Los campos de cultivo agrícola se ven afectados en la producción por diversos factores, entre los cuales se encuentra el ataque de plagas de insectos, siendo una medida para su control y exterminio el uso de insecticidas sintéticos, sin embargo, la mayoría genera una alta contaminación ambiental. Debido a esto, los bioinsecticidas de origen vegetal surgieron como una alternativa menos contaminante por su rápida degradación en el ambiente y baja peligrosidad para el hombre. El presente trabajo evaluó la toxicidad de los extractos acuosos, etanólicos y hexánicos de las hojas de Minthostachys mollis (Lamiaceae) “muña” y semillas de Annona muricata (Annonaceae) “guanábana”, Lupinus mutabilis (Fabaceae) “tarwi” y Chenopodium quinoa (Chenopodiaceae) “quinua” sobre hembras adultas del ácaro Tetranychus urticae (Trombidiformes: Tetranychidae) “arañita roja” y larvas del primer instar de Chrysoperla externa (Neuroptera: Chrysopidae) “león de áfidos”. Se emplearon dos concentraciones para todos los extractos: 10% y 20% (p/v), en un periodo de exposición entre las 24 y 72h. Los datos obtenidos fueron sometidos al análisis de varianza (ANDEVA) y la prueba post hoc de Duncan con un nivel de significancia de p≤0,05. Los parámetros de toxicidad se observaron en los valores NOEC (Concentración sin efecto observado) y LOEC (Concentración más baja con efecto observado). Se realizó el screening fitoquímico de los extractos botánicos empleados en los bioensayos. El extracto acuoso de M. mollis y el extracto etanólico de C. quinoa, ambos al 20% de concentración, causaron mortalidades en T. urticae del 28,98% y 29,63%, respectivamente. Los extractos hexánicos de A. muricata y M. mollis no presentaron actividad acaricida. El extracto etanólico de M. mollis registró la mayor toxicidad de todos los extractos evaluados a las 72h de exposición en C. externa, con una mortalidad del 75,76%. El extracto hexánico de A. muricata no produjo mortalidad en este insecto a las 24, 48 y 72h de exposición. La diferenciación en toxicidad (mayor a menor) de los extractos vegetales para C. externa fue: etanólico> acuoso> hexánico. Según el CR (cociente de riesgo) obtenido a las 48h de exposición, los extractos acuosos no representaron un riesgo en la mortalidad de C. externa. La secuencia de mayor a menor toxicidad del CR de los extractos acuosos fue: L. mutabilis˃ A. muricata˃ C. quinoa˃ M. mollis.Agricultural crops have been affected by several factors among which are plague of insects attack, being an effective measure for its control and extermination: synthetic insecticides use, however the majority of them produce high levels of environmental pollution. Due to this, bioinsecticides of plant origin emerging as alternative less polluting because of rapid degradation in the environment and low danger to man. This work analizes the toxicity of hexanic, ethanolic and aqueous extracts of leaves of Minthostachys mollis (Lamiaceae) “muña” and seeds of Annona muricata “guanábana” (Annonaceae), Lupinus mutabilis “tarwi” (Fabaceae) and Chenopodium quinoa “quinua” (Chenopodiaceae) on adult female mite of Tetranychus urticae (Trombidiformes: Tetranychidae): "red spider mite" and the first instar stage larva of Chrysoperla externa (Neuroptera: Chrysopidae): "lacewings". Two concentrations were used for all extract: 10% and 20% (w/v) in an exposure period between 24 and 72h. Analysis of variance (ANOVA) and post-hoc test of Duncan were performed with a significant level p ≤ 0.05. Toxicity endpoints were observed with values in NOEC (No Observed Effect Concentration) and LOEC (Lowest Observed Effect Concentration). Phytochemical screening of botanical extracts used in bioassays was performed. Aqueous extract of M. mollis and ethanolic extract of C. quinoa both at concentration of 20% causing losses in T. urticae of 28,98% and 29,63% respectively. Hexanic extracts of A. muricata and M. mollis did not show acaricide activity. Ethanolic extract of M. mollis registered the greater toxicity of all evaluated extracts at 72 hours in exposure of C. externa with mortality 75,76%. Hexanic extract of A. muricata had no significant effect on mortality in this insect at 24, 48 and 72 hours of exposure. Differentiation in toxicity (to a greater up lesser) of vegetal extracts for C. externa was: ethanol> aqueous> hexane. According to obtained quotient risk (CR) at 48 hours of exposure, aqueous extracts did not represent an increased risk of mortality of C. externa. The descending sequence of toxicity of CR of aqueous extracts was: L. mutabilis˃ A. muricata˃ C. quinoa˃ M. mollis.

