Differences in plant structure and host abundance, distribution and density within and between plants may affect host finding success of searching parasitoids. The main objective of this research consisted in developing and validating a model that can predict parasitism by Trichogramma evanescens on various plant structures. Also, we evaluated the effect of both artificial and natural plant structures on host encountering success and on searching behavior of two species of Trichogramma. / Size (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.

During a two years study (1993-1994) in southwestern Quebec, Artogeia rapae and Plutella xylostella were found to be the most important lepidopterous pests of cruciferous crops, followed by Trichoplusia ni and four minor species. The relationship between plant sampling and the use of degree-days, pheromone traps (P. xylostella) or butterflies counts (A. rapae) was assessed for A. rapae and P. xylostella. Three generations of A. rapae were observed annually, with a duration of 319.7 degree-days above $ rm 10 sp circ C (DD sb{10}),$ while P. xylostella had three to four generations with a duration of 277.7 $ rm DD sb{10}.$ Captures of P. xylostella were not linked to the level of infestations. By the end of summer, A. rapae was the most abundant species, especially on broccoli, while P. xylostella was often abundant early in the season. The complex of lepidopterous pests' natural enemies was identified, and the data were analyzed using an illustrated parasitoid web. Fourteen parasitoid and three hyperparasitoid species (12 Hymenoptera, 2 Diptera) were identified. The most important parasitoid, Cotesia rubecula, is a larval parasitoid of A. rapae that is newly established in Quebec. Overall, parasitism of lepidopterous eggs is almost not existent, whereas parasitism and infection of larvae and pupae by pathogens are important, but not significant to reduce butterfly populations. In order to evaluate the potential of oophagous parasitoids, the parasitism of up to 42 species/strains of Trichogramma was studied with different development stages of P. xylostella, A. rapae and T. ni eggs. Generally, Trichogramma females attacked preferably young eggs of a given host species. Females modified the number of offspring according to host size and host age, as fewer offspring emerged from the smallest or the oldest hosts. Host age had no impact on sex allocation. (Abstract shortened by UMI.)

Thesis (doctoral)--Johann Wolfgang Goethe-Universität Frankfurt, 1999. / Includes bibliographical references (p. 130-143).

Resumo: O objetivo do presente trabalho foi avaliar a seletividade dos inseticidas triflumurom, etofenproxi e endossulfam a duas espécies de Trichogramma, T. pretiosum e T. exiguum em ovos de três diferentes hospedeiros, Anagasta kuehniella, Spodoptera frugiperda e Plutella xylostella em condições de laboratório. Os experimentos de seletividade desenvolvidos no Laboratório de Biologia e Criação de Insetos da Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal UNESP foram realizados mediante a utilização de duas metodologias: uma nova metodologia proposta no LBCI, onde foram avaliados o número de ovos parasitados, porcentagem de parasitismo, porcentagem de emergência, longevidade e razão sexual das gerações F1 e F2 dos parasitóides, e no segundo experimento, utilizando-se da metodologia preconizada pela IOBC, foram avaliados o número de ovos parasitados, porcentagem de parasitismo, porcentagem de emergência e redução no parasitismo. Observou-se que nas duas metodologias os inseticidas endossulfam e etofenproxi não mostraram seletividade aos parasitóides, matando ou inibindo a oviposição, independente do hospedeiro utilizado. Triflumurom mostrou-se seletivo aos parasitóides somente em ovos de hospedeiros naturais quando a nova metodologia (LBCI) foi utilizada. Em testes com a metodologia da IOBC/WPRS triflumurom mostrou-se seletivo às duas espécies de parasitóides, não interferindo nos parâmetros biológicos; entretanto a utilização dessa metodologia interferiu nos resultados quando mais de uma espécie foi utilizada na realização dos experimentos, sendo passível de questionamento. / Abstract: The aim of this work was to evaluate the selectivity of pesticides triflumurom, etofenprox and endosulfan for two species of Trichogramma; T. pretiosum and T. exiguum, in different hosts: A. kuehniella, S. frugiperda and P. xylostella, under laboratory conditions. The research was conducted at Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal (FCAV-UNESP), in the Laboratório de Biologia e Criação de Insetos. The tests were based on two methodologies: a new methodology for selectivity tests which was developed in LBCI and the IOBC/WPRS methodology. Using LBCI methodology parasitized eggs, percentage of emergence, percentage of parasitism, longevity and sex ratio were evaluated for generations F1 and F2. Using IOBC methodology were evaluated parasitized eggs, percentage of emergence, percentage of parasitism and parasitism reduction. The endosulfan and etofenprox were harmful to parasitoids inhibiting the parasitism in all hosts or killing the insects by two methodologies. Triflumurom was selective to parasitoids just in natural host eggs when the new methodology was applied. When the IOBC methodology was applied triflumurom showed selectivity for both species of parasitoids but the use of more than one specie of parasitoid using this methodology influenced the results being this methodology passible for discussions. / Orientador: Sergio Antonio de Bortoli / Coorientador: Dirceu Pratissoli / Banca: Luis Garrigós Leite / Banca: Marcelo da Costa Ferreira / Mestre

