Doctor of Philosophy(PhD) / The European red fox (Vulpes vulpes L.) is a well known predator of native species and domestic stock, and is recognised as one of Australia’s most devastating vertebrate pests. Current fox management relies heavily on poisoning using baits impregnated with sodium monofluoroacetate (1080). This reliance on 1080 is likely to continue given the lack of viable alternatives for controlling foxes, so that, in the meanwhile, it is important to improve the efficiency of the current techniques. Factors affecting the susceptibility of individual foxes to bait include their ability to locate it, as well as the bait’s palatability and toxicity. The economic costs associated with using different bait types, the pattern and density of their distribution will also affect the efficiency of control programs. It is essential to examine and refine all such issues to ensure efficient use of the 1080 baiting technique. This thesis focuses generally on problems associated with management of the fox in eastern Australia. More specifically, I investigate the factors affecting the efficiency of fox baiting practices on the central tablelands of New South Wales. The study was conducted largely on agricultural lands near the town of Molong (33010’ 37”S, 148087’15”E) on the central tablelands of New South Wales. This area was chosen as it is broadly representative, in terms of land use, of a large region of eastern Australia. The highly modified, predominantly agricultural landscapes near Molong are well suited to foxes, and conflict with the predominantly pastoral community means that fox management is widely undertaken. I determined the persistence of 1080 in two commonly used bait types, Foxoff® and chicken wingettes, under different climatic and rainfall conditions. The rate of 1080 degradation did not change significantly between the central tablelands and the relatively hotter and drier western slopes. Foxoff® baits remained lethal for longer than wingettes under all conditions, although their rate of degradation generally increased with increasing rainfall. I confirmed the presence of defluorinating micro-organisms in thesoils of eastern Australia for the first time, and suggest that, following removal from the bait, 1080 would not persist in the environment for long. Bait should be attractive and highly palatable to ensure that the target species will find and consume it upon discovery. Caching, where discovered food is removed but not immediately consumed, may potentially reduce the efficacy and cost-effectiveness of baiting campaigns. I quantified the caching of chicken wingette, day-old chick and Foxoff® baits by inserting transmitters into bait material and assessing whether it was eaten or cached following removal. The intensity of caching did not change significantly between seasons. Type of bait had the largest influence on caching intensity, with a greater percentage of non-toxic Foxoff® baits (66.9%) being cached than either wingettes (5.7%) or day-old chicks (4.5%). The percentage of toxic (1080) baits cached was even greater, suggesting that 1080 bait may be less palatable, and detectable to foxes. I also investigated the use of conditioned taste aversion to reduce multiple bait uptake by foxes. Levamisole, an illness-inducing chemical, was added to bait and the fate of removed bait was again monitored via radio-telemetry. Following consumption of a levamisole-treated bait, foxes avoided eating treated baits but consumed untreated baits. I concluded that a reduction in bait consumption was achieved through learned aversion to levamisole rather than via conditioned taste aversion to baits. Adding levamisole to baits, especially non-toxic bait such as rabies vaccines, could potentially be used to reduce bait monopolisation by individual foxes. Fox density and den site preferences were assessed by investigating the distribution and density of fox natal dens on one property (9.6 km2) over three consecutive years. A total of 9 natal dens were located in 2000 and 2001, declining to 6 in 2002. No preference was shown for den sites on the basis of habitat, slope or aspect, but more dens were located under, or adjacent to cover. Assuming that each natal den represents a breeding pair and that the population sex ratio did not differ from parity (1:1), the site contained a prebreeding density of 1.9 foxes/km2 in 2000 and 2001, and 1.25 foxes/km2 in 2002. Given that the mean number of cubs is 4.0, the post-breeding density was estimated at 5.6 and 3.75 foxes/km2 in 2000/2001 and 2002, respectively. The results demonstrated that high densities of foxes occur on agricultural lands. The success and likely accuracy of the technique to monitor fox density suggests that it may be used to calibrate more efficient abundance estimates that will be essential for the strategic management of foxes in future. Pest animal management strategies are traditionally assessed for their effectiveness, with less consideration being given to the efficiency or cost of achieving the desired effect. I used cost-effectiveness analyses to compare between different baiting strategies based on the longevity, palatability and handling/replacement costs associated with each bait type. The results indicated that, when measured on a total cost-per-bait-consumed basis, wingettes and day-old chicks were the most cost-effective baits for campaigns of up to 4 weeks duration. This demonstrates the importance of including the longevity, and particularly the palatability of bait, when assessing cost-effectiveness. However, it is recognised that other factors, including the consistency of dosage and uptake by nontarget species, may be equally or more important in deciding the appropriate baiting