• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 31
  • 24
  • 10
  • 6
  • 3
  • 1
  • 1
  • Tagged with
  • 101
  • 101
  • 35
  • 16
  • 15
  • 15
  • 15
  • 13
  • 13
  • 11
  • 10
  • 8
  • 8
  • 8
  • 8
  • 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.
31

Comportamento alimentar e distribuição vertical de botões florais atacados por Anthonomus grandis Boh. em cultivares de algodoeiro

Grigolli, José Fernando Jurca [UNESP] 17 February 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-17Bitstream added on 2014-06-13T20:48:09Z : No. of bitstreams: 1 grigolli_jfj_me_jabo.pdf: 355083 bytes, checksum: 9d8e7b89c1a1a845a5387f948235891d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O conhecimento do comportamento de uma praga é fundamental para o entendimento da intensidade de seus danos. O objetivou deste trabalho foi estudar o comportamento de alimentação e produção de danos por Anthonomus grandis em cinco cultivares de algodoeiro, avaliando as épocas de maior e menor preferência alimentar e de oviposição de A. grandis, a distribuição vertical no dossel das plantas de botões florais com orifícios de alimentação e oviposição, a preferência alimentar por botões florais de diferentes idades e o respectivo tempo de abscisão. Utilizou-se o delineamento em blocos ao acaso em esquema de parcelas subdivididas com oito repetições. Semanalmente foram avaliadas 5 plantas/parcela. Para o estudo da preferência alimentar por botões florais de diferentes idades e o tempo para sua abscisão, utilizou-se 20 botões florais ao acaso por cultivar, avaliados acompanhados diariamente. NuOPAL, DeltaOPAL e FMX-910 foram utilizadas para alimentação em todo período de florescimento e frutificação das plantas e FMT-701 e FMX-993 apenas no início e no final deste período. DeltaOPAL, FMX-910 e FMX-993 foram utilizadas para oviposição em todo período de florescimento e frutificação das plantas e NuOPAL e FMT-701, apenas no início e no final deste período. Botões florais do terço superior foram mais preferidos para oviposição e botões florais dos terços médio e superior para alimentação. A preferência alimentar foi maior sobre botões florais com 2 dias em NuOPAL e FMX-910 e com 7 dias em DeltaOPAL, FMT-710 e FMX-993. Nas 5 cultivares o tempo para abscisão dos botões florais foi 1 a 2 dias após a primeira punctura de alimentação / The knowledge of a pest behavior is essential for the damage intensity understanding. The objective was to study the feeding behaviour and damage output by Anthonomus grandis in five cotton cultivars. It was evaluated the period of A. grandis major and minor feeding and oviposition preference, the within-plant distribution of flower buds with feeding and oviposition punctures on the plant canopy, the feeding preference for squares at different ages and also the square abscission time after the first feeding puncture. It was used a randomized block design in a split plot design with eight repetitions. Evaluations were performed weekly on five plants per plot. For feeding preference for squares at different ages and the time for its abscission after the first feeding puncture study, were observed in 20 plants/cultivar 20 randomly squares, which were monitored daily. NuOPAL, DeltaOPAL, and FMX-910 were used for feeding throughout the flowering and fruiting period, and FMT-701 and FMX-993 only at the beginning and end of this period. DeltaOPAL, FMX-910, and FMX-993 were used for oviposition throughout the flowering and fruiting period, and NuOPAL and FMT-701 only at the beginning and end of this period. It was observed a feeding preference for flower buds on the medium ans upper parts of the plants and oviposition preference for flower buds on the upper part of the plants for all five cultivars. The boll weevil feeding preference was on squares with two days on NuOPAL and FMX-910 and seven days on DeltaOPAL, FMT-701, and FMX-993. The square abscission time was 1 to 2 days after the first feeding puncture in all cultivars
32

Cassidinae of Panama, part 1 (Coleoptera: Chrysomelidae) / Cassidinae of Panama, part 1 (Coleoptera: Chrysomelidae)

SEKERKA, Lukáš January 2009 (has links)
The study deals with taxonomy of Cassidinae of Panama and is based on extensive new material compared with the type specimens in various museums. Totally is listed 178 species of which 33 and two genera are described as new to science.
33

