Dissertations / Theses on the topic 'Biological control, and natural enemy'
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Straub, Cory Severen. "Exploring the relationship between natural enemy biodiversity and herbivore suppression." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Dissertations/Fall2006/c_straub_111306.pdf.
Full textRodríguez-Gasol, Neus. "Habitat management in Mediterranean fruit orchards to foster pollinator and natural enemy communities." Doctoral thesis, Universitat de Lleida, 2019. http://hdl.handle.net/10803/668668.
Full textLa intensificación agrícola impulsó la producción de alimentos durante la Revolución Verde del siglo pasado pero también causó la pérdida de biodiversidad. Además, se espera que la demanda de alimento aumente un 15% en los próximos 10 años, por lo que el reto actual de la agricultura es el de proveer más, y de un modo más sostenible. En este contexto, el objetivo de esta tesis es el de aportar nuevos conocimientos sobre diversos aspectos relacionados con el mantenimiento y promoción de servicios ecosistémicos (polinización y control biológico) en cultivos frutícolas mediterráneos. La primera parte de la tesis evalúa los efectos del riego y la consecuente intensificación agrícola en abejas silvestres y sírfidos. Con esta finalidad, analizamos las comunidades de polinizadores en el área frutícola de Lleida. Nuestros resultados demostraron que la transformación de secano a regadío provoca una mayor abundancia de flores, una distinta composición floral y una reducción de la cobertura de hábitats seminaturales en las áreas regadas. Estos cambios ambientales resultan en una transformación drástica de la comunidad de abejas silvestres: aumenta la presencia de abejas sociales, pero disminuye la de abejas solitarias, reduciendo, consecuentemente, la diversidad global de especies (Capítulo 1). La segunda parte de la tesis se centra específicamente en la evaluación de estrategias de manejo del hábitat para la promoción de fauna auxiliar. Primero estudiamos la atracción de un margen floral a enemigos naturales de pulgones del manzano (Dysaphis plantaginea y Eriosoma lanigerum), luego caracterizamos los enemigos naturales presentes en las colonias de pulgón y finalmente, evaluamos la contribución de este margen al control biológico de pulgones. Nuestros resultados destacan la importancia de los parasitoides presentes en los alrededores de las fincas de frutales en el parasitismo de colonias de D. plantaginea (Capítulo 2). La tercera parte de la tesis, estudia la atracción de distintas características florales a sírfidos con la finalidad de entender mejor su comportamiento de búsqueda de alimento. Observamos que la forma, el número y el color de las flores suscitan diversos comportamientos en los sírfidos: preferían ramos de flores circulares y planas, y combinaciones de amarillo y blanco eran preferidas ante combinaciones con azul. Además, observamos que hembras apareadas y no apareadas se comportaban de modo distinto (Capítulo 3). La última parte aborda el potencial y las dificultades de utilizar sírfidos como proveedores de servicios ecosistémicos en los sistemas agrícolas. Para tal efecto, hicimos una revisión de la literatura existente relacionada con estos insectos beneficiosos, con especial énfasis en los aspectos clave de su ecología que pueden maximizar su potencial como polinizadores y depredadores (Capítulo 4).
Agricultural intensification boosted food production during the Green Revolution of the last century but it also caused loss of biodiversity. Nowadays the demand for food is expected to raise by a 15% in the next 10 years, so agriculture must face the challenge of providing more food in a sustainable way. In this context, the aim of this thesis was to give further insight in several aspects of the maintenance and promotion of ecosystem services (pollination and biological control) in Mediterranean fruit orchards. The first part of the thesis evaluates the effects of irrigation and the consequent agricultural intensification on two of the main groups of pollinators: wild bees and hoverflies. For that, we assessed these pollinator communities in the fruit-tree growing area of Lleida. Our results showed that the transformation of dryland into irrigation caused a higher flower abundance, different flower composition and reduced cover of semi-natural habitats in the irrigated areas. These environmental changes resulted in a drastic transformation of the wild bee communities: in the irrigated areas the presence of social bees increased but the presence of other solitary species was hindered, reducing overall wild bee species diversity (Chapter 1). The second part of the thesis specifically focuses on the evaluation of habitat management strategies to promote beneficials. First, we assessed the attractiveness of a specific flower margin to natural enemies of apple aphids (Dysaphis plantaginea and Eriosoma lanigerum), then we characterized the natural enemies present in the aphid colonies and finally, we evaluated the contribution of this margin to aphid biological control. Our results highlight the importance of parasitoids present in the surroundings of the orchards on the parasitism of D. plantaginea colonies (Chapter 2). The third part of the thesis studies the attractiveness of different flower traits to hoverflies to better understand the foraging behavior of these insects. We observed that flower shape, number and color elicit diverse behaviors in hoverflies: they showed a predilection for flat circle-shaped flowers bouquets and, that combinations with yellow and white are preferred to those that contain blue. In addition, we found behavioral differences between mated and unmated females with regard to their flower foraging (Chapter 3). The last part of the thesis addresses the potential and difficulties of using hoverflies as providers of ecosystem services in agricultural systems. For that purpose, we reviewed the existing literature related to these beneficials, with an emphasis on the key aspects of their ecology that can maximize their potential as pollinators and predators (Chapter 4).
ASIIMWE, PETER, PETER C. ELLSWORTH, and STEVEN E. NARANJO. "Natural enemy impacts on Bemisia tabaci (MEAM1) dominate plant quality effects in the cotton system." WILEY-BLACKWELL, 2016. http://hdl.handle.net/10150/621978.
Full textTrostle, Duke Marcia Katherine. "Classical biological control of Mediterranean fruit fly, Ceratitis capitata (Wiedemann), (Diptera:Tephritidae): natural enemy exploration and nontarget testing." Texas A&M University, 2003. http://hdl.handle.net/1969.1/3877.
Full textMorse, Stephen. "The integration of partial plant resistance with biological control by an indigenous natural enemy complex in affecting populations of cowpea aphid (Aphis craccivora Koch)." Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237839.
Full textFerreira, Filho Pedro José [UNESP]. "Dinâmica populacional do psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera: Psyllidae) e parasitismo por Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) em floresta de eucalipto." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/105466.
Full textO gênero Eucalyptus (Myrtaceae) é originário da Austrália e hospeda várias espécies de insetos da família Psyllidae. Dentre elas, o psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), que é considerada uma das principais pragas introduzidas desta cultura no Brasil e em outros países. O parasitóide Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) é indicado como principal agente no controle biológico desta praga. Devido a sua importância econômica, esse trabalho objetivou estudar as populações de G. brimblecombei e de P. bliteus em floresta de Eucalyptus camaldulensis para determinação de sua distribuição espacial, flutuação populacional, a relação com fatores meteorológicos (temperatura e precipitação), e determinar o índice de parasitismo pós liberação de P. bliteus em campo. O estudo da dinâmica populacional do psilídeo-de-concha e do seu parasitóide foi realizado através da utilização de 53 armadilhas amarelas e da coleta de 53 ramos/avaliação em um talhão de 19 ha com E. camaldulensis em Luiz Antônio, SP, com 42 avaliações, entre janeiro de 2006 a janeiro de 2008. Concluiu-se que as populações de ambas espécies apresentaram distribuição espacial agregada, possuem correlação inversamente proporcional à temperatura, e a precipitação pluviométrica; ocorreu aumento no índice de parasitismo em todos os pontos de liberação de P. bliteus. no período avaliado
The genus Eucalyptus is originally from Australia and hosts several species of insects of the family Psylidae. Among them, the red gum lerp psyllid is considered one of the main pests of this crop introduced in Brazil and other countries. However, for the control of phytophagous hemiptera, the treatment with insecticides proved to be expensive and unsustainable. The psylllid specific parasitic wasp Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) is indicated as the main biological control agent of this pest. Due to its economic importance, this study aimed to evaluate G. brimblecombei and P. bliteus population in Eucalyptus camaldulensis plantations to determine their spatial distribution, population fluctuation with weather interactions (temperature and rainfall), and also to determine parasitism rates in the field after release of P. bliteus. The study of population dynamic of red gum lerp psyllid and its parasitoid (53 traps sampled and 53 branches sampled per sampling dates) was carried out on E. camaldulensis plantations in 19 ha area in Luiz Antônio municipality (SP, Brazil), from January 2006 to January 2008 (42 sampling dates). This research indicated that population of both species noticed especial aggregated distribution, inversely proportional subject to temperature. Besides, was found correlation between both species and rainfall. There was also at measured period an increase in the parasitism rate at all release points of P. bliteus
Miller, Stephanie M. "Biological control tactics for suppression of adult striped cucumber Acalymma vittatum, with natural enemy parasitoid, Celatoria setosa, and insect parasitic nematode, Heterorhabditis bacteriophora." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1399901618.
Full textVan, Wert Kristina K. "Attractiveness of English thyme (Thymus vulgaris L.) to arthropod natural enemies and its suitability as a dual use resource." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2179.
Full textFerreira, Filho Pedro José 1978. "Dinâmica populacional do psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera: Psyllidae) e parasitismo por Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) em floresta de eucalipto /." Botucatu : [s.n.], 2010. http://hdl.handle.net/11449/105466.
