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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Habitat manipulation to enhance biological control of light brown apple moth (Epiphyas Postvittana)

Begum, Mahmuda January 2004 (has links)
Trichogramma carverae Oatman and Pinto is mass-released for biological control of the leafroller pest, light brown apple moth, Epiphyas postvittana (Walker) in Australian vineyards. Parasitoid performance can, however, be constrained by a lack of suitable adult food and no information is available on the effect of nectar on the parasitism and longevity of T. carverae. To address this, the effect of alyssum, Lobularia maritima (L.) flowers on E. postvittana parasitism was studied in a vineyard experiment with and without releases of T. carverae. Egg parasitoid activity was assessed with E. postvittana egg �sentinel cards� and no parasitism was recorded in plots without T. carverae releases. Where T. carverae were released, there was no significant enhancement of parasitism by the presence of L. maritima flowers. Three hypotheses were subsequently tested to account for the lack of an effect: (i) T. carverae does not benefit from L. maritima nectar, (ii) T. carverae was feeding on nectar from other flowering plants (weeds) present in the vineyard, (iii) T. carverae was feeding on sugars from ripe grapes. A growth-cabinet experiment using potted L. maritima plants with and without flowers did not support hypothesis one. No parasitism was recorded after day two for T. carverae caged without flowers whilst parasitism occured until day eight in the presence of flowers. A laboratory experiment with common vineyard weeds (Trifolium repens, Hypochoeris radicata, Echium plantagineum) as well as L. maritima did not support hypothesis one but gave partial support to hypothesis two. Survival of T. carverae was enhanced to a small but statistically significant extent in vials with intact flowers of L. maritima, white clover (T. repens) and catsear (H. radicata) but not in vials with flowering shoots of these species from which flowers and flowering buds had been removed. Paterson�s curse (E. plantagineum) flowers had no effect on T. carverae survival. In a laboratory study, punctured grapes significantly enhanced T. carverae survival compared with a treatment without grapes, supporting hypothesis three. Trichogramma carverae performance in the field experiment was probably also constrained by relatively cool and wet weather. Further work on the enhancement of T. carverae efficacy by L. maritima and other carbohydrate sources is warranted. Greenhouse and field experiments were conducted to investigate whether T. carverae benefit from different groundcover plant species. Ten T. carverae adults (<24h after eclosion) were caged with different groundcover species and a control with no plant materials. Epiphyas postvittana egg sentinel cards were used to measure parasitism and longevity was recorded visually. Survival and realised parasitism of T. carverae was significantly higher in L. maritima than in Brassica juncea, Coriandrum sativum, shoots of these species from which flowers had been removed and nil control treatments. A similar experiment with Fagopyrum esculentum (with- and without-flowers) and a control treatment showed that survival was significantly higher in intact F. esculentum than in without-flower and control treatments. There was no significant treatment effect on parasitism in the early stages of that experiment, though parasitism was recorded in the presence of F. esculentum flowers for 12 days, compared with 6 days in other treatments. Higher parasitism was observed in intact Borago officinalis than in the flowerless shoot, water only and no plant material control treatments in a third experiment. There was no significant treatment effect on parasitism. Fitted exponential curves for survival data differed significantly in curvature in the first, second and third experiments but the slope was a non-significant parameter in the second and third experiments. In a second series of laboratory experiments, one male and one female T. carverae were caged with groundcover species to investigate male and female longevity and daily fecundity. Both male and female longevity in F. esculentum and L. maritima treatments were significantly higher than on shoots of these species from which flowers had been removed, and than in the control treatments. Daily fecundity was significantly greater in the intact L. maritima treatment than in all other treatments. Fitted exponential curves for daily fecundity differed significantly in position and slope but not in curvature. There was no significant treatment effect on longevity or parasitism when a male and female were caged with intact B. juncea, B. officinalis or without-flower of these species, nor in the treatment with no plant materials. No parasitism was observed in a survey of naturally occurring egg parasitoids on two sites close to Orange and Canowindra in New South Wales, illustrating the importance of mass releases of T. carverae in biological control of E. postvittana. In an experiment on the Canowindra site, parasitism was significantly higher on day one and day two after T. carverae release when with-flower treatments were compared with without-flower treatments. Parasitism was significantly higher in the F. esculentum treatment than in C. sativum, L. maritima, vegetation without-flowers and control treatments on these dates. On day five, parasitism was higher in C. sativum than in all other treatments. There was no significant increase in parasitism in a second experiment conducted on the Orange site. Coriandrum sativum, F. esculentum and L. maritima appear to be suitable adult food sources for T. carverae and offer some scope for habitat manipulation in vineyards The adults of many parasitoid species require nectar for optimal fitness but very little is known about flower recognition. Flight cage experiments showed that the adults of T. carverae benefited from L. maritima bearing white flowers to a greater extent than was the case for light pink, dark pink or purple flowered cultivars, despite all cultivars producing nectar. Survival and realised parasitism on non-white flowers were no greater than when the parasitoids were caged on L. maritima shoots from which flowers had been removed. The possibility that differences between L. maritima cultivars were due to factors other than flower colour, such as nectar quality, was excluded by dyeing white L. maritima flowers by placing the roots of the plants in 5% food dye (blue or pink) solution. Survival of T. carverae was lower on dyed L. maritima flowers than on undyed white flowers. Mixing the same dyes with honey in a third experiment conducted in the dark showed that the low level of feeding on dyed flowers was unlikely to be the result of olfactory or gustatory cues. Flower colour appears, therefore, to be a critical factor in the choice of plants used to enhance biological control, and is likely to also be a factor in the role parasitoids play in structuring invertebrate communities. Provision of nectar producing plants to increase the effectiveness of biological control is one aspect of habitat manipulation, but care needs to be taken to avoid the use of plant species that may benefit pest species. Greenhouse experiments were conducted to investigate whether the adult E. postvittana and larvae benefit from nectar producing groundcover species. Newly emerged E. postvittana adults were caged with different groundcover species and a honey-based artificial adult diet. The longevity of male and female E. postvittana when caged with shoots of borage (B. officinalis) and buckwheat (F. esculentum) bearing flowers was as long as when fed a honey-based artificial diet. This effect was not evident when caged with shoots of these plants from which flowers had been removed. Longevity was significantly lower than in the artificial diet treatment when caged with coriander (C. sativum) or alyssum (L. maritima) irrespective of whether flowers were present or not. There was no significant treatment effect on the lifetime fecundity of E. postvittana. A second experiment with mustard (B. juncea) (with- and without-flowers), water only and honey-based artificial adult diet showed no significant treatment effects on the longevity of male and female E. postvittana or on the lifetime fecundity of E. postvittana. The anomalous lack of a difference between the water and honey-based diet treatments precludes making conclusions on the value of B. juncea for E. postvittana. Two greenhouse experiments were conducted to evaluate the effects of groundcover species on the larval development of E. postvittana. In the first experiment, larval mortality was significantly higher in C. sativum, and L. maritima than in B. juncea, B. officinalis and white clover (T. repens) a known host of E. postvittana. Coriandrum sativum and L. maritima extended the larval period. In B. juncea and B. officinalis, mortality did not differ from that in T. repens. In F. esculentum, larval mortality was significantly higher than in T. repens. A short larval period was observed on B. juncea, B. officinalis and F. esculentum. Fitted exponential curves for larval mortality differed significantly in curvature between plant treatments. Similarly, successful pupation was significantly lower in C. sativum, F. esculentum and L. maritima than in T. repens. The percentage of successful pupation in B. juncea and B. officinalis did not differ from F. esculentum and T. repens. Fitted exponential curves for pupation differed significantly in curvature. A similar trend was observed in a second experiment with potted plants. The overall results suggest that C. sativum and L. maritima denied benefit to E. postvittana adults and larvae, so could be planted as vineyard groundcover with minimal risk of exacerbating this pest. Overall results suggest that T. carverae require nutrients to reach their full reproductive potential and flowers provide such nutrients. Lobularia maritima and C. sativum may be considered �selective food plants� for T. carverae whereas F. esculentum appears to be a �non-selective food plant�; both T. carverae and E. postvittana benefited from it. Fruits such as grapes can be used as food resources in habitat manipulation and this merits further research. This result also suggests that within species flower colour is an important factor for flower selection in habitat manipulation.
