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No description available.

The larvae (wireworms) of some click beetle genera inhabit the soil in agricultural land and are crop pests. In the UK, a pest complex of Agriotes species, A. obscurus, A. sputator and A. lineatus, has been identified as the cause of the majority of damage. However, studies on their ecology are lacking, despite knowledge of this being important for the development of sustainable risk assessment and pest management strategies, in part due to the morphologically cryptic nature of wireworms. The ecology of economically important click beetle species was investigated, focusing on UK Agriotes species. The relationship between sex pheromone trapped male Agriotes adults and wireworms, identified using a molecular tool (T‐RFLP), was influenced by sampling method, and some environmental variables significantly correlated with species distributions. Scale of sampling influenced the observed distribution of wireworms and other soil insect larvae. Other wireworm species were trapped together with Agriotes species, but mitochondrial 16S rRNA sequences could not be matched to those of other UK species. Sequences from Canadian wireworm samples revealed possible cryptic species. Differences in adult movement rates were found in laboratory tests (A. lineatus > A. obscurus > A. sputator). Molecular markers (AFLPs) were developed to assess dispersal in adult male Agriotes but further protocol optimisation is required. The results show the importance of identifying wireworms to species for assessing adult and wireworm distributions, since the Agriotes pest complex may not be present or as 3 widespread as previously assumed. Sex pheromone trapping of adults may not be appropriate for risk assessment as the relationship between aboveground adult and belowground wireworm species distribution is not straightforward. The differences observed in Agriotes species’ ecology have implications for the implementation of pest management strategies. The techniques used here can be applied in future studies to provide information on other economically important click beetle species worldwide.

Management of pest species is ordinarily required in the production of protected crops. Integrated pest management (IPM) is commonly used when controlling insects. The European Union Sustainable Use Directives states that "integrated pest management’ means careful consideration of all available plant protection methods and subsequent integration of appropriate measures that discourage the development of populations of harmful organisms and keep the use of plant protection products and other forms of intervention to levels that are economically and ecologically justified and reduce or minimise risks to human health and the environment. ‘Integrated pest management’ emphasises the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms.” Effectively monitoring pests is a key component of IPM, with decisions to use biological control agents (BCA) and insecticides often based on the presence of pests in traps. A commonly used monitoring tool is the sticky trap; these traps are coloured and rely primarily on their visual attractiveness to the pest. The capture efficiency of sticky traps can potentially be increased with the addition of light emitting diodes (LEDs). The objective of this project was to use LEDs to enhance the efficacy of yellow sticky traps for trapping a range of insect pests, to enable more effective timing of pest management by optimising pest monitoring. The addition of LEDs may also enable more effective mass trapping via yellow sticky traps, and minimize the trapping of beneficial insects. Comparisons between standard yellow sticky traps and those equipped with green (540 nm) or blue (480 nm) LEDs were carried out at four commercial growing facilities. Green (540 nm) LED equipped traps were compared with standard yellow traps in a mass release of the biological control agent Encarsia formosa Gahan (Hymenoptera: Aphelinidae), to determine if there are negative consequences to the addition of green (540 nm) LEDs when using this biological control agent. Relative spectral preferences of western flower thrips (Frankliniella occidentalis Pergande (Thysanoptera: Thripidea)) and Glasshouse whitefly (Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae)) were determined using a choice test comparing a range of wavelengths in 20 nm steps against a control wavelength. Green (540 nm), and blue (480 nm) LED equipped traps captured significantly more dark-winged fungus gnats (Bradysia difformis Frey (Sciaridae: Diptera)) and diamondback moths (Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae)) than those without. No significant differences were found between green (540 nm) LED equipped traps and those without for E. formosa, and a significant decrease in the capture of the shore fly parasitoid Kleidotoma psiloides Westwood (Hymenoptera: Figitidae) was observed. In behavioural experiments F. occidentalis showed a peak spectral preference at 360, 420, and 480 nm, and T. vaporariorum at 320, 340, and 380 nm. The addition of LEDs to yellow sticky traps enhanced their capture efficiency for some key pests in commercial protected crop growing environments, and has the potential to enable pest detection at an early stage, consequently optimising the timing of pest management options.