Full textBanca: Edson Luiz Lopes Baldin
Banca: Nádia Cristina de Oliveira
Banca: Luiz Alexandre Nogueira de Sá
Banca: Leonardo Rodrigues Barbosa
Resumo: O gênero Eucalyptus (Myrtaceae) é originário da Austrália e hospeda várias espécies de insetos da família Psyllidae. Dentre elas, o psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), que é considerada uma das principais pragas introduzidas desta cultura no Brasil e em outros países. O parasitóide Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) é indicado como principal agente no controle biológico desta praga. Devido a sua importância econômica, esse trabalho objetivou estudar as populações de G. brimblecombei e de P. bliteus em floresta de Eucalyptus camaldulensis para determinação de sua distribuição espacial, flutuação populacional, a relação com fatores meteorológicos (temperatura e precipitação), e determinar o índice de parasitismo pós liberação de P. bliteus em campo. O estudo da dinâmica populacional do psilídeo-de-concha e do seu parasitóide foi realizado através da utilização de 53 armadilhas amarelas e da coleta de 53 ramos/avaliação em um talhão de 19 ha com E. camaldulensis em Luiz Antônio, SP, com 42 avaliações, entre janeiro de 2006 a janeiro de 2008. Concluiu-se que as populações de ambas espécies apresentaram distribuição espacial agregada, possuem correlação inversamente proporcional à temperatura, e a precipitação pluviométrica; ocorreu aumento no índice de parasitismo em todos os pontos de liberação de P. bliteus. no período avaliado
Abstract: The genus Eucalyptus is originally from Australia and hosts several species of insects of the family Psylidae. Among them, the red gum lerp psyllid is considered one of the main pests of this crop introduced in Brazil and other countries. However, for the control of phytophagous hemiptera, the treatment with insecticides proved to be expensive and unsustainable. The psylllid specific parasitic wasp Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) is indicated as the main biological control agent of this pest. Due to its economic importance, this study aimed to evaluate G. brimblecombei and P. bliteus population in Eucalyptus camaldulensis plantations to determine their spatial distribution, population fluctuation with weather interactions (temperature and rainfall), and also to determine parasitism rates in the field after release of P. bliteus. The study of population dynamic of red gum lerp psyllid and its parasitoid (53 traps sampled and 53 branches sampled per sampling dates) was carried out on E. camaldulensis plantations in 19 ha area in Luiz Antônio municipality (SP, Brazil), from January 2006 to January 2008 (42 sampling dates). This research indicated that population of both species noticed especial aggregated distribution, inversely proportional subject to temperature. Besides, was found correlation between both species and rainfall. There was also at measured period an increase in the parasitism rate at all release points of P. bliteus
Doutor
Stefanello, Júnior Getulio Jorge. "Seletividade de agrotóxicos registrados para a cultura do milho a adultos de Trichogramma pretiosum Riley,1878 ( Hymenoptera : trichogrammatidae ) em laboratório." Universidade Federal de Pelotas, 2007. http://repositorio.ufpel.edu.br/handle/ri/2095.
Full textThe selectivity of 64 pesticides registered to the culture were assessed to Trichogramma pretiosum Riley , 1879...................
Avalio-se a seletividade de 64 agrotoxicos registrados para a cultura do milho a Trichogramma pretiosum , 1879.............
Ferreira, Filho Pedro José [UNESP]. "Estudo de populações do psilídeo-de-concha Glycaspis brimblecombei (Hemiptera: Psyllidae) e de seu parasitóide Psyllaephagus bliteus (Hymenoptera: Encyrtidae) em floresta de Euclyptus camaldulensis por dois métodos de amostragem." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/105410.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Empresa Privada
Os psilídeos são um grupo de pragas amplamente distribuídas, causando perdas consideráveis em sistemas agrícolas e florestais. A recente descoberta da ocorrência do psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), no Brasil tornou-se um problema de grande importância, por ser específico de Eucalyptus. O parasitóide Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) é indicado como principal agente no controle biológico desta praga. Portanto, para o monitoramento adequado de ambas espécies é necessário um método eficiente de amostragem. Devido a sua importância econômica, esse trabalho objetivou estudar as populações de G. brimblecombei e de P. bliteus em floresta de Eucalyptus camaldulensis por dois métodos de amostragem, utilizando armadilhas amarelas e coleta de folhas para determinação de sua distribuição espacial, flutuação populacional, a relação com fatores meteorológicos (temperatura e precipitação), proporção sexual, e correlacionar os métodos de amostragem com ambas populações. A determinação da distribuição espacial, flutuação populacional, proporção sexual e correlação dos métodos de amostragem (53 armadilhas amarelas e 53 ramos/avaliação) foi realizada em um talhão de 19 ha com E. camaldulensis em Luiz Antônio, SP, com 10 avaliações, entre janeiro e junho de 2005. Concluiu-se que as populações de ambas espécies apresentaram distribuição espacial agregada, possue correlação inversamente proporcional à temperatura, independente do método de amostragem; não foi constatado correlação entre ambas espécies e a precipitação pluviométrica, as armadilhas adesivas amarelas são viáveis como método de amostragem e a proporção sexual (macho : fêmea) foi baixa para populações de G. brimblecombei e alta para populações de P. bliteus, sendo coletados mais fêmeas que machos para ambas espécies, no período avaliado.
Psyllids are a widespread group of pests, causing severe damage on agricultural and forestry systems. The recent discovery about occurrence of red gum lerp psyllid Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), in Brazil is nowadays a great problem in Eucalyptus forests, mainly in E. camaldulensis. The psyllid specific parasitic wasp Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) is this pest main biological control agent. Thus, the adequate monitoring of both species by a efficient sampling method would facilitate a future decision making. Due to its economic importance, this study aimed to evaluate G. brimblecombei and P. bliteus populations in Eucalyptus camaldulensis plantation by two sampling methods, using yellow traps and foliage samples to determinate their spatial distribution, population fluctuation with weather interactions (temperature and rainfall) and sexual rate and to correlate sampling methods with both populations. The study of the populational fluctuation, the sexual rate, the spatial distribution and correlation sampling methods (53 traps sampled and 53 branches sampled per sampling dates) was carried out on E. camaldulensis plantations in a 19 ha area in Luiz Antônio municipality (SP, Brazil), between January and June, 2005 (10 sampling dates). This research indicated that population of both species noticed special aggregated distribution, inversely proportional correlation subject to temperature. However between sampling methods, there was no correlation between both species with the rainfall, yellow stick traps were useful as sampling methods, sexual rate (male:female) is low to G. brimblecombei populations and high to P. bliteus populations, have been collected more female than male to both species in the evaluated period.
Cripps, M. G. "Influence of natural enemies on Cirsium arvense — a biogeographic perspective." Lincoln University, 2009. http://hdl.handle.net/10182/1411.
Full textFerreira, Filho Pedro José 1978. "Estudo de populações do psilídeo-de-concha Glycaspis brimblecombei (Hemiptera: Psyllidae) e de seu parasitóide Psyllaephagus bliteus (Hymenoptera: Encyrtidae) em floresta de Euclyptus camaldulensis por dois métodos de amostragem /." Botucatu : [s.n.], 2005. http://hdl.handle.net/11449/105410.
Full textBanca: Wilson Badiali Crocomo
Banca: Luiz Alexandre Nogueira de Sá
Resumo: Os psilídeos são um grupo de pragas amplamente distribuídas, causando perdas consideráveis em sistemas agrícolas e florestais. A recente descoberta da ocorrência do psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), no Brasil tornou-se um problema de grande importância, por ser específico de Eucalyptus. O parasitóide Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) é indicado como principal agente no controle biológico desta praga. Portanto, para o monitoramento adequado de ambas espécies é necessário um método eficiente de amostragem. Devido a sua importância econômica, esse trabalho objetivou estudar as populações de G. brimblecombei e de P. bliteus em floresta de Eucalyptus camaldulensis por dois métodos de amostragem, utilizando armadilhas amarelas e coleta de folhas para determinação de sua distribuição espacial, flutuação populacional, a relação com fatores meteorológicos (temperatura e precipitação), proporção sexual, e correlacionar os métodos de amostragem com ambas populações. A determinação da distribuição espacial, flutuação populacional, proporção sexual e correlação dos métodos de amostragem (53 armadilhas amarelas e 53 ramos/avaliação) foi realizada em um talhão de 19 ha com E. camaldulensis em Luiz Antônio, SP, com 10 avaliações, entre janeiro e junho de 2005. Concluiu-se que as populações de ambas espécies apresentaram distribuição espacial agregada, possue correlação inversamente proporcional à temperatura, independente do método de amostragem; não foi constatado correlação entre ambas espécies e a precipitação pluviométrica, as armadilhas adesivas amarelas são viáveis como método de amostragem e a proporção sexual (macho : fêmea) foi baixa para populações de G. brimblecombei e alta para populações de P. bliteus, sendo coletados mais fêmeas que machos para ambas espécies, no período avaliado.