Acarodomácias (ou domácias foliares) são cavidades ou tufos de tricomas localizados nas axilas entre as nervuras na face abaxial das folhas. Por meio dessas estruturas, várias espécies de angiospermas lenhosas estabelecem um mutualismo com ácaros benéficos (fungívoros e predadores). Nessa simbiose, as domácias foliares fornecem abrigo e proteção aos ácaros contra inimigos naturais e dessecação, enquanto os ácaros protegem as plantas contra fungos patogênicos e artrópodes fitófagos. Essas estruturas estão presentes em várias espécies da tribo Bignonieae (Bignoniaceae), um grupo monofilético com cerca de 382 espécies de lianas e arbustos neotropicais. A notável variedade de acarodomácias na tribo, somada à disponibilidade de uma filogenia robusta do grupo, torna Bignonieae um excelente modelo para investigar a evolução dessas estruturas. O presente trabalho visou caracterizar as acarodomácias de Bignonieae e estudar a evolução dessas estruturas no grupo. Além disso, realizou testes de correlação entre a evolução de acarodomácias e a de outras características potencialmente associadas à acarofilia: pilosidade foliolar e nectários extraflorais (NEFs). As acarodomácias estão presentes em 58 das 103 espécies analisadas, abrangendo 12 dos 20 gêneros da tribo presentes na filogenia. Foi constatada a presença de domácias primárias, secundárias e terciárias, e dos componentes bolso, tricomas e cova. A variação intra-específica constatada para esses caracteres foi marcante. Além disso, todos eles revelaram-se homoplásticos (múltiplas evoluções e reversões). Foi encontrada uma correlação positiva entre os padrões de evolução de domácias primárias, secundárias e terciárias, e um surgimento sequencial dessas estruturas: primeiro surgiram as domácias primárias, depois as secundárias e, por fim, as terciárias. Quanto aos componentes, bolso e tricomas mostraram-se onipresentes e revelaram uma evolução correlacionada; a evolução do componente cova, por sua vez, não se mostrou correlacionada a dos outros componentes. O padrão de evolução de pilosidade foliolar revelou que, em geral, primeiro surgiram tricomas sobre as nervuras e, posteriormente, os tricomas se estenderam pela lâmina. A evolução de acarodomácias também se mostrou correlacionada à de pilosidade foliolar. É possível que a pilosidade e as acarodomácias atuem em conjunto no mutualismo planta-ácaro benéfico. Adicionalmente, constatou-se que as evoluções de acarodomácias estão sempre relacionadas à presença de tricomas, sugerindo que os tricomas devem ter uma papel especial na acarofilia. Não se observou correlação entre a evolução de domácias foliares e a de NEFs. Este estudo representa o primeiro trabalho sobre a evolução de acarodomácias, e traz importantes subsídios para pesquisas futuras sobre diferentes aspectos da biologia dessas estruturas em Bignonieae, especialmente no que tange a interação planta-ácaro benéfico. / Acarodomatia (or leaf domatia) are cavities or hair tufts found on the axils of veins on the abaxial surface of leaves. Several species of woody angiosperms mediate a mutualism with benefic mites (fungivorous and predaceous) through these structures. In this symbiotic relation, the leaf domatia provide refuge and protection to mites against natural enemies and desiccating conditions, while the mites protect the plants against pathogenic fungi and phytophagous arthropods. These structures are present in many species of the tribe Bignonieae (Bignoniaceae), a monophyletic group with approximately 382 species of neotropical lianas and shrubs. The wide variation of acarodomatia in the tribe associated with the availability of a robust phylogeny for the group makes Bignonieae an excellent model to address the evolution of these structures. The objective of this study was to characterize the acarodomatia of Bignonieae and investigate the evolution of these structures in the group. Furthermore, this study intended to test for correlated patterns of evolution between leaf domatia and traits potentially associated with acarophily: leaflet pubescence and extra floral nectaries (EFNs). Acarodomatia were found in 58 of the 103 analyzed species, representing 12 of the 20 genera of Bignonieae sampled within the phylogeny of the group. Primary, secondary and tertiary domatia were encountered, as well three different domatia components: pocket, trichomes and pit. High intraspecific variation was encountered in those traits. Furthermore, high homoplasy was also encountered, with multiple evolutions and reversals of each trait being documented. A positive correlation in the pattern of evolution of the primary, secondary and tertiary domatia was found, as well as a sequential evolution of these structures: first primary domatia evolved, which was followed by the evolution of secondary domatia and, subsequently the evolution of tertiary domatia. As far as the components of the acarodomatia are concerned, pockets and trichomes were omnipresent and their evolutionary pattern correlated. The evolution of the pit, on the other hand, was not associated to the evolution of any of the other components. The evolutionary pattern of leaf pubescence indicated that, in general, trichomes over the veins of the leaflets evolved first and subsequently spread throughout the blade. The evolutionary pattern of acarodomatia was also shown to be correlated with the evolution of leaflet pubescence. It is possible that pubescence and acarodomatia might act together to promote a beneficial plant-mite mutualism. In addition, the multiple origins of the acarodomatia were always associated with the presence of trichomes, suggesting that trichomes must have had an important role in acarophily. No correlation was found between the evolution of leaf domatia and the evolution of EFNs. This study represents the first investigation of the evolution of acarodomatia, and brings important contributions for future studies on different aspects of the biology of these structures in Bignonieae, especially in what concerns the beneficial association between plants and mites.

Made available in DSpace on 2017-07-10T17:37:26Z (GMT). No. of bitstreams: 1 Alfredo_de_Gouvea.pdf: 585120 bytes, checksum: 13327c6fef592e68ebb2f4a789930eea (MD5) Previous issue date: 2003-03-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The advance and spread agricultural frontiers and the necessity to meet the needs of market has lead to a change in the mate-tea growth system in the Southern region of Brazil. Pest problems, previously unnoticed in the extraction system, have increased in importance, due to the implantation of single vegetable species, which has lead to the simplification of the environment, with increasingly larger economical losses. More than eighty animal species feed from different parts of the mate-tea plant. A good management is crucial and it should take into consideration the several factors relevant to this peculiar environment, so that disturbances do not promote populational explosions of some of these species. In the event of any such unbalance, the result would be increased cost and decreased quality of the product. In the context, this study was conducted in Dois Vizinhos town, in the State of Paraná, with the objective of studying the phytophagous mites and their population dynamics, as well as that of their natural predators. For this reason, leaf samples from different parts of the plant have been taken, and the number of mites was counted. This research has been done from August 2001 to July 2002. During this period, two species of phytophagous mites, Dichopelmus notus Keifer, 1960 and Oligonichus yothersi (McGregor), 1914, and three species of predators identified as Euseius concordis (Chant, 1959), Iphiseiodes zuluagai Denmark & Muma, 1972and Agistemus sp. were related to the mate-tea plant. The D. notus mite has appeared in large numbers in mature leaves and in the inferior face of leaves. It was more frequent in the inferior part of leaves belonging to the inferior and medium stratum and in leaves from the internal canopy. On the other hand, O. yothersi has mainly occurred in mature leaves, in their superior face. The concentration of E. concordis e I. zuluagai has been larger in the inferior face of the leaves belonging to the inferior and medium stratum, as well as in the inferior face of the leaves in the internal canopy region, and in the inferior face of mature leaves. D. notus, O. yothersi, E.concordis and I. zuluagai mites have attained the ir highest population numbers in periods of mild temperatures and little rain precipitation. In leaves from the external canopy, the largest population density of Agistemus sp. has occurred in periods of