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Nicolau, Manterola Felipe. "Hydrocarbon and insecticide induction of Beauveria bassiana catalysis of organosulfur compounds." Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/3151.
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Catalysts are utilized in 80% of all chemical synthesis operations. The industrial catalysts primarily used in oxidation reactions are highly polluting and expensive metal catalysts. Enzymes and whole cell biocatalysts are used to a lesser extent. Nowadays, several industrial sectors are developing bio-based technologies to reduce the high costs and environmental impact of traditional chemical processes. However, these applications are limited by the challenge of developing economically competitive biologically based systems. The key for adopting these sustainable advancements is the development of novel process designs, which assure robustness, simplicity, and sustainabile operations compatible with the current development of chemical reactions. In this regard, filamentous fungi may be considered good biocatalysts due to their natural biodiversity and their broad heterogeneous enzymatic pattern. The great selectivity of fungal catalysis is now well recognized for the production of commercially valuable steroids in the pharmaceutical industry. Although this inherent capacity is mainly used for functionalization of unactivated carbons, it can be further exploited for the oxidiation of heteroatoms, such as sulfur. Focusing on the oxidation of sulfur compounds, the widely used industrial processes are produced by an organometallic catalyst. This PhD project aims to overcome low substrate conversion and enzymatic expression by proving that exposure of cells to insecticides and hydrocarbons increases cell's oxidative capacity expressed as higher substrate conversion and CYP450 content. This study is focused in the application of pest management strategies, designed to enhance the biopesticide's efficacy, to induce and improve Beauveria bassiana oxidation. B. bassiana has a very flexible metabolism and is widely used as a biocontrol agent. It can metabolize hexadecane as a sole carbon source. In addition, it shows a synergistic effect over pest control efficacy when it is applied with low pesticides (carbaryl and/or imidacloprid) concentrations.
A biocatalytic system was optimized to increase the conversion of organosulfur compounds under different fermentation conditions. Phenothiazine was used as our model substrate. Phenothiazine conversion was followed by GC-MS and HPLC. By NMR and MS fragmentation pattern product, phenothiazine metabolites were identified as (R)-hydroxyl metabolites (63% enatiomeric excess) and sulfoxide, the latter being the main metabolite. Phenothiazine conversions with growing cells resulted in 65±1.4% conversion with initial phenothiazine concentration of 500 ppm and final 325 ppm after 7 days. The highest conversion, 74±1 % was achieved with resting cells at the lowest cell concentration, 0.78 mg cell dry weight (cdw) /mL. Furthermore, the use of insecticides as inducers was an effective way to increase phenothiazine conversion from 47% to 64±3%. The major enzymes involved in catalysis of xenobiotic are heme-binding monooxygenases, in particular cytochrome P450. Heme positive proteins were identified by an SDS benzidine assay as well as the content of CYP450 by the CO difference spectrum. The P450 enzymes content was 12.3±1 pmol/µg protein for hexadecane adapted cells and 8.1± 1 pmol/µg protein for insecticides, respectively. The heme-positive proteins were characterized by MALDI-ToF and their peptide mass fingerprint compared to the available sequences on the SwissProt/Universal Protein Resource catalog of information on proteins (UniProtKB). Hemoproteins were found, including a cluster of catalase-peroxidase, alkane hydroxylase, and chloroperoxidase. The results from this project helped bridge the progress from agricultural biotechnology strain development into industrial biotechnology biocatalyst improvement. The success of this project helps us expand B. bassiana's catalysis and make it a better candidate for industrial biocatalysis.
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Kantachote, Duangporn. "The use of microbial inoculants to enhance DDT degradation in contaminated soil." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phk165.pdf.
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Merlin, Chloé. "Recherche de la signature biologique de la dégradation du chlordécone dans le sol des Antilles françaises." Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS001/document.
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L’utilisation du chlordécone (CLD) pour éradiquer les populations de charançon noir dans les bananeraies des Antilles françaises (Guadeloupe et Martinique) entre 1972 et 1993 a conduit à la contamination des sols et de l’environnement. Cet insecticide organochloré très hydrophobe persiste dans les sols d’où il transfère lentement vers les ressources en eau et vers les biotes terrestre et aquatique (plantes, animaux, poissons, crustacées). Réputé « indégradable », le CLD résiste à la photolyse, à l’hydrolyse et à la biodégradation. A ce jour, il n’existe pas de méthode pour remédier les 20 000 hectares de sols pollués avec cet insecticide. Compte-tenu de l’étendue de la pollution avec le CLD, les procédés biologiques de décontamination paraissent appropriés au contexte antillais. Les objectifs de mon travail de thèse étaient d’explorer les possibilités de transformation microbienne du CLD et l’impact écotoxicologique du CLD sur la communauté microbienne des sols. Mes travaux reposent sur l’hypothèse selon laquelle des populations microbiennes exposées de manière chronique au CLD se seraient adaptées à sa dégradation pour détoxifier leur environnement ou éventuellement pour l’utiliser comme source d’énergie pour leur croissance. Pour cela, j’ai développé une méthode d’analyse du CLD dans les sols et les cultures microbiennes basée sur l’isotopie stable. J’ai conduit des expériences d’enrichissement à partir de sols de Guadeloupe pollués avec le CLD. Une centaine de souches fongiques et près de 200 souches bactériennes ont été isolées. Aucunes souches bactériennes dégradantes n’ont pu être mises en évidence bien que certaines formaient un halo de dissolution du CLD sur milieu gélosé. Parmi les isolats fongiques, seul F. oxysporum sp. MIAE01197 se développait sur un milieu minéral contenant le CLD comme seul source de carbone et dissipait 40% du CLD. Cet isolat était deux fois plus tolérant au CLD qu’un isolat de référence jamais exposé au CLD. Cet isolat minéralisait très peu le 14C-CLD, formait très peu de 14C-métabolites, mais le 14C-CLD s’adsorbait sur les parois fongiques, suggérant que l’adsorption était le principal mécanisme impliqué dans la dissipation du CLD. L’analyse de trois autres isolats appartenant au genre Aspergillus a confirmé que l’exposition au CLD était un des paramètres améliorant la tolérance des souches fongiques au CLD et que la biomasse fongique était capable d’adsorber le CLD dans des proportions proches de celles obtenues avec du charbon actif utilisé pour traiter l’eau potable aux Antilles. L’évaluation de l’impact écotoxicologique du CLD sur la communauté microbienne et les fonctions qu’elle supporte a été menée sur deux sols aux propriétés physicochimiques contrastées n’ayant jamais été exposés au CLD. L’analyse de la structure globale (évaluée par RISA), de l’abondance et de l’activité de la communauté microbienne du sol argilo-limoneux n’étaient pas affectées par le CLD. En revanche, la composition taxonomique (qPCR) et l’activité respiratoire de la communauté microbienne étaient affectées par le CLD dans le sol sableux. Ces résultats montrent que la toxicité du CLD pour la communauté microbienne dépend des propriétés physicochimiques du sol qui conditionne sa