Abstract: Psyllids are a widespread group of pests, causing severe damage on agricultural and forestry systems. The recent discovery about occurrence of red gum lerp psyllid Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), in Brazil is nowadays a great problem in Eucalyptus forests, mainly in E. camaldulensis. The psyllid specific parasitic wasp Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) is this pest main biological control agent. Thus, the adequate monitoring of both species by a efficient sampling method would facilitate a future decision making. Due to its economic importance, this study aimed to evaluate G. brimblecombei and P. bliteus populations in Eucalyptus camaldulensis plantation by two sampling methods, using yellow traps and foliage samples to determinate their spatial distribution, population fluctuation with weather interactions (temperature and rainfall) and sexual rate and to correlate sampling methods with both populations. The study of the populational fluctuation, the sexual rate, the spatial distribution and correlation sampling methods (53 traps sampled and 53 branches sampled per sampling dates) was carried out on E. camaldulensis plantations in a 19 ha area in Luiz Antônio municipality (SP, Brazil), between January and June, 2005 (10 sampling dates). This research indicated that population of both species noticed special aggregated distribution, inversely proportional correlation subject to temperature. However between sampling methods, there was no correlation between both species with the rainfall, yellow stick traps were useful as sampling methods, sexual rate (male:female) is low to G. brimblecombei populations and high to P. bliteus populations, have been collected more female than male to both species in the evaluated period.
Mestre
Dib, Hazem. "Rôle des ennemis naturels dans la lutte biologique contre le puceron cendré, Dysaphis plantaginea Passerini (Hemiptera aphididae) en vergers de pommiers." Phd thesis, Université d'Avignon, 2010. http://tel.archives-ouvertes.fr/tel-00665080.
Full textCasula, Paolo. "Functional agrobiodiversity : the role of natural enemy diversity in pest control functioning." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501472.
Full textTilly, Gaoh Abdouramane. "Potential of selected natural products as repellents against vertebrate pests of crops." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ50896.pdf.
Full textChang, Gary C. "Ecological interaction among natural enemies and its consequences for biological control /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/5205.
Full textJordan, Kristen. "BIOLOGICAL CONTROL OF UV ATTENUATION: NATURAL SUNSCREEN IN A CHANGING WORLD." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/theses/1531.
Full textOlson, David G. "EMERALD ASH BORER (COLEOPTERA: BUPRESTIDAE) HOST EXPANSION; TRADING AN OPTIMAL HOST FOR ENEMY FREE SPACE?" UKnowledge, 2018. https://uknowledge.uky.edu/entomology_etds/43.
Full textAparicio, del Moral Yahana Michelle. "Natural enemies for the conservation biological control of Myzus persicae in Mediterranean peach orchards." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/667311.
Full textEl melocotero y la nectarina pertenecen a la especie Prunus persica (L.) Batsch y es el tercer cultivo frutal con mayor producción a nivel mundial. En Europa, España es uno de los mayores países productores representando más del 30% del total de la producción. La mayoría de las plantaciones de melocotoneros y nectarinas están localizados en Cataluña, al noreste de España. Prunus persica es el huésped primario de Myzus persicae (Sulzer) (Hemiptera: Aphididae), comúnmente conocido como el pulgón verde del melocotonero, que es una de las plagas más dañinas para el cultivo. Hasta la fecha el control de este pulgón se ha basado en la utilización de insecticidas pero, debido al riesgo que representan tanto para la salud humana como para el medio ambiente, se requiere reducir el uso de estos productos. El control biológico puede ser una buena herramienta para mejorar el control de la plaga en este cultivo debido a que los pulgones tienen un amplio rango de enemigos naturales que podrían contribuir a su control. Dentro de las diferentes estrategias de control biológico que se han utilizado contra los pulgones, la conservación de los enemigos naturales ya existentes en el agroecosistema parece ser la más prometedora para los cultivos frutales. Con estos antecedentes, la presente tesis se llevó a cabo para determinar la posibilidad de implementar el control biológico por conservación contra M. persicae en cultivos de melocotón y nectarina en el área del Mediterráneo. El control biológico por conservación, se basa en preservar a los enemigos naturales presentes en la zona e implementar estrategias para mejorar sus poblaciones. Por lo tanto, la identificación de los enemigos naturales clave involucrados en el control de M. persicae, debe ser el primer paso para comenzar un programa de control biológico por conservación. La inclusión de recursos florales cerca del cultivo, podría ayudar a mejorar el control al ofrecer a los enemigos naturales recursos alimenticios como néctar y polen, contribuyendo así a aumentar sus poblaciones en el momento adecuado para controlar eficazmente la plaga. Los dos primeros capítulos de esta tesis, están dedicados a identificar los depredadores y parasitoides clave de M. persicae en la comarca del Segrià (Cataluña), y a evaluar, en condiciones de campo, el potencial de ciertas plantas insectarias para mejorar sus poblaciones. Para recolectar a los enemigos naturales de M. persicae, se utilizaron plantas centinela, es decir plantones de melocotonero expresamente infestados con M. persicae, y para identificar a las especies más abundantes se utilizaron métodos moleculares y morfológicos. Posteriormente se evaluó la atracción de los enemigos naturales hacia manchas florales que incluían las siguientes especies: Achillea millefolium L. (Compositae), Lobularia maritima L. (Brassicaceae), Moricandia arvensis L. (Brassicaceae) y Sinapis alba L. (Brassicaceae). Los resultados mostraron que los enemigos naturales más abundantes de M. persicae fueron parasitoides. A pesar de que existió un amplio rango de especies, Aphidius matricariae Haliday (Hymenoptera: Braconidae: Aphidiinae) fue con mucho la más abundante. De los pulgones parasitados se identificaron, así mismo, diez especies de hiperparasitoides. Sin embargo, la ausencia de hiperparasitoides a principio de la temporada, cuando las poblaciones de M. persicae son elevadas, sugiere que el control biológico de este pulgón no se vería afectado negativamente. En cuanto a los depredadores, Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) y Episyrphus balteatus DeGeer (Diptera: Syrphidae) fueron los más abundantes, seguidos de Orius majusculus Reuter (Hemiptera: Anthocoridae). Los experimentos de campo realizados en esta tesis, mostraron que la presencia de manchas florales fue atractiva para los sírfidos y para los parasitoides y ninguna de las plantas evaluadas fue reservorio de pulgones dañinos para los cultivos de melocotón y nectarina. Entre las cuatro plantas insectarias evaluadas, L. marítima fue uno de los mejores para los enemigos naturales. Sin embargo, la proximidad de las plantas insectarias al cultivo no incrementó la abundancia de las poblaciones de enemigos naturales en las plantas centinela, probablemente a causa del tamaño de las parcelas. Para poder contribuir de manera positiva al estado físico (fitness en inglés) de los enemigos naturales, y por lo tanto al control biológico de M. persicae, las flores de las plantas insectarias deben proporcionar a los parasitoides y depredadores un alimento que puedan aprovechar, tanto en términos de calidad como de accesibilidad. En base a ello, el tercer capítulo de esta tesis se centró en evaluar si la planta insectaria L. marítima es una fuente de alimento adecuada para el parasitoide Aphidius ervi (Haliday) (Hymenoptera: Braconidae: Aphidiinae) y el depredador A. aphidimyza. Con este objetivo, se realizaron experimentos de laboratorio para investigar si ambos enemigos naturales eran atraídos hacia L. marítima en presencia y ausencia de flores. También se evaluaron los efectos de las flores en cuanto a la longevidad y el potencial reproductivo de estos insectos. Los resultados de los experimentos llevados a cabo en el olfactómetro mostraron que los compuestos volátiles producidos por L. maritima, con y sin flores, atraían a ambos enemigos naturales. Sin embargo, esta atracción se vio afectada cuando se comparó la L. marítima con brotes de melocotón infestados con M. persicae. Aunque A. aphidimyza se benefició de una alimentación rica en azúcar, la disponibilidad de L. marítima no mejoró ni la longevidad ni la reproducción del depredador, ya que la morfología floral de esta especie impidió que las hembras se alimentaran del néctar. En cambio, las flores de L. maritima incrementaron la longevidad de las hembras de A. ervi en ausencia de pulgones. Por lo tanto, la provisión de otros recursos azucarados, como nectarios extraflorales o flores con nectarios expuestos, pueden ser un recurso alimenticio viable para los enemigos naturales y por lo tanto ayudarían a mejorar el control biológico de M. persicae. Debido a la gran diversidad de enemigos naturales que atacan a M. persicae en el área de estudio, existe una alta probabilidad de que ocurra depredación intragremial porque estos enemigos naturales no solo compiten por el mismo recurso alimenticio, sino que también pueden depredarse entre sí. Además, dado que el desarrollo de las larvas de los parasitoides ocurre dentro del pulgón, los depredadores pueden comérselos al alimentarse del pulgón. Por otro lado, la presencia de enemigos naturales en una colonia de pulgones también puede producirles cambios en su comportamiento. El último capítulo de esta tesis tuvo como objetivo evaluar las interacciones entre depredadores y parasitoides, y estudiar cómo estas interacciones pueden influir en el control biológico de M. persicae. En ensayos de laboratorio, se determinó la contribución de E. balteatus, A. aphidimyza y O. majusculus al control de M. persicae. También se evaluaron los cambios en el comportamiento del pulgón asociados por las secreciones de los cornículos o sifones, y la interacción de estos depredadores con el parasitoide A. matricariae. Los resultados mostraron que el depredador más voraz fue E. balteatus, seguido de A. aphidimyza. Orius majusculus no redujo la población de M. persicae. La secreción de los cornículos de M. persicae desencadenó una compensación de la fecundidad, es decir, un aumento de la descendencia. Aunque, A. aphidimyza y O. majusculus prefirieron matar los pulgones no parasitados, ambos depredadores fueron capaces de matar a los individuos de M. persicae parasitados pero aún no momificados. Su preferencia por matar pulgones no parasitados indica que la coexistencia de parasitoides y depredadores no sería negativa para el control biológico de M. persicae. Los resultados de esta tesis, sugieren que el control biológico por conservación puede ser una herramienta útil para mejorar el control de M. persicae en cultivos de melocotón y nectarina.
