Submitted by (edna.saturno@ufrpe.br) on 2016-11-29T16:49:22Z No. of bitstreams: 1 Sergio Monteze Alves.pdf: 300642 bytes, checksum: fce1237abc75b8072be0d5a98b316b58 (MD5) / Made available in DSpace on 2016-11-29T16:49:22Z (GMT). No. of bitstreams: 1 Sergio Monteze Alves.pdf: 300642 bytes, checksum: fce1237abc75b8072be0d5a98b316b58 (MD5) Previous issue date: 2012-02-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The bean species, Phaseolus vulgaris (L.), stands out as the most important of the five cultivated in the world. Among the pests of stored beans in Brazil, Zabrotes subfasciatus (Boh.) is considered the major one, whose control is commonly carried out using synthetic protectors and fumigants. New approaches to control have been tested, using less toxic compounds, less expensive, accessible and appropriate to the principles of Integrated Pest Management (IPM). The aims of this study were: (i) toxicity test (contact and fumigation) and repellence of dos Eucaliptus staigeriana F. Muell, Eucaliptus citriodora Hook, Ocimum gratissimum (L.) and Foeniculum vulgare Mill essential oils; (ii) identify and quantify the constituting compounds. The analysis by GC/ME indicated the presence of Limonene (28.73%), Geranial (15.20%) and Neral (12.16%), as main constituents of E. staigeriana oil; and for E. citriodora oil, Citronellyl acetate (3.34%), 1,8-Cineole (2.87%) and β-Pineno (0.94%). Among the oils tested at fumigant action, the most effective in controlling Z. subfasciatus were: O. gratissimum (LC50 = 0.9 μL/L air) and E. citriodora (LC50 = 0.9 μL/L air). In contact tests the highlights were: E. staigeriana (LC50 = 2.73 μL/20g) and F. vulgare (LC50 = 2.74 μL/20g). E. citriodora resented repellent effect from the concentration of 7.6 μl/20g of beans seeds, followed by E. staigeriana 8.0 μl/20g. The oviposition reduction of Z. subfasciatus was 96.2%, 96.4% and 57.2%, respectively, for E. staigeriana, E. citriodora and F. vulgare oils. Similar results were found to adult emergence. / A espécie de feijão comum, Phaseolus vulgaris (L.), destaca-se como a mais importante, entre as cinco cultivadas no mundo. Dentre as pragas do feijão armazenado no Brasil, Zabrotes subfasciatus (Boh.) é considerada uma das mais significativas, sendo seu controle comumente realizado com inseticidas sintéticos protetores e fumigantes. No entanto, novas alternativas aos inseticidas sintéticos vêm sendo testadas, como os produtos naturais, que são menos tóxicos, de menor custo, biodegradáveis e adequados aos princípios do Manejo Integrado de Pragas (MIP). Os objetivos desse trabalho foram: (i) testar a toxicidade (contato e fumigação) e a repelência dos óleos essenciais de Eucaliptus staigeriana F. Muell, Eucaliptus citriodora Hook, Ocimum gratissimum (L.) e Foeniculum vulgare Mill em Z. subfasciatus; (ii) identificar e quantificar os compostos constituintes. A análise por CG/EM revelou a presença de Limoneno (28,73%), Geranial (15,20%) e Neral (12,16%), como constituintes majoritários do óleo de E. staigeriana; e para E. citriodora, Citronelil acetato (3,34%), 1,8-Cineole (2,87%) e β-Pineno (0,94%). Os óleos mais efetivos com efeito fumigante no controle de Z. subfasciatus foram O. gratissimum e E. citriodora com CL50s de 0,9 μL/L de ar. Nos testes de contato se destacaram E. staigeriana (CL50 = 2,73 μL/20g) e F. vulgare (CL50 = 2,74 μL/20g). E. citriodora apresentou efeito repelente para adultos de Z. subfasciatus, a partir de 7,6 μl/20g de feijão, seguido por E. staigeriana à 8,0 μl/20g. A redução da postura de Z. subfasciatus foi de 96,2, 96,4 e 57,2%, respectivamente, para os óleos de E. staigeriana, E. citriodora e F. vulgare. Resultados semelhantes, também, foram encontrados para a emergência de adultos.

