Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-04-05T13:25:49Z No. of bitstreams: 1 texto completo.pdf: 442561 bytes, checksum: 436255b4a2ddd60ae47426064fb6ecb9 (MD5) / Made available in DSpace on 2017-04-05T13:25:49Z (GMT). No. of bitstreams: 1 texto completo.pdf: 442561 bytes, checksum: 436255b4a2ddd60ae47426064fb6ecb9 (MD5) Previous issue date: 2005-11-14 / Fundação de Amparo à Pesquisa do Estado de Minas Gerais / As plantas têm papel ativo no controle do processo de herbivoria pela influência sobre as populações de fitófagos e/ou de inimigos naturais, atuando diretamente sobre o comportamento dos herbívoros ou indiretamente, atraindo populações de inimigos naturais. As investigações dessa tese tiveram como objetivo estudar interações em uma teia alimentar formada pelo morangueiro, Fragaria x ananassa, pelo ácaro-rajado Tetranychus urticae Koch (Acari: Tetranychidae), pelo ácaro-vermelho Oligonychus ilicis e pelo predador Phytoseiulus macropilis. Espera-se que tais estudos sirvam de base para a definição de um programa de controle biológico de ácaros fitófagos na cultura do morangueiro em sistemas de produção orgânica ou integrada. No capítulo I, investigou-se a interação direta entre O. ilicis e T. urticae sobre plantas de morangueiro avaliando-se os padrões de escolha de O. ilicis e T. urticae por sítios de alimentação nessas plantas. Duas hipóteses foram formuladas: a primeira, que a escolha por sítios de alimentação estaria relacionada à aptidão das espécies; a segunda, que essa escolha seria determinada pela presença do ácaro heteroespecífico. Essas hipóteses foram testadas avaliando-se a preferência, a biologia e o sucesso reprodutivo de O. ilicis e T. urticae sobre as faces abaxial e adaxial de folhas de morangueiro infestadas ou não pelo heteroespecífico. Os resultados obtidos permitiram discutir a possibilidade de interação entre O. ilicis e T. urticae sobre plantas de morangueiro. No capítulo II, estudou-se em laboratório a resposta olfativa do ácaro predador P. macropilis à planta de morangueiro infestada por T. urticae e/ou por O. ilicis, com o objetivo de avaliar o efeito da infestação simples e múltipla de plantas por ácaros fitófagos sobre a atração do ácaro predador. Hipotetisou-se que, plantas de morangueiro infestadas por mais de uma espécie de ácaro fitófago seriam menos atrativas ao ácaro predador P. macropilis quando exposto aos voláteis da planta. No capítulo III, testou-se a hipótese de que o risco de predação afetaria a escolha por sítios de alimentação. Primeiramente, foi avaliado o desempenho do predador P. macropilis alimentado com adultos e ovos de O. ilicis e T. urticae. Tal informação forneceu indicativos sobre o valor nutricional dessas espécies para o predador. Em seguida, foi avaliada a escolha de T. urticae e O. ilicis por faces de folhas de morangueiro com pistas do predador P. macropilis. Previamente, era conhecido que T. urticae e O. ilicis possuem maior sucesso reprodutivo sobre as faces abaxial e adaxial de folha de morangueiro, respectivamente. Isto devido, provavelmente, à qualidade do alimento nessas respectivas faces foliares. No capítulo IV, testou-se a hipótese que plantas de morangueiro que sofressem infestações prévias por T. urticae seriam capazes de responder às injúrias com maior rapidez em comparação àquelas que não foram atacadas. As plantas que apresentam defesa direta podem reduzir o desempenho dos predadores pela redução da quantidade e qualidade de presas. Nesse caso, haveria um efeito oposto entre defesas diretas e indiretas em plantas de morangueiro. Ou seja, enquanto as defesas diretas reduzem o efeito do ataque dos fitófagos, os predadores, atraídos pelas defesas indiretas, teriam menor disponibilidade de alimento. / Plants can affect herbivores or natural enemies to reduce the effects of herbivory. This can be done directly through reduction of the population growth of herbivorous population, or indirectly, by attracting or arresting natural enemies to the plant. The interactions in a food web composed of strawberry plants, Fragaria x ananassa, the Two-Spotted Spider Mite Tetranychus urticae Koch, the Southern Red Mite Oligonychus ilicis (McGregor) (Acari: Tetranychidae) and the predatory mite Phytoseiulus macropilis have been studied. The results will provide information that is useful in defining a biological control program for