biodisponibilité. Des études complémentaires devront être menées pour évaluer la toxicité possible du CLD sur des fonctions écosystémiques des sols des AntillesThe use of chlordecone (CLD) to eradicate the weevil populations in the banana plantations in the French West Indies (Guadeloupe and Martinique) between 1972 and 1993 led to the contamination of the soil and the environment. This very hydrophobic organochlorine insecticide persists in the soil where it slowly transfers not only to the water resources but also to terrestrial and aquatic biota (plants, animals, fishes, shellfishes). Deemed “non-degradable”, CLD is resistant to photolysis, hydrolysis and biodegradation. To date, there is no method to remediate the 20,000 hectares of polluted soil with this insecticide. Given the extent of CLD pollution, biological decontamination processes appear appropriate to the Caribbean context. The objectives of my thesis were to explore the possibilities of microbial transformation of CLD and to assess the ecotoxicological impact of CLD on the soil microbial community. My work is based on the hypothesis that microbial populations chronically exposed to CLD would be adapted to its degradation to detoxify their environment or possibly for use as an energy source for growth.To do so, I developed an analysis method in soils and microbial cultures based on the use of stable isotope to trace CLD. I conducted enrichment experiments with CLD polluted soils from Guadeloupe yielding in the isolation of one hundred fungal strains and nearly two hundred bacterial strains. No degrading bacterial strains have been identified although few of them formed dissolution halo of CLD on solid media. Among the fungal isolates, only F. oxysporum sp. MIAE01197 grew on a mineral medium containing CLD as sole carbon source and dissipated 40% of the CLD. This isolate was twice more tolerant than the reference isolate which had never been exposed to CLD. This isolate mineralizes 14C-CLD very lowly, formed very few 14C-metabolites, but the 14C-CLD was adsorbed on the fungal cell walls, suggesting that the adsorption was the main mechanism involved in the dissipation of the CLD. Analysis of three other isolates belonging to the genus Aspergillus confirmed that exposure to CLD was one of the parameters improving the tolerance of fungal strains to CLD and fungal biomass was capable of adsorbing the CLD in proportions close to those obtained with activated carbon used to treat drinking water in the French West Indies.The assessment of the CLD ecotoxicological impact on the microbial community and functions it supports was carried out on two soils never exposed to CLD showing contrasting physicochemical properties. The analysis of the overall structure (evaluated by RISA), the abundance and the activity of the microbial community of the silty-clay soil were not affected by the CLD. However, the taxonomic composition (evaluated by group specific qPCR) and respiratory activity of the microbial community were affected by the CLD in the sandy soil. These results showed that the toxicity of CLD for microbial community depends on the physicochemical properties of the soil which may determine its bioavailability. Further studies are needed to evaluate the possible toxicity of the CLD on Caribbean soil ecosystemic functions
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SANTOS, Lauricí Maria Pires dos. "Efeitos dos fungos Metarhizium anisopliae (Metsch.) SOROK. e Beauveria bassiana (BALS.) VUILL sobre Tuta absoluta (Meyrick) e compatabilidade com inseticidas." Universidade Federal Rural de Pernambuco, 2008. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6055.
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The control of Tuta absoluta (Meyrick) is usually done with intensive insecticide sprays, which has led to the research of alternative control methods as part of the tomato leafminer integrated management in tomato crops. The objective of this work was to evaluate the pathogenicity of Metarhizium anisopliae (Metsch) Sorok. and Beauveria bassiana (Bals.)Vuill isolates on eggs and larvae of T. absoluta, and their compatibility with insecticides used to control this pest. Also, it was investigated the infection process of M. anisopliae on eggs and the effect over fecundity and mortality of females. Although both fungi showed pathogenicity to eggs and larvae of T. absoluta, M. anisopliae showed higher pathogenicity than B. bassiana. Among the isolates of M. anisopliae tested, URPE-6 and URPE-19 caused 95% and 42% infection in eggs and 1st instar larvae, respectively. The LC50-value for T. absoluta eggs was 3.5 x 104 conidia.mL-1 of the URPE-6 isolate. The compatibility of isolates URPE-6 and URPE-19 with neem, chlorfenapyr, indoxacarb, spinosad and abamectin was evaluated. Field dosages of chlorfenapyrand neem were toxic to the isolate URPE-19, while abamectin and neem showed toxicity to the isolate URPE-6. Ultra-structure analysis of URPE-6 infecting eggs showed that the process of conidia penetration occurred within 6 h after application of the fungus. Bodies of hyphae presenceand intense micelle extrusion were observed in eggs at 12 and 72 h after application, respectively. The URPE-6 isolate did not show any effect on egg-laying preference and fecundity of T. absoluta females, but it affected their survivals. The use of entomopathogenic fungi is a potential alternative control for T. absoluta mainly at the egg stage, and it may be associated with insecticides used in the control of this tomato pest
Um dos fatores limitantes da produtividade da cultura do tomateiro é a ocorrência de pragas, destacando-se Tuta absoluta (Meyrick) (Lepidoptera:Gelechiidae). A aplicação intensiva de inseticidas no controle convencional desse inseto torna relevante a busca por métodos alternativos que possam compor o Manejo Integrado desta praga. Esta pesquisa teve como objetivos avaliar a patogenicidade de isolados de Metarhizium anisopliae (Metsch) Sorok. e Beauveria bassiana (Bals.) Vuill para ovos e lagartas de T. absoluta, estudar a compatibilidade destes patógenos com inseticidas, investigar o processo de infecção de M. anisopliae sobre ovos e avaliar seu efeito na fecundidade e mortalidade de fêmeas. Todos os isolados testados apresentaram patogenicidade a ovos e lagartas de T. absoluta, sendo M. anisopliae mais patogênico. Destacaram-se os isolados URPE-6 causando infecção de 95% sobre ovos e URPE-19 com mortalidade de 42% sobre lagartas de primeiro ínstar. Foi determinada a CL50 do isolado URPE-6 de M. anisopliae sobre ovos de T. absoluta, obtendo-se um valor de 3,5 x 104 conídios mL-1. Testou-se a compatibilidadedos isolados URPE-6 e URPE-19 com Nim, Clorfenapir, Indoxacarbe, Espinosade e Abamectina. Os produtos Clorfenapir e Nim foram tóxicos ao isolado URPE-19 e Abamectina e Nim apresentaram toxicidade para o isolado URPE-6, nas dosagens recomendadas pelo fabricante. Aavaliação ultra-estrutural dos ovos infectados pelo isolado URPE-6 de M. anisopliae nos períodos de 6, 12, 24, 48 e 72h após a aplicação do patógeno, demonstrou que o processo de penetração dos conídios ocorreu dentro do período de 6 horas, confirmando sua virulência. Foi observada a presença de corpos hifais no interior do ovo, nos períodos de 12 e 24h. No período de 72h após a infecção ocorreu intensa extrusão do micélio cobrindo a superfície externa dos ovos. O isolado URPE-6 não apresentou efeito sobre a oviposição e fecundidade de T. absoluta, porém afetou a sobrevivência. A utilização de M. anisopliae representa mais uma alternativa no controle de T. absoluta, principalmente no estágio de ovo, sendo possível associação deste patógeno com inseticidas utilizados no controle desta praga.
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Liegeois, Marie-Hélène. "Efficacité et impact environnemental d'un insecticide anti-taupin, le fipronil, en agrosystème simplifié." Grenoble 1, 1998. http://www.theses.fr/1998GRE10175.