Orientador: Carlos Gilberto Raetano / Banca: Vilson Luís Kunz / Banca: Fernando Cesar Bauer / Banca: Marcelo da Costa Ferreira / Banca: Carlos Frederico Wilcken / Resumo: O controle químico de pragas e doenças é uma prática imprescindível no manejo fitossanitário do algodoeiro para a redução das perdas de produtividade. Com o intuito de promover o uso racional dos produtos fitossanitários nessa cultura, esse trabalho teve por objetivo comparar três tecnologias de pulverização: assistida por ar, assistida por ar associada a gotas com carga elétrica e convencional (sem ar e carga elétrica) combinadas aos volumes de 50 e 100L.ha-1, sobre a deposição e cobertura da pulverização, controle de insetos pragas e doenças e produtividade da cultura do algodão. Os experimentos foram conduzidos no delineamento de blocos ao acaso com seis tratamentos e quatro repetições para avaliação da deposição, cobertura e controle de pragas e doenças. As pulverizações foram realizadas em dois estádios de desenvolvimento das plantas conduzidas nos espaçamentos de 0,45 m e 0,90 m entre linhas de semeadura da cultura. Para isso, utilizou-se um pulverizador autopropelido equipado com pontas de pulverização de jato cônico vazio, JA-1 (50L.ha-1) e JA-2 (100L.ha-1) na pressão de 828 kPa. Foi avaliado o efeito das respectivas tecnologias no controle de Pseudoplusia includens, Bemisia tabaci, Aphis gossypii, Spodoptera spp. e Thrips spp. e da doença fúngica Ramularia areola durante todo o ciclo de desenvolvimento da cultura, bem como a produtividade do algodoeiro no sistema de cultivo convencional. As dimensões das parcelas foram 24 m de largura x 100 m de comprimento em ambos os sistemas de semeadura, para os ensaios de deposição e cobertura. Para avaliação da deposição e cobertura foram escolhidas, ao acaso, 10 plantas e, de cada uma delas removida uma folha do ápice e outra folha da base da planta / Abstract: Chemical control has been an essential practice on the pest management of cotton crop to reduce productivity losses. In order to promote rational use of pesticides, this work was aimed to compare three spray technologies: air-assisted, assisted by air associated with electrically charged droplets and conventional spraying (without air and electric charge) combined with volume rates of 50 and 100L.ha-1, on spray deposition, coverage and in the effect of control insect pests and disease. The trials were conducted in a randomized blocks design with six treatments and four replications for evaluation of the deposition, coverage and effect on pests and disease. The spraying was carried out on two growth stages of plants conducted in spacing of 0.45 m and 0.90 m between plant rows of culture. For this, were used a self-propelled sprayer equipped with spray nozzles hollow cone, JA-1 (50L.ha-1) and JA-2 (100L.ha-1) at 828 kPa of work pressure. The effect of these technologies was evaluated on controlling of Pseudoplusia includens, Bemisia tabaci, Aphis gossypii, Spodoptera spp. and Thrips spp. and a fungal disease Ramularia areola all the development cycle of the culture as well as the yield in conventional tillage. The dimensions of the plots were 24 m wide x 100 m length in both sowing systems for deposition and coverage tests. To evaluate the deposition and coverage were selected at random 10 plants and, of each one removed one leaf from the apex and another leaf of the lower part of plant. The tracer dye Brilliant Blue FD & C No. 1 (0.3%), fluorescent pigment ColorLight (0.15%) and Lignosulfonate Vixilperse (0.015%) were the tracer mixture. In experiments in which we evaluated the effect of the treatments on controlling pests and disease, were installed plots of 24 m wide x 250 m length and then weekly samplings were carried out as required spraying / Doutor

Resumo: A soja se destaca com um dos principais produtos do agronegócio brasileiro. No entanto, o ataque de insetos desfolhadores como Anticarsia gemmatalis comprometem a produtividade. O controle dessa praga é baseado na aplicação de inseticidas químicos e no uso de plantas Bt. Contudo, a seleção de populações resistentes é uma séria limitação para o manejo dessa praga. Em vista disso, torna-se necessário um sistema de manejo que também auxilie a retardar a evolução da resistência. Uma alternativa é o uso de agentes de controle microbiano, com o uso de bioinseticidas à base da bactéria Bacillus thuringiensis (Bt). Entretanto, a principal limitação do uso desses bioinseticidas é elevada sensibilidade a fatores