Abiotic factors may interfere in production of plant secondary metabolites and consequently influence the bioactivity of these compounds on insect pests. Thus, this study aimed to evaluate the influence of different agricultural practices (irrigation, mineral fertilizer and organic manure) in chemical composition of the essential oil (EO) of Lippia gracilis and its effects on the maize weevil Sitophilus zeamais.The chemical compositions of EO from plants of L. gracilis cultured on different treatments were analyzed using GC-MS and GC-FID. The carvacrol was the major component of EO in different agricultural practices followed by thymol and ñ-cymene.These three monoterpenes were used in subsequent bioassays. Cultivation practices did not significantly affect the composition of the OEs of L. gracilis. However, small variations in the composition of EOs resulted in different biological responses to S. zeamais. All EOs of L. gracilis and its main monoterpenes applied topically showed low toxicity on S. zeamais after 84 hours exposure at a dose 10 mg g-1. However, these same compounds were highly toxic to S. zeamais by fumigation. The time required to cause 50% mortality of the pest was 28.4 hours on average, ranging from 17.3 to 40.8 hours between treatments. The toxic action of carvacrol, thymol and EOs of L. gracilis (no irrigation/fertilization mineral and 40 t ha-1 organic fertilizer) were the fastest, LT50=18,3. The magnitude of the variation of CL50 and CL99 were 1.9 and 2.1 times. The concentration needed to cause 50 to 99% mortality of the pest was on average 69 and 260 ìl l-1, respectively.Considering the LC50 and LC99, the more toxic OEs of L. gracilis were obtained from plants grown in the absence of mineral fertilizer and in the presence of organic manure with of 20, 40 and 60 t ha-1 (no irrigation) and 40 and 60 t ha-1 (with irrigation). Much of the activity of the EOs of L. gracilis is due to the major compound carvacrol. It took only 27.2 and 92.2 l ìl l-1 to cause 50% and 99 % mortality of adult S. zeamais. The toxic activity of this monoterpene was still one of the fastest (LT50 = 17.3 and LT99 = 70.8 hours). Already the thymol and ñ-cymene awere compounds of low toxicity to adult S. zeamais (LC50= 4,4 e 26,1 respectively). Generally, the EOs of L. gracilis and the monoterpenes applied at lower concentrations (0.01 and 0.1% v/v) showed a neutral effect (not significant) or attractive (negative and significant) in all periods analyzed. At concentration 10% (v/v) almost all treatments were repellents to S. zeamais at any time analyzed (repellence > 50%). Major indexes repellency (54-86%) were observed in treatments irrigated and with maximum organic manure, at concentrations of 1 and 10% (v/v). Thus, our results show the great potential of EO of L. gracilis and its major compound for the development of new products and programs for use in integrated pest management of stored grain. / Fatores abioticos podem interferir na producao de metabolitos secundarios de plantas e consequentemente influenciar na bioatividade destes compostos sobre insetos-praga. Assim, neste trabalho objetivou-se avaliar a influencia de diferentes praticas agricolas (irrigacao, adubacao quimica e organica) na composicao quimica do oleo essencial (OE) de Lippia gracilis e seus efeitos na mortalidade e repelencia do gorgulho do milho Sitophilus zeamais. As composicoes quimicas dos OEs das plantas de L. gracilis cultivadas sobre diferentes tratamentos foram analisadas usando CG-MS e CG-FID. As praticas de cultivo nao afetaram significativamente a composicao dos OEs de L. gracilis, o carvacrol foi o componente majoritario dos OEs nas diferentes praticas agricolas, seguido pelo timol e Ï-cimeno. Estes tres monoterpenos foram utilizados nos bioensaios posteriores. Pequenas variacoes na composicao dos OEs resultaram em diferentes respostas biologicas de S. zeamais. Todos os OEs de L. gracilis aplicados topicamente mostraram baixa toxicidade sobre S. zeamais apos 84 horas de exposicao na dose 10 mg g-1. Contudo, estes mesmos compostos foram altamente toxicos a S. zeamais por fumigacao. O tempo necessario para causar 50% de mortalidade desta praga foi em media 28,4 horas; variando de 17,3 a 40,8 horas entre os tratamentos. A acao toxica do carvacrol, timol e do OEs de L. gracilis (ausencia de irrigacao/adubacao mineral e 40 t ha-1 de adubacao organica) foram as mais rapidas, TL50=18,3. A magnitude da variacao das CL50 e CL99 foram de 1,9 e 2,1 vezes. A concentracao necessaria para causar 50 e 99% de mortalidade desta praga foi em media 69 e 260 Êl l-1, respectivamente. Considerando as CL50 e CL99, os OEs de L. gracilis mais toxicos foram obtidos de plantas cultivadas na ausencia de adubacao mineral e presenca de adubacao organica com 20, 40 e 60 t ha-1 (sem irrigacao) e 40 e 60 t ha-1 (com irrigacao). Grande parte da atividade dos OEs de L. gracilis deve-se ao composto majoritario carvacrol. Foram necessarios apenas 27,2 e 92,2 Êl l-1 para causar 50 e 99% de mortalidade a adultos de S. zeamais. A atividade toxica deste monoterpeno foi de TL50 = 17,3 e TL99 = 70,8 horas. Ja o timol e Ï-cimeno foram os compostos de menor toxicidade a adultos de S. zeamais (CL50= 4,4 e 26,1 respectivamente). De forma geral, os OEs de L. gracilis e os monoterpenos utilizados nas menores concentracoes (0,01 e 0,1% v/v) apresentaram efeito neutro (nao significativo) ou atrativo (negativo e significativo) em todos os tempos analisados. Ja na concentracao 10% (v/v) quase todos os tratamentos foram repelentes a S. zeamais em qualquer tempo analisado (repelencia > 50%). Maiores indices de repelencia (54-86%) foram observadas nos tratamentos irrigados com maxima adubacao organica e concentracao 1 e 10% (v/v). Assim, nossos resultados mostram o grande potencial do OE de L. gracilis e seu composto majoritario para o desenvolvimento de novos produtos e utilizacao em programas de manejo integrado de pragas de graos armazenados.