Submitted by (edna.saturno@ufrpe.br) on 2016-11-23T13:41:55Z No. of bitstreams: 1 Andre Malacarne Milanez.pdf: 1324658 bytes, checksum: adee6c780c08c674412b2e646d09b54f (MD5) / Made available in DSpace on 2016-11-23T13:41:55Z (GMT). No. of bitstreams: 1 Andre Malacarne Milanez.pdf: 1324658 bytes, checksum: adee6c780c08c674412b2e646d09b54f (MD5) Previous issue date: 2009-02-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Trichoplusia ni (Hübner) (Lep.: Noctuidae) is a pest of great importance in horticulture, because of the use of wide range of hosts. The control of this pest is basically done with chemical insecticides. The use of egg parasitoids of the genus Trichogramma is an alternative for biological control of lepidopteran-pest. However, for the efficiency of these parasitoids are needed studies regarding selection of species and/or strains considering the environment and hosts. Thus, the performance of two strains of Trichogramma exiguum Pinto & Platner, six strains of Trichogramma pretiosum Riley, Trichogramma atopovirilia Oatman & Platner, Trichogramma acacioi Brun, Moraes & Soares, Trichogramma marandobai Brun, Moraes & Soares and Trichogramma demoraesi Nagaraja (Hym.: Trichogrammatidae) parasitizing eggs of T. ni were studied. The biological parameters evaluated were: percentage of parasitism and viability, sex ratio and number of individuals emerging per egg of the host. T. pretiosum strain (Tpsd) obtained the best performance in the parameters of the percentage of parasitism and viability. Based on these results, the influence of the host densities and age of the host was investigated for T.pretiosum strain (Tspd) at 20, 25 and 30 ºC. The proportion of eggs of T. ni offered, at the threetemperatures, influence number of eggs parasitized, percentage of parasitism and individuals emerged per egg. In addition, the best ratio of host egg per Trichogramma, regardless of temperature studied, was 15:1. Eggs up to 24 hours in any temperature allowed the best performance in the biological parameters measured, except in the number of individuals per egg. Thus, T. pretiosum exhibited better performance parasitizing eggs up to 24 hours of age and with host ratio of 15 eggs per female. / Trichoplusia ni (Hübner) (Lep.: Noctuidae) é uma praga de grande importância na olericultura, e seu controle é feito basicamente com produtos químicos. A utilização de parasitóides de ovos do gênero Trichogramma é uma alternativa no controle biológico de lepidópteros-praga. No entanto, para que haja eficiência no uso destes parasitóides são necessários à realização de estudos básicos visando à seleção de espécies e/ou linhagens em relação ao ambiente e seus hospedeiros. Desta forma, comparou-se o desempenho de duas linhagens de Trichogramma exiguum Pinto & Platner, seis linhagens de Trichogramma pretiosum Riley, Trichogramma atopovirilia Oatman & Platner, Trichogramma acacioi Brun, Moraes & Soares, Trichogramma marandobai Brun, Moraes & Soares e Trichogramma demoraesi Nagaraja (Hym.: Trichogrammatidae) parasitando ovos de T. ni. Os parâmetros biológicos avaliados foram: porcentagem de parasitismo e viabilidade; razão sexual e número de indivíduos por ovo. T. pretiosum linhagem (Tpsd) obteve o melhor desempenho nos parâmetros de porcentagem de parasitismo e viabilidade. Com base nesses resultados, estudos visando esclarecer a influência do número e idade dos ovos da praga sobre os parâmetros biológicos de T. pretiosum linhagem(Tspd) nas temperaturas de 20, 25 e 30 ºC foram realizados. A proporção de ovos de T. ni, nas três temperaturas, influênciou o número de ovos parasitados, a porcentagem de parasitismo e o número de individuo por ovos, sendo que a relação ideal de ovos da praga por Trichogramma, independente da temperatura estudada, é de 15:1. Ovos com até 24 horas, em qualquer temperatura, proporcionam os melhores desempenhos nos parâmetros biológicos avaliados. Desta forma, T. pretiosum tem melhor desempenho em ovos com até 24 horas de desenvolvimento embrionário e que esteje em proporção próximos a 15 ovos por fêmea.