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Le fipronil, molecule insecticide appliquee en traitement de pelliculage sur les semences de mais, penetre directement, via un flux transtegumentaire ou transpedicellaire, dans l'albumen et le scutellum. Un taux maximal de 7% de la quantite appliquee penetre dans la graine des la phase de pelliculage. La penetration transtegumentaire dans la graine redemarre ensuite lors de la phase de gonflement et de germination de la semence, pour atteindre 20% de la quantite initiale apportee par le pelliculage, dans la plantule, apres 6 jours de croissance. Pour les parties neoformees du mais, c'est l'eau du sol qui devient le vecteur du fipronil (apres solubilisation a partir du pelliculage). Cette eau, chargee en fipronil, conduit aussi a un chargement du complexe argilo-humique dans la zone de la graine. Dans la plante de mais, comme l'ont montre les etudes realisees par rhone-poulenc ainsi que nos observations au sein d'un agrosysteme simplifie, le fipronil est partiellement metabolise. Compte tenu de la longue periode (5 mois) entre le traitement et la fructification du mais et des aptitudes a la degradation que presentent cette espece, pour donner des metabolites relativement lipophiles, il est peu probable de trouver des residus importants dans les grains. La larve de taupin, ravageur souterrain des cultures de mais et organisme cible du fipronil, acquiert cette matiere active principalement par ingestion. Nous avons demontre que, pour un plant de mais, ce sont les reserves de la graine qui sont les plus appetentes pour le taupin et qu'elles sont consommees. Pour les atteindre, les larves consomment pelliculage et teguments et acquierent ainsi la quantite de fipronil declenchant la letalite. La quantite de fipronil absorbe par le taupin, par voie transtegumentaire, a ete determinee comme etant faible, et nous n'avons pas mis en evidence de metabolisation du produit au sein de la larve. Au niveau du sol, le fipronil est en equilibre de partition entre l'eau du sol et le c omplexe argilo-humique, sur lequel il va s'adsorber. Deux elements importants dans la dissipation du fipronil sont les vers de terre et la biomasse microbienne. La biomasse microbienne acquiert le fipronil a la mesure de sa partition avec l'eau du sol. Cette flore bacterienne est susceptible de metaboliser cette matiere active (resultats presentes dans le dossier d'homologation). Parallelement, les vers de terre sont potentiellement susceptibles de concentrer des quantites importantes de fipronil, et de le metaboliser en un produit majoritaire gardant des proprietes insecticides. Cependant, le ver ne manifeste aucune atteinte toxique, ce qui tend fortement a demontrer que ses canaux chlore ne sont pas atteints par le fipronil, contrairement a ceux des insectes. Le ver apparait aussi comme un acteur potentiellement important de la chaine de dissipation du fipronil. Nous avons etudie en detail le processus de partition du fipronil entre l'eau et divers etres vivants (differents organes du mais, taupins, micro-organismes, vers de terre). L'equilibre de partition analyse et mesure est une fonction non seulement de la teneur en lipides libres des etres ou organes etudies, mais aussi de la presence de proteines a sites lipophiles comme la zeine ou de polymeres lipophiles comme la lignine. Dans l'agrosysteme simplifie etudie au laboratoire en conditions controlees, il semble que l'efficacite anti-taupin depende directement de la presence du fipronil dans les reserves des graines ou associe aux reserves lors de l'ingestion. Le fipronil contenu dans les organes neoformes ou adsorbe sur le complexe argilo-humique ne semblent jouer qu'un role mineur du point de vue de l'efficacite insecticide. L'apport du fipronil par le biais du traitement de semences sur mais, dans la lutte anti-taupin, presente des caracteristiques tres interessantes d'un point de vue environnemental. La surface de sol traitee est faible, la matiere active presente une faible mobilite dans le sol et la position enfouie du fipronil autour des semences ecarte la possibilite d'une contamination atmospherique. Des modifications de la formulation utilisee en traitement de semences sont suggerees pour augmenter la penetration de la matiere active dans l'albumen lors de la phase de pelliculage des semences. Ceci pourrait conduire a une diminution de la quantite necessaire de fipronil a l'hectare, tout en gardant l'efficacite agronomique, en raison d'une diminution de la quantite liee au sol. Evidemment, le succes d'une telle modification necessiterait l'absence de phytotoxicite au niveau de la semence et de la plantule.
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Manwill, Preston Kim. "Discovery and Development of Natural Products from Plant and Microbial Sources: Drimane Sesquiterpenes and Abyssomicins as Mosquito Control and Antimicrobial Agents." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1591285556969447.
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Hubert, Marie. "Structure de mycotoxines et d'analogues- recherche de leurs métabolites chez un insecte hôte." Rouen, 1998. http://www.theses.fr/1998ROUES037.
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Dans l'optique d'utiliser les mycotoxines en tant que bioinsecticides potentiels de nouvelle génération, nous nous sommes intéressés à celles de deux champignons entomopathogènes, Metarhizium anisopliae et Paecilomyces farinosus. Celles de M. Anisopliae, les destruxines (DTXs), sont des cyclohexadepsipeptides connus depuis plusieurs décennies. Sur le plan structural, une systématique de fragmentation de ces composés a été mise au point par PFAB/MS/Linked Scan. Au niveau biologique, nous avons complété les études sur le comportement in vivo des destruxines. Les métabolites des DTXs A et E, destruxines les plus toxiques et les plus abondamment produites par M. Anisopliae, avaient été mis en évidence chez un insecte modèle, le criquet Locusta migratoria. Ici, nous les avons étudies à l'aide de deux techniques analytiques complémentaires, la spectrométrie de masse et l'HPLC, dans l'hémolymphe d'un insecte ciblé, les larves du lépidoptère Galleria mellonella. Ainsi, pour la DTXE, un processus de détoxication identique à celui observé chez le criquet a été décelé chez G. Mellonella : hydrolyse (DEDiol), conjugaison par le glutathion (DESG) puis métabolisation ultérieure en conjugué cystéinique (DESCys) et enfin conjugaison en dérivé phosphate et/ou sulfate (DEDiolP ou DEDiolS). En revanche, pour la DTXA, le processus se révèle différent selon les deux insectes. Chez le criquet, la DTXA se métabolise en peptide linéaire, tandis que chez G. Mellonella, elle mène principalement au DEDiolP, en passant vraisemblablement par la DTXE et la DTXEDiol. En outre, le comportement in vivo d'analogues synthétiques des destruxines a été étudié. C'est d'ailleurs la première fois qu'une telle étude est menée. Pour ces deux diastéréoisomères, dont l'un est actif et l'autre inactif, un processus de métabolisation identique a été mis en évidence. Il s'agit de la formation du peptide linéaire résultant d'une hydrolyse au niveau de la liaison lactone. Cependant, le processus d'excrétion semble différent. En effet, l'isomère inactif disparaît alors que l'actif est toujours présent après 24h d'incubation. En ce qui concerne les toxines de P. Farinosus souche KVL420, elles n'ont malheureusement pu être caracterisées. Il s'agit de molécules de petites tailles, très hydrophiles. Aucune méthode de séparation adéquate et préalable à des analyses par spectrométrie de masse et RMN n'a pu être determinée à ce jour.
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Maloney, Sarah Elizabeth. "Microbial transformation of synthetic pyrethroid insecticides." Thesis, University of Greenwich, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292367.
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Weitzman, Matthew D. "Characterization of Panolis flammea nuclear polyhedrosis virus." Thesis, Oxford Brookes University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278796.
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Al-Hafidh, E. M. T. "The integration of Nosema whitei and some insecticides on Tribolium castaneum." Thesis, University of Newcastle Upon Tyne, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353790.
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Tavares, Fernando Martins [UNESP]. "Avaliação de nematóides entomopatogênicos contra o bicudo da cana-de-açúcar Sphenophorus levis Vaurie, 1978, e efeito da associação desses agentes com inseticidas químicos." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/97218.