52

Habitat manipulation to enhance biological control of light brown apple moth (Epiphyas Postvittana)

Begum, Mahmuda January 2004 (has links)
Trichogramma carverae Oatman and Pinto is mass-released for biological control of the leafroller pest, light brown apple moth, Epiphyas postvittana (Walker) in Australian vineyards. Parasitoid performance can, however, be constrained by a lack of suitable adult food and no information is available on the effect of nectar on the parasitism and longevity of T. carverae. To address this, the effect of alyssum, Lobularia maritima (L.) flowers on E. postvittana parasitism was studied in a vineyard experiment with and without releases of T. carverae. Egg parasitoid activity was assessed with E. postvittana egg �sentinel cards� and no parasitism was recorded in plots without T. carverae releases. Where T. carverae were released, there was no significant enhancement of parasitism by the presence of L. maritima flowers. Three hypotheses were subsequently tested to account for the lack of an effect: (i) T. carverae does not benefit from L. maritima nectar, (ii) T. carverae was feeding on nectar from other flowering plants (weeds) present in the vineyard, (iii) T. carverae was feeding on sugars from ripe grapes. A growth-cabinet experiment using potted L. maritima plants with and without flowers did not support hypothesis one. No parasitism was recorded after day two for T. carverae caged without flowers whilst parasitism occured until day eight in the presence of flowers. A laboratory experiment with common vineyard weeds (Trifolium repens, Hypochoeris radicata, Echium plantagineum) as well as L. maritima did not support hypothesis one but gave partial support to hypothesis two. Survival of T. carverae was enhanced to a small but statistically significant extent in vials with intact flowers of L. maritima, white clover (T. repens) and catsear (H. radicata) but not in vials with flowering shoots of these species from which flowers and flowering buds had been removed. Paterson�s curse (E. plantagineum) flowers had no effect on T. carverae survival. In a laboratory study, punctured grapes significantly enhanced T. carverae survival compared with a treatment without grapes, supporting hypothesis three. Trichogramma carverae performance in the field experiment was probably also constrained by relatively cool and wet weather. Further work on the enhancement of T. carverae efficacy by L. maritima and other carbohydrate sources is warranted. Greenhouse and field experiments were conducted to investigate whether T. carverae benefit from different groundcover plant species. Ten T. carverae adults (<24h after eclosion) were caged with different groundcover species and a control with no plant materials. Epiphyas postvittana egg sentinel cards were used to measure parasitism and longevity was recorded visually. Survival and realised parasitism of T. carverae was significantly higher in L. maritima than in Brassica juncea, Coriandrum sativum, shoots of these species from which flowers had been removed and nil control treatments. A similar experiment with Fagopyrum esculentum (with- and without-flowers) and a control treatment showed that survival was significantly higher in intact F. esculentum than in without-flower and control treatments. There was no significant treatment effect on parasitism in the early stages of that experiment, though parasitism was recorded in the presence of F. esculentum flowers for 12 days, compared with 6 days in other treatments. Higher parasitism was observed in intact Borago officinalis than in the flowerless shoot, water only and no plant material control treatments in a third experiment. There was no significant treatment effect on parasitism. Fitted exponential curves for survival data differed significantly in curvature in the first, second and third experiments but the slope was a non-significant parameter in the second and third experiments. In a second series of laboratory experiments, one male and one female T. carverae were caged with groundcover species to investigate male and female longevity and daily fecundity. Both male and female longevity in F. esculentum and L. maritima treatments were significantly higher than on shoots of these species from which flowers had been removed, and than in the control treatments. Daily fecundity was significantly greater in the intact L. maritima treatment than in all other treatments. Fitted exponential curves for daily fecundity differed significantly in position and slope but not in curvature. There was no significant treatment effect on longevity or parasitism when a male and female were caged with intact B. juncea, B. officinalis or without-flower of these species, nor in the treatment with no plant materials. No parasitism was observed in a survey of naturally occurring egg parasitoids on two sites close to Orange and Canowindra in New South Wales, illustrating the importance of mass releases of T. carverae in biological control of E. postvittana. In an experiment on the Canowindra site, parasitism was significantly higher on day one and day two after T. carverae release when with-flower treatments were compared with without-flower treatments. Parasitism was significantly higher in the F. esculentum treatment than in C. sativum, L. maritima, vegetation without-flowers and control treatments on these dates. On day five, parasitism was higher in C. sativum than in all other treatments. There was no significant increase in parasitism in a second experiment conducted on the Orange site. Coriandrum sativum, F. esculentum and L. maritima appear to be suitable adult food sources for T. carverae and offer some scope for habitat manipulation in vineyards The adults of many parasitoid species require nectar for optimal fitness but very little is known about flower recognition. Flight cage experiments showed that the adults of T. carverae benefited from L. maritima bearing white flowers to a greater extent than was the case for light pink, dark pink or purple flowered cultivars, despite all cultivars producing nectar. Survival and realised parasitism on non-white flowers were no greater than when the parasitoids were caged on L. maritima shoots from which flowers had been removed. The possibility that differences between L. maritima cultivars were due to factors other than flower colour, such as nectar quality, was excluded by dyeing white L. maritima flowers by placing the roots of the plants in 5% food dye (blue or pink) solution. Survival of T. carverae was lower on dyed L. maritima flowers than on undyed white flowers. Mixing the same dyes with honey in a third experiment conducted in the dark showed that the low level of feeding on dyed flowers was unlikely to be the result of olfactory or gustatory cues. Flower colour appears, therefore, to be a critical factor in the choice of plants used to enhance biological control, and is likely to also be a factor in the role parasitoids play in structuring invertebrate communities. Provision of nectar producing plants to increase the effectiveness of biological control is one aspect of habitat manipulation, but care needs to be taken to avoid the use of plant species that may benefit pest species. Greenhouse experiments were conducted to investigate whether the adult E. postvittana and larvae benefit from nectar producing groundcover species. Newly emerged E. postvittana adults were caged with different groundcover species and a honey-based artificial adult diet. The longevity of male and female E. postvittana when caged with shoots of borage (B. officinalis) and buckwheat (F. esculentum) bearing flowers was as long as when fed a honey-based artificial diet. This effect was not evident when caged with shoots of these plants from which flowers had been removed. Longevity was significantly lower than in the artificial diet treatment when caged with coriander (C. sativum) or alyssum (L. maritima) irrespective of whether flowers were present or not. There was no significant treatment effect on the lifetime fecundity of E. postvittana. A second experiment with mustard (B. juncea) (with- and without-flowers), water only and honey-based artificial adult diet showed no significant treatment effects on the longevity of male and female E. postvittana or on the lifetime fecundity of E. postvittana. The anomalous lack of a difference between the water and honey-based diet treatments precludes making conclusions on the value of B. juncea for E. postvittana. Two greenhouse experiments were conducted to evaluate the effects of groundcover species on the larval development of E. postvittana. In the first experiment, larval mortality was significantly higher in C. sativum, and L. maritima than in B. juncea, B. officinalis and white clover (T. repens) a known host of E. postvittana. Coriandrum sativum and L. maritima extended the larval period. In B. juncea and B. officinalis, mortality did not differ from that in T. repens. In F. esculentum, larval mortality was significantly higher than in T. repens. A short larval period was observed on B. juncea, B. officinalis and F. esculentum. Fitted exponential curves for larval mortality differed significantly in curvature between plant treatments. Similarly, successful pupation was significantly lower in C. sativum, F. esculentum and L. maritima than in T. repens. The percentage of successful pupation in B. juncea and B. officinalis did not differ from F. esculentum and T. repens. Fitted exponential curves for pupation differed significantly in curvature. A similar trend was observed in a second experiment with potted plants. The overall results suggest that C. sativum and L. maritima denied benefit to E. postvittana adults and larvae, so could be planted as vineyard groundcover with minimal risk of exacerbating this pest. Overall results suggest that T. carverae require nutrients to reach their full reproductive potential and flowers provide such nutrients. Lobularia maritima and C. sativum may be considered �selective food plants� for T. carverae whereas F. esculentum appears to be a �non-selective food plant�; both T. carverae and E. postvittana benefited from it. Fruits such as grapes can be used as food resources in habitat manipulation and this merits further research. This result also suggests that within species flower colour is an important factor for flower selection in habitat manipulation.