spider mites on organically produced strawberries and in integrated production systems. In the first chapter, the direct interaction and choice for feeding sites of O. ilicis and T. urticae on strawberry plants are investigated, using two hypotheses: 1. the choice of feeding site is related to the fitness of the individual; 2. the choice of feeding site is affected by the presence of a heterospecific mite. The preference, biology and reproductive success of O. ilicis and T. urticae were evaluated on both sides of strawberry leaves either infested by the heterospecific mite or without previous damage. O. icilis preferred to stay on the upper side while T. urticae preferred the underside. The preference for the leaf surface correlated with the reproductive success of the species. The results provide information on the interaction between O. ilicis and T. urticae on strawberry plants. In the second chapter, the attraction of predatory mites by plants damaged by T. urticae and/or by O. ilicis was studied under laboratory conditions. The role of multiple infestations in the attraction of predatory mite was studied. In the third chapter, the hypothesis that predation risk is an important factor on food site selection by spider mites was tested. An experiment on the effect of predation risk by Phytoseiulus macropilis on the food site choice of the spider mites Tetranychus urticae and Oligonychus ilicis was carried out on strawberry plants. The performance of the predator P. macropilis fed with adults and eggs of O. ilicis and T. urticae was evaluated. The effect of pre-infestation of strawberry plants by Tetranychus urticae on the development and reproduction of the mite species was discussed in the fourth chapter. The preinfestation induced the production of direct defenses, which can reduce the population growth rate of the herbivores. Possibly, an opposite effect between direct and indirect defenses in strawberry plants could occur. Whereas direct defenses reduce the effects of herbivore attack, predators attracted by indirect defenses could have low food availability. This requires further investigation. / Não foi localizado o cpf do autor.

Master of Science / Department of Entomology / David C. Margolies / Yoonseong Park / Phytoseiulus persimilis (Acari: Phytoseiidae) is a specialist predator on tetranychid mites, especially on the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). The foraging environment of the predatory mites consists of prey colonies distributed in patches within and among plants. Quantitative genetic studies have shown genetic variation in, and phenotypic correlations among, several foraging behaviors within populations of the predatory mite, P. persimilis. The correlations between patch location, patch residence, consumption and oviposition imply possible fitness trade-offs. We used molecular techniques to investigate genetic variation underlying the foraging behaviors. However, these genetic studies require a sufficiently large amount of DNA which was a limiting factor in our studies. Therefore, we developed a method for obtaining DNA from a single mite by using a chelex extraction followed by whole genome amplification. Whole genome amplification from a single mite provided us with a large quantity of high-quality DNA. We obtained more than a ten thousand-fold amplified DNA from a single mite using 0.01ng as template DNA. Sequence polymorphisms of P. persimilis were analyzed for nuclear DNA Inter Transcribed Spacers (ITS1 & ITS2) and for a mitochondrial 12S rRNA. The sequence comparisons among individuals identified a number of polymorphisms in the 12S sequences. The foraging gene (for) associated with rover-sitter behavioral strategies of Drosophila is known to have role in feeding behaviors of honeybee and other arthropods. We surmised that the same or a similar gene may be present in P. persimilis. Among the foraging behavior(s) exhibited by this predatory mite, we were particularly interested in resource/prey-dependent dispersal behavior. We isolated a partial sequence that is presumed to be the orthologue of the foraging (for) gene. We named the putative foraging gene as Ppfor (for Phytoseiulus persimilis foraging gene). We used a fragment of Ppfor gene as a molecular marker between populations and among individuals and, further, to help understand behavioral phenotypes.