strategy. The spatial and temporal application of fox baiting in the region overseen by the Molong Rural Lands Protection Board was examined between January 1998 and December 2002 as a case study to evaluate the apparent effectiveness of cooperative management practices. Most landholders (78.8%) did not bait for foxes during this period. Based on known dispersal distances, the effect of fox immigration into baited areas was determined. The results indicated that no areas baited for foxes were separated by a sufficient buffer distance (>9.58 km) from unbaited areas to be protected from fox immigration. This suggests that, at current levels of coordination, the effectiveness of most baiting operations in eastern Australia is compromised over the long term by fox immigration. However, it is recognised that short-term reductions in fox density may sometimes be all that are required to reduce predation to acceptable levels, especially for seasonally-susceptible prey. Ultimately, the cost-effectiveness of control should be evaluated in terms of the response of the prey rather than that of the predator. This study has highlighted deficiencies in current ‘best-practice’ baiting techniques. Specific recommendations for current baiting practices, in addition to future research, are also given. In brief, these include minimising free-feed baiting, increasing the minimum distance between bait stations, and, where possible, presenting the most palatable bait. Continued research into conditioned taste aversion, aerial baiting, and techniques to reduce caching are recommended as potential techniques to improve the efficiency of baiting practices.

Doctor of Philosophy(PhD) / The European red fox (Vulpes vulpes L.) is a well known predator of native species and domestic stock, and is recognised as one of Australia’s most devastating vertebrate pests. Current fox management relies heavily on poisoning using baits impregnated with sodium monofluoroacetate (1080). This reliance on 1080 is likely to continue given the lack of viable alternatives for controlling foxes, so that, in the meanwhile, it is important to improve the efficiency of the current techniques. Factors affecting the susceptibility of individual foxes to bait include their ability to locate it, as well as the bait’s palatability and toxicity. The economic costs associated with using different bait types, the pattern and density of their distribution will also affect the efficiency of control programs. It is essential to examine and refine all such issues to ensure efficient use of the 1080 baiting technique. This thesis focuses generally on problems associated with management of the fox in eastern Australia. More specifically, I investigate the factors affecting the efficiency of fox baiting practices on the central tablelands of New South Wales. The study was conducted largely on agricultural lands near the town of Molong (33010’ 37”S, 148087’15”E) on the central tablelands of New South Wales. This area was chosen as it is broadly representative, in terms of land use, of a large region of eastern Australia. The highly modified, predominantly agricultural landscapes near Molong are well suited to foxes, and conflict with the predominantly pastoral community means that fox management is widely undertaken. I determined the persistence of 1080 in two commonly used bait types, Foxoff® and chicken wingettes, under different climatic and rainfall conditions. The rate of 1080 degradation did not change significantly between the central tablelands and the relatively hotter and drier western slopes. Foxoff® baits remained lethal for longer than wingettes under all conditions, although their rate of degradation generally increased with increasing rainfall. I confirmed the presence of defluorinating micro-organisms in thesoils of eastern Australia for the first time, and suggest that, following removal from the bait, 1080 would not persist in the environment for long. Bait should be attractive and highly palatable to ensure that the target species will find and consume it upon discovery. Caching, where discovered food is removed but not immediately consumed, may potentially reduce the efficacy and cost-effectiveness of baiting campaigns. I quantified the caching of chicken wingette, day-old chick and Foxoff® baits by inserting transmitters into bait material and assessing whether it was eaten or cached following removal. The intensity of caching did not change significantly between seasons. Type of bait had the largest influence on caching intensity, with a greater percentage of non-toxic Foxoff® baits (66.9%) being cached than either wingettes (5.7%) or day-old chicks (4.5%). The percentage of toxic (1080) baits cached was even greater, suggesting that 1080 bait may be less palatable, and detectable to foxes. I also investigated the use of conditioned taste aversion to reduce multiple bait uptake by foxes. Levamisole, an illness-inducing chemical, was added to bait and the fate of removed bait was again monitored via radio-telemetry. Following consumption of a levamisole-treated bait, foxes avoided eating treated baits but consumed untreated baits. I concluded that a reduction in bait consumption was achieved through learned aversion to levamisole rather than via conditioned taste aversion to baits. Adding levamisole to baits, especially non-toxic bait such as rabies vaccines, could potentially be used to reduce bait monopolisation by individual foxes. Fox density and den site preferences were assessed by investigating the distribution and density of fox natal dens on one property (9.6 km2) over three consecutive years. A total of 9 natal dens were located in 2000 and 2001, declining to 6 in 2002. No preference was shown for