high temperature and heavy rain. There was indication of mutual influence between these species. / O avanço da fronteira agrícola e a necessidade de atender um mercado em crescimento, levaram a uma mudança no sistema de cultivo da erva-mate, Ilex paraguariensis St. Hilarie, na região Sul do Brasil. Os problemas fitossanitários, desapercebidos no sistema e exploração extrativista, começaram a ter importância, pois a implantação do monocultivo levou à simplificação do ambiente e as perdas passaram a ser economicamente significativas. Por ser uma essência nativa, a erva-mate possui mais de oitenta espécies de animais se alimentando de diferentes partes da planta. Um manejo que considere os diversos fatores envolvidos neste agroecossistema particular é fundamental para que perturbações não venham promover uma explosão populacional de algumas destas espécies, podendo aumentar o custo de produção e baixa a qualidade do produto. Neste contexto foi realizado em Dois Vizinhos-PR um trabalho com objetivo de estudar a dinâmica populacional de ácaros fitófagos e seus predadores. Para tanto, foram realizadas de agosto de 2001 a julho de 2002, coletas de folhas de diferentes partes da planta e contado o número de ácaro ao microscópio estereoscópico. Durante o período estudado foram constadas associadas às plantas de erva-mate duas espécies de ácaros fitófagos Dichopelmus notus Keifer, 1960 e Oligonichus yothersi (McGregor), 1914 e três espécies de predadores identificados como sendo Euseius concordis (Chant, 1959), Iphiseiodes zuluagai Denmark & Muma, 1972 e Agistemus sp. O ácaro D. notus ocorreu em maior número em folhas maduras e na face inferior de folhas dos estratos inferior e médio e nas folhas da região interna da copa e O yothersi predominou em folhas maduras e na face superior das folhas. A concentração de E. concordis e I. zuluagai sempre foi maior na face inferior das folhas maduras localizadas nos estratos inferior e médio, na região interna da copa. Os ácaros D. notus, O. yothersi, E. concordis e I. zuluagai tiveram picos populacionais em período de temperatura amena e baixa precipitação pluviométrica. Nas folhas da região externa da copa das plantas a maior densidade populacional de Agistemus sp. também ocorreu na face inferior, mas seu pico populacional ocorreu em período de alta temperatura e precipitação pluviométrica elevada, sendo observado indicadores de influência mutua entre estas espécies.

Psoroptic mange, caused by the Astigmatid mite Psoroptes ovis, is an ectoparasitic disease of significant economic importance to agriculture on a global scale and poses a serious welfare concern. With the current chemotherapeutic controls considered unsustainable, there is pressing need for novel control strategies. RNA interference has been proposed as a potential high throughput approach for the identification of novel therapeutic targets with high specificity, speed and at a relatively low cost compared to the existing methods. The presence of the components of the RNA interference (RNAi) pathway in P. ovis was first confirmed through in silico analyses of the P. ovis transcriptome and, following development of a non-invasive immersion method of double stranded RNA (dsRNA) delivery, gene silencing by RNAi was demonstrated in P. ovis. Statistically-significant reduction of transcript level was measured for the three genes targeted: P. ovis mite group 2 allergen (Pso o 2), P. ovis mu class glutathione S-transferase (PoGST-mu1) and P. ovis beta tubulin (Poβtub). This is the first demonstration of gene silencing by RNAi in P. ovis and provides a key mechanism for mining transcriptomic and genomic datasets in the future for novel targets of intervention against P. ovis. The first assessment of gene silencing was also performed in two related Astigmatid mites of high medical importance; the European house dust mite Dermatophagoides pteronyssinus and the scabies mite Sarcoptes scabiei. A statistically-significant reduction in expression of a D. pteronyssinus mu class glutathione S-transferase (DpGST-mu1) transcript was observed. No significant reduction in expression of a S. scabiei mu class glutathione S-transferase (SsGST-mu1) transcript was observed. Additionally, microRNAs (miRNAs) from the related miRNA pathway were identified in a P. ovis small RNA sample and were sequenced and annotated.