This dissertation describes the development of CAMBIUM, an agent-based forest sector model for large-scale strategic analysis. This model is designed as a decision support tool for assessing the effect that changes in forest product demand and resource inventories can have on the structure and economic viability of the forest sector. CAMBIUM complements existing forest sector models by modeling aggregate product supply as an emergent property of individual companies’ production decisions and stand-level ecological processes. Modeling the forest products sector as a group of interacting autonomous agents makes it possible to introduce production capacity dynamics and the potential for mill insolvencies as factors in modeling the effects of market and forest inventory based disturbances. This thesis contains four main manuscripts. In the first manuscript I develop and test a dispersal algorithm that projects aggregated forest inventory information onto a lattice grid. This method can be used to generate ecologically and statistically consistent datasets where high-quality spatial inventory data is otherwise unavailable. The second manuscript utilizes this dataset in developing a provincial-level resource dynamics model for assessing the timber supply effects of introducing weevil-resistant spruce. This model employs a stand-level approach to simulating weevil infestation and associated merchantable volume losses. Provincial-level impacts are determined by simulating harvest activities over a 350 year time horizon. In the third manuscript I shift the focus to interactions between forest companies. I analyze the effects of strategic decisions on sector structure by developing CAMBIUM as an agent-based model of competition and industry structure evolution. The forest sector is modeled as a group of autonomous, interacting agents that evolve and compete within the limitations posed by resource inventories and product demand. In the final manuscript I calibrate CAMBIUM to current conditions in the British Columbia forest sector. Industry agents compete for roundwood inputs, as well as for profits in finished product markets for pulp, panel products, and lumber. To test the relevance and utility of this model, CAMBIUM is used to quantify the cumulative impacts of a market downturn for forest products and mountain pine beetle induced timber supply fluctuations on the structure of the forest sector. / Forestry, Faculty of / Graduate

Abstract This thesis is a study of the odour responses of insect olfactory (or odorant) receptor neurons (ORN) of blowfly (Calliphora vicina), mosquito (Aedes communis), fruitflies (Drosophila melanogaster and D. virilis) and large pine weevil (Hylobius abietis). A power-law dependence (similar to Stevens' law in psychophysics) was obtained for the action potential rate of ORN responses vs. odour concentration in measurements with metal microelectrodes from blowfly ORNs and an analysis system was developed for the extracellularily recorded action potentials (or nerve pulses). Odour exposure sequences were used to study action potential rates quantitatively as a function of odour concentration in air exposure. For an odour exposure sequence, a known initial amount of the odour compound in a filter paper inside a Pasteur pipette at the beginning of repeated exposures caused a gradual dilution of the odour concentration in the exposure sequence. The concentration at each exposure was calculated according to the discrete multiple headspace extraction and dilution (DMHED) method. The estimated odour concentration was assumed to obey in the method an exponential law with respect to the exposure number in the sequence. Despite that many uncontrollable parameters remain for measuring quantitatively the characteristics of the ORNs, the results obtained, e.g., sensitivity, specificity, adaptability, and the power-law realation are both biologically and technically very interesting. A time-to-voltage converter (TVC) was utilized for the response analysis in determining action potential intervals originating from a single ORN. A precision analysis of TVC was also performed. With the mosquito (Aedes communis), fruitflies (Drosophila melanogaster and D. virilis) and large pine weevil (Hylobius abietis) antennae were tested for inhibitory and excitatory effects to find out repellents and attractants. Human sweat was found to cause strong stimulus exposure in the responses of the mosquito ORNs and Neutroil® caused inhibitory responses in pine weevil ORNs, respectively. The power-law exponents for blowfly ORNs were about 0.19 in the case of 1-hexanol (HX), 0.065 in the case of 1,4-diaminobutane (14DAB) and 0.32 in the case of butyric acid (BA). The corresponding Stevens' law exponent values 0.39 and 0.33 have been reported for HX and BA, respectively, by Patte et al. (1975).