Comportamento de genÃtipos de feijÃo-de-corda sob infestaÃÃo de pragas / Behavior of genotypes of cowpea under infestation of plagues

JoÃo Gutemberg Leite Moraes 27 April 2007 (has links)
O pulgÃo-preto (Aphis craccivora Koch, 1854), a cigarrinha-verde (Empoasca sp.) e o manhoso (Chalcodermus bimaculatus Fiedler, 1936) sÃo importantes pragas do feijÃo-de-corda [Vigna unguiculata (L.) Walp.] em vÃrias regiÃes do Nordeste do Brasil, por lhe causarem danos diretos e indiretos. O objetivo desta pesquisa foi avaliar o comportamento de genÃtipos de feijÃo-de-corda, em condiÃÃes de campo e sob infestaÃÃo natural de pragas, quanto à sua preferÃncia de ataque. Para isto, efetuou-se um ensaio em delineamento em blocos ao acaso, cujas repetiÃÃes variaram, no tempo, de acordo com a praga a ser avaliada. As avaliaÃÃes eram realizadas semanalmente. Os tratamentos foram dispostos em parcelas constituÃdas de cinco fileiras de quatro metros lineares, cada, espaÃadas entre si de 0,80m e com cinco plantas por metro linear. Em cada amostragem, avaliavam-se cinco plantas, aleatoriamente, dentro da Ãrea Ãtil da parcela (trÃs fileiras centrais). Os dados foram submetidos a uma anÃlise de variÃncia e as mÃdias foram separadas pelo teste de Tukey a 5% de probabilidade de erro. Constatou-se que: em condiÃÃes de campo os genÃtipos estudos sÃo igualmente preferidos pelo pulgÃo-preto, porÃm em condiÃÃes protegidas, a cultivar Epace-10 apresenta-se menos preferida ao ataque do afÃdeo; a cultivar Vita-7 apresenta resistÃncia do tipo nÃo-preferÃncia ao ataque da cigarrinha-verde; os genÃtipos Epace-10, Paulistinha, PitiÃba e BRS Marataoà sÃo menos preferidos para alimentaÃÃo e postura do manhoso em relaÃÃo à cultivar BR 17-GurguÃia. / The black aphid (Aphis craccivora Koch, 1854), leafhopper (Empoasca sp.), and cowpea curculio (Chalcodermus bimaculatus Fiedler, 1936) are importants pests of cowpea in northeast of Brazil, for their direct and indirect effects. The aim of this research was to value the behaviour of cowpea genotypes, in field and greenhouse conditions. Treatments were applied to plants in a randomized complete block design separated in the time. The treatments were disposed in five rows (four linear meters), with 0,8m theyselves, and 0,2m between plants. The samples were realizated, at random, with 3 rows in the experimental unit. Data were transformed using the formule (x + 0,5)1/2, submitted to variance analisys, and means were separated by Tukey test at 5% of error. The evaluations were realizated weekly. The experimental unit consisted of 10 for parcel, from where were quantified the insects, in case of black aphid and leafhopper, and damage in pods for cowpea curculio.
34

Efeitos do tempo e da temperatura de armazenamento de grãos de feijoeiro Phaseolus vulgaris L. na manifestação da resistência ao caruncho Acanthoscelides obtectus (Say, 1831)(Coleoptera: Bruchidae). / Effects of the time and temperature of storage bean grains Phaseolus vulgaris L. on the expression of the resistance to the bean weevil Acanthoscelides obtectus (Say, 1831) (Coleoptera: Bruchidae).

