Xylophagous borers and termites that damage "timber-in-service" cause millions of dollars loss annually throughout mainland Australia. I developed field-based feeding assays with practical relevance to preventative action and remedial treatment of infestations of xylophagous insects in the built environment. Essential to this work is facilitating a high termite risk by maintaining an environment conducive to sustained foraging by termites. Feeding assays conducted in low termite risk areas are unduly prolonged, with inherently erratic termite feeding responses. I successfully developed feeding assays with a high termite risk. To establish whether a physical barrier, retrofitted as a sleeve, could prevent termites from damaging wooden poles, eighty poles were established within Beerburrum State Forest, south-east Queensland, Australia. Poles within sets were interconnected with buried timber to facilitate a high risk to Coptotermes acinaciformis (Froggatt). Mesh sleeves to a depth of 1.5m did not prevent termite damage to the poles. Hoop pine Araucaria cunninghamii Ait. ex D.Don dowels ("dip-sticks") were useful termite monitoring devices on the poles. The depth of foraging by termites has implications for the effectiveness of retrofitted physical and chemical barriers in general. Timber quantity and quality has a pivotal influence on the aggregation of large numbers of feeding termites necessary for baiting work and for producing efficacy data of relevance to the protection of timber-in-service from termites. Seasonal variation in termite foraging was examined. Both C. acinaciformis and Coptotermes lacteus (Froggatt) were more active feeding in summer than in autumn. In general, mass loss followed mean ambient temperature. Suppression of C. acinaciformis feeding responses relative to C. lacteus during summer, particularly during January, is thought to be due to excessive temperatures in the containers attached to infested trees. Termite foraging behaviour and responses to both varying masses of softwood timbers and varying exposure times were investigated. The rate of mass loss was independent of the number of test specimens and appeared linear. Colonies regulate the number of foragers directly according to the mass of susceptible timber available. This phenomenon was exploited throughout the remainder of the thesis. Of particular significance was the considerable intra- and inter-specific variation in susceptibility of softwoods to C. acinaciformis and Mastotermes darwiniensis Froggatt. The sapwoods tested were susceptible, but the heartwoods were generally resistant to damage by termites. These data confirm that termites are discriminating feeders, and some more so than others. A novel methodology, developed to maintain an environment conducive to sustained foraging by termites during field-testing, is presented. Consistency in timber acceptance and susceptibility to termites is considered to be important in determining the frequency of inspection and the success of bait systems. I evaluate the termiticidal activity of the bait toxicants hexaflumuron and chlorfluazuron for the management of the subterranean termite C. acinaciformis in the field. The Sentricon Colony Elimination System with Baitube-devices containing 0.1% and 1% mass/mass (m/m) hexaflumuron bait toxicant in dry wood flour (Recruit) was successful in eliminating field colonies of C. acinaciformis. Similarly, the Exterra Termite Interception and Baiting System with cellulose-acetate powder containing either 0.05% m/m or 0.25% m/m chlorfluazuron (Requiem) eliminated C. acinaciformis. Indicators (including "dip-sticks") used to monitor colony health were reliable. By using C. acinaciformis, which builds mounds (epigeous nests) in northern Australia, I was able to avoid the use of multiple mark-release schemes to verify the effects of the bait toxicant on the termite colonies. Problems with multiple mark-release schemes, used elsewhere in the world, are discussed. I continued the focus on bait quality and placement by evaluating termite responses to two aspects of treated stakes, their attractiveness and their susceptibility. Three experiments were undertaken near Townsville and at Beerburrum, with Coptotermes and Schedorhinotermes. Whilst there were no significant differences in the rate of location and foraging, with respect to treatments, differences in foraging, with respect to C. acinaciformis and Schedorhinotermes seclusus (Hill) were significant. Coptotermes acinaciformis displayed greater foraging site tenacity than S. seclusus at Beerburrum. Increased consumption of bait, due to the addition of a phagostimulant, needs to be observed in the field before an increase in the efficacy of baits in a termite management program can be claimed. In Australia, softwood timbers are extensively used in building construction and are generally highly susceptible to damage by termites. I focussed on field feeding assays to test efficacy of borate-treated softwoods against termites and to define "adequate" protection thresholds. Laboratory and field data reported in the literature were confusing with regard to what constitutes "adequate" protection thresholds. The confusion was compounded by differences in termite species, timber species used and test methodology. Laboratory data indicated a borate loading of 0.5% m/m boric acid equivalent (BAE) would cause > 90% termite mortality and restrict mass loss in test specimens to 5%. Field data generally suggested that borate loadings in excess of 0.5% m/m BAE were required. The main contribution of the work to increasing our understanding of management options for termites in the built environment was in resolving the confusion