Dans les agroécosystèmes, la biodiversité fonctionnelle et la biodiversité associée fournissent de nombreux services à l'homme dont la pollinisation, la régulation biologique et le cycle des nutriments. L'association des cultures est une pratique agricole qui augmente la diversité des plantes dans les agroécosystèmes, fournit des ressources alimentaires alternatives et structure les communautés des arthropodes. Elle favorise les prédateurs généralistes pour la régulation biologique des ravageurs. Cette étude vise à comprendre comment la diversité des plantes, à l'échelle de la parcelle, structure les réseaux trophiques des arthropodes et peut participer à améliorer la régulation biologique des ravageurs. Tout d'abord, une méta-analyse a été réalisée afin de rechercher la relation générale liant la diversité végétale considérée à l'échelle locale et le contrôle des insectes ravageurs par les prédateurs généralistes. Ensuite, sur un réseau de 20 parcelles paysannes de la région de Njombé au Cameroun, nous avons étudié l'effet de la diversité des plantes cultivées sur la structure du réseau trophique des arthropodes. Les résultats ont montré que l'abondance des prédateurs était positivement corrélée avec la diversité des plantes alors que celle des herbivores était négativement corrélée avec la diversité des plantes. L'effet inverse de la diversité des plantes sur les abondances des prédateurs et des herbivores suggère que des effets top-down structurent la communauté des arthropodes dans les parcelles de plantain. Enfin, l'effet de trois cultures couramment associées au plantain (maïs Zea mays, macabo Xanthosoma sagittifolium, et pistache Lagenaria siceraria) sur i) la structure de la communauté des fourmis et ii) les dégâts de Cosmopolites sordidus ont été étudiés dans un essai réalisé en station expérimentale. Les trois cultures associées ont eu un effet significatif sur l'abondance de tous les taxa de fourmis collectés mais le sens et la magnitude de cet effet ont varié selon les taxa. Cela montre le levier que constituent les cultures associées pour structurer la communauté des prédateurs généralistes de l'agroécosystème. Les abondances de tous les taxa de fourmis étaient également corrélées avec les dégâts de C. sordidus. Les abondances de Camponotus spp., Monomorium spp., Paratrechina longicornis et Tetramorium sp. étaient négativement corrélées avec les dégâts de C. sordidus montrant leur potentiel de régulation de ce ravageur. Cette étude à l'échelle de la communauté de l'agroécosystème suggère qu'il est nécessaire de prendre en compte les effets de la diversité végétale à tous les niveaux trophiques pour espérer maximiser le service de régulation des ravageurs.Mots clés : Diversité des plantes, cultures associées, réseaux trophiques, arthropodes, fourmis, structure de la communauté / Functional diversity and associated biodiversity in agroecosystems provide and promote important services to human society such as pollination, biological control, and nutrient cycling. Intercropping is a practical way to increase plant diversity in agroecosystems and participates to provide alternative foods and to structure arthropod communities, including generalist predators involved in pest control. To better understand how plant diversity structures the arthropod food web and how the control of pest may be optimized, we first made one meta-analysis to understand the mechanisms linking plant diversity to pest control by generalist predators at local scale. We second studied the effect of plant diversity on the arthropod community in contrasted plantain fields. We showed that predator abundance was positively correlated with plant diversity while herbivore abundance was negatively correlated with plant diversity. This strong and inverse effect of plant diversity on herbivore and predator abundance suggests that top-down forces structure the arthropod community in plantain fields and that it should be possible to structure the predator community to better control herbivores including pests. In a third step, we measured the effect of combinations of three associated crops maize Zea mays, cocoyam Xanthosoma sagittifolium and gourd Lagenaria siceraria as intercrops on ant community structure and then the effect relation between ant abundances with Cosmopolites sordidus damages. The three associated plants had a significant effect on abundance of all ant species but in different magnitudes and with either negative or positive effect showing that the selection of plant species that are intercropped is an efficient way to structure the ant community. The abundances of all species of ants were positively or negatively correlated with the damages of C. sordidus larvae. The abundances of Camponotus spp., Monomorium spp., Paratrechina longicornis and Tetramorium sp. were negatively correlated to C. sordidus damage. These ants appear to be the best candidates for C. sordidus control. These findings will help in the design of plantain agroecosystems that enhance pest control services.Keywords: Plant diversity, intercropping, arthropod food webs, ants, interspecific interactions, habitat structure