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tavares_fm_me_botfca.pdf: 1326049 bytes, checksum: 86d24916183c6adc243be54cbe86a695 (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Fundação de Apoio à Pesquisa Agrícola (FUNDAG)
Secretaria Agricultura
Buscando-se novas alternativas para o controle do bicudo da cana-de-açúcar, Sphenophorus levis Vaurie, 1978, foi testado em laboratório, em estufa e no campo, a ação dos nematóides entomopatogênicos Heterorhabditis indica Poinar, 1992 e Steinernema sp., e o efeito da associação desses agentes com subdosagens dos inseticidas químicos fipronil (Regent 800WG), thiamethoxam (Actara 250WG) e imidacloprid (Confidor 700WG), no controle de larvas e adultos do inseto. Inicialmente foram avaliadas diferentes dosagens dos nematóides contra larvas do inseto. O nematóide Steinernema sp. apresentou-se mais eficiente no controle de larvas, podendo ser utilizada na menor dosagem avaliada (2,4 JI/cm2), já que ocasionou 69% de mortalidade corrigida do inseto em estufa, não diferindo significamente das maiores dosagens. Esse nematóide apresentou-se mais eficiente também contra adultos do inseto, em teste de laboratório, proporcionando níveis de mortalidade do inseto igual ou superior a 70% nas dosagens de 2,4, 12 e 60 JI/cm2, quando avaliado em associação com o inseticida thiamethoxam na subdosagem de 250 g p.c./ha. No teste de campo foi possível verificar nas parcelas tratadas com Steinernema sp., na dosagem de l,0xl08 JI/ha, associado ao thiamethoxam na dose de 500 g p.c./ha, ganho superior a 28 toneladas de cana crua quando 2 comparada a testemunha. Quanto ao efeito de fipronil e thiamethoxam sobre a viabilidade dos nematóides em laboratório, esses produtos químicos apresentaram-se compatíveis a esses agentes, não afetando a viabilidade dos juvenis infectivos. O nematóide Steinernema sp. é uma alternativa viável para o controle de S. levis, podendo ser usado isoladamente ou associado com subdosagem de thiamethoxam. Palavras-chave: controle microbiano, controle biológico, bicudo da cana de açúcar, inseticida químico, nematóide entomopatogênico.
With the purpose to find new alternatives to control the sugarcane billbug Sphenophorus levis, this study aimed to evaluate in laboratory, green house and field conditions, the effect of the nematodes Heterorhabditis indica and Steinernema sp., in combinations with sub-dosages of the chemical insecticides fipronil (Regent 800WG), thiametoxam (Actara 250WG) and imidacloprid (Confidor700WG), against larva and adults of this pest. Firstly, several dosages of the nematodes were evaluated against larvae. The nematode Steinernema sp. was the most efficient against larva, with its dosage of 2,4 IJ/cm2 showing to be the best one for the insect control since it provide 69% larva mortality, not significantly differing from the other dosages. This nematode was also the most efficient against adults in laboratory test, providing insect mortality levels equal or higher than 70% when evaluated at the dosages of 2,4; 12 and 60 IJ/ha, in combination with thiametoxam at the sub-dosage 250 g c.p./ha. The insecticides fipronil and thiamethoxam did not affected the viability of the infect juveniles. For the field test, the combination of Steinernema sp. (108 IJ/ha) plus thiamethoxam (500 g c.p./ha) provided an increasing to the sugarcane production higher than 28 ton/ha. The nematode Steinernema sp. seems to be a viable alternative for the 4 controlling of S. levis, providing expressive increasing to the sugarcane production when used alone or in combination with thiamethoxam.
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Tavares, Fernando Martins 1979. "Avaliação de nematóides entomopatogênicos contra o bicudo da cana-de-açúcar Sphenophorus levis Vaurie, 1978, e efeito da associação desses agentes com inseticidas químicos /." Botucatu : [s.n.], 2006. http://hdl.handle.net/11449/97218.
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Orientador: Antonio Batista FilhoBanca: Carlos Frederico Wilcken
Banca: Luis Carrigos Leite
Resumo: Buscando-se novas alternativas para o controle do bicudo da cana-de-açúcar, Sphenophorus levis Vaurie, 1978, foi testado em laboratório, em estufa e no campo, a ação dos nematóides entomopatogênicos Heterorhabditis indica Poinar, 1992 e Steinernema sp., e o efeito da associação desses agentes com subdosagens dos inseticidas químicos fipronil (Regent 800WG), thiamethoxam (Actara 250WG) e imidacloprid (Confidor 700WG), no controle de larvas e adultos do inseto. Inicialmente foram avaliadas diferentes dosagens dos nematóides contra larvas do inseto. O nematóide Steinernema sp. apresentou-se mais eficiente no controle de larvas, podendo ser utilizada na menor dosagem avaliada (2,4 JI/cm2), já que ocasionou 69% de mortalidade corrigida do inseto em estufa, não diferindo significamente das maiores dosagens. Esse nematóide apresentou-se mais eficiente também contra adultos do inseto, em teste de laboratório, proporcionando níveis de mortalidade do inseto igual ou superior a 70% nas dosagens de 2,4, 12 e 60 JI/cm2, quando avaliado em associação com o inseticida thiamethoxam na subdosagem de 250 g p.c./ha. No teste de campo foi possível verificar nas parcelas tratadas com Steinernema sp., na dosagem de l,0xl08 JI/ha, associado ao thiamethoxam na dose de 500 g p.c./ha, ganho superior a 28 toneladas de cana crua quando 2 comparada a testemunha. Quanto ao efeito de fipronil e thiamethoxam sobre a viabilidade dos nematóides em laboratório, esses produtos químicos apresentaram-se compatíveis a esses agentes, não afetando a viabilidade dos juvenis infectivos. O nematóide Steinernema sp. é uma alternativa viável para o controle de S. levis, podendo ser usado isoladamente ou associado com subdosagem de thiamethoxam. Palavras-chave: controle microbiano, controle biológico, bicudo da cana de açúcar, inseticida químico, nematóide entomopatogênico.
Abstract: With the purpose to find new alternatives to control the sugarcane billbug Sphenophorus levis, this study aimed to evaluate in laboratory, green house and field conditions, the effect of the nematodes Heterorhabditis indica and Steinernema sp., in combinations with sub-dosages of the chemical insecticides fipronil (Regent 800WG), thiametoxam (Actara 250WG) and imidacloprid (Confidor700WG), against larva and adults of this pest. Firstly, several dosages of the nematodes were evaluated against larvae. The nematode Steinernema sp. was the most efficient against larva, with its dosage of 2,4 IJ/cm2 showing to be the best one for the insect control since it provide 69% larva mortality, not significantly differing from the other dosages. This nematode was also the most efficient against adults in laboratory test, providing insect mortality levels equal or higher than 70% when evaluated at the dosages of 2,4; 12 and 60 IJ/ha, in combination with thiametoxam at the sub-dosage 250 g c.p./ha. The insecticides fipronil and thiamethoxam did not affected the viability of the infect juveniles. For the field test, the combination of Steinernema sp. (108 IJ/ha) plus thiamethoxam (500 g c.p./ha) provided an increasing to the sugarcane production higher than 28 ton/ha. The nematode Steinernema sp. seems to be a viable alternative for the 4 controlling of S. levis, providing expressive increasing to the sugarcane production when used alone or in combination with thiamethoxam.