53

Ecologia química no controle biológico de fitófagos e respectivos predadores e parasitoides / Chemical ecology on the biological control of phytophagous insects and its predators and parasitoids

Fraga, Diego Felisbino [UNESP] 22 February 2016 (has links)
Submitted by DIEGO FELISBINO FRAGA null (diegofraga@fazu.br) on 2016-03-08T21:00:47Z No. of bitstreams: 1 Tese_Diego_Felisbino_Fraga.pdf: 1816202 bytes, checksum: 645838702bb204f2d81827bcc74d32f0 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-09T18:05:33Z (GMT) No. of bitstreams: 1 fraga_df_dr_jabo.pdf: 1816202 bytes, checksum: 645838702bb204f2d81827bcc74d32f0 (MD5) / Made available in DSpace on 2016-03-09T18:05:33Z (GMT). No. of bitstreams: 1 fraga_df_dr_jabo.pdf: 1816202 bytes, checksum: 645838702bb204f2d81827bcc74d32f0 (MD5) Previous issue date: 2016-02-22 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O Controle Biológico Natural, ou Conservativo, é uma ferramenta indispensável para o sucesso do Manejo Integrado de Pragas, pois permite uma interação entre os componentes do ambiente, o que o coloca na linha de frente das táticas e estratégias de manejo de pragas em agroecossistemas. Basicamente, esta interação, denominada interação tritrófica, envolve as plantas, os organismos fitófagos e seus inimigos naturais. Neste contexto, diversos fatores são importantes para o controle biológico, tais como condições abióticas e bióticas, destacando-se características das plantas (compostos metabólitos secundários e arquitetura, por exemplo) e potenciais presas/hospedeiros (semioquímicos, etc.). Inimigos naturais podem utilizar estes recursos durante o seu processo de busca e localização do hospedeiro, de modo que o conhecimento sobre o comportamento de inimigos naturais em função da fenologia e arquitetura das plantas, bem como sobre o potencial de voláteis emitidos por plantas e presas é fundamental para um programa de manejo integrado de pragas. Desta forma, o presente trabalho teve por objetivos: a) avaliar a dinâmica populacional e a distribuição vertical de ovos de Chrysodeixis includens (Lepidoptera: Noctuidae) e de seus ovos parasitados por Trichogramma spp. (Hymenoptera: Trichogrammatidae) na cultura da soja; b) determinar a resposta comportamental do percevejo predador Orius insidiosus (Hemiptera: Anthocoridae) para voláteis associados à Halyomorpha halys (Hemiptera: Pentatomidae). Sendo assim, em Jaboticabal, SP, Brasil, durante as safras agrícolas de 2012/13 e 2013/14, foram realizadas coletas de ovos de C. includens presentes em diferentes terços das plantas de soja, durante diferentes estádios fenológicos da cultura. Semanalmente, o número de ovos presentes nas plantas foi anotado e os mesmos eram coletados e levados para laboratório para aguardar a emergência de lagartas ou de adultos de Trichogramma spp. O número de adultos do parasitoide emergido por ovo era registrado, bem como a razão sexual. Os adultos foram identificados ao nível específico, encontrando-se a espécie Trichogramma pretiosum presente na cultura da soja. Fêmeas de C. includens preferiram ovipositar com mais intensidade nos terços médio e inferior das plantas, principalmente durante os estádios reprodutivos da cultura. O parasitismo de ovos por T. pretiosum apresentou uma tendência semelhante, em que a medida que se aumentou a densidade de ovos de C. includens nas plantas, também elevou-se o número médio de ovos parasitados, indicando uma forte correlação positiva entre a praga e o inimigo natural. Para atingir o segundo objetivo desta tese, e fornecer alternativas para o controle biológico de H. halys, um pentatomídeo invasor nos EUA, foram conduzidos experimentos para testar a atratividade de O. insidiosus para voláteis emitidos pela presa e por plantas de feijoeiro atacadas por ela. Foram conduzidos experimentos em casa-de-vegetação, laboratório e em campo, em que foi identificado altas concentrações do composto tridecano. Foi avaliado a atratividade de O. insidiosus para diferentes concentrações deste composto, bem como os efeitos desta atração na predação de ovos. Foi observado que O. insidiosus é atraído por tridecano, no entanto, esta atração não afeta a predação de ovos, em casa de vegetação e no campo. / Natural ou Conservative Biological Control is a valuable tool for the success of Integrated Pest Management as it allows a natural interaction between the components of the environment, which places it at the forefront of the tactics and pest management strategies in agroecosystems. This interaction, so-called tritrophic interaction, involves plants, phytophagous organisms and their natural enemies. In this context several factors are important for biological control, such as biotic and abiotic conditions, highlighting plant characteristics (secondary metabolites compounds and plant architecture, for example) and possible prey/hosts (semiochemicals, etc.). Natural enemies can use this information during the its host foraging behavior, so the knowledge of the behavior of natural enemies according to the phenology and plant architecture as well as potential volatiles emitted by prey plants and potential is key for an integrated pest management program. Thus, this study aimed to: a) assess the population dynamics and vertical distribution of natural biological control of Chrysodeixis includens (Lepidoptera: Noctuidae) eggs by Trichogramma spp. (Hymenoptera: Trichogrammatidae) in soybean field; b) determine the behavioral response of the predator Orius insidiosus (Hemiptera: Anthocoridae) for volatile associated with Halyomorpha halys (Hemiptera: Pentatomidae). Thus, in Jaboticabal, SP, Brazil, during the growing seasons of 2012/2013 and 2013/2014, samples were taken from C. includens eggs present on different thirds of soybean plants during different phenological stages of the crop. Weekly, number of eggs present in plants was recorded and the eggs were collected ant taken to the laboratory to await the emergence of larvae or adult Trichogramma spp. The number of adult Trichogramma spp. emerged per egg was noted, as was the sex ratio. The adults were identified to species level, finding Trichogramma pretiosum as the main species present in soybeans. Females of C. includens intensively preferred to lay eggs in the middle and lower thirds of the plants, especially during the reproductive stages of soybean plants. Egg parasitism by T. pretiosum presented a similar tendency, which as the C. includens eggs density increased in plants, also increased the average number of parasitized eggs, indicating a strong positive correlation between the pest and the natural enemy. To achieve the second objective of this thesis, and provide alternatives for the biological control of H. halys (an invasive pentatomid in the US). experiments were conducted to test the attractiveness of O. insidiosus to volatiles emitted by the prey and bean plants attacked by it. Experiments were conducted under greenhouse, laboratory and field conditions. It was identified that tridecane was the major compound in damage-bean pods as well as on H. halys. The attractiveness of O. insidiosus was evaluated for different concentrations of this compound as well as the effects of this attraction as predators of eggs. It was observed that O. insidiosus is attracted to tridecane, however, this attraction not poisitivamente affected the predation of eggs in the greenhouse and in the field. / CNPq: 164869/2014-0
54

Seleção de linhagens e efeito do hospedeiro na qualidade de Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) para o controle de Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) em tomateiro / Strain selection and host effect on Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) quality for Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) control in tomato crops

Guilherme dos Reis Vasconcelos 17 January 2013 (has links)