Master of Science / Department of Entomology / David C. Margolies / James R. Nechols / The study of how extrinsic factors affect the foraging efficiency and behavior of predaceous arthropods like Phytoseiulus persimilis is important to understand their various processes of acquiring prey, mates, refuges, oviposition sites, and overcoming obstacles posed by the environment. Many intrinsic and extrinsic factors affect predator foraging efficiency and behavior. One of the most influential extrinsic factors may be the host plant on which herbivorous prey are found. Recent studies suggest that plant architecture plays an important role in tritrophic interactions. In this work, I studied the effects of cucumber plant architecture and prey distribution on the foraging efficiency (prey-finding time and prey-consumption rate) and behavior (time allocated between moving, resting and feeding) of P. persimilis. Plant architecture represented differences in leaf number and size; however, all plants had the same total surface area. Plants with 6 small leaves (ca. 82.98 square cm each) were considered as complex architecture, whereas plants with only 2 large leaves (ca. 240.60 square cm each) were considered as simple. The prey distributions were: prey patch on a single basal leaf (closest leaf to the soil) and prey patch on all leaves. The foraging efficiency was assessed by measuring prey-finding time and prey-consumption rate, whereas the behavior was assessed by conducting observational studies on specific foraging activities. When placed either on the top or at the base of the plant P. persimilis encountered prey more rapidly (interval 0-30 minute) on complex and simple plants with prey patches distributed on all leaves. Differences in prey density (number of prey per leaf) had no effect on the prey-finding time of P. persimilis. The predator consumed more eggs on complex plants with prey patches distributed on all leaves. Phytoseiulus perismilis tended to find prey patches more quickly as well as consume more eggs on leaves close to its release point. Furthermore, the predator was observed to lay more eggs on leaves where it had consumed higher number of prey eggs. The dimensions of individual parts of the plant e.g., stem, petiole and leaf, affected the time allocated by P. persimilis between searching, resting and feeding. The predatory mite spent more time foraging on the stems and petioles of the simple plants whereas on complex plants it spent more time foraging on the leaves.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-21T16:01:30Z No. of bitstreams: 1 Alberto Belo Esteves Filho.pdf: 564769 bytes, checksum: 5fa5b6739b0d8ac06a2e177101cc0daf (MD5) / Made available in DSpace on 2016-11-21T16:01:30Z (GMT). No. of bitstreams: 1 Alberto Belo Esteves Filho.pdf: 564769 bytes, checksum: 5fa5b6739b0d8ac06a2e177101cc0daf (MD5) Previous issue date: 2012-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work studied the lethal and sublethal effects, repellency, toxicity and residual effects of natural and synthetic acaricides on the two spotted mite, Tetranychus urticae Kock (Acari: Tetranychidae), and its predator, Phytoseiulus macropilis (Acari: Phytoseiidae). The synthetic acaricides fenpropathrin, chlorfenapyr, diafenthiuron, abamectin and spiromesifen and the botanicals oils of neem, Azadirachta indica A. Juss. (Meliaceae), Azadirachtin 1% and Azadirachtin A/B, Jatropha curcas L. (Euphobiacea) and Ricinus communis L. (Euphorbiacea) were tested. Based on LC50s e LC90s, spiromesifen was the most toxic to female mites and J. curcas to T. urticae eggs. To P. macropilis, the acaricides that caused more adverse effects were spiromesifen, J. curcas and Azadirachtin 1%. Oil of J. curcas used at sublethal concentrations was the only able to extinguish the population of T. urticae. Spiromesifen, R. communis and Azadirachtin A/B affected negatively the growth population of the two spotted spider mite. Population of P. macropilis exposed to spiromesifen, oil of J. curcas, and Azadirachtin 1% trended to extinction. However, when exposed to oil of R. communis and Azadiracthin A/B continued to grow. All acaricides tested, except oil of R. communis, were repellent to T. urticae females and affected oviposition of T. urticae. The treatment with oil of R. communis, J. curcas, and Azadiracthin 1% were repellent to the predatory female mites and affected its oviposition. The residual effect of fenpropathrin, chlorfenapyr, diafenthiuron, and abamectin caused mortality to T. urticae female over 90% up to the fourth evaluation. Fenpropathrin, diafenthiuron, abamectin, and spiromesifen