climáticos, como radiação UV, temperatura e umidade. A maioria dos estudos disponíveis sobre persistência de Bt são antigos e foram realizados no hemisfério Norte em espécies ornamentais e florestais, onde as condições climáticas diferem do hemisfério Sul. Os bioinseticidas a base de Bt são utilizados em todo o mundo, visando o controle de pragas agrícolas. Dentre as suas principais vantagens em relação aos inseticidas convencionais se destacam a seletividade aos inimigos naturais e risco reduzido ao meio ambiente. Apesar de algumas limitações, esses bioinseticidas foram muito importantes para suprimir surtos recentes de lepidópteros praga no Brasil, onde os inseticidas convencionais falharam. Diante disso, faz-se necessário estudos de persistência em condições de campo. Os ens... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The soybean stands out as one of the main products of Brazilian agribusiness. However the attack of defoliating insects such as Anticarsia gemmatalis compromises productivity. Control of this pest is based on the application of chemical insecticides and the use of Bt plants. However, the selection of resistant populations is a serious limitation for the management of this pest. Given this, a management system that also helps to retard the evolution of resistance becomes necessary. An alternative is the use of microbial control agents with the use of Bacillus thuringiensis (Bt) -based Biopesticide. However, the main limitation of the use of these bioinsecticides is their high sensitivity to climatic factors such as UV radiation, temperature, and humidity. Most of the available studies on Bt persistence are old and have been carried out in the northern hemisphere on ornamental and forest species, where climatic conditions differ from the southern hemisphere. Bt B. thuringiensisbased Bioinsecticides are used worldwide to agricultural pest control. Among its main advantages over conventional insecticides are selectivity to natural enemies and reduced risk to the environment. Despite some limitations, these bioinsecticides have been very important in suppressing recent outbreaks of pest Lepidoptera in Brazil, where conventional insecticides have failed. Therefore, persistence studies under field conditions are necessary. Field Bt persistence tests were conducted on soybean crop in... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:34:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-19Bitstream added on 2014-06-13T19:44:45Z : No. of bitstreams: 1 serra_me_dr_botfca.pdf: 858146 bytes, checksum: 84a2ab1f09b242594389dd1466b66b56 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O controle químico de pragas e doenças é uma prática imprescindível no manejo fitossanitário do algodoeiro para a redução das perdas de produtividade. Com o intuito de promover o uso racional dos produtos fitossanitários nessa cultura, esse trabalho teve por objetivo comparar três tecnologias de pulverização: assistida por ar, assistida por ar associada a gotas com carga elétrica e convencional (sem ar e carga elétrica) combinadas aos volumes de 50 e 100L.ha-1, sobre a deposição e cobertura da pulverização, controle de insetos pragas e doenças e produtividade da cultura do algodão. Os experimentos foram conduzidos no delineamento de blocos ao acaso com seis tratamentos e quatro repetições para avaliação da deposição, cobertura e controle de pragas e doenças. As pulverizações foram realizadas em dois estádios de desenvolvimento das plantas conduzidas nos espaçamentos de 0,45 m e 0,90 m entre linhas de semeadura da cultura. Para isso, utilizou-se um pulverizador autopropelido equipado com pontas de pulverização de jato cônico vazio, JA-1 (50L.ha-1) e JA-2 (100L.ha-1) na pressão de 828 kPa. Foi avaliado o efeito das respectivas tecnologias no controle de Pseudoplusia includens, Bemisia tabaci, Aphis gossypii, Spodoptera spp. e Thrips spp. e da doença fúngica Ramularia areola durante todo o ciclo de desenvolvimento da cultura, bem como a produtividade do algodoeiro no sistema de cultivo convencional. As dimensões das parcelas foram 24 m de largura x 100 m de comprimento em ambos os sistemas de semeadura, para os ensaios de deposição e cobertura. Para avaliação da deposição e cobertura foram escolhidas, ao acaso, 10 plantas e, de cada uma delas removida uma folha do ápice e outra folha da base da planta / Chemical control has been an essential practice on the pest management of cotton crop to reduce productivity losses. In order