between laboratory and field data for borate wood-preservatives. These apparently conflicting results were explained by the presence or absence of untreated feeder material in the test environment. In the absence of untreated feeder material, retention of 0.5% BAE provides adequate protection from Coptotermes sp., whereas in the presence of untreated feeder material, increased retentions are required. Furthermore, the retentions required increase with increased amounts of susceptible material. Some termites, Nasutitermes sp. and M. darwiniensis, for example, are borate-tolerant and borate wood-preservatives are not a viable management option. The lack of uniform standards for termite-test methodology and assessment criteria for efficacy across the world is recognized as a difficulty with research into the performance of wood preservatives with termites. The many variables in laboratory and field assays make "prescriptive" standards difficult to recommend. The use of "performance" standards to define efficacy criteria ("adequate" protection) is discussed. Whilst the majority of the work involves subterranean termites ("termites"), I examine the question of how to define a hardwood timber species as "not susceptible" to lyctine beetle damage. Aspects of the biology, behaviour and management of Lyctus brunneus (Stephens) are reviewed and a novel field sampling and testing protocol to establish lyctine susceptibility of timber species is presented. A sound understanding of the biology and behaviour of xylophagous insects in the field is essential to ensure that management options implemented in the built environment have a strong ecological basis. The success of this study in achieving stated aims, the need for further work and the implications for test methodologies in the field with practical relevance to infestations of xylophagous insects in the built environment are discussed.

Xylophagous borers and termites that damage "timber-in-service" cause millions of dollars loss annually throughout mainland Australia. I developed field-based feeding assays with practical relevance to preventative action and remedial treatment of infestations of xylophagous insects in the built environment. Essential to this work is facilitating a high termite risk by maintaining an environment conducive to sustained foraging by termites. Feeding assays conducted in low termite risk areas are unduly prolonged, with inherently erratic termite feeding responses. I successfully developed feeding assays with a high termite risk. To establish whether a physical barrier, retrofitted as a sleeve, could prevent termites from damaging wooden poles, eighty poles were established within Beerburrum State Forest, south-east Queensland, Australia. Poles within sets were interconnected with buried timber to facilitate a high risk to Coptotermes acinaciformis (Froggatt). Mesh sleeves to a depth of 1.5m did not prevent termite damage to the poles. Hoop pine Araucaria cunninghamii Ait. ex D.Don dowels ("dip-sticks") were useful termite monitoring devices on the poles. The depth of foraging by termites has implications for the effectiveness of retrofitted physical and chemical barriers in general. Timber quantity and quality has a pivotal influence on the aggregation of large numbers of feeding termites necessary for baiting work and for producing efficacy data of relevance to the protection of timber-in-service from termites. Seasonal variation in termite foraging was examined. Both C. acinaciformis and Coptotermes lacteus (Froggatt) were more active feeding in summer than in autumn. In general, mass loss followed mean ambient temperature. Suppression of C. acinaciformis feeding responses relative to C. lacteus during summer, particularly during January, is thought to be due to excessive temperatures in the containers attached to infested trees. Termite foraging behaviour and responses to both varying masses of softwood timbers and varying exposure times were investigated. The rate of mass loss was independent of the number of test specimens and appeared linear. Colonies regulate the number of foragers directly according to the mass of susceptible timber available. This phenomenon was exploited throughout the remainder of the thesis. Of particular significance was the considerable intra- and inter-specific variation in susceptibility of softwoods to C. acinaciformis and Mastotermes darwiniensis Froggatt. The sapwoods tested were susceptible, but the heartwoods were generally resistant to damage by termites. These data confirm that termites are discriminating feeders, and some more so than others. A novel methodology, developed to maintain an environment conducive to sustained foraging by termites during field-testing, is presented. Consistency in timber acceptance and susceptibility to termites is considered to be important in determining the frequency of inspection and the success of bait systems. I evaluate the termiticidal activity of the bait toxicants hexaflumuron and chlorfluazuron for the management of the subterranean termite C. acinaciformis in the field. The Sentricon Colony Elimination System with Baitube-devices containing 0.1% and 1% mass/mass (m/m) hexaflumuron bait toxicant in dry wood flour (Recruit) was successful in eliminating field colonies of C. acinaciformis. Similarly, the Exterra Termite Interception and Baiting System with cellulose-acetate powder containing either 0.05% m/m or 0.25% m/m chlorfluazuron (Requiem) eliminated C. acinaciformis. Indicators (including "dip-sticks") used to monitor colony health were reliable. By using C. acinaciformis, which builds mounds (epigeous nests) in northern Australia, I was able to avoid the use of multiple