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Aston, R. P. "The use of Bacillus thuringiensis (Berliner) for the control of Heliothis armigera (Hubner) (Lepidoptera : Noctuidae) on cotton." Thesis, Cranfield University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234528.
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Sitch, Joanne Claire. "The resistance of non target invertebrates to infection by the entomopathogenic fungus Verticillium lecanii (Zimm.) viegas." Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388348.
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Celestino, Flávio Neves. "Potencial do óleo de mamona e associação com Beauveria bassiana (BALS.) Vuillemin visando o manejo da broca-do-café." Universidade Federal do Espírito Santo, 2011. http://repositorio.ufes.br/handle/10/6546.
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Previous issue date: 2011-02-11The coffee cultivation is a very important social and agricultural activity. However, some phytosanitary problems can cause losses, diminishing productivity and ultimately their profitability economic. Among the insects the coffee berry borer, Hypothenemus hampei (Ferrari, 1867) (Coleoptera: Scolytidae), is a major pest of the crop. This study evaluates the potential use of castor oil and its association with the entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin, 1912, in order to controlling of H. hampei. The potential of castor oil through the mortality of the coffee berry borer using three different routes of application was evaluated: (1) ingestion, (2) contact and (3) combined (ingestion + contact), beyond the estimate of LC50. In association between castor oil and B. bassiana the germination, vegetative growth and sporulation were evaluated, and the biological index (BI) determined. The route application combined (ingestion + contact) has increased mortality at concentrations of 0.5, 1.0 and 3.0% (v/v), differing from the other routes of application. However, on the concentrations 1.5, 2.0 and 2.5% (v/v) there was no significant differences between the routes of application contact and contact + ingestion, and these differ from the route of application by ingestion. The route of application by ingestion + contact presented 92% mortality on the concentration 3.0% (v/v), higher than the other routes of application. This route of application also presented an LC50 of 1.31% (v/v). The CCA-UFES/Bb-4 and CCA-UFES/Bb-15 isolated showed the highest values of germination. Only CCA-UFES/Bb-4 isolate presented the vegetative growth reduced in function of increasing concentrations of castor oil. This isolate was one that showed greater sporulation at all concentrations. The oil acts both by ingestion and contact, and that the association of both provides a more efficient control. All isolates present great potential for use associated with castor oil
A cafeicultura é uma atividade de extrema importância social e agrícola. Contudo, alguns problemas fitossanitários podem ocasionar prejuízos, diminuindo a produtividade e, consequentemente, a sua rentabilidade econômica. Dentre os insetos, a broca-do-café Hypothenemus hampei (Ferrari, 1867) (Coleoptera: Scolytidae), é considerada a principal praga da cultura. No presente estudo foi avaliado o potencial de uso do óleo de mamona e a associação com o fungo entomopatogênico Beauveria bassiana (Bals.) Vuillemin, 1912, visando o controle de H. hampei. Avaliou-se a potencialidade do óleo de mamona sobre a mortalidade da broca-do-café utilizando três diferentes vias de aplicação: (1) ingestão, (2) contato e (3) ingestão + contato, além da estimativa da CL50. Na associação entre o óleo de mamona e B. bassiana foram avaliados os parâmetros de germinação, crescimento vegetativo e esporulação, e determinado o índice biológico (IB). A via aplicação por ingestão + contato apresentou maior mortalidade nas concentrações de 0,5; 1,0 e 3,0% (v/v) diferindo das demais vias de aplicação. Por sua vez, nas concentrações 1,5; 2,0 e 2,5% (v/v) não houve diferença entre as vias de aplicação por contato e ingestão + contato, sendo que estas diferiram da via de aplicação por ingestão. A aplicação via ingestão + contato apresentou 92% de mortalidade na concentração 3,0% (v/v), superior as demais vias de aplicação. Esta via de aplicação também apresentou CL50 de 1,31% (v/v). Os isolados CCA-UFES/Bb-4 e CCA-UFES/Bb-15 foram os que apresentaram os maiores valores de germinação. Somente o isolado CCA-UFES/Bb-4 apresentou crescimento vegetativo reduzido em função do aumento das concentrações do óleo de mamona. Esse isolado foi o que apresentou a maior esporulação em todas as concentrações. O óleo atua tanto por ingestão quanto por contato, sendo que a associação de ambos proporciona uma melhor eficiência de controle. Todos os isolados apresentam grande potencial de utilização associados com óleo de mamona
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Fabre, Bernard. "Recherche de microorganismes producteurs d'insecticides criblage, production, purification et identification des produits /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37604872d.
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Klafke, Guilherme Marcondes. "Diagnóstico e mecanismos de resistência a ivermectina em Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42135/tde-26102011-091517/.
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Rhipicephalus (Boophilus) microplus é o parasito de maior importância econômica para a produção bovina. Há suspeita de resistência disseminada a ivermectina (IVM), droga amplamente utilizada para seu controle e seu diagnóstico preciso se faz necessário. Neste trabalho foram padronizados testes diagnósticos in vitro que, ao serem aplicados a campo no Brasil, diagnosticaram a resistência em 18 de 30 populações testadas. A resistência in vitro foi confirmada por teste in vivo. Testes com sinergistas sobre cepa resistente isolada indicaram que a destoxificação enzimática tem papel secundário na resistência. Não foram encontradas mutações associadas à resistência no trecho analisado do gene GluCl. Informações obtidas sobre evolução da resistência a campo e em laboratório poderão ser úteis para o uso de IVM no controle de R. (B.) microplus. Os estudos conduzidos sobre mecanismos de resistência podem servir para o desenvolvimento de marcadores moleculares diagnósticos de resistência a IVM.Rhipicephalus (Boophilus) microplus is the most economically important parasite for cattle production. There is suspicion of widespread resistance to ivermectin (IVM), a drug widely used for their control and being necessary its accurate diagnosis. In this study were standardized in vitro diagnostic tests that, when applied to the field in Brazil, diagnosed resistance in 18 of 30 populations tested. The in vitro resistance was confirmed by a field trial. Tests with synergists on an isolated resistant strain indicated that enzyme detoxification has a secondary role in resistance. There were no mutations associated with resistance in the analyzed fragment of the gene GluCl. Information obtained about the evolution of resistance in field and laboratory may be useful for the use of IVM in the control of R. (B.) microplus. The conducted studies on resistance mechanisms may serve for the development of diagnostic molecular markers of resistance to IVM.
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Hill, Catherine Alexandra. ""The mode of action of Bacillus thuringiensis (Berliner) against the sheep louse, Bovicola ovis (Schrank)"." Title page, contents and summary only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phh6449.pdf.
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Bibliography: leaves 120-145. Reports Bt crystal protein toxicity to a phthirapteran species. Although Bt strain WB3516 may produce other unidentified toxins effective against B. ovis, the results provide strong evidence that the [delta]-endotoxin crystal proteins of strain WB3516 significantly contribute to the lousicidal toxicity of this strain.
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Tobin, Michael. "The characterisation of a nucleopolyhedrovirus infecting the insect Trichoplusia ni." Thesis, Cape Peninsula University of Technology, 2019. http://hdl.handle.net/20.500.11838/2979.