Doctor of Philosophy / Department of Entomology / C. Michael Smith / The wheat curl mite, Aceria tosichella (Keifer), is an important global pest of bread wheat, Triticum aestivum L. Chronic and often severe reductions of winter wheat yield due to A. tosichella infestations have occurred in North America and all other wheat-production areas for over five decades. Moreover, A. tosichella is the only vector which transmits the three most important wheat viruses in the Great Plains, which are Wheat Streak Mosaic Virus (WSMV), the most economically important wheat virus in North America; Triticum Mosaic Virus (TriMV) and High Plains Wheat Mosaic Virus (HPWMoV). Mite infestation alone causes stunted, chlorotic plants in susceptible wheat varieties. To date, mite resistant wheat cultivars have been the only sufficient method to control A. tosichella. The discovery of new genes for A. tosichella resistance and their introgression into wheat cultivars are essential steps to combat the development of new and/or different A. tosichella biotypes which can develop to overcome resistance genes. Both A. tosichella biotype 1 and 2 exist in U. S. Great Plains wheat producing areas. Elucidating and predicting A. tosichella population composition changes based on climatic and geographic variables is a key to continued effective mite management. Experiments were conducted to: 1) assess A. tosichella virulence in mites collected from 25 sample sites in six states to wheat plants harboring the Cmc2, Cmc3 and Cmc4 mite resistance genes and the Wsm2 WSMV resistance gene in 2014 and 2015, and determine the distribution of WSMV, TriMV and HPWMoV present in mites collected; 2) assess A. tosichella biotype composition using internal transcribed spacer 1 (ITS1) and cytochrome oxidase I (COI) polymorphisms; 3) use generalized additive modeling to capture the spatio-temporal factors contributing to the prevalence of A. tosichella biotypes 1 and 2; and 4) screen Kansas advanced breeding lines for resistance to A. tosichella biotypes 1 and 2. Results indicated that A. tosichella collected from 92% of the sample area were virulent to susceptible Jagger wheat plants with no Cmc resistance genes; that mites from 36% of the sample area were virulent to the Cmc2 gene, and that mites collected from 24% of sample area were virulent to Cmc3. Mite populations from only 8% of the sample sites exhibited virulence to plants containing Cmc4 + Wsm2 or Cmc4. The WSMV virus was predominant and present in 76% of all mites sampled. HPWMoV and TriMV were less apparent and present in 16% and 8% of all mites sampled, respectively. These results will enable breeders to increase the efficiency of wheat production by releasing wheat varieties containing A. tosichella resistance genes that contribute to reducing virus transmission. Results of spatio-temporal factor modeling provide new, more accurate information about the use of ground-cover and precipitation as key predictors of biotype prevalence and ratio. Experiments to determine if Kansas State University advanced breeding lines contain A. tosichella resistance found no resistance to biotype 1, resistance to biotype 2 in breeding lines AYN3-37 and AYN3-34; and moderate resistance to biotype 2 in breeding lines AYN2-28 and AYN2-36. The demonstrated correlation between reduced A. tosichella population size and avirulence; characterization and prediction of the A. tosichella biotype composition; and the identification of new sources of A. tosichella resistance in wheat can help entomologists and wheat breeders increase wheat production efficiency by releasing additional wheat cultivars containing A. tosichella resistance genes.

The spider mite family (Tetranychidae) is a well known pest group in agriculture. Within this family, Willamette spider mite (Eotetranychus willamettei) causes physical harm and potential damage to grapevines (Vitis vinifera) along the central and north coast of California as well as Washington and Oregon. Willamette spider mite prefers cooler climates and feeds by puncturing the plant leaf tissue; therefore removing plant nutrients in the early stages of plant growth. Amending soils with fertilizer is a common cultural practice used in commercial vineyards, but no study has documented the interaction between the effects fertilizer concentrations have on Willamette spider mite. This project consisted of a field study (at Cambria Vineyards & Winery, Santa Maria, CA) and a laboratory study (at a California Polytechnic State University, San Luis Obispo campus greenhouse). The field study tested the effects potassium, nitrogen, and control (unfertilized) treatments had on Willamette spider mite on ‘Chardonnay’ grapes. Field results showed no significant difference among the three treatments, but suggest a response, given that mite density peaked highest in the potassium treatment and had a second high peak in the nitrogen treatment. In addition, egg density peaked highest in the potassium treatment. The lab study tested the effect four different nitrogen treatments had on Willamette spider mites. Treatments ranged from High N (1500 ppm N fertilizer), Med-High N (1500 ppm N fertilizer), Med–Low N (500 ppm N fertilizer), and Low N (0-50 ppm N fertilizer). Four parameters were tested: male and female days to maturation, male and female survivorship to adult, adult female longevity and oviposition. Longevity and oviposition lab results indicate that Willamette spider mite has a non-linear response to grape N concentration. Performance was better within the two medium treatments compared to High N and Low N treatments. Survivorship suggests the same as days to maturation although not statistically significant.