Els préssecs i les nectarines Prunus persicae (L.) Batsch és el tercer conreu fruiter amb més producció a escala mundial. Dins d'Europa, Espanya és un dels majors productors amb el 30% del total de la producció europea. La majoria de camps de presseguer i nectarina estan localitzats a Catalunya, al nord-est d'Espanya. Prunus persicae és l'hoste primari del pugó verd del préssec, Myzus persicae (Sulzer) (Hemiptera: Aphididae) que és una de les plagues més nocives per al cultiu. Fins a la data actual, el control d'aquest pugó s'ha basat en l'ús d'insecticides, però el risc que representen tant per a la salut humana com per al medi ambient, fa necessari reduir-ne l’ús. El control biològic pot ser una bona eina per millorar el control d’aquesta plaga en els camps de cultiu, ja que els pugons tenen un ampli rang d'enemics naturals que podrien contribuir al seu control. Dins de les diferents estratègies de control biològic que s'han utilitzat contra els pugons, la conservació dels enemics naturals ja existents en l'agroecosistema sembla ser la més prometedora pels cultius de fruiters. Amb aquests antecedents, la present tesi es va dur a terme amb l'objectiu de determinar la possibilitat d'implementar el control biològic per conservació contra M. persicae en cultius de préssec i nectarina en l'àrea del Mediterrani. El control biològic per conservació es basa en preservar als enemics naturals presents a la zona i en la implementació d'estratègies per millorar les seves poblacions en l'agroecosistema. Per tant, la identificació dels enemics naturals clau involucrats en el control de M. persicae ha de ser el primer pas per a començar un programa de control biològic per conservació. La implementació de recursos florals prop dels camps, podria ajudar a millorar el control, ja que ofereixen als enemics naturals recursos alimentaris com nèctar i pol·len, contribuint així a augmentar les seves poblacions en el moment adient per a controlar eficaçment la plaga. Els dos primers capítols d'aquesta tesi, estan dedicats a identificar els depredadors i parasitoides clau de M. persicae en la comarca del Segrià (Catalunya), així com a avaluar, en condicions de camp, el potencial de certes plantes insectàries per incrementar les poblacions d’enemics naturals. Per a determinar els enemics naturals de M. persicae es van utilitzar plantes sentinella, plançons de presseguer expressament infestats amb M. persicae. Per identificar les espècies més abundants es van utilitzar mètodes moleculars i morfològics. Posteriorment es va avaluar l'atracció dels enemics naturals clau cap a marges florals que incloïen les següents espècies: Achillea millefolium L. (Compositae), Lobularia maritima L. (Brassicaceae), Moricandia arvensis L. (Brassicaceae) i Sinapis alba L. (Brassicaceae). Els resultats van mostrar que els enemics naturals predominants de M. persicae eren els parasitoides. Tot i l’ampli rang d'espècies, Aphidius matricariae Haliday (Hymenoptera: Braconidae: Aphidiinae) va ser amb diferència la més abundant. Dels pugons parasitats es van identificar també deu espècies d'hiperparasitoides. Amb tot, l'absència d'hiperparasitoides a principi de la temporada, quan les poblacions de M. persicae són elevades, suggereix que el control biològic d'aquest pugó no es veuria afectat negativament. Pel que fa als depredadors, Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) i Episyrphus balteatus DeGeer (Diptera: Syrphidae) van ser els més abundants, seguits de Orius majusculus Reuter (Hemiptera: Anthocoridae). Els experiments de camp realitzats en aquesta tesi, mostren que la presència de taques florals va ser atractiva per als sírfids i per als parasitoides, i cap de les plantes avaluades va ser reservori de pugons nocius per al cultiu. Entre les quatre plantes insectari avaluades, L. marítima va ser un bon recurs per als enemics naturals. No obstant això, la proximitat de les plantes insectàries no va incrementar l'abundància de les poblacions d'enemics naturals en les plantes sentinella, probablement degut a la mida de les parcel·les. Per a poder contribuir de manera positiva al estat físic (fitness en anglès) dels enemics naturals, i per tant al control biològic de M. persicae, les flors de les plantes insectàries han de proporcionar als parasitoides i depredadors aliment que puguin aprofitar tant pel que fa a la qualitat com a l’accessibilitat. Basat en l'anterior, el tercer capítol d'aquesta tesi es va centrar en avaluar si la planta insectària L. marítima és una font d'aliment adequada per al parasitoide Aphidius ervi (Haliday) (Hymenoptera: Braconidae: Aphidiinae) i el depredador A. aphidimyza. Amb aquest objectiu, es van realitzar experiments de laboratori per investigar si tots dos enemics naturals eren atrets cap a L. marítima en presència i absència de flors. També es van avaluar els efectes de les flors pel que fa a la longevitat i el potencial reproductiu. Els resultats dels experiments duts a terme en l'olfactòmetre van mostrar que els compostos volàtils produïts per L. maritima, amb i sense flors, atreien tots dos enemics naturals. Amb tot aquesta atracció es veia afectada quan L. marítima es van comparar amb brots de presseguer infestats amb M. persicae. Tot i que A. aphidimyza es va beneficiar d'una alimentació rica en sucre, la disponibilitat de L. maritima no va millorar ni la longevitat ni la reproducció d’aquest depredador, ja que la morfologia floral d'aquesta espècie va impedir que les femelles s'alimentessin del nèctar. D'altra banda, la disponibilitat de flors de L. maritima va incrementar la longevitat de les femelles d’ A. ervi en absència de pugons. Per tant, la provisió d'altres recursos rics en sucre, com nectaris extraflorals i flors amb nectaris exposats poden ser una opció per millorar el control biològic de M. persicae. A causa de la gran diversitat d'enemics naturals que ataquen a M. persicae en l'àrea d'estudi, existeix una alta probabilitat que hi hagi depredació intragremial, ja que aquests enemics naturals no només competeixen pel mateix recurs alimentari, sinó que també poden depredar-se entre ells. A més, degut al desenvolupament de les larves dels parasitoides dins del pugó, els depredadors se’ls poden menjar en alimentar-se de pugó. D’altra banda, la presència d'enemics naturals en una colònia de pugons també pot produir-los-hi canvis de comportament. L'últim capítol d'aquesta tesi va tenir com a objectiu avaluar les interaccions entre depredadors i parasitoides, i com aquestes interaccions poden influir en el control biològic de M. persicae. Es va determinar la contribució d’E. balteatus, A. aphidimyza i O. majusculus al control de M. persicae. També es van avaluar els canvis en el comportament del pugó derivats de el líquid secretat per les cornícules o sifons i la interacció d'aquests depredadors amb el parasitoide A. matricariae. Els resultats van mostrar que el depredador més voraç va ser E. balteatus, seguit d’ A. aphidimyza. Orius majusculus no va reduir la població de M. persicae. El líquid secretat per les cornícules de M. persicae va desencadenar una compensació de fecunditat, és a dir, un augment en la descendència. Tot i que, A. aphidimyza i O. majusculus van preferir matar pugons no parasitats, els dos depredadors van ser capaços de matar als individus de M. persicae parasitats que encara no estaven momificats. La seva preferència per matar pugons no parasitats suggereix que la coexistència de parasitoides i depredadors no seria negativa pel control biològic de M. persicae. Els resultats d'aquesta tesi, suggereixen que el control biològic per conservació, pot ser una eina útil per millorar el control de M. persicae en cultius de préssec i nectarina.
Dye, Jeremiah M. "An evaluation of two strains of Cyrtobagous salviniae Calder and Sands as natural enemies of the aquatic weeds salvinia molesta Mitchell and Salvinia minima Baker." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3331.
Full textGingras, Daniel. "Effect of artificial and natural plant structures on host searching behavior of the egg parasitoid Trichogramma SPP. (Hymenoptera:Trichogrammatidae)." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36939.
Full textSize (S), heterogeneity (H) and connectivity (C) define plant structure. The development of the model of parasitism was based on laboratory experiments using three dimensional artificial plants of different combinations of S, H and C. The model was then validated with experiments, within greenhouse, using natural cruciferous plants of different structures. Significant regressions of observed values of parasitism as a function of those predicted by the model were obtained.
The effect of plant structure on two species of Trichogramma was studied by using three species of Lepidoptera and three structurally different but closely related crucifers. Also the distribution pattern of parasitized eggs according to leaf side and plant height was characterized. A repeated measure ANOVA in time where plant ages defined the repeated measures showed that all three main effects (plant, host, parasitoid) had significant effect on parasitism and only the parasitoid x plant structure interaction was significant. Mean percent of parasitism was higher on cabbage, intermediate on broccoli and lower on Brussels sprouts whereas cabbage appeared to be intermediate in plant structure, broccoli appeared to be the most simple and Brussels sprouts the most complex plant structure. On simple plant structure, both wasp species performed well on the three varieties of plant but T. evanescens outperformed T. pretiosum more often on the various plant structures. A doubly repeated measures ANOVA in space revealed significant effects of leaf side and plant height on parasitism, being greatest under leaf surface and at the base of the plant. The interaction between those two variables was not significant.