O objetivo do presente trabalho foi selecionar a linhagem mais adequada de T. pretiosum para o controle de T. absoluta na cultura do tomate, dentre as linhagens da coleção do Laboratório de Biologia de Insetos do Departamento de Entomologia e Acarologia da Escola Superior de Agricultura \"Luiz de Queiroz\", e comparar a qualidade dos insetos criados em ovos do hospedeiro alternativo, Anagasta kuehniella (Zeller, 1879) com aquela dos insetos oriundos de ovos de T. absoluta, com vistas à utilização do parasitoide para o controle da traça-do-tomateiro. Para atingir tal objetivo foram realizadas as seguintes etapas: seleção de linhagens, efeito da idade do hospedeiro no parasitismo, efeito do hospedeiro na qualidade do parasitoide e número de parasitoides a ser liberado por ovo da praga. A linhagem PR de T. pretiosum, proveniente do Paraná, foi, entre as estudadas, a mais adequada para o uso em programas de controle biológico de T. absoluta. T. pretiosum parasitou igualmente ovos de T. absoluta de 0 a 48 horas de idade. A capacidade de parasitismo, longevidade, capacidade locomotora e o tamanho do parasitoide foram reduzidos quando provenientes de ovos da traça-do-tomateiro em comparação a insetos emergidos de ovos de A. kuehniella. O número ideal de T. pretiosum a ser liberado na cultura do tomate para o controle de T. absoluta foi superior a 50 parasitoides/ovo. Portanto, T. pretiosum pode ser utilizado em programas de Controle Biológico Aplicado, visto que, devido à menor qualidade dos parasitoides provenientes de ovos de T. absoluta, o inimigo natural terá dificuldades em se estabelecer no campo, indicando ser necessário um grande número de liberações, pois T. pretiosum terá uma ação contra T. absoluta semelhante a um inseticida, desde que os parasitoides que nascerem nas gerações subsequentes às liberações serão menos agressivos e competitivos do que os insetos da natureza. / The aim of this study was to select the most suitable T. pretiosum strain for the biological control of T. absoluta in tomato crops, within the existing strains in the Laboratório de Biologia de Insetos\' colection at Escola Superior de Agricultura \"Luiz de Queiroz\", and compare the quality of the insects reared on eggs of the alternative host Anagasta kuehniella (Zeller, 1879) and on eggs of T. absoluta. For this, the following characteristics were studied: strain selection, host age effect on parasitism, different host effect on parasitoid quality and ideal number of released parasitoid per pest egg. The T. pretiosum strain PR, originated in Paraná state, was the most suitable for its use in T. absoluta biological control programs. T. pretiosum parasitism rate was the same for eggs aged from 0 to 48 hours. T. pretiosum\'s parasitism capability, longevity, mobility capability and parasitoid size were reduced when reared on T. absoluta eggs in comparison to the ones reared on A. kuehniella eggs. The ideal parasitoid number for release in order to control T. absoluta in tomato crops is over 50 per egg. Since the quality of parasitoids hatched from T. absoluta eggs is lower, populations of T. pretiosum will present difficulties to establish itself in the field. Therefore, T. pretiosum should be used in applied biological control programs, where a large number of parasitoids is released in the field from time to time, which will act similarly to insecticides.
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Exigências térmicas e monitoramento de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crampidae), como suporte ao seu controle biológico / Thermal requirements and monitoring of Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), as support for its biological control

Bruno Freitas De Conti 11 June 2012 (has links)
O incremento aos programas de bioenergia em nosso país, aponta para uma provável duplicação da área plantada de cana-de-açúcar, num futuro bastante próximo. Neste contexto, a sustentabilidade da cultura deve ser preservada, evitando-se que sejam colocados em risco os avanços obtidos nas últimas cinco décadas no Controle Biológico de suas pragas. Para tanto, são necessárias pesquisas que atendam às necessidade das diversas etapas de um programa de Controlo Biológico. No presente estudo, avaliou-se o uso de temperaturas diferentes para criar cada fase do desenvolvimento de Diatraea saccharalis (Fabricius, 1794), com o objetivo de fornecer informações importantes para sua criação massal. Avaliou-se também, o raio de ação de uma armadilha contendo fêmeas virgens, a dinâmica populacional de D. saccharalis e o seu desenvolvimento em plantas de cana-de-açúcar, visando desenvolver um modelo de previsão da praga, com vistas ao seu controle biológico pelos parasitoides T. galloi e C. flavipes. As combinações de temperaturas 28°C-25°C-25°C, 28°C-28°C-28°C, 30°C-25°C-25°C e 30°C-22°C- 22°C para criar lagartas, pupas e adultos, respectivamente, destacaram-se das demais por promover rápido desenvolvimento aliado a altas taxas reprodutivas e podem assim, serem utilizadas para a criação massal de Diatraea saccharalis (Fabricius, 1794) e de seu parasitoide Cotesia flavipes (Cameron, 1891). O aumento de densidade de criação de 1 lagarta por tubo para 250 lagartas por frasco, não afetou o desenvolvimento e reprodução de D. saccharalis. Foi possível prever o momento de liberação de C. flavipes em cana-de-açúcar com base em modelos de exigências térmicas, assim como, orientar as liberações de T. galloi ao definir o período de ocorrência dos ovos de D. saccharalis. Os parâmetros climáticos determinaram uma faixa térmica de atuação para as armadilhas contendo fêmeas virgens (temperatura média acima de 24°C), faixa na qual foram observadas altas correlações entre a captura de machos e amostragem de lagartas, realizada 21 dias após a captura dos machos de D. saccharalis. De acordo com a dinâmica populacional de D. saccharalis, foram identificadas quatro gerações ao longo do ciclo da cultura. Para a utilização do parasitoide de ovos T. galloi deve-se usar uma armadilha contendo 4 fêmeas virgens de D. saccharalis para amostrar 12,5 ha, área determinada em função do raio de ação de 200 metros. / The increase of bioenergy programs in our country indicates a probable duplication of the planted area with sugar cane in a near future. In this context, the sustainability of the culture must be preserved, avoiding the risk of loose the progress achieved in the last five decades in the Biological Control of its pests. For this, it is necessary researches that attend the needs of the various steps of a biological control program. In this study, was evaluated the use of different temperatures to rear each phase of the development of Diatrea saccharalis (Fabricius, 1794), aimed to provide important informations for its mass rearing. It was also evaluated the radius of action of a trap containing virgin females, the population dynamics of D. saccharalis and its development in sugar cane, aimed the development of a prediction model of the occurence of D. saccharalis in sugar cane, suporting its biological control by the parasitoids T. galloi and C. flavipes. The temperatures combination 28°C-25°C-25°C, 28°C-28°C-28°C, 30°C-25°C-25°C, and 30°C-22°C- 22°C used to rear caterpillar, pupae and adults stood out from the others by promoting fast development combined with high reproductives rates and can be used for mass rearing of Diatraea saccharalis (Fabricius, 1794) and its parasitoids Cotesia flavipes (Cameron, 1891). The rearing of caterpillars individually or in groups of 250 did not interfere in the development and reproduction of D. saccharalis. It was possible to predict the release time of C. flavipes in sugar cane based in thermal requirements models and advise the releases of T. galloi deffining the period of occurrence of D. saccharalis eggs. The climatic parameters determined a temperature range of action for the pheromone traps with the virgin females (average temperatures above 24°C), range at which high correlations were observed between the males capture and caterpillar sampling performed 21 days after the capture of the D. saccharalis males. According to the population dynamics of D. saccharalis, four generations have been identified during the crop cycle. For the use of the egg parasitoid T. galloi, it should be used a trap containing four virgin femeales of D. saccharalis to sample 12.5 ha, area determined by the action radius of 200 meters.
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Bioecologia de duas espécies de Trichogramma para o controle de Ecdytolopha aurantiana (Lima, 1927) (Lepidoptera: Tortricidae) em citros. / Bioecology of two species of trichogramma to control ecdytolopha aurantiana (Lima, 1927) (Lepidoptera: Tortricidae) in citrus.

