Your search resulted in 32 documents. Displaying 25 entries per page.
Response of laboratory groups of Reticulitermes speratus (Kolbe) to different quantities of food
2003 - IRG/WP 03-10489
As part of a project aimed at improving understanding of the foraging biology of Japan’s most widespread wood-destroying termite, different sized groups of Reticulitermes speratus (0.5; 1 and 2 g) from two colonies were kept on 16 or 64 cm3 of sapwood of Cryptomeria japonica for 12 weeks in the laboratory. Patterns of wood consumption, wood consumption rates and survival are discussed.
M Lenz, T Yoshimura, K Tsunoda
Studies on the infesting behaviour of the Formosan termite, Coptotermes formosanus Shiraki and its physical control
1983 - IRG/WP 1174
An outline of termite damage to buildings in Japanese National Railways, wood-infesting behavior, attacked traces in PVC-sheathed cables by termites, detection method of termites and the physical control method of the Formosan termite are given in the present paper.
Changes in the degree of decay of lignocellulosic substrate used in a screening test of fungicidal wood preservatives
1977 - IRG/WP 287
This report contains results of investigations aimed at: a) determination of the effect of the kind of substrate and species of test fungus on quantitative changes in used samples prepared from spruce cardboard, and b) comparison of the threshold fungicidal values of come fungicides determined with accelerated method, with values obtained by block method. During performed investigations, the method described in Document No.: IRG/WP/262 was used. Assesment of decomposition degree was based on the loss of weight and amount of NaOH consumption by the substrate.
Differences in feeding activity among colonies of Formosan subterranean termite Coptotermes formosanus Shiraki
1983 - IRG/WP 1202
Feeding activities of 7 colonies of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were examined. Wood-consumption rates among colonies differed significantly, ranging from 23.80-78.48 mg/g/day. This large intraspecific variation raised a question of whether differences in feeding activity reported for other termite species were due to interspecific differences. When rates were expressed as mg wood consumed by one g termite per day (mg/g/day), termites of larger body weight appeared to consume less wood. This negative correlation, however, was not significant when rates were expressed as mg wood consumed by an individual per day (mg/worker/day).
N-Y Su, J P La Fage
Implications for comparability of laboratory experiments revealed in studies on the variability in survival and wood consumption between colonies of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae
1983 - IRG/WP 1196
(Summary of paper 1193) Groups of Coptotermes acinaciformis, originating from six colonies, three taken from each of two localities, 1500 km apart, in northern Australia (Townsville, Darwin) were kept at population densities of 0.005, 0.01 and 0.02 g termites/mL. Survival and wood consumption of the groups after 8 weeks followed a similar pattern in the colonies from both collection areas. Groups were least vigorous at the lowest population density; their performance reached a maximum at a population density of 0.01 g/mL. The subsequent decline in vigour was less marked as the highest population density was approached. However, the actual values for survival and wood consumption varied widely between colonies, irrespective of their origin. It is recommended that in all laboratory experiments which use survival and wood consumption as indicators of termite vigour, controls of a favourable as well as an unfavourable food type are included which would serve to monitor the vigour of the termites. Results from termite sources whose vigour falls below a certain threshold value would have to be treated with caution and could not be used in definative data, as e.g. in defining critical retentions of wood preservatives.
Reticulitermes (Ins., Isopt.) in Central and Western Europe
1969 - IRG/WP I 5A
Reticulitermes flavipes (Kollar) has established itself in Hamburg and Hallein coming from the east of North America. In France, on the northern boundary of termit occurrence, Reticulitermes santonensis are distinguished from Reticulitermes lucifugus by special activity and resistance. According to comparative investigations with colonies of several Reticulitermes species of different origins regarding the influence of temperature and soil moisture on the feeding activity and the viability of termite groups, Reticulitermes flavipes from Hamburg and one originating from Wisconsin (USA) show racial differences from the Hallein species originating from South Carolina. The first shows a daily rhythm of activity and are strong gallery builders, while the two latter lack these properties. Certain morphological differences may be correlative to the two bio-ecological races of Reticulitermes flavipes. Reticulitermes santonensis shows biologically and ecologically far greater similarity with Reticulitermes flavipes from Hamburg and Wisconsin than with Reticulitermes lucifugus. The samples from La Rochelle have symbiotic flagellate species which were otherwise only found either with Reticulitermes lucifugus or with the American Reticulitermes species. Morphologically the species occupies an intermediate position. Reticulitermes santonensis is likely to be a hybrid of Reticulitermes flavipes and Reticulitermes lucifugus, with the properties of a vigorous hybrid. So far it has been impossible to explain why up to now only Reticulitermes flavipes was able to establish itself sporadically in Central and West Europe.