den sites on the basis of habitat, slope or aspect, but more dens were located under, or adjacent to cover. Assuming that each natal den represents a breeding pair and that the population sex ratio did not differ from parity (1:1), the site contained a prebreeding density of 1.9 foxes/km2 in 2000 and 2001, and 1.25 foxes/km2 in 2002. Given that the mean number of cubs is 4.0, the post-breeding density was estimated at 5.6 and 3.75 foxes/km2 in 2000/2001 and 2002, respectively. The results demonstrated that high densities of foxes occur on agricultural lands. The success and likely accuracy of the technique to monitor fox density suggests that it may be used to calibrate more efficient abundance estimates that will be essential for the strategic management of foxes in future. Pest animal management strategies are traditionally assessed for their effectiveness, with less consideration being given to the efficiency or cost of achieving the desired effect. I used cost-effectiveness analyses to compare between different baiting strategies based on the longevity, palatability and handling/replacement costs associated with each bait type. The results indicated that, when measured on a total cost-per-bait-consumed basis, wingettes and day-old chicks were the most cost-effective baits for campaigns of up to 4 weeks duration. This demonstrates the importance of including the longevity, and particularly the palatability of bait, when assessing cost-effectiveness. However, it is recognised that other factors, including the consistency of dosage and uptake by nontarget species, may be equally or more important in deciding the appropriate baiting strategy. The spatial and temporal application of fox baiting in the region overseen by the Molong Rural Lands Protection Board was examined between January 1998 and December 2002 as a case study to evaluate the apparent effectiveness of cooperative management practices. Most landholders (78.8%) did not bait for foxes during this period. Based on known dispersal distances, the effect of fox immigration into baited areas was determined. The results indicated that no areas baited for foxes were separated by a sufficient buffer distance (>9.58 km) from unbaited areas to be protected from fox immigration. This suggests that, at current levels of coordination, the effectiveness of most baiting operations in eastern Australia is compromised over the long term by fox immigration. However, it is recognised that short-term reductions in fox density may sometimes be all that are required to reduce predation to acceptable levels, especially for seasonally-susceptible prey. Ultimately, the cost-effectiveness of control should be evaluated in terms of the response of the prey rather than that of the predator. This study has highlighted deficiencies in current ‘best-practice’ baiting techniques. Specific recommendations for current baiting practices, in addition to future research, are also given. In brief, these include minimising free-feed baiting, increasing the minimum distance between bait stations, and, where possible, presenting the most palatable bait. Continued research into conditioned taste aversion, aerial baiting, and techniques to reduce caching are recommended as potential techniques to improve the efficiency of baiting practices.

In Western Australia dried meat baits containing 1080 are used extensively by agricultural and conservation organisations to control foxes and dingoes for the protection of agricultural production and native fauna. Field trials were conducted to assess 1080 loss from dried meat baits and this required the analysis of over five hundred baits. Because of this large number of baits it was essential to have a simple and efficient 1080 extraction procedure and method of 1080 analysis. In this study three methods of 1080 extraction and the new bioassay method for 1080 analysis were investigated. A simple and cost-effective 1080 extraction method using water with a 98% 1080 recovery rate was developed and modifications to the bioassay method were made.Factory-produced 1080 dried meat baits were laid in the field during different seasons at four locations in Western Australia, samples were collected over time and analysed for 1080 content using the bioassay. Rainfall was recorded and temperature data was collected for each site. Baits were exposed to the elements but were placed in mesh or wire cages to restrict invertebrate attack and prevent removal by vertebrates. Some baits were placed on the surface and others were buried. Initially 1080 loss from baits from all 4 sites was minimal, ranging from 0 - 21% at day 7 - 9. Further loss was gradual even when rainfall was recorded. Generally baits had to be exposed to at least 50 mm of rain before 1080 loss increased to 50%. At some sites baits continued to remain toxic to foxes even after long exposure. The mean 1080 content of baits from the Carnarvon site at day 226 was 2.0 mg (55% of the mean 1080 content of baits at day zero) with 137 mm of rainfall recorded for that period. Loss of 1080 from baits buried occurred at a faster rate than from baits placed on the surface during the same time period. By day 14 no 1080 was ++ / detected in the buried baits compared to the 68% detected in the surface baits. Under certain conditions 1080 loss from baits was minimal. Levels of 1080 in baits from Nangeen Hill remained fairly constant during the months of September to December 1995, and again during February to April 1996.Gastrolobium plant tissue and soil samples from the southwest of Western Australia were investigated for the presence of 1080 degrading microorganisms. Microbes were isolated and individually tested in solution containing 1080 as the sole carbon