Made available in DSpace on 2016-05-02T13:55:18Z (GMT). No. of bitstreams: 1 Michel Reis Oliveira-dissertacao.pdf: 1249067 bytes, checksum: 4ae64064d15ad83dcd3762beddfbdb81 (MD5) Previous issue date: 2011-12-14 / In order to assess growth promoters for Passaricultura two sequenced experiments were proposed: the first to find the most appropriate diet for nutrition of different species, establishing five treatments: T1 - Mixture of Grains, T2 - Extruded Feed, T3 - Commercial mash, T4 - Test and mash and Test mash with added grainwith added grains, tested in vitro, to microbiological safety and chemical quality through multiple samplings and tests in triplicate and in vivo for the maintenance and productivity of birds. The second aimed to test the effects of major antimicrobial available today, establishing five other treatments: T1 Control, T2 - sulfamethoxazole and trimethoprim, T3 - Sulfaquinoxaline and neomycin, T4 - Tylosin tartrate and Clopidol, and T5 - Clopidol tested in vivo for maintenance, productivity and sanitization of poultry , provided orally , added to the dry diet (diet), using the doses recommended by the manufacturers. In vivo tests, we used 50 females of polygamous Oryzoborus maximilliani (Weevil) and Serinus canarius (Canary), in equivalent proportions in each experiment (total 100 animals) with ten repetitions to five treatments, ad libitum treated, then settling in a completely randomized design (CRD ) for the first experiment and Randomized block design (RBD) for the second experiment. Tukey test at 5 % significance level for multiple comparisons being used by SISVAR ® program for all variables of both experiments. Given the results of the first experiment , it was concluded that the use of dry feed grains to test without captive passerines is the most suitable for maintaining optimal conformation of birds and provide quality and food safety. In the second experiment treatments 4 and 5 were similar and with better results (p<0.5) in the control of coccidiosis and mycoplasmosis of birds in the other treatments, however the tartrate Tylosin and Clopidol ( T4 ) by itself treat drug combination, uses a lower dose of the same, assuming best value . / Com o objetivo de avaliar promotores de crescimento para a Passaricultura foram propostos dois experimentos sequenciados: o primeiro para encontrar a ração mais adequada para nutrição de diversas espécies, estabelecendo cinco tratamentos: T1 Mistura de Grãos, T2 Ração Extrusada, T3 Farelada Comercial, T4 Farelada Teste e T5 Farelada Teste com adição de grãos, testados tanto in vitro, para a segurança microbiológica e qualidade bromatológica, através de múltiplas amostragens e provas em triplicatas, quanto in vivo para a manutenção e produtividade das aves. O segundo objetivou testar os efeitos dos principais antimicrobianos disponíveis atualmente no mercado, estabelecendo outros cinco tratamentos: T1 - Controle, T2 Sulfametoxazol e Trimetoprima, T3 Sulfaquinoxalina e Neomicina, T4 Tartarato de Tilosina e Clopidol; e T5 Clopidol, testados in vivo para a manutenção, produtividade e sanitização das aves, fornecidos por via oral, adicionados a dieta seca (ração), utilizando-se as doses preconizadas pelos fabricantes. Os testes in vivo, utilizaram 50 fêmeas polígamas de Oryzoborus maximilliani (Bicudo) e Serinus canarius (Canário), em proporções equivalentes, em cada experimento (totalizando 100 animais) com dez repetições para cinco tratamentos, tratadas ad libidum, estabelecendo-se então, um delineamento inteiramente casualizado (DIC), para o primeiro experimento e um Delineamento em Blocos Casualizado (DBC) para o segundo experimento, sendo utilizado o teste de Tuckey a 5% de significância para as comparações múltiplas através do programa SISVAR®, para todas as variáveis de ambos experimentos. Em vista dos resultados do primeiro experimento, concluiu-se que a utilização da ração farelada teste sem grãos para passeriformes cativos é o mais indicado, por manter a conformação ideal das aves e proporcionar qualidade e segurança alimentar. No segundo experimento os tratamentos 4 e 5, mostraram-se semelhantes e com melhores resultados (p<0,5) no controle da coccidiose e micoplasmoses dos pássaros em relação aos demais tratamentos, entretanto o Tartarato de Tilosina e Clopidol (T4) por se tratar de associação de fármacos, utiliza uma dose menor dos mesmos, pressupondo melhor custo benefício.