caused reduction on female fecundity. The natural products tested were efficacious to two spotted spider mite adults only during the first evaluation. All tested acaricides exhibited efficacious control of T. urticae, but among the tested products the Azadiracthin A/B produced promising results to mite control in cotton ecosystem and was less harmful to the predatory mite. / O objetivo deste trabalho foi estudar os efeitos letais e subletais, repelência, toxicidade e efeito residual de acaricidas sintéticos e produtos naturais sobre Tetranychus urticae Kock (Acari: Tetranychidae) e Phytoseiulus macropilis (Banks) (Acari: Phytoseiidae). Os acaricidas fenpropatrina, clorfenapir, diafentiurom, abamectina e espiromesifeno e os óleos emulsionáveis de nim, Azadirachta indica A. Juss. (Meliaceae) (Azadiractina 1% e Azadiractina A/B), Jatropha curcas L. (Euphorbiaceae) e Ricinus communis L. (Euphorbiaceae) foram estudados. De acordo com as CLs50 e CLs90, espiromesifeno foi o mais tóxico para fêmeas, e J. curcas para ovos de T. urticae. Os acaricidas que causaram maior efeito adverso para P. macropilis, foram espiromesifeno, J. curcas e Azadiractina 1%. Espiromesifeno foi o único acaricida nocivo para P. macropilis. Quando testados em concentrações subletais, J. curcas foi o único capaz de extinguir a população de T. urticae. Espiromesifeno, R. communis e Azadiractina A/B afetaram, negativamente, o crescimento populacional da praga. A população de P. macropilis, quando exposta a espiromesifeno, J. curcas e Azadiractina 1%, tendeu à extinção. Porém, quando exposta a R. communis e Azadiractina A/B continuou crescendo. Todos os acaricidas, com exceção de R. communis, repeliram fêmeas e postura de T. urticae. Para o predador, R. communis, J. curcas e Azadiractina 1% também repeliram fêmeas e postura. Espiromesifeno e Azadiractina A/B repeliram apenas postura. Em relação à eficiência residual, fenpropatrina, clorfenapir, diafetiurom e abamectina, causaram mortalidade de fêmeas adultas de T. urticae superior a 98% até a quarta avaliação. Fepropatrina, diafentiurom, abamectina e espiromesifeno foram os que mais reduziram a fecundidade. Os produtos naturais foram eficientes para adultos, apenas na primeira avaliação, enquanto a redução de postura variou. Todos os acaricidas testados foram eficientes no controle de T. urticae, entretanto, Azadiractina A/B foi o mais promissor para o seu manejo no agroecossistema algodoeiro, pois, foi o menos nocivo para o predador.

Las arañas rojas constituyen una de las plagas más importantes en la producción de hortalizas del litoral mediterráneo español, tanto en invernadero como al aire libre. Estos ácaros son controlados por medios químicos, lo cual representa costos significativos en términos económicos y ecológicos. Otra alternativa sería el control biológico usando fitoseidos que son depredadores naturales de los tetraníquidos. Sin embargo, se desconocen informaciones básicas sobre la dinámica y la óptima relación depredador-presa necesarias para que el control biológico sea efectivo. Este trabajo evaluó la relación depredador-presa de los fitoseidos nativos Phytoseiulus persimilis Athias- Henriot y Neoseiulus californicus (McGregor) con las arañas rojas T. urticae Koch, T. turkestani Ugarov y Nikolski y T. evansi Baker y Pritchard. El estudio incluyó ensayos de laboratorio y de invernadero, realizados en plantas de judía (Phaseolus vulgaris L.) y patata (Solanum tuberosum L.), al igual que simulaciones de la dinámica poblacional de los fitoseidos depredadores y los ácaros fitófagos. En el laboratorio se estudió el consumo de presa y los principales parámetros biológicos y demográficos de los dos depredadores cuando se alimentan de T. urticae. Los resultados del laboratorio indicaron que la duración del desarrollo, la fecundidad y los parámetros demográficos de poblaciones locales de N. californicus y P. persimilis eran similares a los de otras regiones geográficas y que cuando estos depredadores consumían T. urticae sus parámetros alcanzaban valores óptimos. En el invernadero se evaluó su eficacia en tres relaciones depredador-presa: 1:12, 1:8 y 1:4 para los ensayos con T. urticae, y de1:16, 1:8 y 1:4 para ensayos con T. turkestani y T. evansi. También se determinó el índice de daño y la distribución de los ácaros en las plantas y su comportamiento dispersivo en función del tiempo y de la densidad poblacional. / Gómez Moya, CA. (2007). Dinámica del sistema depredador-presa de las arañas rojas y los fitoseidos (Acari: Tetranychidae, Phytoseiidae) en cultivos hortícolas [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/15228