source. Isolates which showed 1080 degrading ability were further tested for their degrading efficiency in McClung carbon-free solution with added 1080 as the sole source of carbon and in factory 1080 waste solution, at 1080 concentrations of 20 and 200 mM. The effect of temperature on their rate of degradation was also examined. Thirteen isolates (7 fungi and 6 bacteria) showing varying degrees of 1080 degrading ability were obtained. Rates of 1080 degradation varied among isolates but were highest in the factory waste solution at the 20 mM concentration and in the McClung solution, where 1080 was the sole source of carbon, at the higher concentration of 200 mM. The most efficient isolates OSK and 10H (both Pseudomonas species) degraded all the 1080 present in sterile factory waste solution up to 20 mM 1080 concentration in 4 days and the isolate 1AF (Fusarium oxysporum) degraded 93% of 200 mM 1080 in the McClung solution in 9 days. The optimum temperatures for 1080 degradation were 30 degrees celsius and fluctuating ambient temperatures of 15 28 degrees celsius.

Commercial termite baiting systems were utilized and evaluated under real-world conditions in order to provide a comparison of efficacy in the management of subterranean termites. Three commercial termite baiting systems available for comparison included: FirstLine® (FMC Corp.), Sentricon® (Dow AgroSciences), and Terminate® (United Industries, Inc). The time required for foraging termites to locate and begin feeding on both the Sentricon® and the Terminate® bait stations was approximately one-half the time required to locate and begin feeding on the FirstLine® system, for both R. flavipes and C. formosanus. The time required for C. formosanus to locate and begin feeding on all termite baiting systems was approximately one-half the time required for R. flavipes. There were no significant differences in efficacy between the three baiting treatment systems against R. flavipes, with a mean of 84% efficacy for all systems. The Sentricon® system was able to achieve efficacy (88%) results with few additional residual liquid termiticide treatments. FirstLine® efficacy (80%) and Terminate® efficacy (84%) results required initial and subsequent multiple spot treatments with residual termiticide for comparable results. The Sentricon® baiting system yielded positive results in the management of C. formosanus, if utilized in an aggressive, active management program, involving multiple supplementary in-ground and above-ground bait stations at both points of active infestation and at areas with conditions conducive to infestation. Optimum results were achieved when monitoring of the bait stations occurred twice each month, rather than the standard monthly monitoring regime. The two termite baiting systems with Sulfluramid as the active ingredient required spot treatments with termiticides in order to protect the structures. Grids of bait stations were installed and termite activity and foraging strategies were monitored for a five-year period. Treatment with sulfluramid required 472 active ingredient tubes, over a 37-month period, in order to reduce subterranean termite populations. Observations of seasonal variation and spatial patterns of foraging by native subterranean termites, R. flavipes, in a typical urban/suburban setting provided information with direct application to an effective termite baiting system program.

Commercial termite baiting systems were utilized and evaluated under real-world conditions in order to provide a comparison of efficacy in the management of subterranean termites. Three commercial termite baiting systems available for comparison included: FirstLine® (FMC Corp.), Sentricon® (Dow AgroSciences), and Terminate® (United Industries, Inc). The time required for foraging termites to locate and begin feeding on both the Sentricon® and the Terminate® bait stations was approximately one-half the time required to locate and begin feeding on the FirstLine® system, for both R. flavipes and C. formosanus. The time required for C. formosanus to locate and begin feeding on all termite baiting systems was approximately one-half the time required for R. flavipes. There were no significant differences in efficacy between the three baiting treatment systems against R. flavipes, with a mean of 84% efficacy for all systems. The Sentricon® system was able to achieve efficacy (88%) results with few additional residual liquid termiticide treatments. FirstLine® efficacy (80%) and Terminate® efficacy (84%) results required initial and subsequent multiple spot treatments with residual termiticide for comparable results. The Sentricon® baiting system yielded positive results in the management of C. formosanus, if utilized in an aggressive, active management program, involving multiple supplementary in-ground and above-ground bait stations at both points of active infestation and at areas with conditions conducive to infestation. Optimum results were achieved when monitoring of the bait stations occurred twice each month, rather than the standard monthly monitoring regime. The two termite baiting systems with Sulfluramid as the active ingredient required spot treatments with termiticides in order to protect the structures. Grids of bait stations were installed and termite activity and foraging strategies were monitored for a five-year period. Treatment with sulfluramid required 472 active ingredient tubes, over a 37-month period, in order to reduce subterranean termite populations. Observations of seasonal variation and spatial patterns of foraging by native subterranean termites, R. flavipes, in a typical urban/suburban setting provided information with direct application to an effective termite baiting system program.