Edson Luiz Lopes Baldin 01 November 2001 (has links)
Visando avaliar os efeitos do tempo e da temperatura de armazenamento de grãos de feijoeiro, Phaseolus vulgaris L., sobre a manifestação da resistência ao caruncho Acanthoscelides obtectus (Say, 1831), realizaram-se ensaios com e sem chance de escolha sob condições de laboratório. Em casa-de-vegetação avaliou-se a preferência para oviposição e os danos causados pelo caruncho em vagens e grãos. Os genótipos utilizados nos ensaios foram Arc.1S, Arc.3S, Arc.5S, Carioca Pitoco, Ipa 6, Porrillo 70, Onix, Arc.1, Arc.2, Arc.3 e Arc.4. Em teste com chance de escolha utilizando-se grãos de diferentes idades, observou-se que os genótipos selvagens Arc.1S e Arc.5S expressaram antibiose e/ou não-preferência para alimentação como mecanismos de resistência a A. obtectus; os genótipos Arc.1 e Arc.2 apresentaram somente antibiose; já Arc.3S expressou não-preferência para oviposição e baixos níveis de antibiose. Em teste sem chance de escolha, os genótipos Arc.1S, Arc.3S, Arc.5S, Arc.1 e Arc.2 expressaram antibiose. Em teste onde avaliou-se a influência do tamanho de grãos na manifestação da resistência, os genótipos selvagens Arc.1S, Arc.3S e Arc.5S expressaram antibiose e/ou não-preferência para alimentação; Arc.1 e Arc.2 expressaram antibiose. No estudo com grãos armazenados sob diferentes temperaturas observou-se antibiose em grãos de Arc.1S e Arc.2, independentemente da temperatura em que estiveram confinados; já com Arc.1, notou-se que os efeitos antibióticos de seus grãos foram reduzidos à medida que a temperatura de armazenamento se elevou. Constatou-se também que 25°C não é a melhor temperatura para discriminar genótipos em estudos de resistência, comparativamente à 20°C e 30°C. Em casa-de-vegetação observou-se que as vagens e grãos do genótipo Arc.4 foram mais preferidos para oviposição e alimentação por A. obtectus em relação aos demais materiais; por sua vez Arc.1, Arc.5S, Ipa 6, Arc.3S e Porrillo 70 revelaram-se menos preferidos para oviposição e alimentação pelo caruncho. / Aiming to evaluate the effects of the time and temperatures of storage bean grains Phaseolus vulgaris L. on the expression of the resistance to the bean weevil Acanthoscelides obtectus (Say, 1831), free and no choice tests were accomplished under laboratory conditions. The preference for oviposition and damages caused by the weevil in pods and grains were evaluated under greenhouse conditions. The genotypes used in the assays were Arc.1S, Arc.3S, Arc.5S, Carioca Pitoco, Ipa 6, Porrillo 70, Onix, Arc.1, Arc.2, Arc.3 and Arc.4. In free choice test using grains of different ages, the wild genotypes Arc.1S and Arc.5S expressed antibiosis and/or no-preference for feeding as resistance mechanisms to A. obtectus; the genotypes Arc.1 and Arc.2 presented only antibiosis; Arc.3S expressed no-preference for oviposition and low antibiosis levels. In no-choice test, the genotypes Arc.1S, Arc.3S, Arc.5S, Arc.1 and Arc.2 expressed antibiosis. In test where the influence of the size of grains was evaluated in the expression of resistance, the wild genotypes Arc.1S, Arc.3S and Arc.5S expressed antibiosis and/or no-preference for feeding; Arc.1 and Arc.2 expressed antibiosis. In the study with grains stored under different temperatures, antibiosis was observed in grains of Arc.1S and Arc.2, independently of the confinement temperature; in Arc.1, it was observed that the antibiotic effects of its grains were reduced as the storage temperature increased. It was also verified that 25°C was not the best temperature to discriminate genotypes in studies of resistance, comparatively to 20°C and 30°C. In greenhouse the pods and grains of Arc.4 were the most preferred for oviposition and feeding by A. obtectus, comparing to the other materials; Arc.1, Arc.5S, Ipa 6, Arc.3S and Porrillo 70 were the least preferred for oviposition and feeding by the bean weevil.
35

Expressional divergence of insect GOX genes: From specialist to generalist glucose oxidase