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Thesis (MSc (Biomedical Sciences))--Cape Peninsula University of Technology, 2019Background: Baculoviruses have great potential as alternatives to conventional chemical insecticides. The large scale adoption of such agents has however been hampered by the slow killing times exhibited by these bio-insecticides, limitation to single target insect and difficulty of large scale production of these preparations. Trichoplusia ni single nucleopolyhedrovirus (TnSNPV), initially identified in the Eastern Cape region of South Africa, has potential as a biocontrol agent as it possesses a higher speed of kill compared to other baculoviruses. Aims and methods: The main objective of this study was the identification, molecular characterisation and cloning of a structural core gene (polyhedrin) and three auxiliary genes, the inhibitor of apoptosis (iap2 and iap3) and the ecdysteroid UDP-glucosyltransferase (egt) genes, from TnSNPV in order to delineate its phylogenetic relationship to a Canadian isolate of the same virus and to other baculoviruses. In addition, the genes were expressed in an Escherichia coli (E. coli) based system as a prelude to genetic modification to increase the pesticidal property of the virus. Results: The genome size of the South African strain of TnSNPV was estimated at 160 kb and is significantly larger than the Canadian isolate of TnSNPV and may reflect genetic variation as the two strains have adapted to varying environmental conditions. Occlusion bodies of the South African strain of TnSNPV were visualised by Transmission Electron Microscopy and consisted of rod shaped single virions composed of a single enveloped nucleocapsid. Insect bioassays showed that the median lethal time (LT50) of the virus strain averaged 1.8 days which is significantly faster than other baculoviruses. The South African and Canadian strains of TnSNPV share nucleotide similarities greater than 95% for the genes analysed in this study, which indicates that they are closely related. From this analysis, the South African strain of TnSNPV identifies as a Group II NPV with the closest relatives being the Canadian strain of TnSNPV and ChchNPV. The topology of the tree for the polyhedrin protein was better resolved than that of the IAP2, IAP3 and EGT proteins and was comparable to the tree inferred from a concatenated data set consisting of complete polyhedrin/granulin, LEF8, and LEF9 proteins of 48 completely sequenced genomes. For the IAP2, IAP3 and EGT proteins, the separation of the lepidopteran and hymenopteran specific baculoviruses was not evident while the separation of Group I and II Alphabaculoviruses diverged from that observed from the baculovirus core gene polyhedrin as well as the tree inferred from complete polyhedrin/granulin, LEF8, and LEF9 proteins. Five distinct groups relating to IAP-1, 2, 3, 4 and 5 could be distinguished from the tree inferred from all IAP proteins from 48 fully sequenced baculoviruses. From this analysis, the IAP protein from the South African isolate of TnSNPV can be designated as an IAP3 due to sequence homology to other IAP3 proteins. Similarly, the IAP2 can be confirmed as an IAP2 protein as it clusters with other IAP2 proteins. RNA transcripts of the four genes were detected by RT-PCR at one hr after induction with Larabinose in BL21-A1 E. coli and persisted until four hrs post induction. Antisera directed against the C-terminal 6X His tag was able to detect the recombinant proteins at two hours after induction confirming the rapid rise in expression of the proteins which persisted at high levels until four hrs after induction. The discrepancy observed with the predicted molecular mass of the EGT protein and the migration on SDS-PAGE may be due to the absence of posttranslational modification in the E. coli expression system and the hydrophobic residues present in the N-terminal signal sequence. Conclusion: Sequence and phylogenetic analysis suggest that the two isolates of TnSNPV have been exposed to similar evolutionary pressures and evolved at similar rates and represent closely related but distinct variants of the same virus. The difference in genome size between the two strains is likely to reflect actual genetic differences as the strains have adapted to their local environments and hosts and the extent of the differences will only be apparent as more sequencing results become available. Phylogenetic analysis of the IAP and EGT proteins yields a tree that varies from the phylogenetic reconstruction observed for the polyhedrin gene as well as the concatenated data set consisting of complete polh/gran, LEF8, and LEF9 proteins and highlights the risks inherent in inferring phylogenetic relationships based on single gene sequences. The tree inferred from the concatenated data set of polh/gran, LEF8, and LEF9 proteins was a quick and reliable method of identification particularly, when whole genome data is unavailable and mirrors the accepted lineage of baculoviruses. Expression of the recombinant IAP2, IAP3, EGT and polyhedrin was confirmed by RT-PCR and immunoblot analysis and rose rapidly after induction and persisted at high levels. It is as yet unclear if the expressed proteins are functional particularly as post translation modifications are lacking in this system.
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Freidenreich, Ariel. "Comparison of Synthetic Versus Organic Herbicides/Insecticides on Arbuscular Mycorrhizal Fungi in Abelmoschus esculentus." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2601.
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Arbuscular mycorrhizal fungi (AMF) play a crucial role in improving the growth of a vast majority of plants. Past researchers have discovered that agricultural practices have a significant negative effect on the diversity of AMF. Arbuscular mycorrhizal fungi are reported to enhance plant nutrient uptake, stress tolerance, and soil aggregate formation which are key aspects of productive low-input farming. The objective of this study was to investigate the effects of four pesticides on the ability of AMF to colonize the roots of okra plants (Abelmoschus esculentus). The pesticides being tested include two synthetic chemicals (glyphosate and carbaryl) and two organic chemicals (neem oil and citrus oil). The tested parameters included crop yield, plant biomass, leaf matter CNP, and the percentage of mycorrhizal colonization in roots. The results of this study show that the organic chemicals had no significant effect on AMF colonization while the synthetic chemicals did have somewhat of a negative effect on colonization.
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Dauthuille, Dominique. "Etude écopathologique de deux baculovirus pathogènes de Spodoptera Frugiperda (J. E. Smith) (lépidoptère : noctuidae) en prairie guyanaise à Digitaria Swazilandensis Stent." Paris 6, 1986. http://www.theses.fr/1986PA066484.
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Deux baculovirus, une granulose et une polyédrose nucléaire, isolés de S. F. En Guyane française sont décrits. Les deux maladies sont responsables d'enzooties dans les populations du ravageur en prairie à d. S. La valeur maximale de la mortalité larvaire naturelle engendrée par les deux virus, déterminée après échantillonnage et élevage au laboratoire, est de 32%. La cyclicité de la présence sur une même parcelle de la noctuelle et de ses baculovirus est due au mode de conduite des exploitations agricoles. Les taux de mortalité larvaire par granulose et par polyédrose nucléaire sont variables d'une parcelle à une autre, et un équilibre dynamique se maintient entre les deux viroses. L'introduction d'un mélange des deux virus a permis de montrer que les larves jouent un rôle important dans la dissémination des pathogènes dans la prairie.
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Charles, Jean-François. "Bacillus thuringiensis sérotype H 14 et bacillus sphaericus : sporulation, biogenèse des cristaux larvicides et cytopathologie sur larves de moustiques (diptères; culicidae)." Paris 6, 1987. http://www.theses.fr/1987PA066303.
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Santoso, Teguh. "Contribution a l'etude des relations entre la fertilisation du vegetal-hote et l'intoxication de spodoptera littoralis boisd. Par bacillus thuringiensis berliner." Paris 6, 1987. http://www.theses.fr/1987PA066027.
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L'insecticide microbiologique bacillus thuringiensis provoque des reponses de niveaux divers chez les especes susceptibles lorsqu'elles sont alimentees par differents especes vegetales. Il a ete emis l'hypothese que ces manifestations sont dependantes du systeme intestinal, lui-meme conditionne par le type d'alimentation. L'objet de ce travail est l'etude de l'effet de la fertilisation minerale du vegetal consomme sur la sensibilite de spodoptera littoralis a l'intoxication par bacillus thuringiensis
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Opoku-Debrah, John Kwadwo. "Studies on existing and new isolates of Cryptophlebia leucotreta granulovirus (CrleGV) on Thaumatotibia leucotreta populations from a range of geographic regions in South Africa." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1005466.