The effect of plant structure on searching behavior of T. evanescens was determined by direct observation of individual females searching on simple and complex plant structures during 1 hour. Time, frequence and sequence associated to activities and plant parts explored were obtained and analyzed. Plant structure had significant effect on time budget associated to activities (walking, resting, flying) and plant parts explored.
This study demonstrates that plant structure mediates ecological interactions by affecting host finding success and this may have important implications in population dynamics, evolution of hosts and parasitoids but also in biological control programs.
Saleh, Azzam. "Biological and ecological studies on the polyphagous predatory bug Dicyphus tamaninii Wagner (Heteroptera : Miridae) as a natural enemy of the melon aphid Aphis gossypii Glover (Homoptera: Aphididae)." Bonn : Rheinische Friedrich-Wilhelms-Universität, Institut für Pflanzenkraknheiten, 2002. http://hss.ulb.uni-bonn.de/diss_online/landw_fak/2002/saleh_azzam/0026.pdf.
Full textWhalen, Rebecca Anne. "Influence of Selective Insecticides and Cropping System on Arthropod Natural Enemies in Soybean." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/71653.
Full textPh. D.
Heunis, J. M. (Juanita Maria). "The influence of synthetic pyrethroids on phytophagous mites and their natural enemies in apple orchards." Thesis, Stellenbosch : Stellenbosch University, 1992. http://hdl.handle.net/10019.1/69805.
Full textOne copy microfiche.
ENGLISH ABSTRACT: The effects of synthetic pyrethroids on the spider mite, Tetranychus urticae Koch, and its natural enemies was investigated. The pyrethroid cyfluthrin, sprayed for the control of fruit weevil Phlyctinus callosus, did not cause mite outbreaks and was not harmful to the predators when sprayed before they appeared on the apple trees. This spray also gave good control of thrips, bollworm (Heliothis armigera) and fruit weevil (P. callosus). A late season spray of deltamethrin against codling moth, caused an increase in the phytophagous mite population. This was assosiated with a temporary reduction in the population level of the predatory beetle, Oligota fageli. The plants found on the orchard floor were examined. The plant diversity was low and plants that acted as hosts of phytophagous mites during the winter were scarce. However, Solanum nigum carried high mite populations and infected the adjacent apple trees. The plants were too few to have an effect on the whole orchard. Eight synthetic pyrethroids were tested for repellency in a leafdisk dip and spray bioassay using T. urticae. Deltamethrin and fenvalerate caused no walk-off. Cyfluthrin and fluvalinate caused moderate walk-off and bifenthrin, cyhalothrin and lambda-cyhalothrin caused high walk-off.
AFRIKAANSE OPSOMMING: Die invloed van sintetiese piretroIedes op die rooispinmyt, Tetranychus urticae Koch en hul natuurlike vyande is ondersoek. Die piretroIed, cyfluthrin, gespuit vir die beheer van snuitkewer, P4ctinus callosus, het the mytuitbrake veroorsaak the en was ook the skadelik vir predatore nadat dit vroeg in die seisoen, voordat myte in die appelbome verskyn het, gespuit is the. Die bespuiting het ook goeie beheer van blaaspootjies, bolwurm (Heliothis amdgera) en P. callosus gegee. Deltametrien wat later in die seisoen toegedien is vir die beheer van kodlingmot, Cydia pomonella, het 'n mytuitbraak veroorsaak. Dit word geassossieer met die tydelike onderdrukking van die populasievlak van die predatoriese kewer, Oligota fageli. Die plante in die dekgewas is ondersoek. Die plant-verskeidenheid was laag en plante wat kon dien as oorwinterings gashere vir fitofage myte kon dien was skaars. Solanum nigrum het egter groot bevolkings myte gedra wat die appelbome naaste aan hulle eerste besmet het. Daar was egter te min van hierdie plante om 'n invloed op die hele boord te he. Agt piretroIedes is vir afwering van T. urticae in 'n blaarskyf doop en spuit bioessal getoets. Deltamethrin en fenvalerate het geen afwering getoon the. Cyfluthrin en fluvalinate het 'n redelike afwering, terwyl bifenthrin, cyhalothrin en lamda-cyhalothrin het 'n hod mate van afwering getoon
Shand, Peter. "Biological control of marine sediment stability by the mussels Mytilus edulis L. and Modiolus modiolus (L.)." Thesis, University of Glasgow, 1987. http://theses.gla.ac.uk/2320/.
Full textMthombeni, Lestinah. "Mathematical modeling in the sustainable use of natural resources." University of the Western Cape, 2015. http://hdl.handle.net/11394/4346.
Full textThe sustainable use of natural resources is of utmost importance for every community. In particular, it is important for every given generation to plan in such a way that proper provision is made for future generations. The scientific understanding of resources use and appreciation for its life-supporting capacity is therefore essential. Mathematical modeling has proved useful to inform the planning and management of strategies for sustainable use of natural resources. Some specific topics in resource management has been studied intensively through many decades. In particular, mining, fisheries, forestry and water resources are among these. Instead of presenting a study of the latter topics, this dissertation presents a variety of cases of mathematical modeling in resource management. The aim is to improve the general understanding of the relevant problems. We expand on existing literature, papers of other authors, and add to such studies by focusing on specific items in the work, illuminating it with further explanations and graphs, or by modifying the models through the introduction of stochastic perturbations. In particular this dissertation makes contributions by giving more explanation, on the so-called environmental Fisher information or EFI for brevity (Section 2.4 and Chapter 6), and by introducing stochasticity into a pest control model (Chapter 4) and into a savanna vegetation model (Chapter 5). In Chapter 3 we present a model from the literature pertaining to the problem of shifting cultivation, i.e, the use of forest land when used for subsistence level agricultural purposes, until the land is so degraded that the occupants abandon it and move on to a new stand. The model used to study the shifting period is similar to the forest rotation problem. A model, already in the literature, for biological control of a pest is studied in Chapter 4. Onto the deterministic model we impose a stochastic perturii bation, so that we obtain a stochastic differential equation model. We prove stochastic stability of the disease-free state, when the basic reproduction number of the pest is below unity. We have performed simulations of solutions of the stochastic system. In Chapter 5 we review an existing ordinary differential equation model for the competition between trees and grass in savanna environment. The competition between them is for soil water, fed by annual rainfall. On the other hand, trees and grass are perturbed by fire, and some other environmental forcings such as herbivores. For this ODE model, we introduce stochastic perturbations. The stochastic perturbations are in the form of three mutually independent Brownian motions. Simulations to illustrate the effect of the stochasticity are shown. We present a three-tiered predator-prey model and consider its stability in terms of Fisher information. This appears as Chapter 6. The Fisher information is defined on the basis of the so-called sustainable measures hypotheses. The model is already in the literature and in the dissertation we present several computations to show the influence of carrying capacity of prey and of mortality rate on EFI. Another problem that we consider, in Chapter 7, is that of lake eutrophication caused by excessive phosphorus inflow. The computation illustrates the management of the runoff nutrients into or out of the lake. Necessary and the sufficient conditions for an optimal utility management are obtained using standard optimal control theory. The results of this dissertation demonstrate the modeling techniques in the sustainable use of natural resources. Sustainability is the quest for equal opportunities over all generations. The manner in which this sustainability is quantified in models is being debated and improved all the time. The discourse on sustainability is especially important in view of a growing world population, and with forcings such as climate change. The most important original contribution in this dissertation is the stochastic analysis on the pest control model and the savanna model.
Calabuig, Gomar Altea. "Ants, pests and natural enemies in Mediterranean citrus. Ecological interactions and practical implications for biological control." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/54122.