O arroz sofre danos principalmente pelo ataque de insetos, causando grandes perdas qualitativas e quantitativas, devido a isso, a presente pesquisa teve como objetivo verificar a viabilidade da radiação gama como método de conservação do arroz (Oryza sativa L.), sua eficiência no controle de uma importante praga de grão armazenado Sitophilus oryzae L. e os efeitos que a irradiação pode apresentar nos grãos irradiados considerando o aspecto sensorial e alteração no amido. As amostras foram constituídas de arroz polido e as doses de radiação gama utilizadas foram 0,5; 1,0; 3,0; e 5,0 kGy, sendo mantidas em temperatura ambiente. Foram realizadas análises da porcentagem de quebra do grão durante o beneficiamento e análise da longevidade e reprodução do gorgulho arroz. Foram realizadas também, as análises da composição centesimal, ácido fítico, conteúdo de amilose aparente e propriedades de pasta dos amidos além das análises para cor (instrumental) em arroz e a aceitabilidade (teste hedônico) visando à determinação da qualidade sensorial do arroz cru e cozido. Verificou-se que a irradiação não alterou de maneira significativa à quebra dos grãos durante o beneficiamento e causou efeito negativo no desenvolvimento dos insetos. A irradiação não alterou de maneira significativa à composição centesimal. Não foi encontrado valor significativo de ácido fítico, devido ao arroz ter sofrido o beneficiamento, retirando a parte externa (farelo) onde contém 85 &#150; 92% de fitatos totais. Foram encontrados valores de 17,33 a 18,44% para conteúdo de amilose aparente, sendo que a irradiação não afetou significativamente a conteúdo de amilose do amido do arroz. Os resultados da propriedade de pasta foram significativamente alterados, ocorrendo à redução da temperatura de pasta, diminuição do tempo para ocorrência do pico viscosidade, redução nos valores de viscosidade máxima e viscosidade final e a tendência de retrogradação se tornou menos acentuada nos amidos com doses crescente de radiação gama. Foram detectadas diferenças estatísticas (p<0,05) no aspecto sensorial entre as amostras irradiadas e não irradiadas, sendo que a amostra irradiada com a dose de 1,0 kGy obteve maiores médias para os atributos sensoriais. Para os resultados encontrados na cor instrumental observou a diferença estatística nos valores b* indicando que o arroz sofreu mudanças de branco para amarelada com o aumento da dose de radiação gama. Conclui-se que o uso da radiação gama, especialmente a dose de 1,0 kGy, mesmo apresentando diferença significativa (p< 0,05) nas propriedades de pasta, proporcionou maior aceitação pelos provadores, não afetou as análises físico-químicas, assegurando maior vida-útil contra o ataque de insetos, desde que não haja reinfestação, sendo portanto a dose recomendável para a conservação do arroz polido. / Rice is exposed to injuries especially due to the attack of insects, which represent great qualitative and quantitative losses. The aim of the present research was to verify the viability of the gamma irradiation as rice (Oryza sativa L.) conservation method; its efficiency in the control of an important pest for stored grains Sitophilus oryzae L. and the effects that irradiation may present in irradiated grains in relation to the sensory aspect and starch alterations. Samples were composed of polished rice and the gamma irradiation dosages used were 0.5; 1.0; 3.0; and 5.0 kGy, and kept at room temperature. Analyses of the grain breakage percentages during processing and the longevity and reproduction of the rice weevil were performed. Analyses of the centesimal composition, phytic acid, apparent amylose content and starch paste properties were also conducted, as well as analyses of the rice color (instrumental) and acceptability (hedonic test), aimed at the determination of the raw and cooked rice sensory quality. It was verified that the gamma irradiation did not change the grain breakage percentage significantly and caused a negative effect on the insect development. Irradiation did not change the centesimal composition significantly. No significant values of phytic acid