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Baculoviruses are arthropod-specific DNA viruses that are highly virulent to most lepidopteran insects. Their host specificity and compatibility with IPM programmes has enabled their usage as safe microbial insecticides (biopesticides). Two baculovirus-based biopesticides, Cryptogran and Cryptex, which have been formulated with Cryptophlebia leucotreta granulovirus (CrleGV) have been registered for the control of false codling moth (FCM), Thaumatotibia (=Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae) in South Africa and have been successfully incorporated into IPM programmes. However, several studies have indicated that insects can develop resistance to baculovirus-based biopesticide as was shown with field populations of codling moth (CM), Cydia pomonella (L.), which developed resistance to the biopesticide Cydia pomonella granulovirus (CpGV-M) in Europe. Other studies have shown that, under laboratory conditions, FCM populations differ in their susceptibility to Cryptogran and Cryptex. In order to investigate difference in susceptibility as well as protect against any future resistance by FCM to Cryptogran and Cryptex, a search for novel CrleGV-SA isolates from diseased insects from different geographic regions in South Africa was performed. Six geographic populations (Addo, Citrusdal, Marble Hall, Nelspruit, Baths and Mixed colonies) of FCM were established and maintained in the laboratory. Studies on the comparative biological performance based on pupal mass, female fecundity, egg hatch, pupal survival, adult eclosion and duration of life cycle of the Addo, Citrusdal, Marble Hall, Nelspruit and Mixed colonies revealed a low biological performance for the Citrusdal colony. This was attributed to the fact that FCM populations found in the Citrusdal area are not indigenous and may have been introduced from a very limited gene pool from another region. When insects from five colonies, excluding the Baths colony, were subjected to stress by overcrowding , a latent baculovirus resident in the Addo, Nelspruit, Citrusdal, Marble Hall and Mixed colonies was brought into an overt lethal state. Transmission electron micrographs revealed the presence of GV occlusion bodies (OBs) in diseased insects. DNA profiles obtained by single restriction endonuclease analysis of viral genomic DNA using BamH 1, Sa/1, Xba1 , Pst1, Xh01 , Kpn1, Hindlll and EcoR1 revealed five CrleGV-SA isolates latent within the insect populations. The new isolates were named CrleGV-SA Ado, CrleGV-SA Cit, CrleGV-SA Mbl, CrleGVSA Nels and CrleGV-SA Mix isolates. The novelty of the five CrleGV-SA isolates was confirmed by the presence of unique submolar bands, indicating that each isolate was genetically different. PCR amplification and sequencing of the granulin and egt genes from the five isolates revealed several single nucleotide polymorph isms (SNPs) which, in some cases, resulted in amino acid substitutions. DNA profiles from RFLPs, as well as phylogenetic analysis based on granulin and egt sequencing showed the presence of two CrleGV-SA genome types for the CrleGV-SA isolate. Cryptex and CrleGV-SA Ado, CrleGV-SA Cit, CrleGV-SA Mbl and CrleGV-SA Mix were placed as members of Group one CrleGV-SA, and Cryptogran and CrleGV-SA Nels isolate were placed into Group two CrleGV-SA. In droplet feeding bioassays, the median survival time (STso) for neonate larvae inoculated with Group one and two CrleGV-SA were determined to range from 80 - 88 hours (3.33 - 3.67 days), for all five colonies. LDso values for Group one and two CrleGV-SA against neonates from the Addo, Citrusdal, Marble Hall, Nelspruit and Mixed colonies varied between some populations and ranged from 0.80 - 3.12 OBs per larva, indicating some level of variation in host susceptibility. This is the first study reporting the existence of genetically distinct CrleGV baculovirus isolates infecting FCM in different geographical areas of South Africa. The results of this study have broad-ranging implications for our understanding of baculovirus-host interactions and for the application of baculovirus basedbiopesticides.
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Rey, Delphine. "Un exemple de coévolution plante-arthropode : étude de la phytotoxicité des composés phénoliques de la litière d'Alnus glutinosa (Bétulacées) et perspectives d'application en démoustication." Université Joseph Fourier (Grenoble), 2000. http://www.theses.fr/2000GRE10074.
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Dans les gites a moustiques de l'avant-pays alpin, les composes phenoliques issus de la decomposition de la litiere de la vegetation ripariale sont impliques dans la segregation ecologique de la faune arthropodienne detritivore. Cette relation plante-arthropode a ete exploree au niveau ecotoxicologique, evolutif et applique. Des bioessais comparatifs sur des larves de dipteres et des crustaces planctoniques ont confirme la sensibilite differentielle des animaux aux composes phenoliques de l'acide tannique et de la litiere decomposee d'aulne. Cette sensibilite est en rapport avec le potentiel enzymatique detoxifiant de chaque espece (ou ecotype), notamment au niveau des mono-oxygenases a p 450, esterases et gst. L'acquisition de ce potentiel de detoxication a permis aux especes (ou ecotypes) resistants de coloniser des gites fermes, a litiere riche en composes phenoliques (type aulne). L'effet toxique de ces xenobiotiques vegetaux s'exerce sur l'epithelium du mesenteron selon un scenario deletere comparable a celui induit par le bacterio-insecticide bacillus thuringiensis var israelensis (bti). Le pouvoir toxique est lie a la litiere qui doit subir un long processus de decomposition in natura. Une analyse phytochimique preliminaire a permis de le localiser, apres extraction selective, dans une fraction phenolique insoluble du materiel vegetal correspondant a la paroi. L'absence de correlation entre phylogenie moleculaire et sensibilite larvaire aux composes phenoliques, suggere que la coevolution (non reciproque) plante-moustique dans les hydrosystemes alpins est un phenomene recent, associe a une radiation evolutive rapide. La comparaison des potentialites insecticides des composes phenoliques vegetaux a celles de deux insecticides conventionnels (bti et temephos) suggere la possibilite d'utilisation de ces composes naturels en demoustication de zones anthropisees, riches en especes invasives, vulnerantes et vectrices (type culex pipiens, aedes aegypti, a. Albopictus).
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Carrington, Terry R. "Factors influencing habitat selection and activity of ground beetles (Coleoptera: Carabidae) in central Appalachia Part I : The influence of soil and soil surface characteristics on habitat selection by Carabidae ; Part II : Precipitation and temperature fluctuations : effects on Carabidae activity ; Part III : The effects of two microbial insecticides for gypsy moth control on Carabidae populations /." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2368.
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Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains viii, 114 p. : ill., maps. Vita. Includes abstract. Includes bibliographical references.
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CHIEN, CHANG YU, and 簡彰佑. "The partial characteristics of physiology and pathogenecity of Metarhizium anisopliae var. anisopliae MA-126 and feasibility as microbial insecticide." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/97u45y.