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-28T12:40:36Z No. of bitstreams: 1 Luziani Rezende Bestete.pdf: 403712 bytes, checksum: 4a5246d287630547b7bb138f6fc4cd2f (MD5) / Made available in DSpace on 2016-11-28T12:40:36Z (GMT). No. of bitstreams: 1 Luziani Rezende Bestete.pdf: 403712 bytes, checksum: 4a5246d287630547b7bb138f6fc4cd2f (MD5) Previous issue date: 2011-02-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The tomato fruitworm (TFW), Helicoverpa zea (Boddie) (Lep.: Noctuidae) is considered an important pest in several crops. The purpose of the study was to evaluate the use of castor bean oil, garlic and tobacco extracts to control H. zea larvae, and the influence of these products on the egg parasitoid Trichogramma pretiosum Riley (Hym: Trichogrammatidae). Larval mortality of TFW was investigated when treated with the alternative products at different concentrations through ingestion and contact aplication. Tests of selectivity and susceptibility of T. pretiosum were performed by spraying TFW eggs prior and post parasitism. Castor bean oil at 3% (v/v) through ingestion and contact treatments of TFW larvae caused mortality of 44 and 20%, respectively. Garlic extract at all concentrations and type of application resulted in TFW mortality equal or greater than the tobacco extract. The number of eggs parasitized by T. pretiosum was reduced by castor bean oil, while other biological parameters were not affected. Garlic extract positively interacted with T. pretiosum resulting in greater number of eggs parasitized, although it was observed a lower number of individuals emerging per parasitized egg in selectivity test. Castor bean oil was toxic to TFW larvae in both types of application. Garlic extract produced better results when ingested by TFW larvae and it was superior when compared to tobacco extract to control TFW larvae. Based on the results, castor bean oil and garlic extract are compatible with T. pretiosum, but the former one should be applied after the parasitoid release. Therefore, castor bean oil and garlic extract are promising as phytosanitary tools to control H. zea larvae. / A broca-grande (BRG), Helicoverpa zea (Boddie) (Lep.: Noctuidae) é considerada uma praga importante em diversas culturas. Assim, neste trabalho foi avaliado o uso do óleo de mamona e os extratos de alho e fumo para o controle de H. zea, e a influência desses sobre o parasitóide de ovos Trichogramma pretiosum Riley (Hym.: Trichogrammatidae). Foram estudadas as vias de aplicação por ingestão e contato, em diferentes concentrações, sobre a mortalidade larval da BRG. Testes de seletividade e susceptibilidade de T. pretiosum foram realizados através da pulverização dos ovos de BRG antes e após o parasitismo. O óleo de mamona a 3% (v/v) via ingestão e contato ocasionou 44 e 20% de mortalidade de larvas, respectivamente. O extrato de alho em todas as concentrações e em ambas as vias de aplicação foi sempre igual ou superior ao extrato de fumo, ocasionando as maiores mortalidades de larvas. O número de ovos da BRG parasitados por T. pretiosum foi afetado pelo óleo de mamona, porém os demais parâmetros não foram influenciados. O extrato de alho interagiu positivamente com T. pretiosum obtendo maior número de ovos parasitados, porém no teste de seletividade reduziu o número de indivíduos emergidos por ovo. O óleo de mamona mostrou toxicidade em ambas às vias de aplicação para a BRG. O extrato de alho foi mais eficiente para o controle da BRG quando comparado ao extrato de fumo, atuando principalmente por ingestão. Com base nos resultados, o óleo de mamona e o extrato de alho são compatíveis com a utilização de T. pretisoum, porém o óleo de mamona deve ser utilizado após a liberação do parasitóide. A utilização do óleo de mamona e extratos de alho é viável para o emprego em programas de manejo fitossanitário de H. zea.