to promote rational use of pesticides, this work was aimed to compare three spray technologies: air-assisted, assisted by air associated with electrically charged droplets and conventional spraying (without air and electric charge) combined with volume rates of 50 and 100L.ha-1, on spray deposition, coverage and in the effect of control insect pests and disease. The trials were conducted in a randomized blocks design with six treatments and four replications for evaluation of the deposition, coverage and effect on pests and disease. The spraying was carried out on two growth stages of plants conducted in spacing of 0.45 m and 0.90 m between plant rows of culture. For this, were used a self-propelled sprayer equipped with spray nozzles hollow cone, JA-1 (50L.ha-1) and JA-2 (100L.ha-1) at 828 kPa of work pressure. The effect of these technologies was evaluated on controlling of Pseudoplusia includens, Bemisia tabaci, Aphis gossypii, Spodoptera spp. and Thrips spp. and a fungal disease Ramularia areola all the development cycle of the culture as well as the yield in conventional tillage. The dimensions of the plots were 24 m wide x 100 m length in both sowing systems for deposition and coverage tests. To evaluate the deposition and coverage were selected at random 10 plants and, of each one removed one leaf from the apex and another leaf of the lower part of plant. The tracer dye Brilliant Blue FD & C No. 1 (0.3%), fluorescent pigment ColorLight (0.15%) and Lignosulfonate Vixilperse (0.015%) were the tracer mixture. In experiments in which we evaluated the effect of the treatments on controlling pests and disease, were installed plots of 24 m wide x 250 m length and then weekly samplings were carried out as required spraying

The stink bugs, (Pentatomidae) harlequin bug (Murgantia histrionica), brown marmorated stink bug (Halyomorpha halys), and southern green stink bug (Nezara viridula) are significant agricultural pests both in the United States and globally. The aggregation or sex pheromones produced by these insects are known to be bisabolene-type sesquiterpenoids; however, the biosynthetic pathways in the formation of these pheromones are unknown. Here we provide evidence that Pentatomidae produce sesquiterpene aggregation pheromones de novo and discuss the evolution of terpene biosynthesis in stink bugs. According to transcriptome analyses, the investigated stink bug species express at least two isoprenyl diphosphate synthases (IDSs), one of which makes (E,E)-farnesyl diphosphate (FPP) as the general precursor in sesquiterpene synthesis, whereas other IDS-type proteins function as terpene synthases (TPSs) generating intermediates in sesquiterpene pheromone formation. The TPS genes are expressed in a sex- and tissue-specific manner. Based on phylogenetic analysis, these IDS-type TPSs arose from trans-IDS progenitors in divergence from bona fide IDS proteins. Compared to microbes and plants, the evolution of TPS function from IDS progenitors in insects appears to have occurred more recently. The discovery of TPS genes in stink bugs provides valuable insight into pentatomid and insect terpene biosynthesis. Moreover, the identified genes may be used in developing alternative management strategies for stink bug pests. / PHD / The stink bugs harlequin bug, brown marmorated stink bug, and southern green stink bug are significant agricultural pests both in the United States and globally. These stink bugs, as many others, release terpene type pheromones for aggregation and mating. In contrast to the general notion that insects depend on their host plants or microbes as sources of terpene pheromones, we provide evidence that stink bugs produce these pheromones de novo. We found that stink bug pheromone formation depends on proteins with terpene synthase activity, which are derived from enzymes producing linear intermediates in the core terpene metabolic pathway (isoprenyl diphosphate synthases). Expression of the terpene synthase genes is confined to specific tissues of males according to the male-specific release of the pheromones. Compared to microbes and plants, the evolution of terpene synthase function from isoprenyl diphosphate synthase progenitors in insects appears to have occurred more recently. The discovery of terpene synthase genes in stink bugs provides valuable insight into pentatomid and insect terpene biosynthesis. Moreover, the identified genes may be used in developing alternative management strategies for stink bug pests.