Rosa Maria da Silva Molina 10 March 2003 (has links)
Com o objetivo de avaliar o potencial de utilização de espécies/linhagens de Trichogramma como mais um componente do manejo de Ecdytolopha aurantiana (Lima, 1927), importante praga da citricultura paulista, foram realizadas avaliações biológicas envolvendo seleção de linhagens, biologia em diferentes temperaturas, exigências térmicas, capacidade de parasitismo e número de ideal de parasitóides a ser liberado por ovo da praga. A seleção de linhagens/espécies de Trichogramma é básica para o controle de E. aurantiana, pois ocorreu uma grande variação no parasitismo de ovos da praga dentre os vários materiais biológicos estudados. A razão sexual das espécies/linhagens não foi afetada pela temperatura na faixa de 18 a 32ºC, sendo a temperatura de 25ºC a mais adequada para as espécies/linhagens estudadas. A duração do período ovo-adulto de T. atopovirilia Oatman & Platner, 1983 e de T. pretiosum Riley, 1879 foi inversamente relacionada como aumento da temperatura, na faixa térmica de 18 a 32ºC, sendo as exigências térmicas dessas espécies muito próximas, em torno de 108 GD. O hospedeiro de criação natural, E. aurantiana ou o alternativo, Anagasta kuehniella (Zeller, 1879) não afetaram o parasitismo das espécies/linhagens selecionadas. Em laboratório, obteve-se maior parasitismo expondo-se 30 ovos de E. aurantiana por fêmea de Trichogramma spp. durante 34 horas. As maiores taxas de parasitismo de ovos de bicho-furão para as duas espécies/linhagens ocorreram quando os parasitóides foram provenientes de ovos de E. aurantiana. A proporção estimada de 36 parasitóides por ovo de E. aurantiana possibilitou a maior porcentagem de parasitismo por T. pretiosum. Os resultados obtidos indicaram que os parasitóides de ovos do gênero Trichogramma apresentam potencial de controle de E. aurantiana, desde que liberados em grandes quantidades por unidade de área e em torno das plantas. / In order to evaluate the potential of use of Trichogramma species/strains as an additional component in the management of Ecdytolopha aurantiana (Lima, 1927), an important pest of Citrus in the state of São Paulo, biological trials were carried out involving strain selection, biology at different temperatures, thermal requirements, parasitism capacity and optimal number of parasitoids to be released per pest egg. The selection of Trichogramma strains/species is basic to control E. aurantiana for the egg parasitism of the pest varied greatly among several biological materials studied. The sex ratio of the species/strains was not affected by the temperature at a 18-32ºC range, and 25ºC was the more suitable temperature for the species/strains studied. The duration of the egg-adult period of T. atopovirilia Oatman & Platner, 1983 and T. pretiosum Riley, 1879 was inversely related to the increased temperature at a thermal range of 18-32ºC, and the thermal requirements of these species are very close, ranging 108 DD (degree days). Neither the natural rearing host, E. aurantiana, nor the factitious host, Anagasta kuehniella (Zeller, 1879) affected the parasitism of the selected species/strains. The proportion of 30 eggs of E. aurantiana per Trichogramma spp. female provided a higher parasistism rate, with eggs exposed to the parasitoid for 34 hours. The higher parasitism rates of the eggs of citrus fruit borer for the two species/strains occurred when the parasitoids were reared on eggs of E. aurantiana. The estimated ratio of 36 parasitoids per egg of E. aurantiana allowed a higher parasitism percentage of T. pretiosum. The results achieved showed that the egg parasitoids of Trichogramma have a potential to control E. aurantiana provided that they are released in large amounts per area unit and surrounding the plants.
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Efeito do milho geneticamente modificado (Mon810) em Spodoptera frugiperda (J.E.Smith, 1797) e no parasitóide de ovos Trichogramma spp. / Effect of genetically modified corn (mon810) on spodoptera frugiperda (j. e. smith, 1797) and on egg parasitoid trichogramma spp.

Odnei Donizete Fernandes 14 March 2003 (has links)
A presente pesquisa teve por objetivo estudar a biologia de Spodoptera frugiperda (J. E. Smith, 1797) no milho MON810, que expressa a proteína Cry1Ab de Bacillus thuringiensis Berliner, bem como avaliar a interação tritrófica: milho MON810 vs S. frugiperda vs Trichogramma spp.. A biologia de S. frugiperda foi avaliada, por três gerações sucessivas em laboratório, utilizando-se o milho convencional e MON810. Os insetos mantidos em folhas de milho MON810 apresentaram maior duração do período larval e pré-pupaL, com menor viabilidade do que aqueles alimentados em milho convencional. A fase de pupa (fêmea e macho) foi similar entre os tratamentos, apesar da menor viabilidade e menor peso de pupas no milho MON810. Apesar da ação deletéria da proteína Bt, presente no milho geneticamente modificado para as fases imaturas de S. frugiperda, a longevidade dos adultos, o período de oviposição, o número de posturas, o número médio de ovos por postura e a duração da fase de ovo foram semelhantes entre os tratamentos. O número total de ovos por fêmea, no entanto, foi menor no milho geneticamente modificado. A duração média do ciclo biológico (ovo – adulto) foi maior em insetos mantidos em milho MON810, sendo a viabilidade total menor neste substrato. Foi observado que a taxa líquida de reprodução (Ro) e a razão finita de aumento (ë) foram menores nos insetos alimentados em milho MON810. As lagartas de S. frugiperda apresentaram comportamento canibal independente do substrato alimentar utilizado; porém, tal canibalismo foi mais acentuado no milho MON810, provavelmente devido a presença da proteína Bt. O consumo de área foliar por lagartas de S. frugiperda foi menor no milho MON810, sendo a eficiência do alimento digerido (ECD) menor e o custo metabólico maior neste substrato, em relação ao milho convencional. Em nível de campo, através de experimentos com infestações artificiais e naturais de S. frugiperda, observou-se que o milho MON810 determinou a redução populacional deste lepidóptero, nos diferentes estádios fenológicos estudados, protegendo a cultura do dano da praga. Os estudos de interação milho MON810 vs S. frugiperda vs Trichogramma atopovirilia (Oatman & Platner, 1983) foram efetuados por cinco gerações consecutivas do parasitóide e da praga em laboratório. Observou-se que não houve diferenças quanto a capacidade de parasitismo, a porcentagem de emergência, o número de parasitóides emergidos, a razão sexual e a longevidade do parasitóide quando T. atopovirilia foi criado em ovos de fêmeas que alimentaram-se de milho MON810 ou milho convencional. A qualidade nutricional dos ovos de S. frugiperda foi semelhante entre os tratamentos, não ocorrendo prejuízos ao parasitismo por T. atopovirilia. Em campo, a distribuição de posturas de S. frugiperda, em relação ao estádio fenológico da planta e superfície da folhas, foi semelhante entre os milhos MON810 e convencional. A porcentagem de ovos naturalmente parasitados por Trichogramma spp. também foi similar entre estes tratamentos, ocorrendo a predominância da espécie T. pretiosum (Riley, 1879) em relação a T. Atopovirilia condições de campo. / The objectives of this research were to study the biology of Spodoptera frugiperda (J. E. Smith, 1797) on MON810, that expresses the protein Cry1Ab from Bacillus thuringiensis Berliner, and to evaluate the tritrophic interactions: MON810 vs S. frugiperda vs Trichogramma spp.. The biology of S. frugiperda was evaluated under laboratory conditions for three consecutive generations on MON810 and conventional corn leaves. Insects that fed on MON810 showed longer larval and pre pupae stages duration and lower viability, compared to the larvae that fed on conventional corn. The duration of pupae stage (for both female and male) was similar for both treatments, however the viability of this stage was lower on MON810 and the pupae were smaller on this food source. Despite of the deleterious effect of the Bt protein expressed by MON810 to the larvae of S. frugiperda, the adult longevity, oviposition stage duration, number of egg laying, number of eggs per egg laying and egg stage duration were also similar for both treatments. However the total number of eggs was lower on genetically modified corn. The total biological life cycle (egg – adult) was longer for insects that fed on MON810, and the total viability was lower on this food source. It was observed that the net reproduction rate (Ro) and finite increase rate (ë) were also lower for insects that fed on MON810. The cannibalistic behavior of S. frugiperda occurred regardless of the food source (conventional corn or MON810); but this behavior was more pronounced when MON810 leaves were used as food source. The leaf area consumption by S. frugiperda was lower on MON810 and the insects had lower efficiency of conversion of digested (ECD) and higher metabolic cost than on conventional corn. Field experiments carried out with artificial and natural infestations of S. frugiperda showed that MON810 was very effective to reduce the population of this pest in different corn phenological stages. The studies on the interaction among MON810 vs S. frugiperda vs Trichogramma atopovirilia (Oatman & Platner, 1983) were carried out under laboratory conditions for five consecutives generations of both parasitoid and pest. It was not observed difference between both treatments for the parasitism, emergence, number of parasitoids, sexual ratio, and parasitoid longevity when T. atopovirilia was reared on eggs from females that fed on either MON810 or conventional corn. These data suggest that the nutritional quality of S. frugiperda eggs was similar between MON810 and conventional corn as food source, with no effect in the parasitism by T. atopovirilia. Field experiments showed that the distribution of S. frugiperda egg laying, according to the phenological stage and surface of the leaf, was similar between MON810 and conventional corn. The natural parasitism of S. frugiperda eggs by Trichogramma spp. was similar between MON810 and conventional corn, with the predominance of Trichogramma pretiosum (Riley, 1879), followed by T. atopovirilia in field conditions.
