field trials are currently in progress.
J R J French, T Pynsent, M Susic
A review of the current status of the estimation of emissions from preserved wood and their use in the environmental risk assessment of wood preservatives under the Biocidal Products Directive
2005 - IRG/WP 05-50224-7
A review and update of the status of the issues concerning the estimation of emissions from preserved wood (e.g. amendments to the proposed ‘OECD Guidelines’), and the environmental risk assessment of wood preservatives under the Biocidal Products Directive (e.g. compartmental sizes, emissate ecotoxicity testing).
E F Baines