mark-release schemes to verify the effects of the bait toxicant on the termite colonies. Problems with multiple mark-release schemes, used elsewhere in the world, are discussed. I continued the focus on bait quality and placement by evaluating termite responses to two aspects of treated stakes, their attractiveness and their susceptibility. Three experiments were undertaken near Townsville and at Beerburrum, with Coptotermes and Schedorhinotermes. Whilst there were no significant differences in the rate of location and foraging, with respect to treatments, differences in foraging, with respect to C. acinaciformis and Schedorhinotermes seclusus (Hill) were significant. Coptotermes acinaciformis displayed greater foraging site tenacity than S. seclusus at Beerburrum. Increased consumption of bait, due to the addition of a phagostimulant, needs to be observed in the field before an increase in the efficacy of baits in a termite management program can be claimed. In Australia, softwood timbers are extensively used in building construction and are generally highly susceptible to damage by termites. I focussed on field feeding assays to test efficacy of borate-treated softwoods against termites and to define "adequate" protection thresholds. Laboratory and field data reported in the literature were confusing with regard to what constitutes "adequate" protection thresholds. The confusion was compounded by differences in termite species, timber species used and test methodology. Laboratory data indicated a borate loading of 0.5% m/m boric acid equivalent (BAE) would cause > 90% termite mortality and restrict mass loss in test specimens to 5%. Field data generally suggested that borate loadings in excess of 0.5% m/m BAE were required. The main contribution of the work to increasing our understanding of management options for termites in the built environment was in resolving the confusion between laboratory and field data for borate wood-preservatives. These apparently conflicting results were explained by the presence or absence of untreated feeder material in the test environment. In the absence of untreated feeder material, retention of 0.5% BAE provides adequate protection from Coptotermes sp., whereas in the presence of untreated feeder material, increased retentions are required. Furthermore, the retentions required increase with increased amounts of susceptible material. Some termites, Nasutitermes sp. and M. darwiniensis, for example, are borate-tolerant and borate wood-preservatives are not a viable management option. The lack of uniform standards for termite-test methodology and assessment criteria for efficacy across the world is recognized as a difficulty with research into the performance of wood preservatives with termites. The many variables in laboratory and field assays make "prescriptive" standards difficult to recommend. The use of "performance" standards to define efficacy criteria ("adequate" protection) is discussed. Whilst the majority of the work involves subterranean termites ("termites"), I examine the question of how to define a hardwood timber species as "not susceptible" to lyctine beetle damage. Aspects of the biology, behaviour and management of Lyctus brunneus (Stephens) are reviewed and a novel field sampling and testing protocol to establish lyctine susceptibility of timber species is presented. A sound understanding of the biology and behaviour of xylophagous insects in the field is essential to ensure that management options implemented in the built environment have a strong ecological basis. The success of this study in achieving stated aims, the need for further work and the implications for test methodologies in the field with practical relevance to infestations of xylophagous insects in the built environment are discussed.

Xylophagous borers and termites that damage "timber-in-service" cause millions of dollars loss annually throughout mainland Australia. I developed field-based feeding assays with practical relevance to preventative action and remedial treatment of infestations of xylophagous insects in the built environment. Essential to this work is facilitating a high termite risk by maintaining an environment conducive to sustained foraging by termites. Feeding assays conducted in low termite risk areas are unduly prolonged, with inherently erratic termite feeding responses. I successfully developed feeding assays with a high termite risk. To establish whether a physical barrier, retrofitted as a sleeve, could prevent termites from damaging wooden poles, eighty poles were established within Beerburrum State Forest, south-east Queensland, Australia. Poles within sets were interconnected with buried timber to facilitate a high risk to Coptotermes acinaciformis (Froggatt). Mesh sleeves to a depth of 1.5m did not prevent termite damage to the poles. Hoop pine Araucaria cunninghamii Ait. ex D.Don dowels ("dip-sticks") were useful termite monitoring devices on the poles. The depth of foraging by termites has implications for the effectiveness of retrofitted physical and chemical barriers in general. Timber quantity and quality has a pivotal influence on the aggregation of large numbers of feeding termites necessary for baiting work and for producing efficacy data of relevance to the protection of timber-in-service from termites. Seasonal variation in termite foraging was examined. Both C. acinaciformis and Coptotermes lacteus (Froggatt) were more active feeding in summer than in autumn. In general, mass loss followed mean ambient temperature. Suppression of C. acinaciformis feeding responses relative to C. lacteus during summer, particularly during January, is thought to be due to excessive temperatures