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Bases biológicas para utilização de Trichogramma pretiosum Riley, 1879(Hymenoptera: Trichogrammatidae) para controle de Pseudoplusia includens (Walker, 1857) e Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae) em soja / Biological base for using Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae to control Pseudoplusia includens (Walker, 1857) and Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae) in soybean

Regiane Cristina Oliveira de Freitas Bueno 11 August 2008 (has links)
Com o objetivo de avaliar o potencial de utilização de Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) no manejo de Pseudoplusia includens (Walker, 1857) e Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae), foram realizados diferentes bioensaios incluindo seleção de linhagens, avaliação das características biológicas, capacidade de parasitismo, exigências térmicas, determinação do número ideal de parasitóide a ser liberado por ovo da praga, capacidade de dispersão e tempo de permanência no campo do parasitóide e seletividade dos agroquímicos ao parasitóide. Através da seleção de espécies/linhagens de Trichogramma e Trichogrammatoidea verificou-se que T. pretiosum, linhagem coletada em Rio Verde, GO (RV) apresentou melhor desempenho biológico dentre as demais. A duração do período de desenvolvimento de T. pretiosum linhagem RV, criado em ovos de ambas as pragas apresentou relação inversa com o aumento de temperatura. A emergência da referida linhagem em ovos de A. gemmatalis não foi afetada na faixa de temperatura estudada, porém quando criada em ovos de P. includens, a temperatura de 32oC afetou tal parâmetro biológico. O limiar térmico inferior de desenvolvimento de T. pretiosum linhagem RV foi menor em ovos de P. includens (10,6ºC) quando comparado com o de A. gemmatalis (11,6ºC) e conseqüentemente, a constante térmica também variou sendo de 152 GD para P. includens e de 128 GD para A. gemmatalis. O número estimado de gerações de T. pretiosum linhagem RV, por ciclo da soja variou de 21 e 20 gerações para Rio Verde, GO e 22 e 21 gerações Barreiras, BA, em ovos de P. includens e A. gemmatalis, respectivamente. O ritmo de parasitismo de T. pretiosum linhagem RV foi influenciado pelas temperaturas testadas, com concentração do parasitismo nos primeiros dias de vida das fêmeas, exceto na temperatura de 18oC em ovos P. includens e nas temperaturas de 18 e 20oC para A. gemmatalis em que o parasitismo ocorreu durante toda a vida do parasitóide. O parasitismo total foi influenciado pelas temperaturas, com maiores valores entre as temperaturas de 22 a 28oC em ovos de P. includens e entre 25 e 28oC em ovos de A. gemmatalis. Em condições de semi-campo, determinou-se que o maior parasitismo foi obtido com uma proporção de 25,6 parasitóides por ovo da praga para as duas espécies de pragas. A capacidade de dispersão na cultura da soja é de 8,0 m, sendo a área de dispersão de 85,18m2. Assim, há a necessidade de 117 pontos de liberação do parasitóide por hectare para uma distribuição homogênea do parasitóides em toda a área. Após a liberação de T. pretiosum linhagem RV os parasitóides permaneceram na cultura da soja por doze dias, embora o parasitismo seja efetivo até o quarto dia. Os resultados básicos obtidos em ovos de P. includens e A. gemmatalis apontam para a possibilidade de controle conjunto destas duas pragas na cultura da soja, com utilização desse parasitóide de ovos. Os inseticidas, herbicidas e fungicidas utilizados na cultura da soja afetaram diferentemente o parasitismo e a viabilidade de T. pretiosum linhagem RV, sendo classificados desde seletivos até nocivos. / Different bioassays were carried out aiming to evaluate the potential of using Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) to manage Pseudoplusia includens (Walker, 1857) and Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae). Among those bioassays there were the strains selection, biological characteristics and parasitism capacity, thermal requirements, establishment of ideal number of parasitoids to be released per number of pest eggs, parasitoid dispersal capacity, amount of time that the parasitoids remain active in the field after releasing and pesticide selectivity to the parasitoid. Throughtout the species/strains selection of Trichogramma and Trichogrammatoidea it was possible to determine that Trichogramma pretiosum, strain collected in Rio Verde (RV), showed the best biological performance among the tested species/strains. Trichogramma pretiosum RV development time, when it was reared in eggs of both pest species, was inversely related to the increase in temperature. T. pretiosum RV reared in A. gemmatalis eggs had not its emergency (%) modified by temperature changes, however, when it was reared in P. includens eggs, it had a lower emergency (%) at 32oC. The lower temperature threshold (Tb) was lower for T. pretiosum RV in P. includens eggs (10.6oC) when compared to T. pretiosum in A. gemmatalis eggs (11.6oC) and consequently the thermal constant (K) was also different being 152 and 128 GD for P. includens and A. gemmatalis eggs, respectively. The estimated number of generations of T. pretiosum RV in eggs of both species varied along soybean crop season being 21 and 20 generations for Rio Verde, GO and 22 and 21 generations for Barreiras, BA in P. includens and A. gemmatalis eggs, respectively. The parasitism rhythm of T. pretiosum RV was changed by the tested temperatures, concentrating the parasitism during the first days except at 18oC in P. includens eggs and at 18 and 20oC in A. gemmatalis eggs when the parasitism occurred during the whole parasitoid lifespan. The total parasitism was influenced by the temperatures, being higher among 22 and 28oC in P. includens eggs and among 25 and 28oC in A. gemmatalis eggs. The higher parasitism rate is reached at 51.2 and 25.6 female parasitoid per P. includens and A. gemmatalis eggs, respectively, accordingly to what was established at greenhouse trials. T. pretiosum RV dispersing capacity in soybean fields is 8.0 m and its dispersal area is 85.18 m2. Therefore, it is required a minimum of 117 parasitoid releasing points per hectare in order to have a homogeneous parasitoid distribution in the field. After T. pretiosum RV release, parasitoids remained in the soybean crop for 12 days. However, the parasitism was effective up to 4 days. The results from this research for P. includens and A. gemmatalis eggs indicate that the control of both pests might be possible using the T. pretiosum RV. Insecticides, herbicides and fungicides commonly used in soybean fields impacted differently the parasitism of T. pretiosum RV, being classified since harmless (class 1) to harmful (class 4).