Full text[ES] Las hormigas constituyen un elemento importante del agroecosistema de los cítricos, en el que actúan simultáneamente como insectos depredadores y como mutualistas de hemípteros. Como consecuencia, las hormigas pueden afectar a la composición y a la dinámica poblacional de un amplio grupo de artrópodos, en los que se incluye herbívoros productores y no productores de melaza, así como a sus enemigos naturales. Se han llevado a cabo estudios de exclusión de hormigas en tres parcelas comerciales de cítricos en las que, en cada una de ellas, predominaba una especie de hormiga (Lasius grandis Forel, Pheidole pallidula (Nylander) y Linepithema humile (Mayr)). El principal objetivo ha sido el de esclarecer las interacciones ecológicas existentes entre las hormigas y los artrópodos productores y no productores de melaza, así como con los enemigos naturales a nivel de comunidad. Se ha cuantificado el efecto de la exclusión de hormigas sobre los niveles de infestación y el parasitismo de tres de las plagas más importantes de los cítricos de la zona, la plaga productora de melaza Aleurothrixus floccosus (Maskell) y las plagas que no producen melaza Aonidiella aurantii (Maskell) y Phyllocnistis citrella (Stainton). Las densidades poblacionales de A. aurantii en frutos i de A. floccosus fueron significativamente menores en el tratamiento de exclusión de hormigas. Curiosamente, no se encontraron diferencias en el porcentaje de parasitismo entre los dos tratamientos. Estos resultados sugieren que otros factores, más allá de la interferencia con los parasitoides, podrían explicar los incrementos poblacionales de plagas observados en presencia de hormigas. Por ello, se comparó la abundancia, riqueza de especies, diversidad y estructura de la comunidad de depredadores y parasitoides entre los tratamientos de exclusión y presencia de hormigas. Se capturaron e identificaron un total de 176,000 artrópodos pertenecientes a 81 taxones distintos. En cuanto a la abundancia, la respuesta de los enemigos naturales a la exclusión de hormigas fue específica para cada especie. Los parasitoides mostraron mayores abundancias en presencia de hormigas, mientras que la mayoría de los depredadores generalistas fueron menos abundantes. De igual modo, la riqueza de especies y el Índice de diversidad de Shannon de los parasitoides fueron mayores en presencia de hormigas, mientras que la riqueza de especies de los depredadores fue menor. La estructura de la comunidad de depredadores y parasitoides no difirió entre tratamientos. El impacto negativo de las hormigas sobre los depredadores generalistas puede tener importantes implicaciones sobre la regulación de las poblaciones de plagas. Finalmente, se estudió una novedosa hipótesis en la que se planteó la existencia de competencia por la melaza que producen los hemípteros, entre las hormigas y los enemigos naturales. Mediante el uso de cromatografía líquida de alta resolución (HPLC) se relacionó la actividad de las hormigas con las reservas energéticas y las fuentes alimenticias utilizadas por especímenes de enemigos naturales colectados en el campo. Se encontró una correlación significativamente negativa entre la actividad de las hormigas y el contenido total de azúcares y la alimentación a base de melaza del parasitoide Aphytis chrysomphali (Mercet) en verano. La actividad de las hormigas se correlacionó negativamente con la alimentación a base de azúcares del depredador Chrysoperla carnea s.l en primavera. Esta interacción indirecta en la que las hormigas interfieren con el estado fisiológico de los enemigos naturales no ha sido documentada previamente. Dado que la ausencia de azúcares en la alimentación de muchas especies de depredadores y parasitoides es perjudicial para su estado físico, esta interacción puede tener importantes consecuencias para la composición de la comunidad de artrópodos e implicaciones prácticas sobre el control biológico de plagas.
[CAT] Les formigues són un element important de l'agroecosistema dels cítrics, en el que poden actuar simultàniament com a insectes depredadors i com a mutualistes d'hemípters. Com a conseqüència, poden afectar a la composició i la dinàmica poblacional d'un ampli grup d'artròpodes, incloent herbívors productors i no productors de melassa així com els seus enemics naturals. Les espècies de formigues més abundants i esteses als cítrics de l'est de la Península Ibèrica són les espècies natives Lasius grandis Forel i Pheidole pallidula (Nylander) mentre que l'espècie invasora Linepithema humile (Mayr) es troba també present però no de forma estesa. S'han dut a terme estudis d'exclusió de formigues en tres parcel·les comercials de cítrics en les que, en cada una d'elles, predominava una de les tres espècies de formigues. El principal objectiu ha estat el d'esclarir les interaccions ecològiques existents entre les formigues i els artròpodes productors i no productors de melassa així com els enemics naturals a nivell de comunitat. S'ha quantificat l'efecte de l'exclusió de formigues sobre els nivells d'infestació i el parasitisme de tres de les plagues més importants dels cítrics de la zona, la plaga productora de melassa Aleurothrixus floccosus (Maskell) i les plagues no productores de melassa Aonidiella aurantii (Maskell) i Phyllocnistis citrella (Stainton). Les densitats poblacionals d' A. aurantii en fruits i d'A. floccosus foren significativament menors en el tractament d'exclusió de formigues. Curiosament, no es trobaren diferències en el percentatge de parasitisme entre els dos tractaments per a ninguna de les plagues estudiades. Aquests resultats suggereixen que altres factors, més enllà de la interferència amb els parasitoides, podrien explicar els increments poblacionals de plagues observats en presència de formigues. Davant aquests resultats, es va comparar l'abundància, riquesa d'espècies, diversitat i estructura de la comunitat de depredadors i parasitoides entre els tractaments d'exclusió i presència de formigues. Es capturaren i identificaren un total de 176,000 artròpodes pertanyents a 81 taxons distints. En quant a l'abundància, la resposta dels enemics naturals a l'exclusió de formigues fou específica per a cada espècie. Els parasitoides mostraren majors abundàncies en presència de formigues mentre que la majoria de depredadors generalistes foren menys abundants. La riquesa d'espècies i l'Índex de diversitat de Shannon dels parasitoides foren majors en presència de formigues mentre que la riquesa d'espècies dels depredadors fou menor. L'estructura de la comunitat de depredadors i parasitoides fou similar entre tractaments. L'impacte negatiu de les formigues sobre els depredadors generalistes pot tenir importants implicacions per a la regulació de les poblacions de plagues. Finalment s'estudià una novedosa hipòtesi en la que es va plantejar l'existència de competència per la melassa que produeixen els hemípters entre les formigues i els enemics naturals. Mitjançant l'ús de cromatografia líquida d'alta resolució (HPLC) es va relacionar l'activitat de les formigues amb les reserves energètiques i les fonts alimentàries utilitzades per espècimens d'enemics naturals recol·lectats al camp. Es va trobar una correlació significativament negativa entre l'activitat de les formigues i el contingut total de sucres i l'alimentació a base de melassa del parasitoide Aphytis chrysomphali (Mercet) en estiu. L'activitat de les formigues es va correlacionar negativament amb l'alimentació a base de sucres del depredador Chrysoperla carnea s.l. en primavera. Aquesta interacció indirecta en la que les formigues interfereixen en l'estat fisiològic dels enemics naturals no ha sigut documentada prèviament. Donat que l'absència de sucres en l'alimentació de moltes espècies de depredadors i parasitoides és perjudicial per al seu estat físic, aquesta interacció pot ten
Calabuig Gomar, A. (2015). Ants, pests and natural enemies in Mediterranean citrus. Ecological interactions and practical implications for biological control [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/54122
TESIS
Meyhöfer, Rainer [Verfasser]. "Intra- and interspecific interactions among natural enemies and consequences for biological control of arthropods / Rainer Meyhöfer." Hannover : Gottfried Wilhelm Leibniz Universität, 2019. http://d-nb.info/1182532675/34.
Full textGrbin, Lynne C. "Sublethal effects of Bacillus thuringiensis Berliner on the diamondback moth, Plutella xylostella (L.), and its natural enemy, Cotesia plutellae Kurdjumov : implications for resistance management." Title page, table of contents and summary only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phg785.pdf.
Full textSilva, Roberta Kélia Bezerra. "Técnica de criação e aspectos do parasitismo de Opius sp. (Hymenoptera: Braconidae) sobre a mosca-minadora, Liriomyza trifolii (Diptera: Agromyzidae), em meloeiro." Universidade Federal Rural do Semi-Árido, 2008. http://bdtd.ufersa.edu.br:80/tede/handle/tede/70.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior
The leafminer Liriomyza trifolii is nowadays the main pest of melon orchards in the region of Chapada do Apodi, Northeast of Brazil. In order of the high infestation level of this insect, the control based only in pesticides has not been plenty satisfactory. However, considerable parasitism levels occasioned by Opius sp. have been found in field, mainly in the beginning of the production. Because of this fact, the first studies with this parasitoid are been developed in the Entomology Laboratory of UFERSA. The present study had the objective of adapting a rearing technique to the parasitoid Opius sp. in laboratory conditions, and study the aspects of it s parasitism, aiming the future utilization of this parasitoid in the leafminer integrated management programs, in the Semi-Arid conditions of Rio Grande do Norte State. Initially, infested melon leaves with L. trifolii larvae were collected in field to obtain the parasitoids. From the first parasitoids obtained from field, a technique to multiply them in L. trifolii on melon plants was developed. In the observations of the parasitism aspects of Opius sp., was perceived that it prefer to oviposite in 2nd and 3rd instar larvae. In addition, was observed that females present the highest levels of parasitism in the first two days of life
A mosca-minadora Liriomyza trifolii (Diptera: Agromyzidae), é atualmente a principal praga do meloeiro Cucumis melo L., na região da Chapada do Apodi, nordeste brasileiro. Devido às altas infestações deste inseto, o controle baseado exclusivamente no uso de inseticidas não tem sido plenamente satisfatório. Por outro lado, índices consideráveis de parasitismo, ocasionados pelo parasitóide Opius sp. (Hymenoptera: Braconidae), têm sido constatado em campo, principalmente no início da safra. Em função deste fato, estudos básicos com este parasitóide estão sendo realizados no Laboratório de Entomologia da UFERSA, Mossoró, RN. Dessa forma, o presente trabalho objetivou descrever uma técnica para criação de Opius sp., em condições de laboratório, e estudar aspectos de seu parasitismo, visando sua utilização em futuros programas de manejo integrado da mosca-minadora do meloeiro, nas condições do semi-árido do Rio Grande do Norte. Inicialmente, folhas de meloeiro infestadas com larvas da mosca-minadora foram coletadas em campo para obtenção dos parasitóides. A partir dos primeiros parasitóides obtidos foi adaptada uma técnica para multiplicação destes sobre L. trifolii em plantas de meloeiro. Nas observações sobre os aspectos do parasitismo do Opius sp., constatou-se que estes preferem ovipositar em larvas de 2º e 3º ínstar. Além disso, foi observado que as fêmeas do Opius sp. apresentam maiores índices de parasitismo nos primeiros dois dias de vida
Hatherly, Ian Stuart. "Establishment potential of non-native glasshouse biological control agents, with emphasis on 'Typhlodromips montdorensis' (Schicha) (Acari : Phytoseiidae) in the UK." Thesis, University of Birmingham, 2005. http://etheses.bham.ac.uk//id/eprint/107/.