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-28T12:51:34Z No. of bitstreams: 1 Marciene Dantas Moreira.pdf: 367488 bytes, checksum: 1c62f7268fdd87f4772b0530a6eaab2b (MD5) / Made available in DSpace on 2016-11-28T12:51:34Z (GMT). No. of bitstreams: 1 Marciene Dantas Moreira.pdf: 367488 bytes, checksum: 1c62f7268fdd87f4772b0530a6eaab2b (MD5) Previous issue date: 2007-07-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / During the parasitism process many factors can lead to host rejection by the parasitoid. Thus, it was evaluated bio-ecological aspects of Trichogramma pretiosum Riley (Hym.: Trichogrammatidae) parasiting Sitotroga cerealella Oliver (Lep.: Gelechiidae) eggs. The study was conducted in free-choice test, alternating parasitized and unparasitized eggs, and no-choice test, using only parasitized eggs. For the parasitism study, mated females of T. pretiosum 12 to 24h-old were used. And, parasitized eggs of S. cerealella 24, 72 and 120h-old were used as host. To evaluate the biological characteristics of T. pretiosum superparasitism, S. cerealella eggs were exposed to the parasitism by one or more parasitoid females aiming oviposition of one or two eggs of the parasitoid per host. The parasitism rejection on 72 e 120h previously parasitized S. cerealella eggs was approximately 100% in relation to the 24h-parasitized eggs (ca. 71.3%). On the other hand, the contact time of the female on 24h-parasitized eggs was around twice longer than on 72 and 120h-parasitized eggs. The offspring produced from single egg laid per host werelarger, exhibited no deformation and greater capacity of parasitism, and in contrast of those produced from two eggs laid per host. We concluded that T. pretiosum exhibited ability inrecognizing eggs previously parasitized and that the superparasitism resulted in reduction of reproductive success of the parasitoid. / Durante o processo de parasitismo diversos fatores podem levar à rejeição do hospedeiro pelo parasitóide. Dessa forma, avaliou-se aspectos comportamentais e biológicos de Trichogramma pretiosum Riley (Hym.: Trichogrammatidae) parasitando ovos de Sitotroga cerealella Oliver (Lep.: Gelechiidae). O estudo foi conduzido com chance de escolha, alternando-se ovos parasitados e não parasitados, e sem chance de escolha, utilizando-se apenas ovos parasitados. Para o parasitismo, foram utilizadas fêmeas acasaladas de T. pretiosum de 12 a 24h de idade. Foram utilizados ovos de S. cerealella com 24, 72 e 120h de parasitados. Para a avaliação das características biológicas em situação de parasitismo e superparasitismo, ovos de S. cerealella foram submetidos a uma ou mais fêmeas de T. pretiosum, possibilitando a oviposição de 1 a 2 ovos do parasitóide por hospedeiro. A porcentagem de rejeição de ovos de S. cerealella com 72 e 120h de parasitados foi de aproximadamente 100% em relação aos ovos com apenas 24h de parasitados (71,3%). Em contrapartida, o tempo de contato da fêmea sobre ovos de 24h deparasitados foi, aproximadamente, duas vezes maior que em ovos com 72 e 120h de parasitados. Os descendentes originados de um único ovo do parasitóide/hospedeiro apresentaram-se todos sem deformações, maiores e com maior capacidade de parasitismo, ao contrário dos descendentes emergidos de dois ovos do parasitóide/hospedeiro. Dessa forma, conclui-se que T. pretiosum apresentou habilidade em reconhecer ovos previamente parasitados e que o superparasitismo resultou em redução do sucesso reprodutivo do parasitóide.

No description available.

No description available.

Orientador: Antonio Carlos Busoli / Coorientador: Cesar Rodriguez Saona / Banca: José Maurício Simões Bento / Banca: Marcos Doniseti Michelotto / Banca: Arlindo Leal Boiça Junior / Banca: Nilza Maria Martinelli / Resumo: 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: Pentato... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: 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. incl... (Complete abstract click electronic access below) / Doutor