in the containers attached to infested trees. Termite foraging behaviour and responses to both varying masses of softwood timbers and varying exposure times were investigated. The rate of mass loss was independent of the number of test specimens and appeared linear. Colonies regulate the number of foragers directly according to the mass of susceptible timber available. This phenomenon was exploited throughout the remainder of the thesis. Of particular significance was the considerable intra- and inter-specific variation in susceptibility of softwoods to C. acinaciformis and Mastotermes darwiniensis Froggatt. The sapwoods tested were susceptible, but the heartwoods were generally resistant to damage by termites. These data confirm that termites are discriminating feeders, and some more so than others. A novel methodology, developed to maintain an environment conducive to sustained foraging by termites during field-testing, is presented. Consistency in timber acceptance and susceptibility to termites is considered to be important in determining the frequency of inspection and the success of bait systems. I evaluate the termiticidal activity of the bait toxicants hexaflumuron and chlorfluazuron for the management of the subterranean termite C. acinaciformis in the field. The Sentricon Colony Elimination System with Baitube-devices containing 0.1% and 1% mass/mass (m/m) hexaflumuron bait toxicant in dry wood flour (Recruit) was successful in eliminating field colonies of C. acinaciformis. Similarly, the Exterra Termite Interception and Baiting System with cellulose-acetate powder containing either 0.05% m/m or 0.25% m/m chlorfluazuron (Requiem) eliminated C. acinaciformis. Indicators (including "dip-sticks") used to monitor colony health were reliable. By using C. acinaciformis, which builds mounds (epigeous nests) in northern Australia, I was able to avoid the use of multiple mark-release schemes to verify the effects of the bait toxicant on the termite colonies. Problems with multiple mark-release schemes, used elsewhere in the world, are discussed. I continued the focus on bait quality and placement by evaluating termite responses to two aspects of treated stakes, their attractiveness and their susceptibility. Three experiments were undertaken near Townsville and at Beerburrum, with Coptotermes and Schedorhinotermes. Whilst there were no significant differences in the rate of location and foraging, with respect to treatments, differences in foraging, with respect to C. acinaciformis and Schedorhinotermes seclusus (Hill) were significant. Coptotermes acinaciformis displayed greater foraging site tenacity than S. seclusus at Beerburrum. Increased consumption of bait, due to the addition of a phagostimulant, needs to be observed in the field before an increase in the efficacy of baits in a termite management program can be claimed. In Australia, softwood timbers are extensively used in building construction and are generally highly susceptible to damage by termites. I focussed on field feeding assays to test efficacy of borate-treated softwoods against termites and to define "adequate" protection thresholds. Laboratory and field data reported in the literature were confusing with regard to what constitutes "adequate" protection thresholds. The confusion was compounded by differences in termite species, timber species used and test methodology. Laboratory data indicated a borate loading of 0.5% m/m boric acid equivalent (BAE) would cause > 90% termite mortality and restrict mass loss in test specimens to 5%. Field data generally suggested that borate loadings in excess of 0.5% m/m BAE were required. The main contribution of the work to increasing our understanding of management options for termites in the built environment was in resolving the confusion between laboratory and field data for borate wood-preservatives. These apparently conflicting results were explained by the presence or absence of untreated feeder material in the test environment. In the absence of untreated feeder material, retention of 0.5% BAE provides adequate protection from Coptotermes sp., whereas in the presence of untreated feeder material, increased retentions are required. Furthermore, the retentions required increase with increased amounts of susceptible material. Some termites, Nasutitermes sp. and M. darwiniensis, for example, are borate-tolerant and borate wood-preservatives are not a viable management option. The lack of uniform standards for termite-test methodology and assessment criteria for efficacy across the world is recognized as a difficulty with research into the performance of wood preservatives with termites. The many variables in laboratory and field assays make "prescriptive" standards difficult to recommend. The use of "performance" standards to define efficacy criteria ("adequate" protection) is discussed. Whilst the majority of the work involves subterranean termites ("termites"), I examine the question of how to define a hardwood timber species as "not susceptible" to lyctine beetle damage. Aspects of the biology, behaviour and management of Lyctus brunneus (Stephens) are reviewed and a novel field sampling and testing protocol to establish lyctine susceptibility of timber species is presented. A sound understanding of the biology and behaviour of xylophagous insects in the field is essential to ensure that management options implemented in the built environment have a strong ecological basis. The success of this study in achieving stated aims, the need for further work and the implications for test methodologies in the field with practical relevance to infestations of xylophagous insects in the built environment are discussed.