Full textAbraham, Yvonne Jane. "Evaluation of Pineu Pini (macquart) (Homoptera: Adelgidae) insect natural enemies for the biological control of Pineus spp." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299557.
Full textBiganski, Sarah [Verfasser], Johannes A. [Akademischer Betreuer] Jehle, and Gerhard [Akademischer Betreuer] Thiel. "Evaluation of Natural Antagonists for Biological Control of Drosophila suzukii / Sarah Biganski ; Johannes A. Jehle, Gerhard Thiel." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2020. http://d-nb.info/1218692383/34.
Full textSmith, Risa Barbara. "Plant size, resource concentration and natural enemies : a comparison of four herbivores in monocultures of brussels sprouts and dicultures of brussels sprouts/peppermint." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30791.
Full textLand and Food Systems, Faculty of
Graduate
Serrano, Ana Maria Villa. "Ecological infrastructures in sustainable olive growing: studies about Prays oleae (Bernard) and its natural enemies." Doctoral thesis, ISA-UL, 2016. http://hdl.handle.net/10400.5/12034.
Full textThe olive tree (Olea europaea L.) has been shaping and characterizing landscape and culture in the Mediterranean basin. This tree is attacked by pest that can cause significant losses. This thesis was focused on the conservation biological control of one of its most damaging pests: the olive moth, Prays oleae (Bernard). Naturally, a large number of parasitoid and predator species are associated to this pest, and in order to satisfy their needs they make use of ecological infrastructures occurring in the olive grove agroecosystem. However, how these ecological infrastructures can be used to enhance the olive moth conservation biological control needs to be disentangled. For that, two approaches were followed. First, the influence of ecological infrastructures on P. oleae and its natural enemies was analyzed through field surveys. Then, different food resources were evaluated as potential foods for P. oleae and its natural enemies, i.e., the parasitoid Elasmus flabellatus (Fonscolombe) and the predator Chrysoperla carnea s. l. (Stephens). In the first approach, P. oleae was found to disperse throughout non-crop patches, although the implications for the pest population are unknown. The heterogeneous landscapes composed by herbaceous and woody vegetation around the olive groves were exploited by syrphids as food sources. Finally, ground covers within the olive groves favored the parasitoid Ageniaspis fuscicollis (Dalman) while the herbicide application diminished it. In the second approach, insects’ honeydews [Saissetia oleae (Olivier) and Euphyllura olivina (Costa)] and the flowers of Malva sylvestris L. favored the survival and/ or reproduction of P. oleae, C. carnea and E. flabellatus. Several plant species such as Daucus carota L., Veronica persica Poir, and Lamium purpureum L. showed to be potential food resources for the studied natural enemies. From the results obtained in this research various applications for managing the olive grove agroecosystem are proposed
Arsenault, Arielle. "Behavioral Ecology and Genetics of Potential Natural Enemies of Hemlock Woolly Adelgid." ScholarWorks @ UVM, 2013. http://scholarworks.uvm.edu/graddis/10.
Full textNeves, Juliana Alves. "Dinâmica predador presa, relações funcionais e o potencial de Heterópteros no manejo de pragas." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-03062014-153807/.
Full textBecause of the environmental modifications made by anthropic actions, the ecological systems have been losing their organisms, resulting in simplification of trophic interactions, which bring out species instability, especially at agricultural and forest systems. Thus, to understand the performance of natural enemies it is primordial to their usage at integrated pest management programs. In this study, the predator prey interactions of two species from the suborder Heteroptera, Podisus nigrispinus and Graptocleptes bicolorwere investigated, to understand their dynamics and functional responses, with some preys from the Lepidoptera order.
Formentini, Aline Carraro. "Lepidópteros associados à cultura da soja : diversidade e parasitismo natural por insetos e fungos entomopatogênicos." reponame:Repositório Institucional da UCS, 2009. https://repositorio.ucs.br/handle/11338/490.
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In soybean plantations, the equilibrium between insect pests and their natural enemies can be influenced by various factors such as soil management, use of phytosanitary products and soybean cultivar. This study evaluated the diversity of Lepidoptera associated with soybean crops in the Americas, and the specific abundance of these organisms and their natural enemies (parasitoids and entomopathogenic fungi) on conventional and transgenic RR soybean, treated with selective herbicides and glyphosate formulations. The experiment was carried out in Vacaria, Rio Grande do Sul state. Conventional BRS 133 and transgenic RR soy were each planted on three, one-hectare plots and treated with either selective herbicides or a glyphosate formulation. During weekly sampling, Lepidoptera were collected using the drop cloth method and maintained in the laboratory until adults and associated parasitoids and fungi could be obtained. Entomopathogenic fungi were isolated from soil samples. Based on literature data one list of 71 species of Lepidoptera that had been previously reported as feeding on soybean crop was prepared. In the present study, 1634 Lepidoptera larvae were identified in 22 taxa, including the following well-represented species: A. gemmatalis, P. includens e R. nu (83.05% of the larvae collected). The glyphosate treatments reduced the mean number of larvae when compared with the selective herbicide treatments. Hymenopterans, dipterans and strepsipterans were responsible for 34.52% of the total caterpillar parasitism. A large percentage of the larvae parasitized (93.05%) belong to the three most common species of Lepidoptera in our sampling, particularly to the Plusiinae, which were more heavily parasitized than A. gemmatalis. The entomopathogenic fungus N. rileyi was the only species isolated from the caterpillars and was responsible for 1.41% of the deaths amongst the three most common species. The numbers of colony-forming unities of Beauveria, Metarhizium and Paecilomyces, isolated from soil samples, did not differ among the plots.
McCullough, Christopher Thomas. "The effects of wildflower plots and diverse landscapes on ecosystem services, bee communities, and on-farm tick abundance." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/98733.
Full textDoctor of Philosophy
Conservation of natural habitats and planting wildflower plots are two strategies to enhance pollination services and biological control of crop pests. These two ecosystem services are of needed to improve agricultural production without further damaging the environment. There are several programs at various levels of government in the United States that landowners can use to subsidize the costs of implementing these strategies. European studies have shown these government programs to be successful. However, these programs have not been evaluated in the United States on their ability to enhance pollination services and biological control. Furthermore, studies investigating potential ecosystem disservices these strategies. In this study, we evaluated the effects of natural habit and wildflower plots on biological control, pollination services, bee communities, and tick populations in Eastern Virginia and Maryland. This research was conducted on 22 farms. 10 of these farms had wildflower plots that were designed by Natural Resource Conservation Service personnel, and implemented by cooperating farmers. Collards, strawberries, tomatoes, and squash were used as model systems. We measured pest density, egg predation, crop damage, seed pollination, and yield. We also sampled the bee community, and recorded tick abundance in wildflower plots. There were no consistent trends for many measures of biological control and pollination services in response to the wildflower plots and natural habit. However, the proportion of high quality yield for all four crops increased with increasing natural habitat in the landscape. Bee communities between sites with and without wildflower plots were not different. Bee abundance did increase at wildflower sites when natural habitat comprised a certain proportion of the habitat around the site. Ticks were sampled from wildflower plantings, but not in greater abundance compared to field margins. In this study, the effects of wildflower plots were overshadowed by the landscape effects of natural habitat. Government personnel that oversee these programs may need to consider the surrounding landscape when helping implement on-farm conservation measure like wildflower plots. Such measures, do not perform an ecosystem disservice in regards to ticks.
McCullough, Christopher T. "The effects of wildflower plots and diverse landscapes on ecosystem services, bee communities, and on-farm tick abundance." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/98733.
Full textDoctor of Philosophy
Conservation of natural habitats and planting wildflower plots are two strategies to enhance pollination services and biological control of crop pests. These two ecosystem services are of needed to improve agricultural production without further damaging the environment. There are several programs at various levels of government in the United States that landowners can use to subsidize the costs of implementing these strategies. European studies have shown these government programs to be successful. However, these programs have not been evaluated in the United States on their ability to enhance pollination services and biological control. Furthermore, studies investigating potential ecosystem disservices these strategies. In this study, we evaluated the effects of natural habit and wildflower plots on biological control, pollination services, bee communities, and tick populations in Eastern Virginia and Maryland. This research was conducted on 22 farms. 10 of these farms had wildflower plots that were designed by Natural Resource Conservation Service personnel, and implemented by cooperating farmers. Collards, strawberries, tomatoes, and squash were used as model systems. We measured pest density, egg predation, crop damage, seed pollination, and yield. We also sampled the bee community, and recorded tick abundance in wildflower plots. There were no consistent trends for many measures of biological control and pollination services in response to the wildflower plots and natural habit. However, the proportion of high quality yield for all four crops increased with increasing natural habitat in the landscape. Bee communities between sites with and without wildflower plots were not different. Bee abundance did increase at wildflower sites when natural habitat comprised a certain proportion of the habitat around the site. Ticks were sampled from wildflower plantings, but not in greater abundance compared to field margins. In this study, the effects of wildflower plots were overshadowed by the landscape effects of natural habitat. Government personnel that oversee these programs may need to consider the surrounding landscape when helping implement on-farm conservation measure like wildflower plots. Such measures, do not perform an ecosystem disservice in regards to ticks.