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Bioatividade de nanoformulações de nim e extratos de outras Meliaceae e a sua interação com agentes de controle biológico visando ao controle de Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) / Bioactivity of neem nanoformulations and extracts of other Meliaceae and their interactions with biological control agents aiming to control Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Fátima Teresinha Rampelotti Ferreira 13 May 2011 (has links)
A bioatividade de nanoformulações de nim e de extratos de outras Meliaceae foi avaliada, em tomateiro, em laboratório e em casa de vegetação, visando ao controle de Tuta absoluta (Meyrick). Incialmente foram testadas 22 nanoformulações (incluindo nanocápsulas e nanoesferas) e os extratos em hexano, em diclorometano e em etanol de folhas e ramos de Trichilia pallida Swartz, Trichilia catigua A. Juss, Trichilia claussenii C. DC, Guarea guidonia (L.) Sleumer e Toona ciliata M. Roemer. O óleo de nim Organic Neem® também foi utilizado nos bioensaios com as nanoformulações e como controle foram utilizadas água destilada e/ou acetona. A partir desses bioensaios, selecionaram-se as nanoformulações NC40 aquoso e NC40 pó (NC40=nanocápsulas de poli- -hidroxibutirato) e os extratos etanólicos de T. ciliata e de T. catigua, que foram avaliados em relação ao efeito sobre o desenvolvimento e longevidade do inseto e em relação aos modos de ação (translaminar, sistêmico e de contato) e ao poder residual. O efeito dos tratamentos selecionados sobre os entomopatógenos Beauveria bassiana (Bals.) Vuill. e Phothorimaea operculella granulovírus (PhopGV) foram avaliados in vitro e in vivo, respectivamente. A seguir, foi avaliada a possível interação dos derivados vegetais com os entomopatógenos. Finalmente, foi avaliada a seletividade ao parasitoide de ovos Trichogramma pretiosum Riley, segundo as recomendações da IOBC. Os resultados obtidos demonstraram que, entre os tratamentos testados, constatou-se bioatividade com oito nanoformulações e com os extratos de G. guidonia em diclorometano; T. ciliata em hexano, em diclorometano e em etanol; T. catigua em hexano, em diclorometano e em etanol; T. claussenii em etanol e T. pallida em hexano. A fase do inseto mais afetada foi a larval, no entanto a oviposição das fêmeas foi diminuída quando as plantas foram tratadas com o extrato etanólico de T. ciliata. Constatou-se efeito translaminar e sistêmico para as nanoformulações e para o óleo de nim. A ação de contato variou com o modo de exposição e com a idade das lagartas. O efeito residual do óleo de nim e da nanoformulação NC40 aquoso foi de sete dias, enquanto para NC40 pó foi de três dias. As nanoformulações e os extratos etanólicos de T. ciliata e de T. catigua foram compatíveis com o fungo e com o granulovírus. Quando os entomopatógenos foram misturados aos derivados vegetais observou-se que o nim reduziu drasticamente a sobrevivência larval na mistura com os dois entomopatógenos, sendo o maior efeito causado pelo derivado vegetal. Na mistura dos entomopatógenos com o extrato de T. ciliata, observou-se maior redução da sobrevivência larval com PhopGV. No bioensaio de seletividade a T. pretiosum, constatou-se que apenas o óleo de nim afetou a capacidade de parasitismo, sendo levemente nocivo. Para NC40 aquoso e extrato de T. ciliata não foram constatados efeitos sobre o parasitismo e sobre o desenvolvimento do parasitoide. / The bioactivity of neem nanoformulations and extracts of other Meliaceae was evaluated in tomato plants in the laboratory and in greenhouse aiming to control Tuta absoluta (Meyrick, 1917). Initially, 22 nanoformulations were tested (including nanocapsules and nanospheres) in addition to the hexane, dichloromethane and ethanol extracts of leaves and branches of Trichilia pallida Swartz, Trichilia catigua A. Juss, Trichilia claussenii C. DC, Guarea guidonia (L.) Sleumer and Toona ciliata M. Roemer. The neem oil Organic Neem® was also used in the bioassays with the nanoformulations and distilled water and/or acetone were used as controls. From these bioassays the aqueous NC40 and powdered NC40 (NC40 = Poly- -hydroxibutirate nanocapsules) nanoformulations as well as the ethanolic extracts of Toona ciliata and Trichilia catigua were selected. These treatments were evaluated regarding their effect on insect development and longevity, mode of action (translaminar, systemic and contact) and residual action. The effects of the selected treatments on the entomopathogens Beauveria bassiana (Bals.) Vuill. and Phthorimaea operculella granulovirus (PhopGV) were evaluated in vitro and in vivo, respectively. Then the possible interaction between plant derivates and entomopathogens was evaluated. Finally, a selectivity bioassay to the egg parasitoid Trichogramma pretiosum Riley was evaluated according to IOBC recommendations. The results obtained demonstrate that among these treatments eight nanoformulations and the extracts of G. guidonia in dichloromethane; T. ciliata in hexane, dichloromethane and ethanol; T. catigua in hexane, dichloromethane and ethanol; T. claussenii in ethanol and T. pallida in hexane showed bioactivity on the insect. The most affected insect stage was the larva, but oviposition was reduced when these plants were treated with T. ciliata ethanolic extract. The nanoformulations and neem oil presented translaminar and systemic effect. Contact action varied with exposure mode and caterpillar age. The residual effect of neem oil and aqueous NC40 nanoformulations was seven days while for powdered NC40 was three days. The nanoformulations and the ethanolic extracts of T. ciliata and T. catigua were compatible with the fungus and the granulovirus. When the entomopathogens were mixed to the plant derivates, neem drastically reduced larval survival in the mixture with both entomopathogens and the plant derivate produced a greater effect than the entomopathogen. In the mixture of entomopathogens with T. ciliata extract there was a greater reduction of larval survival with PhopGV. In the T. pretiosum selectivity bioassay only the neem oil was slightly harmful and affected parasitism capacity. For aqueous NC40 and T. ciliata extract no effects over parasitism or parasitoid development were seen.