Inventaire des "déchets" ou produits connexes de la filière bois
1993 - IRG/WP 93-50001-33
Reticulitermes (Ins., Isopt.) in Mittel- und West-Europa
1969 - IRG/WP I 4
In Hamburg und Hallein hat sich Reticulitermes flavipes (Kollar) aus dem Osten von Nordamerika eingebürgert. An der Nordgrenze des Termitenvorkommens im Westen Frankreichs zeichnet sich Reticulitermes santonensis Fetaud gegenüber Reticulitermes lucifugus durch besondere Aktivität und Widerstandsfähigkeit aus. Nach vergleichenden Untersuchungen an Kolonien verschiedener Reticulitermes-Arten mehrerer Herkünfte über den Einfluß von Temperatur und Bodenfeuchtigkeit auf Fraßtätigkeit und Lebensfähigkeit von Termitengruppen weisen die Reticulitermes flavipes-Tiere von Hamburg und einer Herkunft aus Wisconsin (USA) gegenüber den Tieren von Hallein und einer Herkunft aus South-Carolina Rassenunterschiede auf. Die ersteren zeigen einen Tagesrhythmus der Aktivität und eine starke Galleriebautätigkeit, die den beiden letzten fehlen. Gewisse morphologische Unterschiede lassen sich den beiden ökologisch-biologischen Rassen von Reticulitermes flavipes zuordnen. Reticulitermes santonensis ähnelt biologisch und ökologisch Reticulitermes flavipes von Hamburg und Wisconsin weit mehr als Reticulitermes lucifugus. Die Tiere von La Rochelle besitzen symbiotische Flagellaten-Arten, die sonst nur entweder bei Reticulitermes lucifugus oder bei amerikanischen -Arten vorkommen. Morphologisch nimmt die Art eine Zwischenstellung ein. Reticulitermes santonensis dürfte eine Kreuzung aus Reticulitermes flavipes und Reticulitermes lucifugus mit Eigenschaften eines luxurierenden Bastards sein. Bisher läßt sich nicht erklären, warum sich bislang nur Reticulitermes flavipes vereinzelt in Mittel- und Westeuropa einbürgern konnte.
Protection of beech veneer for fruit and vegetable boxes
1981 - IRG/WP 3176
In Yugoslavia about 50,000 m³ of low quality beech logs annually are rotary cut into veneer from which boxes are made for transporting fruit and vegetables. Because of steaming before rotary cutting, beech veneer becomes extremely sensitive to mould attack which decreases the quality and commercial value of the final product. To avoid mould attack, veneer sheets are dried to 16% moisture content immediately after cutting. However, during transportation or cold storage of fruit, veneers or ready-made boxes can become rewetted and the mould problem can appear again. Some research work to determine suitable and non-tainting chemicals to prevent mould attack on veneers and boxes is described in this paper.
Laboratory bioassay on the termiticidal efficacy of two ACQ formulations
1999 - IRG/WP 99-30199
The termiticidal efficacy of two ammoniacal copper quaternary ammonium formulations (ACQ) was evaluated in a laboratory bioassay using two species of subterranean termites, Mastotermes darwiniensis Froggatt and Coptotermes acinaciformis (Froggatt). Five retentions (1.0, 2.0, 4.0, 6.0 and 8.0 kg/m3 of active ingredient) of each ACQ formulation (MitrexACQ and ACQ97) were assessed in sapwood specimens of the softwood Pinus radiata D. Don and compared with the same retentions of the conventional benchmark preservative CCA (Tanalith C). All specimens (including controls) were subjected to an artificial weathering schedule prior to the bioassay. Under the conditions of the laboratory bioassay, both MitrexACQ and ACQ97 showed considerable potential as water-borne preservatives for preventing significant attack of P. radiata sapwood from two of Australia's most economically significant species of termite. At each of the retentions tested, MitrexACQ and ACQ97 performed comparably or better than equivalent retentions of CCA.