No description available.

This study examines an aspect of earnings management that I refer to as audit management. I define audit management as a client's strategic use of techniques (e.g., baiting tactics) to prevent auditors from discovering earnings management during the audit. Specifically, I examine whether two baiting tactics, diversionary statements and distracting errors, affect an auditor's ability to uncover an accounting error used to manage earnings. Auditors performed analytical review on financial statements that contained an earnings management error (i.e., an intentional error that results in the client meeting an earnings target). I manipulated whether management provided a diversionary statement that explicitly identified risk in other areas of the audit, and whether management seeded easier, distracting errors into those other areas, both of which were designed to lure the auditor away from the earnings management error. I found that when auditors were intentionally directed to error free accounts they were unlikely to uncover an earnings management error elsewhere in the financial statements. On the other hand, auditors were most accurate in identifying earnings management when they were directed to audit areas that contained distracting errors. These results suggest that managers can use certain baiting tactics to strategically manage the outcome of the audit, but that, in some circumstances, baiting tactics may actually make auditors more likely to uncover managed earnings.

Baiting with sodium monofluoroacetate (1080) to protect lambs (Ovis aries) from red foxes (Vulpes vulpes L.) has become more frequent in NSW and other parts of Australia during the last 10 years despite the lack of reported evidence evaluating the effects of fox baiting on lamb survival. NSW Agriculture has developed fox control recommendations aimed at minimising impact, but these guidelines have not been tested experimentally. Defining the extent of a pest problem and the effectiveness of pest control are key components of a strategic approach to vertebrate pest management as it is the damage of pests that justifies their control. This thesis describes an experimental evaluation of the recommended practice of fox control in NSW. The effects of three levels of fox control were tested in the experiment; no treatment, baiting once a year before lambing (the recommended practice) and baiting three times a year (thought to be the maximum farmers would instigate). Each treatment had two replicates. No previous manipulative experiment using synchronous controls and matched replicates has been undertaken to test the effects. The study quantifies the level of fox predation on healthy lambs and the level of predation on lambs that had other causes including illness and mismothering contributing to this fox predation. It also examines the response of the fox population, lamb predation and lambing outcomes to different levels of fox control. The cost effectiveness of fox control is examined in relation to lamb predation and an investigation of the optimum level of fox control is begun. The experiment also provides the first chance to consider the examination of multiple response variables and the scale of field ecology experiments required to recognise a significant response and avoid a Type II error due to between replicate variability even with tightly controlled site selection criteria to standardise experimental sites, and with the synchrony of experimental control and treatment surveys. The study occurred on five sheep properties near Boorowa (34°28'S, 148°32'E) and Murringo (34°18'S, 148°3 1'E) in south-eastern Australia. The terrain was undulating to hilly with a maximum elevation of 660 m above sea level. The main agricultural enterprises in the district are Merino wool, fat lamb and beef cattle production and winter cereal cropping. The native vegetation of Eucalyptus woodland has been mostly cleared, though remnant patches occur. Most of the area is now sown with pasture of Phalaris tuberosa, Lolium spp. and clover Trifolium spp.. The experimental properties grazed self-replacing Merino flocks, primarily for wool production, so lamb survival was vital to the economic operation of the farm. Over 50 selection criteria including lamb survival rates, ewe fertility and bloodline, sheep management practices, climate and