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碩士美和科技大學
生技科技系健康產業碩士班
102
The entomopathogenic fungus Metarhizium anisopliae ‘MA-126’ used in this study comes from a mutant screened by chemical mutagenesis of a wild strain of Metarhizium anisopliae ‘MA-1’. The results showed 28 ℃ is the best temperature for MA-126 mycelial growth and conidial germination. Peptone and KNO3 with their colony diameters being 6.1 cm and 4.3 cm, respectively, are the best nitrogen sources, while urea could not promote the mycelial growth of MA-126. Maltose was the best carbon source with a colony diameter of 6.7 cm. The germination rate of MA-126 maintained at 97.5% for the first 12 hours after exposing to 280 ~ 320 nm UV-B radiation for 120 minutes. On the contrary, 333 ppm 50% benomyl and 66 ppm 10% hexaconazole completely inhibited the mycelial growth of MA-126. 4 ℃is a better storage temperature for the storage of MA-126 mycelial and spores powders. The germination rate of formula A at 4 ℃(41.7%) was better than that of at 28 ℃ (0%) after six months storage. The mortality rates and half-lethal times (LT50) for two instar larvaes of cabbage white butterfly treated with 6 kinds of MA-126 spore suspension concentrations for 3 days were: 104 conidia/mL, 15 %; 105 conidia/mL, 36 % and 5.11 d; 106 conidia/mL, 65 % and 3.37 d; 107 conidia/mL, 75 % and 2.95 d; 108 conidia/mL, 92 % and 2.69 d as well as 109 conidia/mL, 100 % and 2.58 d, respectively. Indoor biological control experiments found the control rate of MA-126 at 107 conidia/mL Nilaparvata lugens(Stal) was 40.5% which was more efficient than that of the 39.6% of imidacloprid (9.6%, 1500 times). The half-lethal times for Pieris rapae crucivora Boisduval larvaes fed with leaves dipped with MA-126 spore suspension at a concentration of 7.19 × 107 conidia/mL was 2.76 days. The biological control rate of MA-126 at 109 conidia/mL Nilaparvata lugens(Stal) in a field experiment at Guilai, Pingtung county was 47.9% which was more efficient than that of the 9.0% of imidacloprid (9.6%) at 1500 times. The biological control rates of MA-126 at 109 conidia/mL against cabbage Pieris rapae crucivora Boisduval in the field experiments at Guilai and Wanluan, Pingtung county were 60.3% and 58.1%, respectively. In contrast, the control rates of Bacillus thuringiensis at 1:1500 10667 IU/mg were 34.3% and 38.0%, respectively. And the control rates of emamectin benzoate at 2000 times were 83.2% and 81.7%, respectively. In summary, based on the above-mentioned results, Metarhizium anisopliae ‘MA-126’ is effective in the control of Nilaparvata lugens(Stal) and cabbage Pieris rapae crucivora Boisduval and can serve as microbial pesticides in the future.
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Chiu, Tzu-Chuan, and 邱子權. "Study on biodegradation of organo-chlorinated insecticides and its anaerobic microbial community." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/34414253095445636378.
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博士國立臺灣大學
農業化學研究所
93
Anaerobic microbial degradation is as an important mechanism for degrading organochlorine pesticides (OCPs) in low-oxygen environment. The present research was designed to investigate the potential of anaerobic degradation of OCPs by indigenous microorganisms of river sediment. The effects of several factors including OCP concentrations, incubation temperatures and carbon sources, on both OCPs degradation and metabolite formation were studied. Denaturing gradient gel electrophoresis (DGGE) was used for analyzing the bacterial community structures during OCP degradation periods. Four OCPs, p,p’-DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)-ethane), heptachlor (1,4,5,6,7,8,8-heptachloro-3a,4,7,7a- tetrahydro-4,7-methanoindene), aldrin (1,2,3,4,10,10-hexachloro-1,4,4a,5,8,8a-hexahydro-1,4-endo-exo-5,8- dimethanonaphthalene) and dieldrin (1,2,3,4,10,10-hexachloro-6,7-epoxy- 1,4,4a,5,6,7,8,8a-octahydro-1,4-endo-exo-5,8-dimetha-nonaphthalene), were chosen for this study. According to the results, these OCPs under anaerobic conditions were more easily degraded in a 2,3,4-trichlorobiphenyls-adapted mixed culture than those in sterilized medium. Incubation temperature was an important factor in determining the degradation rates of the OCPs. The degradation rates of OCPs were faster at 40℃ than other lower temperatures (10 ~ 30℃). Microbial degradation can proceed better in the presence of OCPs in the mixed culture, at concentrations between 0.5 to 10 μg/mL. However, the microbial degradation was inhibited by adding 50 or 100 μg/mL of OCPs to the culture. Based on the addition of different carbon sources (yeast extracts, sodium acetate, or glucose), anaerobic mixed cultures exhibited diverse abilities in the OCPs degradation. The highest degradation activity was observed in the case of culture augmented with yeast extract. In 2,3,4- trichlorobiphenyls-adapted mixed cultures, the degradation rates of DDT, heptachlor and dieldrin were slightly affected by the addition of electron acceptor such as NaHCO3 or Na2SO4, but strongly inhibited by NaNO3. The evolution of metabolites occurred simultaneously with the degradation of OCPs. Metabolites of OCPs were identified by matching their retention times and mass spectra with authentic chemicals. Gas chromatography (GC) analysis indicated that p,p’-DDT and heptachlor were dechlorinated to p,p’-DDD and chlordene, respectively. Dieldrin was transformed to aldrin via epoxide reduction during the incubation periods. Anaerobic toxicity analysis (ATA) was carried out by measuring the production of methane from the anaerobic mixed culture. The production of methane was inhibited by the presence of p,p’-DDT and heptachlor, but slightly enhanced by the presence of aldrin and dieldrin. DGGE analysis of the 16S rDNA fragments obtained from mixed cultures indicated that microbial community structure was shifted during the incubation periods. Cluster analysis showed that the microbial community structures were significantly different between the OCPs-treated and nontreated cultures. Partial sequences of some bands observed in OCPs-treated culture showed that these sequences were most similar to the groups of Clostridium sp., Acidaminobacter hydrogenoformans, and Sedimentibacter saalensis, separately. Moreover, according to their physiological features of these groups, these bacteria may play significant roles during the OCPs degradation periods.
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Dogan, Elif Bar��in. "Development and reproduction of convergent lady beetle feeding on green peach aphid exposed to Btt." Thesis, 1994. http://hdl.handle.net/1957/35166.
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黃文英. "Production and application of microbial insecticides: cultivation of bacillus thuringiensis and characteristics of crystal protoin." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/92086228061713729846.
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QIU, SHU-YUAN, and 邱淑媛. "Studies on production and application of microbial insecticides : characteristics of crystal protein and^^conditions of formulation in Bacillus thuringiensis." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/72621340750515348183.
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Du, Rand Nicolette. "Isolation of entomopathogenic gram positive spore forming bacteria effective against coleoptera." Thesis, 2009. http://hdl.handle.net/10413/1235.
Full textAbstract:
Fourteen spore-forming bacterial strains were isolated and screened for entomopathogenic activity. Five displayed toxicity towards the common mealworm, Tenebrio molitor L., (Coleoptera: Tenebrionidae). The majority of the isolates were obtained from insect larvae and insect rich environments. The three bacterial species identified were Bacillus thuringiensis Berliner, Brevibacillus laterosporus Laubach and Bacillus cereus Frankland and Frankland. Bioassays were conducted using T. molitor larvae. The one isolate of B. cereus required the highest concentration of bacterial cells to achieve its LC50, whereas one of the isolates of B. laterosporus required the lowest cell concentration to achieve its LC50. Dose response curves were generated for the five best isolates, which showed that the isolate of B. laterosporus (NDR2) was substantially more toxic than the other isolates.Thesis (Ph.D.) - University of KwaZulu-Natal, Pietermaritzburg, 2009.