J W Creffield, A F Preston, N Chew
Size of food resource determines brood placement in Reticulitermes flavipes (Isoptera: Rhinotermitidae)
2000 - IRG/WP 00-10351
Most species of subterranean termite house and care for larvae in specialised chambers or complex nurseries. In addition to these chambers, the genus Reticulitermes also keeps larvae at sites where foragers are feeding, a trait more commonly found in damp wood and dry wood termites. This phenomenon of holding larvae at foraging sites is quite well known among researchers who work with Reticulitermes, yet it has not been investigated to any extent. Consequently, the underlying causes of larvae placement at foraging sites are only poorly understood. During assessments of the resistance of materials to Reticulitermes flavipes attack at the Harrison Experimental Forest, near Saucier, Mississippi, USA, significant numbers of 1 st and 2 nd stage larvae were often found in Pinus spp bait wood stakes. This paper describes the results from the first of a series of ongoing experiments to test whether food resources affected termite presence and larval placement. The experiment used a variable number of pine stakes in eight plots (four in stands of pine, four in grassy forest clearings) where termites were offered a choice of food resources of different size (bundles of 1 to 4 pine stakes of equal size). The number of larvae recorded from feeding sites was a close reflection of the number of workers attracted to a given food source. The more substantial and suitable a food source is, the more foragers will visit it, and in turn the more likely that they will transport larvae and eggs to these feeding sites.
M Lenz, B M Kard, J K Mauldin, T A Evans, J L Etheridge, H M Abbey
Variance in feeding on equivalent wood blocks by the Formosan subterranean termite (Coptotermes formosanus Shiraki)
1987 - IRG/WP 1325
We tested whether laboratory groups of Coptotermes formosanus Shiraki forage randomly when they are given 4 equivalent wood blocks, and whether group size affects variance of feeding on equivalent blocks. In all cases, foraging was not random, but, rather, the termites concentrated on a few preferred blocks. Group size did not affect this pattern of non-randomness. These data are useful for designing choice tests, and recommended sample sizes for a simulated experiment are given.
J P La Fage, K S Delaplane
Respiratory response of the wood boring teredinid, Lyrodus pedicellatus (Quatrefages) to copper stress
2004 - IRG/WP 04-10528
Wood boring teredinid molluscs engulf most of the wooden particles scrapped by them while actively boring into wood, obtaining nourishment for their metabolic activities. In order to protect the wooden structures from the biodeteriorating activity of such organisms, the wood is treated with different chemical formulations to prolong their service life. Copper chrome arsenic (CCA) is one such wood preservative chemical offering excellent protection to wood under marine conditions. Field observations with CCA treated test stakes as well as actual wooden structures have, however, shown that they are not free from wood borer attack after considerable service life. The successful settlement and growth of these organisms are a reflection of their metabolic ability under such adverse chemical stress conditions. As copper and arsenic are known to be metabolic inhibitors, a study was undertaken to investigate the respiratory behaviour of Lyrodus pedicellatus (Quatrefages), the most virulent teredinid wood borer at Visakhapatnam harbour, East Coast of India. As a first step, experiments were conducted on this aspect under copper stress. The results show that in situ oxygen consumption of the animal under normal conditions was found to range from 0.8 – 5.6 μl.mg-1.hr-1 averaging 2.43 μl.mg-1.hr-1. Under acute toxicity of 0.5 ppm copper, the oxygen demand was observed to fall almost to half the normal levels (0.4 – 3.5 μl.mg-1.hr-1), but showed a gradual increase subsequently during the next 24 hours. However, when the stress was continued for 96 hours, the oxygen uptake gradually decreased again to 0.2 – 2.1 μl.mg-1. hr-1.