habitat features that affect lamb survival, past fox control practices and prey species were used to select sites Sites were representative of most sheep farming properties in the region, but were also extremely similar in factors that affected fox abundance and ewe and lamb survival, thus minimising variation between replicate sites. The manufactured meat baits used to poison foxes contained 3 mg of sodium monofluoroacetate (compound 1080). A replacement baiting program was carried out in 1995 and 1996. Fox control programs were carried out over the experimental units and adjacent buffer zones covering approximately two fox territories, approximately 6km2, around the lambing paddock under study. The recommended fox control practices described by NSW Agriculture also included neighbouring farmers taking part in an extended group baiting program. In all the area baited at varying intensities totalled 3400 km2. Synchronised lambing with neighbours was a further recommended practice to reduce fox predation and was carried out on these sites. Lambing occurred during a six to eight week period in late winter on all sites, a practice known as 'spring lambing', and on many surrounding properties so a surplus of lambs was available to foxes over a relatively short time. The benefits of fox control were measured directly as enhanced lamb survival derived from differences in lamb marking rates between ultrasounded flocks of approximately 1000 ewes and the predation of lambs was measured from over 2000 lamb carcases post-mortemed in 1994, 1995 and 1996. A mean of 138 lambs were expected at ultrasounding from 100 ewes and 113 lambs per 100 ewes were alive at lamb marking. There was no significant (P>0.05) effect of fox control on lambing performance (the number of lambs per 100 ewes that lambed) Fox predation was inferred as the cause of lamb death in a minimum of 0.8% and a maximum of 5.3% of lamb carcases during 1995 and 1996. There was a significant (P<0 05) effect of fox control on the minimum possible percentage of lamb carcases classified as healthy lambs killed by foxes, with the percentage declining from 1.50% (no fox control), to 0.90% (fox control once per year) to 0.25% (fox control three times per year). There was also a significant (P<0.005) effect of fox control on the maximum possible percentage of lamb carcases classified as healthy lambs killed by foxes with the percentage declining from 10.25% (no fox control), to 6.50% (fox control once per year) to 3.75% (fox control three times per year). The observed results were used to estimate the number of treatment replicates needed to be confident of detecting an effect of predator control on lamb marking performance. The estimated numbers were very high if small effects were to be detected. No significant correlation between the fox density and the minimum and maximum possible number of lambs carcases classified as killed by foxes was found. Bait uptake was monitored as were the costs of fox control.

The growing demand for strawberries has imposed challenges, especially regarding the control of pests. Many farmers report problems with reduced chemical control efficiency, probably due to selection of resistant populations of insects and mites. An alternative is the use of biological control using pathogenic fungi as a tool in integrated pest management. Metarhizium spp. (Hypocreales: Clavicipitaceae) are generalist entomopathogenic fungi with worldwide distribution and can cause diseases in a large number of hosts. Many studies on the development of Metarhizium as a biological control agent were performed, but this bulk of knowledge is in remarkable contrast to the lack of research on the fundamental ecology of Metarhizium in agroecosystems. This thesis aimed to evaluate the establishment, persistence and dispersal of these entomopathogenic fungi in strawberry crop soil in Inconfidentes, Minas Gerais, Brazil; and to study the diversity and abundance of species of Metarhizium isolated from organic and conventional strawberry crop soils, and the field margins in Brazil and Denmark. The effectiveness of new species of Metarhizium recently found in Brazil, was evaluated against two spotted spider mite, Tetranychus urticae. Applied isolates of M. anisopliae (ESALQ1037) and M. robertsii (ESALQ1426) were able to persist for up to 12 months after the application within the soil, and disperse to other plots and colonize the rhizosphere of strawberry plants. In the plots where ESALQ1037 and ESALQ1426 were applied, 25% and 87.5% of the isolates recovered after 12 months consisted of the same isolates inoculated. A new taxonomically unassigned lineage, referred to as Metarhizium sp. Indet. 