were found because during rice processing, the outer part (bran) containing 85-92% of total phytates was removed. Values from 17.33 to 18.44% for the apparent amylose content were found, and irradiation did not affect the rice starch amylose content significantly. The paste properties results were significantly changed, where reduction on the paste temperature, decrease on the time for the occurrence of the peak viscosity, reduction on the final viscosity values were observed. The retrogradation tendency became less intense in starches with increasing irradiation dosages. Statistical differences (p<0.05) were detected in the sensory aspect between irradiated and non-irradiated samples, and the sample irradiated with 1.0 kGy obtained the highest means for the sensory attributes. For results obtained for instrumental color, a statistical difference was observed in b* values, indicating that the rice color changed from white to yellowish with increased irradiation dosages. One concluded that the use of the gamma irradiation especially at dosage of 1.0 kGy, even presenting significant difference (p<0.05) in the paste properties, obtained higher acceptance; this irradiation level did not affect the rice physical-chemical analyses and provided longer shelf-life against the attack of insects, being therefore, the recommended dosage for the conservation of the polished rice.

Farmers in Nepal lose about a third of their harvested grain due to postharvest handling and storage. This has led to food insecurity and economic losses. Despite the importance of postharvest, the grain storage system in Nepal relies on traditional storage structures like bamboo granaries. The incidence of storage pests is reported up to 100% in these structures. To minimize the storage loss, farmers use different grain protection methods including toxic chemicals. Multiple cases of pesticides-related poisoning and deaths have been caused by misuse and overuse of pesticides. To push safer, chemical-free alternatives like hermetic storage it is important to understand current pest challenges and management practices in Nepal. Adaptation of chemical-free pest management strategies like hermetic storage largely depends upon basic and applied laboratory research findings. Determining the baseline adult mortality under various hypoxia levels and subsequent insect emergence will help determine the effectiveness of a low oxygen environment in controlling <i>Sitophilus oryzae</i> (L.). This would increase our understanding of hermetic storage technology and help improve its application to both farmers and commercial users and serve as a possible substitute to traditional or chemical pest control methods. In chapter one, I report the result of the survey conducted in Nepal to understand i) current post-harvest storage practices and (ii) assessment of the best delivery approach for storage innovations. In chapter 2, I report the result from laboratory experiment conducted to understand the lethality of hypoxia at 5% oxygen level and below against <i>Sitophilus oryzae</i> (L.), which is a major storage pest reported by farmers in Nepal.

Two field trials were conducted to determine the impact of water management on the efficacy of insecticide seed treatments against rice water weevil, Lissorhoptrus oryzophilus Kuschel, in rice at the Delta Research and Extension Center during 2011 and 2012. The performance of thiamethoxam, chlorantraniliprole, and clothianidin was evaluated when the permanent flood was established at different timings (6 and 8 weeks after planting) and the effect of flush number (0, 1, or 2) on seed treatment performance was evaluated. Seed treatment efficacy was not impacted by delayed flooding, but 2 flushes reduced efficacy of some seed treatments. Experiments were also conducted to determine the impact of reduced seeding rates found in hybrid rice production on the efficacy of insecticide seed treatments targeting rice water weevil. Efficacy was similar when comparing currently labeled rates of thiamethoxam, chlorantraniliprole, and clothianidin with higher rates of these products.