Wantuch, Holly Anne. "Investigating the natural history and predator complex of the native pine bark adelgid (Pineus strobi) in southwestern Virginia." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/93205.
Full textPh. D.
Lawrence, Janet L. "Conservation of insect natural enemies in heterogeneous vegetable landscapes." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1092761676.
Full textTitle from first page of PDF file. Document formatted into pages; contains xvi, 166 p.; also includes graphics (some col.). Includes bibliographical references. Available online via OhioLINK's ETD Center.
Corlay, Herrera Favio Raul. "Seasonal development and natural enemies of an invasive exotic species, the swede midge Contarinia nasturtii (Kieffer), in Quebec." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100787.
Full textJenkins, Paul E. "Control of the grape berry moth, Paralobesia viteana, using reduced-risk insecticides, cultural controls, and conservation of natural enemies." Diss., Connect to online resource - MSU authorized users, 2006.
Find full textFraga, Diego Felisbino [UNESP]. "Distribuição vertical e temporal de ovos de Alabama argillacea e de Heliothis virescens (Lepidoptera: Noctuidae) e parasitismo natural por Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/91327.
Full textConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O conhecimento do comportamento de infestação dos insetos em sistemas agrícolas facilita as amostragens, economiza tempo sem perder a confiabilidade para a tomada de decisões no sistema de manejo de pragas. Assim o objetivo foi estudar a distribuição vertical e temporal de ovos de Alabama argillacea e de Heliothis virescens, e o parasitismo de ovos por Trichogramma pretiosum em cultivares de algodoeiro. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos (cultivares DeltaOPAL, FMX-933, FMT-701, FMX-910 e NuOPAL), com oito repetições. As avaliações foram semanais, a partir da emergência das plantas. Para a distribuição vertical, as plantas foram avaliadas nas partes superior, média e inferior, anotando-se o número de ovos. Os ovos de A. argillacea e de H. virescens foram parasitados por Trichogramma pretiosum. Não houve preferência para oviposição por A. argillacea e por H. virescens durante os estágios fenológicos das plantas, tal como o grau de parasitismo por T. pretiosum também não foi influenciado. Quanto à distribuição vertical dos ovos, o terço superior e o médio das plantas foram os mais preferidos para oviposição por A. argillacea nas cultivares NuOPAL, DeltaOPAL e FMX-910, enquanto que H. virescens preferiu ovipositar no terço superior das plantas. T. pretiosum preferiu ovipositar em ovos de A. argillacea presentes no terço superior e médio das plantas, sendo que ovos de H. virescens presentes no terço superior das plantas foram mais parasitados por T. pretiosum
The knowledge of a pest infestation behavior on agricultural areas help the sampling and reduce time without lose confidence on decisions in integrated pest management. This work aimed to study the vertical and temporal distribution of Alabama argillacea and Heliothis virescens eggs, as well as parasitism of its eggs by Trichogramma pretiosum in cotton cultivars. The experimental design was randomized blocks with five treatments with five treatments (cultivars DeltaOPAL, FMX-933, FMT-701 and FMX-910 and NuOPAL) and with eight replicates. Evaluations were performed weekly since plant emergence. For the vertical distribution, plants were divided into three parts, upper, middle and bottom. The number of eggs present in plants was recorded. A. argillacea and H. virescens eggs were parasitized by Trichogramma pretiosum. There was no preference for oviposition by A. argillacea and H. virescens during the plants phenological stages, as well as T. pretiosum parasitism. Concerning the vertical distribution of eggs, the upper and middle parts of the plants were the most preferred for oviposition by A. argillacea on cultivars NuOPAL, DeltaOPAL and FMX-910, and H. virescens preferred to oviposit in the upper part of the plants. T. pretiosum preferred to oviposit in A. argillacea eggs on the upper and middle parts of the plants, and in H. virescens on the upper part of the plants
Duffy, Michael Patrick. "Population phenology and natural enemies of paropsis atomaria Olivier (Coleoptera: Chrysomelidae) in South-East Queensland." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16467/1/Michael_Duffy_Thesis.pdf.
Full textDuffy, Michael Patrick. "Population phenology and natural enemies of paropsis atomaria Olivier (Coleoptera: Chrysomelidae) in South-East Queensland." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16467/.
Full textFraga, Diego Felisbino. "Distribuição vertical e temporal de ovos de Alabama argillacea e de Heliothis virescens (Lepidoptera: Noctuidae) e parasitismo natural por Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) /." Jaboticabal : [s.n.], 2012. http://hdl.handle.net/11449/91327.
Full textBanca: Marcos Gino Fernandes
Banca: Nilza Maria Martinelli
Resumo: O conhecimento do comportamento de infestação dos insetos em sistemas agrícolas facilita as amostragens, economiza tempo sem perder a confiabilidade para a tomada de decisões no sistema de manejo de pragas. Assim o objetivo foi estudar a distribuição vertical e temporal de ovos de Alabama argillacea e de Heliothis virescens, e o parasitismo de ovos por Trichogramma pretiosum em cultivares de algodoeiro. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos (cultivares DeltaOPAL, FMX-933, FMT-701, FMX-910 e NuOPAL), com oito repetições. As avaliações foram semanais, a partir da emergência das plantas. Para a distribuição vertical, as plantas foram avaliadas nas partes superior, média e inferior, anotando-se o número de ovos. Os ovos de A. argillacea e de H. virescens foram parasitados por Trichogramma pretiosum. Não houve preferência para oviposição por A. argillacea e por H. virescens durante os estágios fenológicos das plantas, tal como o grau de parasitismo por T. pretiosum também não foi influenciado. Quanto à distribuição vertical dos ovos, o terço superior e o médio das plantas foram os mais preferidos para oviposição por A. argillacea nas cultivares NuOPAL, DeltaOPAL e FMX-910, enquanto que H. virescens preferiu ovipositar no terço superior das plantas. T. pretiosum preferiu ovipositar em ovos de A. argillacea presentes no terço superior e médio das plantas, sendo que ovos de H. virescens presentes no terço superior das plantas foram mais parasitados por T. pretiosum
Abstract: The knowledge of a pest infestation behavior on agricultural areas help the sampling and reduce time without lose confidence on decisions in integrated pest management. This work aimed to study the vertical and temporal distribution of Alabama argillacea and Heliothis virescens eggs, as well as parasitism of its eggs by Trichogramma pretiosum in cotton cultivars. The experimental design was randomized blocks with five treatments with five treatments (cultivars DeltaOPAL, FMX-933, FMT-701 and FMX-910 and NuOPAL) and with eight replicates. Evaluations were performed weekly since plant emergence. For the vertical distribution, plants were divided into three parts, upper, middle and bottom. The number of eggs present in plants was recorded. A. argillacea and H. virescens eggs were parasitized by Trichogramma pretiosum. There was no preference for oviposition by A. argillacea and H. virescens during the plants phenological stages, as well as T. pretiosum parasitism. Concerning the vertical distribution of eggs, the upper and middle parts of the plants were the most preferred for oviposition by A. argillacea on cultivars NuOPAL, DeltaOPAL and FMX-910, and H. virescens preferred to oviposit in the upper part of the plants. T. pretiosum preferred to oviposit in A. argillacea eggs on the upper and middle parts of the plants, and in H. virescens on the upper part of the plants
Mestre
Kleinjan, C. A. "The natural enemies of Asparagus asparagoides (L.) Wight in South Africa and their potential for use as biological control agents in Australia." Master's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/11663.
Full textA form of the southern African plant Asparagus asparagoides (Asparagaceae), is a serious environmental week in Australia, where it is known as bridal creeper. Bridal creeper has an extensive underground tuber system and can invade native vegetation, two factors that make chemical and/or mechanical control difficult. The fruit is bird dispersed which facilitates colonisation of new sites. Surveys for potential biological control agents for use against bridal creeper in Australia were initiated in South Africa during 1989. This dissertation describes the identification, distribution and phenology of A. asparagoides in South Africa, as well as the natural enemies associated with the plant and their potential for use as biological control agents in Australia. Potential biological control agents that attack vegetative growth of bridal creeper included an undescribed Zygina sp. (Cicadellidae), two undescribed Crioceris species (Chrysomelidae - Criocerinae) and the rust fungus, Puccinia myrsiphlli DC. (Uredinales). The seeds of bridal creeper are attacked by an undescribed Eurytoma sp. (Eurytomidae) and the fruits by Zalaca snelleni (Wallengren) (Noctuidae). An organism directly attacking the tuber mass of bridal creeper was not found. Experimental results illustrated that herbivore damage to the above ground parts of the plant resulted in reduced tuber mass and also impacted negatively on fruit production.