V Kuppusamy, M Balaji, M V Rao, K S Rao
Leaching from CCA-impregnated wood to food, drinking-water and silage
1987 - IRG/WP 3433
During the last years The Norwegian Institute of Wood Technology (NIWT) has analysed different foodstuff for contamination by copper, chrome and arsenic from CCA-impregnated wood. There has been some interest for using CCA-impregnated wood in contact with food and drinking-water. Before giving their permission the Norwegian Health Authorities want results from experiments. NIWT therefore started three experiments with 1) analysing stock-fish dried on CCA-treated rack, 2) analysing rainwater collected from wooden roofing of CCA- impregnated boards and 3) leaching from CCA-impregnated grass silos: 1) The results shows very little contamination of the stock-fish. Eating the stock-fish will cause no health hazard. 2) After two years of exposure we still find arsenic and copper in the collected rainwater. The water should not be used as drinking-water. 3) In the grass silo we find an extreme leaching of copper, chrome and arsenic. After exposure for two seasons we find that 20-50% of the copper compound, 50-60% of the chrome compound and 80% of the arsenic compound has leached from the boards. Calculation shows, however, that there is no poisoning hazard for the cattle eating the silage, but the silo's durability may be reduced.
F G Evans
International collaborative laboratory comparison of two wood preservatives against subterranean termites: Update
1994 - IRG/WP 94-20032
It was agreed by members at the termite workshop at the 24th annual meeting of IRG in Orlando, USA, in May 1993 to initiate an international subterranean termite laboratory bioassay to compare the various preferred termite protocols used by IRG termitologists. The author was nominated to co-ordinate this comparative laboratory evaluation of two wood preservatives (CCA and Cu-naphthenate) against the subterranean termites used as test termites in the various countries. Solutions of these two wood preservatives will be prepared and impregnated into Pinus radiata wood blocks to obtain loadings of 0.0, 0.5, 1.0, 2.0 and 4.0 kg/m³ respectively. All preservative treatments will be carried out at the Division of Forest Products in Melbourne. After treatment, blocks will be dispatched to the participating researchers who will subject these specimens to attack by their test termite species. The method of comparative evaluation will be expressed using a standardised unit, namely, the amount of wood consumed (mg) per gram of termite per day per loading of wood preservative. Any termite mortality will be recorded over the test period. Apart from the intrinsic value of comparing protocols used by the various termite researchers, it is hoped that the results will assist the wood preservation industry in evaluating an economic lethal threshold level for potential wood preservatives in preventing attack and damage by major subterraneaan termite species found in the different countries. This paper reports the organisation of this collaborative study to date, lists the collaborators, and the preparation of the treated wood specimens. Delay in treatments have been experienced due to technical delays in the treatment plant. The results of the entire study will be presented to all IRG members when completed.
J R J French
Borate-treated food affects survival, vitamin B12 content, and digestive processes of subterranean termites
1990 - IRG/WP 1448
Toxicity of boron compounds was studied by analyzing survival rates and vitamin B12 contents in Formosan subterranean termites, Coptotermes formosanus Shiraki, that were exposed to dietary treatments for 10 days. The dietary treatments applied in moistened cellulose were (a) 0.05% boric acid equivalent (BAE) of disodium octaborate tetrahydrate, (b) 0.05% BAE of anmonium pentaborate plus sodium sulfate, (c) antibacterial control 0.09% streptomycin D, (d) untreated control-moistened cellulose, and (e) starvation control-no food. The main effects - colony and treatment -, and their interaction were shown to be significant by analysis of variance (ANOVA) tests. Survival of termites on diets (c) and (d) was not significantly different (P <0.05). Survival of termites on diet (d) was significantly higher than survival of termites exposed to diets (a), (b), and (e). Vitamin B12 content of termites exposed to diets (a), (b), (c), and (e) was significantly less than that of termites exposed to diet (d). Ingestion of borate-treated (and molybdate-treated) food by Reticulitermes flavipes (Kollar) suppressed the rates of methane production and H2-dependent reduction of CO2 to acetate by hindgut microbiota, apparently by indirect means. The mechanisms of how borate-treated food affects digestive processes or vitamin B12 contents of termites remains undefined. Results are discussed in relation to termite gut microecology and borate use for wood protection.