<p dir="ltr">Specialty crop growers in the Great Lakes region of the United States and Canada have been struggling for decades to manage the carrot weevil (<i>Listronotus oregonensis</i>). In carrot, parsley, and celery production, growers may experience 40-100% yield loss, despite the intensive use of insecticides (Boivin, 1999; Jasinski, 2008; Telfer et al., 2019). To improve sustainable management of this native pest in commercial vegetable production, we must address existing knowledge gaps in carrot weevil mate-finding behavior, population genetic diversity and gene flow, and grower adoption and efficacy of integrated pest management (IPM) strategies, like cultivar selection, to combat this pest. To date, these factors have not been evaluated in the carrot weevil system, yet together they have significant implications for developing novel monitoring tools, grower decision making, and the potential evolution of insecticide resistance in this damaging pest.</p><p dir="ltr">To address knowledge gaps in grower adoption and the efficacy of IPM strategies, such as cultivar selection, I investigated the influence of carrot cultivar on the oviposition preference of carrot weevil in the laboratory and quantified the diversity of insect assemblages on carrots in Ohio and Indiana. In tandem, I delivered an online survey to specialty crop growers in Indiana and Ohio to measure their knowledge and use of insect-resistant cultivars as a part of an IPM strategy. I found that carrot cultivar did not impact carrot weevil oviposition preference, but rather the number of petiole trichomes was positively correlated with the cumulative number of egg scars found on a given carrot cultivar. Similarly, cultivar did not influence the diversity of insect assemblages associated with carrot foliage, but hemipterans were the dominant group found across cultivars. Moreover, insect diversity across all carrot cultivars was high, with Shannon-Weiner diversity indices ranging from 2.14 to 2.45.</p><p dir="ltr">I analyzed survey responses from vegetable growers regarding their knowledge, current use, and future use of insect-resistant cultivars and found no significant differences between conventional or organic growers, in either Indiana or Ohio, or across experience levels regarding their knowledge and current or future use of insect-resistant cultivars. Although a greater number of organic growers were aware of insect-resistant cultivars, they were not incorporated into their IPM plans. In contrast, half of responding conventional growers indicated implementing insect-resistant cultivars in current IPM plans. Growers indicated that more information about the efficacy, costs, and benefits of insect-resistant vegetable cultivars would be most helpful in informing their decision to incorporate this IPM tactic on their farms.</p><p dir="ltr">To address knowledge gaps regarding carrot weevil mate-finding behavior, I investigated behavioral response to conspecific frass using Y-tube bioassays and the volatiles of frass samples were analyzed using gas-chromatography mass-spectrometry (GC-MS) as starting points to assess the presence of volatile chemical cues that might function as sex or aggregation pheromones. I found that male and female weevils oriented strongly towards volatiles from male frass. However, conspecifics were not attracted to mixed or female frass, suggesting male frass contains behaviorally relevant chemical cues that are unique or present in greater abundance than in female frass. When I analyzed the chemical abundance and composition of the male frass volatiles, I found 16 common compounds across all samples and no compounds were unique to the male volatile blend. Specifically, (1S)-6,6-dimethyl-2-methylene-Bicyclo[3.1.1]heptane and (1R)-2,6,6-Trimethylbicyclo[3.1.1]hept-2-ene were present in significantly higher abundance in extracts of males frass compared to those of female frass.</p><p dir="ltr">Finally, to address knowledge gaps in the genetic diversity and gene flow of carrot weevil populations in the Great Lakes Region of the U. S., I used single nucleotide polymorphisms (SNPs) to compare genetic diversity and structure of agricultural populations of carrot weevil in Michigan and Ohio. I found limited genetic differentiation between three carrot weevil populations collected from celery and parsley fields located in Michigan and Ohio. I also found high inbreeding coefficients and heterozygote deficiency in all populations, suggesting that all carrot weevil populations are locally confined. These results suggest significant gene flow between populations, which has implications for management, specifically the mitigation and management of insecticide resistance.</p><p dir="ltr">Together, the results from my dissertation can be applied to the improvement of carrot weevil IPM across the Great Lakes region of the United States and Canada. Further investigations into the impact of physical characteristics, specifically petiole trichomes, on carrot weevil oviposition behavior can inform the breeding and development of resistant carrot cultivars. Results from my behavioral bioassay studies represent a critical first step towards the identification of an aggregation or sex pheromone, which would greatly improve detection of resident carrot weevil populations when used in conjunction with current monitoring traps. My results also suggest that monitoring and mitigation of insecticide resistance in carrot weevil populations should be considered at the regional scale, at minimum, with significant gene flow between carrot weevil populations within the Great Lakes Region.</p>