La gestion agroécologique durable des paysages agricoles constitue un très fort enjeu social, écologique et économique. Favoriser les différents services écosystémiques que fournissent ces systèmes complexes, caractérisés par une forte variabilité spatio-temporelle liée aux activités anthropiques, est désormais crucial. Le travail développé dans cette thèse s’est focalisé sur les services de régulation des populations de ravageurs, en développant des modèles spatialisés destinés à identifier les interactions entre paysage et populations dans l’optique d’une gestion intégrée du paysage agricole. L’approche conceptuelle utilisée s’est appuyée sur une réflexion sur les choix de niveaux d’organisation et d’échelles spatio-temporelles pertinentes qui a conduit au développement de deux modèles imbriqués : un simulateur de paysages agricoles (ATLAS) reproduisant la variabilité spatio-temporelle des habitats et un automate cellulaire décrivant les dynamiques pluriannuelles d’un puceron des céréales : Rhopalosiphum padi. Une analyse statistique des résultats a permis d’identifier l’effet des différents paramètres du paysage (composition et climat) sur les densités de pucerons à différentes échelles spatiales au cours des saisons. Ont également été évalués les effets potentiels de différents scénarios de gestion plausibles au sein du paysage agricole étudié. Parmi nos résultats, nous identifions que le remplacement du maïs par le sorgho dans le sud-ouest de la France pourrait conduire à une augmentation des densités de R.padi au sein du paysage au printemps, période particulièrement sensible aux infestations. Nous replaçons ce travail dans le cadre plus large de la favorisation des services écosystémiques et apportons des premiers éléments de réflexion pour une gestion durable du paysage agricole; / Sustainable management of agricultural landscapes is a strong social, ecological and economic challenge. Favouring the different ecosystem services provided by these complex systems, characterized by a strong spatio-temporal variability linked to human activity, is by now crucial. The work developed in this thesis has focused on pest population regulation services, by developing spatialized models in order to identify the interactions between the landscape and populations in the context of an integrated management of the agricultural landscape. The conceptual approach we used is based on careful selection of the levels of organization and spatio-temporal scales which lead to the development of two embedded models: an agricultural landscape simulator (ATLAS) reproducing the spatial-temporal variability of habitats and a cellular automaton describing thepluriannual dynamics of a cereal aphid: Rhopalosiphum padi. A statistical analysis of the results highlighted the effects of different landscape parameters (composition and climate) on aphid densities at different spatial scales throughout the seasons. The potential effects of plausible management scenarios were also evaluated. Amongst our results, we identify the replacement of corn by sorghum in the south-western part of France to potentially lead to higher aphid densities within the landscape in spring, which is a season specifically sensible to infestations. We replace this work in the larger context of favouring ecosystem services and propose new ideas for a sustainable management of agricultural landscapes;

O objetivo deste trabalho foi avaliar a distribuição espacial de adultos e ninfas da cigarrinha-das-raízes da cana-de-açúcar, Mahanarva fimbriolata (Stål., 1854) (Hemiptera: Cercopidae), a eficiência do sistema de amostragem atualmente empregado em escala comercial, a possibilidade de estimar a população de ninfas por meio da contagem de espumas e, a partir desses resultados, estabelecer um plano de amostragem confiável, prático e de baixo custo para utilização em programas de manejo integrado desta praga. A determinação da distribuição espacial foi feita em Ourinhos e Guariba-SP, demarcando-se três parcelas de 1,1 ha, em talhão colhido mecanicamente sem a queima da palha e com histórico de ataque da cigarrinha-dasraízes. As avaliações foram feitas em três épocas diferentes, contando-se o número de adultos e ninfas na base das touceiras, em 50% da área da parcela. Os adultos e ninfas de M. fimbriolata distribuem-se de forma agregada ou contagiosa na cultura da cana-de-açúcar e este padrão de distribuição não se altera ao longo das gerações, nem é influenciado pelo nível de infestação ou variedade cultivada. Utilizando-se os dados obtidos nestes experimentos calculou-se, para cada local e época de amostragem, o