Os objetivos do presente trabalho foram: avaliar o processo de biodeterioração do lenho das árvores de tipuana na cidade de São Paulo e relacionar as alterações da sua estrutura anatômica e propriedades físico-mecânicas com o seu risco de queda. Nos passeios públicos de regiões selecionadas da cidade, 1109 árvores de tipuana foram caracterizadas quanto às condições de entorno, estado geral, variáveis dendrométricas, biodeterioração externa e interna e o risco de queda, estimado com modelo de cálculo estrutural desenvolvido pelo IPT. A biodeterioração e os mecanismos de resistência das árvores foram avaliados ao nível macroscópico e microscópico. As alterações nas propriedades do lenho de tipuana foram analisadas por densitometria de raios X e pelos ensaios físico-mecânicos (densidade de massa aparente; resistência à flexão) e aplicado o método de elementos finitos para análise da distribuição de tensões no lenho. As árvores de tipuana de elevada idade não apresentaram sinais de declínio, embora com estado geral considerado como crítico, pelo plantio em locais indequados, manejo inapropriado e/ou ocorrência de injúrias. O lenho foi deteriorado por fungos apodrecedores, cupins-subterrâneos e brocas-de-madeira, sendo os fungos e cupins os principais organismos xilófagos, afetando a região do cerne; a associção entre os fungos, os cupins, as variáveis dendrométricas e o risco de queda foram estatisticamente significantes ao nível de 5 %. O cupim-subterrâneo Coptotermes gestroi ocorreu em elevados níveis de infestação nas árvores, sendo considerado, no entanto, como um organismo-praga secundário, fortemente associado com lenho previamente apodrecido por Ganoderma sp.. Os fungos apodrecedores ocorrentes foram classificados como de podridão branca e mole, sendo a primeira mais comum no cerne das árvores. Como mecanismo de resistência à biodeterioração observou-se a compartimentalização do lenho, caracterizada pelo acúmulo de extrativos nas células. Os fungos xilófagos causaram reduções significativas na densidade de massa aparente, tensão de ruptura à flexão estática e módulo de elasticidade em estágios incipiente e intenso de apodrecimento do lenho. Ruptura do tronco e o risco de queda das árvores de tipuana relacionaram-se, principalmente, com a intensidade da deterioração do lenho e com a sua dendrometria. A alteração da distribuição das tensões no lenho foi analisada em relação ao estágio, tamanho e localização da deterioração no tronco das árvores de tipuana. / The objectives of the present work were to evaluate the process of biodeterioration in the wood of tipuana trees in the city of São Paulo and to relate the alterations in the anatomical structures and physical and mechanical properties with there falling risk. In the sidewalks of selected regions of the city, 1109 trees were characterized taking into consideration aspects as surroundings, general conditions, dendrometric variables, external and internal biodeterioration and falling risk estimated by using a structural model developed by IPT. The biodeterioration and the resistance mechanisms of the trees were evaluated at a macro and microscopic levels. The alterations on the wood properties were analysed by X-rays densitometry and by performing physical and mechanical tests (specific gravity; bending resistance); the tension distribution in the wood was analyze by finite-elements method. The old aged trees encountered, did not show any sign of decline, eventhough, the general aspect of their surroundings was critical by the inadequate places they were planted; inappropriate management and/or occurrence of injuries. The trees had their trunks deteriorated by xylophagous organisms, mainly fungi and subterranean-termites, and some wood borer beetle too, which affected the heartwood. The association between the presence of the first two organinsms, the dendrometric variables and the risk of falling, was statistically significant at the 5% level. The infestation of the trees by the subterranean-termite Coptotermes gestroi was at high levels, however, it was considered as a secundary plague-organism, because its attack was strongly associated with the previously decayed heartwood by Ganoderma sp.. The decaying fungi observed were classified as white rot and soft rot, being the white rot more common in the heartwood of the trees. As a resistance mechanism of the trees against biodeterioration, it was observed the compartimentalization of the wood characterized by the accumulation of extractives in the cells. Decaying fungi caused significant reductions in the following wood properties: specific gravity, rupture strength to bending and modulus of elasticity either in incipient or intense decay. Trees trunk rupture and falling risk were associated mainly to biodeterioration intensity and dendrometric variables. The alteration of tension distribution in the wood was analyzed in relation to the stage, size and position of the deterioration in the wood of the trees.