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Resposta de Telenomus remus Nixon (Hymenoptera: Scelionidae) e Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae) a voláteis de plantas e ovos de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) / Response of Telenomus remus Nixon (Hymenoptera: Scelionidae) and Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae) to volatiles from plants and Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) eggs

Faria, Cristina Arantes de 30 July 2001 (has links)
Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-07-13T13:56:49Z No. of bitstreams: 1 texto completo.pdf: 353935 bytes, checksum: 88d19234c6373988a473eeec24e5ab38 (MD5) / Made available in DSpace on 2017-07-13T13:56:49Z (GMT). No. of bitstreams: 1 texto completo.pdf: 353935 bytes, checksum: 88d19234c6373988a473eeec24e5ab38 (MD5) Previous issue date: 2001-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A lagarta do cartucho Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) é uma praga polífaga de grande importância para várias culturas. Atualmente, vem sendo controlada principalmente através da utilização de inseticidas, entretanto alguns agentes de controle biológico apresentam potencial para reduzir o tamanho das suas populações, entre eles Telenomus remus Nixon (Hymenoptera: Scelionidae) e Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae), que são parasitóides de ovos de S. frugiperda. O entendimento de como os inimigos naturais de determinada praga interagem entre si e com os outros componentes do sistema é fundamental para o manejo de pragas. Dessa forma, foram realizados testes em olfatômetro de 4 braços, com o objetivo de esclarecer como T. remus e T. atopovirilia se relacionam entre si e com diferentes plantas hospedeiras. Teste 1: Avaliou os sinais que as fêmeas das duas espécies de parasitóides utilizam para localizar S. frugiperda, qual a influência de diferentes plantas hospedeiras sobre a busca dos parasitóides e se, através da detecção de diferentes sinais, há separação das guildas dos parasitóides. As fontes de odor utilizadas foram: milho, sorgo, algodão, milho + ovos de S. frugiperda, sorgo + ovos de S. frugiperda, algodão + ovos de S. frugiperda, ovos de S. frugiperda, e ovos de S. frugiperda lavados com hexano. Teste 2: Avaliou se fêmeas de T. remus e T. atopovirilia criadas massalmente, que emergem num ambiente com estímulos provenientes da cultura-alvo (milho) e do hospedeiro (fêmeas experientes), buscam o hospedeiro mais eficientemente e são mais capazes de discriminar entre plantas com e sem hospedeiros do que fêmeas que emergem em condições normais de criação massal (fêmeas inexperientes). Teste 3: Avaliou se T. remus e T. atopovirilia são arrestados da mesma forma por ovos de S. frugiperda parasitados por coespecíficos, por heteroespecíficos e não-parasitados, e se os parasitóides são capazes de discriminar entre ovos parasitados por co ou heteroespecíficos e não-parasitados. Em todos os testes, o parâmetro avaliado foi o tempo que as fêmeas gastaram em cada um dos braços do olfatômetro, sendo os resultados obtidos analisados pelos testes de Wilcoxon ou Kruskal-Wallis, seguido pelo teste de comparações múltiplas (P< 0,05). As fêmeas das duas espécies foram arrestadas por voláteis provenientes das plantas hospedeiras, plantas hospedeiras + ovos, e ovos de S. frugiperda, não sendo arrestadas pelos ovos de S. frugiperda lavados com hexano. Isso indica que as fêmeas utilizam voláteis provenientes de várias plantas hospedeiras e do hospedeiro para sua localização. O fato das fêmeas não terem sido arrestadas por ovos lavados com hexano significa que o(s) composto(s) presente(s) na superfície dos ovos e que são responsáveis pelo arrestamento dos parasitóides, são solúveis nessa substância. Comparando-se as respostas das fêmeas das duas espécies, é possível perceber que não houve diferenças de arrestamento das fontes milho, sorgo, algodão, ovos e ovos lavados, entre elas. Entretanto as fêmeas de T. remus foram significativamente mais arrestadas pelas fontes milho+ovos, sorgo+ovos e algodão+ovos do que as fêmeas de T. atopovirilia, o que indica que semioquímicos do complexo planta+hospedeiro são usados mais eficientemente por T. remus. Quando as fêmeas de T. remus e T. atopovirilia tiveram a chance de escolher entre plantas com e sem posturas, ambas preferiram plantas com postura, exceto T. atopovirilia em sorgo. Isso indica que os parasitóides são capazes de discriminar, utilizando voláteis, áreas com e sem hospedeiros, dessa forma otimizando a busca. Quando tiveram a oportunidade de escolher entre voláteis provenientes de milho, sorgo e algodão, as duas espécies apresentaram respostas semelhantes, indicando que pequenas diferenças interespecíficas na resposta a voláteis de diferentes plantas hospedeiras podem fazer com que haja redução na sobreposição das guildas das duas espécies. Nos testes de aprendizagem foi observado que fêmeas experientes e não-experientes respondem da mesma forma à planta de milho com ovos. Entretanto, quando têm a possibilidade de escolher entre plantas com e sem ovos, as fêmeas de T. remus, ao contrário das fêmeas de T. atopovirilia experientes, são significativamente mais arrestadas para plantas de milho com ovos do que fêmeas inexperientes, indicando que ocorre aprendizagem em T. remus no momento da emergência. O fato de que esse mecanismo torna a busca pelo hospedeiro mais eficiente faz com que seja um método potencial para melhorar o controle promovido por essa espécie de parasitóide. Com relação ao reconhecimento à distância de ovos parasitados intra e interespecificamente, fêmeas das duas espécies foram arrestadas da mesma forma por ovos parasitados por co ou heteroespecíficos e ovos não-parasitados. Além disso, quando estavam na presença de voláteis provenientes de ovos parasitados intra ou interespecificamente e ovos não-parasitados, não houve diferença no arrestamento dos dois tipos de ovos. Isso indica que as substâncias utilizadas para marcar ovos parasitados só atuam à curta distância, o que pode ser explicado pelo fato de que os marcadores que atuam à longa distância podem tornar os hospedeiros marcados mais conspícuos para hiperparasitóides e predadores, sendo dessa forma detrimentais para a espécie. / The fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an important pest for many crops and has been controlled by the use of pesticides. However it can be potentially controlled by the use of natural enemies like Telenomus remus Nixon (Hymenoptera: Scelionidae) and Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae), egg parasitoids of S. frugiperda. Nowadays it is known that the understanding of how the natural enemies of a pest interact among each other and with the other components of the system, have main importance to the pest management. Hence experiments to discover how T. remus and T. atopovirilia interact between each other and with different host plants were performed in a 4 way olfactometer. Test 1: Assessed which cues the females of the two parasitoid species use to find S. frugiperda, how different host plants influenced the parasitoid search and if the parasitoid guilds are separated through the detection of different cues. The odour sources used were: corn, sorghum, cotton, corn + S. frugiperda eggs, sorghum + S. frugiperda eggs, cotton + S. frugiperda eggs, S. frugiperda eggs, and S. frugiperda eggs washed with hexane. Test 2: Assessed if massal raised females of T. remus and T. atopovirilia that emerge in an environment with stimuli from the target pest and crop (experienced females) search for the host more efficiently and are more able to distinguish between plants with and without the host than females that emerge in normal conditions of massal raising (inexperienced females). Test 3: Assessed if T. remus and T. atopovirilia are attracted by eggs parasitized by conspecific, heterospecific and non parasitized; and if the females are able to distinguish between eggs parasitized by con or heterospecifics and non parasitized. For all the tests the parameter evaluated was the time spent in each arm of the olfactometer. The results were analysed by the Wilcoxon test or Kruskal-Wallis test followed by the multiple comparison test (P< 0.05). The females of both species were attracted by volatiles from the host plants, host plants+eggs and S. frugiperda eggs; and were not attracted by the S. frugiperda eggs washed with hexane. It indicates that the parasitoid females use volatiles from many host plants and from the host in the search process. The fact that the females were not attracted by eggs washed with hexane means that the compound(s) on the egg surface that are responsible for the parasitoid attraction are soluble in this substance. By comparing the responses of the females of the two species it is possible to notice that the attractivity of corn, sorghum, cotton, eggs, and eggs washed with hexane were the same for both species. However the females of T. remus were more attracted by corn+eggs, sorgum+eggs and cotton+eggs than T. atopovirilia. It means that the cue plant+host is more efficiently used by T. remus. When the females of T. remus and T. atopovirilia had the chance to choose between plants with and without eggs, both preferred plants with eggs except T. atopovirilia on sorghum. It means that the parasitoids are able to distinguish, through volatiles, areas with and without host, hence optimising the search. When they had the chance to choose among volatiles from corn, sorghum and cotton, the two species showed a slightly different behaviour, indicating that interespecific differences in the responses to volatiles from host plants may cause a reduction of the superposition of the two parasitoids guilds. On the learning tests it was observed that experienced and inexperienced females show the same responses to corn plants with eggs. However when they can choose between plants with and without eggs, experienced T. remus females (but not experienced T. atopovirilia females) are more attracted to plants with eggs than inexperienced females, indicating that a learning process occurs in emergence in T. remus, and as this mechanism makes the T. remus search more efficient, it can be used to increase the level of control promoted by this parasitoid in the field. Concerning the ability to recognise at long range eggs parasitized intra and interespecifically, the females of both species were attracted in the same way by eggs parasitized by con or heterospecifics and non parasitized. Moreover, they could not distinguish between the odour of eggs parasitized intra or interespecifically and nonparasitized eggs, when they were in presence of both types. It means that the substances used to mark parasitized eggs are only perceived at short range or by contact. It can be explained by the fact that marks that could be perceived at long range would make the parasitized hosts more conspicuous to hyperparasitoids and predators, thus being detrimental to the parasitoid. X / Dissertação importada do Alexandria

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