5 in this study, was found in strawberry crop margins. The dominant species of Metarhizium in Brazil and Denmark was Metarhizium robertsii and M. brunneum respectively. Further, Metarhizium pemphigi was first detected in Denmark in this study. Soil in organically grown strawberries harbored a more diverse population of Metarhizium spp. compared with conventionally grown strawberries. These studies showed for the first time the potential of new species of Metarhizium as spider mite biological control agents, the lowest median lethal time (LT50 = 4 ± 0.17 days) was observed in mites treated with the isolate ESALQ1638 of Metarhizium sp. indet. 1. The best isolates were ESALQPL63 of B. bassiana, ESALQ1608 and ESALQ1638 of Metarhizium sp. indet. 1 and ESALQ3069 and ESALQ3222 of M. pingshaense based on the survival curve, total mortality, percentage of sporulated cadavers and LT50. Knowledge of the diversity of Metarhizium spp. and persistence in strawberry soil generated in this study may be useful in developing conservation strategies and maximize the natural biological pest control. / A crescente demanda por morangos vem impondo desafios, especialmente quanto ao controle das pragas. Muitos agricultores relatam problemas com a redução da eficiência do controle químico, provavelmente devido à seleção de populações resistentes de insetos e ácaros. Uma alternativa é o uso de controle biológico com fungos entomopatogênicos como ferramenta dentro do manejo integrado de pragas. Metarhizium spp. (Hypocreales: Clavicipitaceae), são fungos entomopatogênicos generalistas com distribuição cosmopolita e que podem causar doenças em um grande número de hospedeiros. Muitos estudos sobre o desenvolvimento de Metarhizium como agente de controle biológico foram realizados, mas este leque de conhecimento está em contraste com a notável falta de investigação sobre a ecologia de Metarhizium nos agroecossistemas. Esta tese teve como objetivo avaliar o estabelecimento, persistência e dispersão destes fungos entomopatogênicos em solo de morangueiro em Inconfidentes, Minas Gerais, Brasil; bem como estudar a diversidade e abundância de espécies de Metarhizium isolados do solo de cultivos orgânico e convencional de morangueiro, e das margens das plantações no Brasil e Dinamarca. A eficácia de novas espécies de Metarhizium, encontradas recentemente no Brasil, foi avaliada contra o ácaro rajado, Tetranychus urticae. Os isolados inoculados de M. anisopliae (ESALQ1037) e M. robertsii (ESALQ1426) foram capazes de persistir por até 12 meses após a aplicação no solo, além de dispersar para outras parcelas e colonizar a rizosfera dos morangueiros. Nas parcelas onde ESALQ1037 e ESALQ1426 foram aplicados, 25% e 87,5% dos isolados recuperados após 12 meses consistiam dos mesmos isolados inoculados. Uma nova linhagem não taxonomicamente identificada, referida neste trabalho como Metarhizium sp. Indet. 5, foi encontrada nas margens de morangueiros cultivados. A espécie dominante de Metarhizium no Brasil e Dinamarca foi Metarhizium robertsii e M. brunneum, respectivamente. Além disso, Metarhizium pemphigi foi detectado pela primeira vez na Dinamarca neste estudo. Solos de cultivo orgânico de morangueiro em geral apresentaram uma diversidade maior de Metarhizium do que solos de cultivos convencionais. Estes estudos revelaram pela primeira vez o potencial de novas espécies de Metarhizium como agentes de controle biológico do ácaro rajado, sendo o menor tempo letal mediano (TL50= 4 ± 0.17 dias) observado em ácaros tratados com o isolado ESALQ1638 de Metarhizium sp. indet. 1. Os melhores isolados foram ESALQPL63 de B. bassiana, ESALQ1608 e ESALQ1638 de Metarhizium sp. indet. 1 e ESALQ3069 e ESALQ3222 de M. pingshaense baseado na curva de sobrevivência, mortalidade total, porcentagem de cadáveres esporulados e TL50. O conhecimento da diversidade de Metarhizium spp. e persistência em solos de morango, gerados neste estudo, poderão ser úteis no desenvolvimento de estratégias de conservação e maximizar o controle biológico natural de pragas.