A comprehensive evaluation of the effects of an nC24 agricultural mineral oil (AMO) on tritrophic interactions between French bean Phaseolus vulgaris cv. Redlands Pioneer [Fabales : Fabaceae ], two spotted mite (TSM) Tetranychus urticea Koch [Acari: Tetranychidea] and the predatory mite Phytoseiulus persimilus Atheus-Henriot [Acari: Phytoseiidae] was conducted under laboratory conditions. / Doctor of Philosophy (PhD)

With the introduction of the floating-gate transistor into reconfigurable architectures, great advances have been made in the field. Recently, Hall et. al. have proposed the first truly large-scale field programmable analog array (FPAA). As an outgrowth of this work, a new class of FPAAs based on translinear elements has begun to be developed. The use of translinear elements, multiple input translinear elements (MITEs) specifically, allows for extreme versatility in the functions implemented by the system while keeping the computational elements of the FPAA regular. In addition, synthesis procedures have been developed for translinear elements. This facilitates the implementation of large-scale systems on the FPAA because the circuit design can be extracted using the synthesis procedures based on equations entered by the user. Two architectures are proposed for the new FPAA. The first architecture uses fine grain reconfigurability, every gate capacitor and the drain of each MITE can be connected arbitrarily, in order to create reconfigurable MITE networks. Circuits including a squaring circuit, a square root circuit, a translinear loop, a vector magnitude circuit, and a 1st-order log-domain filter were implemented using this architecture and results are presented. In addition, examples are shown to illustrate the compilation of the circuits onto the FPAA. The second proposed architecture uses a mix of fine and medium granularity in order to simplify the implementation of larger systems. Examples are given and again the compilation of the circuits onto the FPAA is shown.

Spleen tyrosine kinase (Syk) plays a critical role in regulation of immune and inflammatory responses. This thesis investigated the role of Syk in the development of the asthma phenotype in acute and chronic mouse models of allergic airways inflammation. Airway hyperresponsiveness (AHR) to methacholine and inflammation increased significantly in HDM-induced compared with the saline control mice. We demonstrated that in vivo inhibition of Syk by selective Syk inhibitors, and genetic deletion of Syk using conditional Syk knockout mice attenuated AHR despite of inflammatory cell influx in the lung. Histological analysis showed airway remodeling in the chronic model, which was attenuated to some degree by deletion of Syk. This study identified a role of Syk in airway hyperresponsiveness and remodeling without significantly affecting leukocyte recruitment in HDM model of airways disease. My results support the improvement of therapeutic strategies in asthma by targeting the Syk pathway.

Spleen tyrosine kinase (Syk) plays a critical role in regulation of immune and inflammatory responses. This thesis investigated the role of Syk in the development of the asthma phenotype in acute and chronic mouse models of allergic airways inflammation. Airway hyperresponsiveness (AHR) to methacholine and inflammation increased significantly in HDM-induced compared with the saline control mice. We demonstrated that in vivo inhibition of Syk by selective Syk inhibitors, and genetic deletion of Syk using conditional Syk knockout mice attenuated AHR despite of inflammatory cell influx in the lung. Histological analysis showed airway remodeling in the chronic model, which was attenuated to some degree by deletion of Syk. This study identified a role of Syk in airway hyperresponsiveness and remodeling without significantly affecting leukocyte recruitment in HDM model of airways disease. My results support the improvement of therapeutic strategies in asthma by targeting the Syk pathway.