índice de dispersão k e o número de amostras necessárias para estimar a população de ninfas, considerando-se diferentes níveis de precisão, e realizaram-se simulações para diferentes tamanhos de amostra e esquemas de caminhamento. O plano de amostragem mais adequado para avaliação da população da cigarrinha-das-raízes em cana-de-açúcar foi determinado por meio do intervalo de confiança da média (P ≤ 0,05) para a Variação Relativa (VR) e Precisão Relativa (PR). Os melhores resultados foram obtidos com 18 amostras de 1 metro linear por hectare, distribuídas na área de forma sistemática. Para a avaliação do método de amostragem comercial, instalaram-se dois experimentos em Ourinhos, demarcando-se duas parcelas de 1,1 ha, nas mesmas condições anteriores. Quinzenalmente, quantificou-se o número de formas biológicas em 300 pontos de 1m linear na parcela (amostragem experimental) e no restante da área do talhão (amostragem comercial), em 4 pontos de dois sulcos de 2m lineares/ha. Comparando-se os dados por meio de uma análise de regressão linear verificou-se que o método de amostragem comercial apresentou boa precisão na estimativa da população de ninfas, porém foi pouco preciso para adultos. Sua acurácia foi baixa para ninfas e adultos, subestimando as populações reais. A relação entre as contagens de espumas e ninfas nas amostragens comercial e experimental foi avaliada por meio de uma análise de regressão linear, observando-se alta correlação entre estes parâmetros, com coeficientes de determinação superiores a 0,96. Os resultados obtidos indicam que, independentemente da época de avaliação e do nível de infestação, é possível estimar a população de ninfas da cigarrinha-dasraízes em cana-de-açúcar por meio da contagem de espumas, com elevado grau de confiabilidade. / The objective of this research was to evaluate the spatial distribution of adults and nymphs of the sugarcane root froghopper, Mahanarva fimbriolata (Stal, 1854) (Hemiptera: Cercopidae), to evaluate the efficiency of the sampling system presently used to monitor the populations in commercial fields, and to estimate nymph populations by counting foam spots. The results obtained in this work were used to establish a low cost and reliable sampling method in order to improve the integrated pest management program for the sugarcane root froghopper. The determination of the spatial distribution was conducted at Ourinhos and Guariba cities, São Paulo State, in three plots of 1.1 ha that had been mechanically harvested without burning and with a history of infestation with sugarcane root froghopper. The evaluations were made in three different periods, counting the number of both adults and nymphs at the base of the stools in 50% of the plot. The adults and the nymphs of M. fimbriolata were distributed in aggregated or contagious form and this pattern did not change during subsequent generations nor was influenced by either the level of infestation or cultivated variety. The data obtained in these experiments was used to estimate, for each site and sampling period, the dispersion index k and the number of samples needed to estimate nymph populations, considering different levels of precision. The data was also used to simulate results with different sample sizes and sampling patterns. The most adequate sampling plan to evaluate sugarcane root froghopper populations was determined using the confidence interval of the mean at P ≤ 0.05 for the Relative Variation (RV) and Relative Precision (RP). The best results were obtained with 18 samples of 1 linear meter per hectare, distributed in the area in a systematic manner. For the evaluation of the commercial sampling method, two experiments were established at Ourinhos, using two 1.1 hectare plots. The number of biological forms in 300 spots of 1 linear meter in the plot (experimental sampling) were checked bi-weekly. Similarly, in the rest of the area, biological forms were counted in 4 spots of 2 linear meters per hectare (commercial sampling). Linear regression analysis presented that the commercial sampling method presented good efficiency for estimating nymphs populations but was not efficient in estimating adult populations. The sampling accuracy was low for both nymphs and adults, underestimating the true populations. The linear correlation between foam counts and nymph in both commercial and experimental sampling was high, with determination coefficient greater than 96%. The results indicate that, independent of the period and level of infestation, it is possible to estimate the population of sugarcane root froghopper nymphs by counting foam spots.