L H Williams, S I Sallay, J A Breznak
Implications for comparibility of laboratory experiments revealed in studies on the variability in survival and wood consumption between colonies of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae
1983 - IRG/WP 1193
Groups of Coptotermes acinaciformis originating from six colonies, three taken from each of two localities 1500 km apart in northern Australia (Townsville, Darwin), were kept at population densities of 0.005, 0.011 and 0.02 g termites/mL. Survival and wood consumption of the groups after 8 weeks followed a similar pattern in the colonies from both collection areas. Groups were least vigorous at the lowest population density; their performance reached a maximum at a population density of 0.011 g/mL. The subsequent decline in vigour as the highest population density was approached was less marked than at the lowest density. However, the actual values for survival and wood consumption varied widely betwesn colonies, irrespective of their origin. It is recommended that in al1 laboratory experiments which use survival and wood consumption as indicators of termite vigour, controls of a favourable as well as an unfavourable food type are included to monitor the vigour of the termites. Results from termite sources whose vigour falls below a certain threshold value would have to be treated with caution and could not be used in definitive data, as for example the defining of critical retentions of wood preservatives.
Laboratory evaluation of the termiticidal effectiveness of TanalithÒ 3485
1995 - IRG/WP 95-10109
The termiticidal effectiveness of the copper azole TANALITH 3485 was evaluated with the benchmark preservative TANALITH C in a laboratory bioassay using two species of subterranean termites, Mastotermes darwiniensis Froggatt and Coptotermes acinaciformis (Froggatt). Retentions of TANALITH 3485 tested were 0.15, 0.24, 0.285 and 0.40% m/m Cu and for TANALITH C 0.025, 0.05, 0.08 and 0.095% m/m Cu. Under the conditions of the bioassay, TANALITH 3485 at the retentions of 0.24, 0.285 and 0.40% m/m Cu and TANALITH C at the retentions of 0.05, 0.08 and 0.095% m/m Cu (0.20, 0.32 and 0.38% m/m total active elements [TAE], respectively) were each successful in protecting Pinus radiata D. Don test specimens against significant attack by Mastotermes darwiniensis. The lowest retention of each formulation failed. When exposed to Coptotermes acinaciformis, all retentions of TANALITH 3485 tested were successful in protecting test specimens whereas TANALITH C at the lowest retention of 0.025% m/m Cu (0.10% m/m TAE) failed. Specimens treated with TANALITH 3485 exhibited little, if any, toxicity to Mastotermes darwiniensis. The formulation appeared to have imparted a repellent and/or antifeedant effect on Mastotermes darwiniensis. In contrast, TANALITH C displayed toxicity to Mastotermes darwiniensis thereby causing a decrease in survival of termites throughout the bioassay as the retention of preservative in test specimens increased.
J W Creffield, J A Drysdale, N Chew, N-K Nguyen
International collaborative laboratory comparison of two wood preservatives against subterranean termites: Second update
1995 - IRG/WP 95-10117
As was agreed by members at the termite workshop at the 24th annual meeting of IRG in Orlando, USA, in May 1993 to initiate an international subterranean termite laboratory bioassay to compare the various preferred termite protocols used by IRG termitologists was initiated. The author was nominated to co-ordinate this comparative laboratory evaluation of two wood preservatives (CCA and Cu-naphthenate) against the subterranean termites used as test termites in the various countries. Solutions of these two wood preservatives will be prepared and impregnated into Pinus radiata wood blocks to obtain loading of 0.0, 0.5, 1.0, 2.0 and 4.0 kg/m³ respectively. All preservative treatments have been carried out at the Division of Forest Products in Melbourne, and following retention calculations, the treated specimens will be dispatched to the participating researchers who will subject these specimens to attack by their test termite species. The method of comparative evaluation will be expressed using a standardised unit, namely, the amount of wood consumed (mg) per gram of termite per day per loading of wood preservative. Any termite mortality will be recorded over the test period.