The growing demand for strawberries has imposed challenges, especially regarding the control of pests. Many farmers report problems with reduced chemical control efficiency, probably due to selection of resistant populations of insects and mites. An alternative is the use of biological control using pathogenic fungi as a tool in integrated pest management. Metarhizium spp. (Hypocreales: Clavicipitaceae) are generalist entomopathogenic fungi with worldwide distribution and can cause diseases in a large number of hosts. Many studies on the development of Metarhizium as a biological control agent were performed, but this bulk of knowledge is in remarkable contrast to the lack of research on the fundamental ecology of Metarhizium in agroecosystems. This thesis aimed to evaluate the establishment, persistence and dispersal of these entomopathogenic fungi in strawberry crop soil in Inconfidentes, Minas Gerais, Brazil; and to study the diversity and abundance of species of Metarhizium isolated from organic and conventional strawberry crop soils, and the field margins in Brazil and Denmark. The effectiveness of new species of Metarhizium recently found in Brazil, was evaluated against two spotted spider mite, Tetranychus urticae. Applied isolates of M. anisopliae (ESALQ1037) and M. robertsii (ESALQ1426) were able to persist for up to 12 months after the application within the soil, and disperse to other plots and colonize the rhizosphere of strawberry plants. In the plots where ESALQ1037 and ESALQ1426 were applied, 25% and 87.5% of the isolates recovered after 12 months consisted of the same isolates inoculated. A new taxonomically unassigned lineage, referred to as Metarhizium sp. Indet. 5 in this study, was found in strawberry crop margins. The dominant species of Metarhizium in Brazil and Denmark was Metarhizium robertsii and M. brunneum respectively. Further, Metarhizium pemphigi was first detected in Denmark in this study. Soil in organically grown strawberries harbored a more diverse population of Metarhizium spp. compared with conventionally grown strawberries. These studies showed for the first time the potential of new species of Metarhizium as spider mite biological control agents, the lowest median lethal time (LT50 = 4 ± 0.17 days) was observed in mites treated with the isolate ESALQ1638 of Metarhizium sp. indet. 1. The best isolates were ESALQPL63 of B. bassiana, ESALQ1608 and ESALQ1638 of Metarhizium sp. indet. 1 and ESALQ3069 and ESALQ3222 of M. pingshaense based on the survival curve, total mortality, percentage of sporulated cadavers and LT50. Knowledge of the diversity of Metarhizium spp. and persistence in strawberry soil generated in this study may be useful in developing conservation strategies and maximize the natural biological pest control. / A crescente demanda por morangos vem impondo desafios, especialmente quanto ao controle das pragas. Muitos agricultores relatam problemas com a redução da eficiência do controle químico, provavelmente devido à seleção de populações resistentes de insetos e ácaros. Uma alternativa é o uso de controle biológico com fungos entomopatogênicos como ferramenta dentro do manejo integrado de pragas. Metarhizium spp. (Hypocreales: Clavicipitaceae), são fungos entomopatogênicos generalistas com distribuição cosmopolita e que podem causar doenças em um grande número de hospedeiros. Muitos estudos sobre o desenvolvimento de Metarhizium como agente de controle biológico foram realizados, mas este leque de conhecimento está em contraste com a notável falta de investigação sobre a ecologia de Metarhizium nos agroecossistemas. Esta tese teve como objetivo avaliar o estabelecimento, persistência e dispersão destes fungos entomopatogênicos em solo de morangueiro em Inconfidentes, Minas Gerais, Brasil; bem como estudar a diversidade e abundância de espécies de Metarhizium isolados do solo de cultivos orgânico e convencional de morangueiro, e das margens das plantações no Brasil e Dinamarca. A eficácia de novas espécies de Metarhizium, encontradas recentemente no Brasil, foi avaliada contra o ácaro rajado, Tetranychus urticae. Os isolados inoculados de M. anisopliae (ESALQ1037) e M. robertsii (ESALQ1426) foram capazes de persistir por até 12 meses após a aplicação no solo, além de dispersar para outras parcelas e colonizar a rizosfera dos morangueiros. Nas parcelas onde ESALQ1037 e ESALQ1426 foram aplicados, 25% e 87,5% dos isolados recuperados após 12 meses consistiam dos mesmos isolados inoculados. Uma nova linhagem não taxonomicamente identificada, referida neste trabalho como Metarhizium sp. Indet. 5, foi encontrada nas margens de morangueiros cultivados. A espécie dominante de Metarhizium no Brasil e Dinamarca foi Metarhizium robertsii e M. brunneum, respectivamente. Além disso, Metarhizium pemphigi foi detectado pela primeira vez na Dinamarca neste estudo. Solos de cultivo orgânico de morangueiro em geral apresentaram uma diversidade maior de Metarhizium do que solos de cultivos convencionais. Estes estudos revelaram pela primeira vez o potencial de novas espécies de Metarhizium como agentes de controle biológico do ácaro rajado, sendo o menor tempo letal mediano (TL50= 4 ± 0.17 dias) observado em ácaros tratados com o isolado ESALQ1638 de Metarhizium sp. indet. 1. Os melhores isolados foram ESALQPL63 de B. bassiana, ESALQ1608 e ESALQ1638 de Metarhizium sp. indet. 1 e ESALQ3069 e ESALQ3222 de M. pingshaense baseado na curva de sobrevivência, mortalidade total, porcentagem de cadáveres esporulados e TL50. O conhecimento da diversidade de Metarhizium spp. e persistência em solos de morango, gerados neste estudo, poderão ser úteis no desenvolvimento de estratégias de conservação e maximizar o controle biológico natural de pragas.