J R J French
Estimates of wood-consumption rates by termites
1983 - IRG/WP 1201
Effects of 2 components; termite-biomass and experiment duration on estimates of wood-consumption rates (mg wood/g termite/day), were examined. Three models; (1) no mortality, (2) linear mortality and (3) nonlinear mortality were used to calculate mean standing-crop biomass of termites. Model (1) predicted a significantly lower wood-consumption rate than those based on models (2) and (3). No significant difference was detected between rates based on models (2) and (3) when data within defined experiment duration were used.
N-Y Su, J P La Fage
Health and safety regulations on the use of wood preservatives in Switzerland
1980 - IRG/WP 3148
There is not any doubt that the chemical protection of wood (besides the architectional-constructional wood protection) is of utmost importance for the increase of the durability of technically used timber. The toxic properties of wood preservatives make certain legal regulations necessary for the protection of human beings, animals and the environment. Thereby wood preservatives fall under the poison law, the food law and the waters protection law. An appropriate and reasonable application of these three laws can protect human beings and animals from injurious effects of wood preservatives. The absence of any legal obligation for compulsary examination of efficiency of wood preservatives against wood pests is a fault. It makes it impossible to eliminate products of low efficiency which nevertheless encumber the environment.
Implications for comparability of laboratory experiments revealed in studies on the effects of population density on the vigour in groups of Coptotermes lacteus (Frogatt) and Nasutitermes exitiosus(Hill) (Isoptera: Rhinotermitidae, Termitidae)
1983 - IRG/WP 1194
The vigour - survival. and wood consumption - of groups of Coptotermes lacteus and Nasutitermes exitiosus was measured when termites were kept at different population densities (g termites/mL) by changing group size and/or volume of the holding container. A characteristic pattern emerges for subterranean-like termite species. At low population densities (<0.01 g/mL) performance of termites improves with an increase in group size; at higher densities it tends to decline. The impact of altering group size and container volume on termite vigour is most pronounced at low population densities; at higher population densities, performance tends to be more stable but declines markedly when termites become overcrowded. In most jar-type experiments on termites, especially those conducted in Europe and the U.S.A., small groups of termites are housed in disproportionately large jars, resulting in very low, sub-optimal population densities. Suggestions are made for improvement in experimental design that would lead to an enhancement of the comparability of results from different laboratories.
M Lenz, R A Barrett, E R Williams
Quality and safety scheme for wood in food contact
1995 - IRG/WP 95-50040-11
When there is no tolerance concerning the content in food of potential contaminants the scheme is limited to a ban of any contaminant with objectives of undetectable amounts at the limits of detection of the chemical analysis. When some tolerances exist, there is a need to check the compliance of a production to such requirements, putting in place the necessary prevention of any accidental situation, within the frame of a clean production flow-sheet. In both cases the introduction of quality assurance, namely at the stage of records and treatability, combined with adapted statistical control on the input and output of a production process and generalisation of cleaner production principles gives a high level of confidence to the wood products. A practical experience is described in this document.
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
Effects of wood-inhabiting marine fungi on food selection, feeding intensity and reproduction of Limnoria tripunctata Menzies (Crustacea, Isop.)
1981 - IRG/WP 480
The paper gives a condensed survey on laboratory tests with Limnoria tripunctata Menzies and pure cultures of 9 different marine wood-inhabiting fungi. Limnoria is able to distinguish between fungus-infested and non-infested wood. Wood with dead mycelium mostly proved to be less attractive or even repellent and was initially consumed less than with living fungi. On non-infested wood, initial feeding is retarded by 2 to 4 days. On fungus-infested wood less eggs degenerated and the number of reproductives was higher than on non-infested wood. Humicola alopallonella-infested wood yielded the highest number of reproductives. But the attractiveness of a fungus, the feeding stimulus produced by it and its nutritional value often did not correspond. It was not possible to make generally valid conclusions for one fungus species.