Yang, Lihong, Wang, Xiongya, Bai, Sufen, Li, Xin, Gu, Shaohua, Wang, Chen-Zhu, Li, Xianchun 07 1900 (has links)
Insect herbivores often secrete glucose oxidase (GOX) onto plants to counteract plant defenses and potential pathogens. Whether generalist herbivores always have significantly higher GOX activities than their specialist counterparts at any comparable stage or conditions and how this is realized remain unknown. To address these two general questions, we subjected larvae of a pair of sister species differed mainly in host range, the generalist Helicoverpa armigera and its specialist counterpart Helicoverpa assulta, to the same sets of stage, protein to digestible carbohydrate (P:C) ratio, allelochemical or host plant treatments for simultaneous analyses of GOX transcripts and activities in their labial glands. GOX activity and transcripts are upregulated concurrently with food ingestion and body growth, downregulated with stopping ingestion and wandering for pupation in both species. The three tested host plants upregulated GOX transcripts, and to a lesser extent, GOX activity in both species. There were significant differences in both GOX transcripts and activity elicited by allelochemicals, but only in GOX transcripts by P:C ratios in both species. GOX activities were higher in H. armigera than H. assulta in all the comparable treatments, but GOX transcripts were significantly higher either in generalists or in specialists, depending on the developmental stages, host plants, P:C ratio and allelochemicals they encounter. These data indicate that the greater GOX activity in generalist herbivores is not achieved by greater transcription rate, but by greater transcript stability, greater translation rate, better enzyme stability and/or their combination.
36

Réponse des femelles de Bactrocera cucurbitae (Diptera, Tephritidae) aux composés volatils de fruits-hôtes / No English title available

Atiama-Nurbel, Toulassi 21 March 2014 (has links)
La localisation des plantes-hôtes est un processus déterminant dans la stratégie adaptative des insectes phytophages et les stimuli olfactifs, qui sont des composés volatils émis par les plantes, jouent un rôle essentiel dans ce processus. Bactrocera cucurbitae (Diptera, Tephritidae) est responsable d'importants dégâts sur maintes cultures maraîchères à l'échelle mondiale et à La Réunion. Si la bio-écologie et la structuration génétique des populations de cette espèce sont relativement bien connues, des connaissances sur la médiation chimique se produisant lors de la localisation des fruits-hôtes restent nécessaires pour améliorer la gestion des populations de cette espèce. L'objectif de la thèse est de caractériser les stimuli olfactifs impliqués dans la localisation à distance par les femelles de B.cucurbitae, d'une large gamme de fruits-hôtes de Cucurbitaceae sauvages et cultivées de La Réunion. Une approche bidisciplinaire (comportementale et chimique) a été adoptée afin d'identifier, parmi 27 fruits-hôtes, les composés volatils responsables de l'attraction des femelles vers leurs sites de ponte. Les résultats soulignent, qu'au sein de la gamme de plantes-hôtes, la réponse des femelles aux effluves de ces fruits est très hétérogène (taux d’attraction de 1 % à 74 %), variant selon l'espèce végétale, la variété et le stade de maturité des fruits. Parallèlement, l'étude de la composition chimique des effluves de ces fruits révèle une chimiodiversité inter- et intraspécifique considérable : 280 composés volatils identifiés au total, avec des profils d'émission différents d'un fruit à l'autre. Ces résultats, complétés par de l’électroantennographie couplée à la chromatographie gazeuse, ont permis de déterminer 34 composés potentiellement impliqués dans l'attraction des femelles. De plus, un mélange à deux composés volatils de synthèse, aussi attractif qu'une odeur de fruits frais, a été identifié à partir des réponses des femelles à 10 des 34 composés, présentés individuellement ou en mélange. Les rôles des composés volatils de fruits-hôtes dans le processus de localisation des sites de ponte et dans la spécialisation écologique de cette espèce de ravageurs sont discutés. Par ailleurs, l'association des résultats de préférence des femelles et de performance larvaire représente une perspective de recherche prometteuse, qui contribuerait à acquérir une connaissance plus fine du phénomène de spécialisation d'hôte. Enfin, il est désormais possible d'envisager l'utilisation du mélange simple à deux composés volatils dans un système de piégeage des femelles, à intégrer dans un schéma de gestion agroécologique des populations de B. cucurbitae. / Locating host-plants is a key process in the adaptive strategy of phytophagous insects, and olfactory stimuli, which arevolatile compounds emitted by plants, play an essential role in this process. Bactrocera cucurbitae (Diptera,Tephritidae) is responsible for significant damage to many vegetable crops in Reunion Island and worldwide. Whilethe bioecology and genetic population structure of this species are relatively well known, understanding the chemicalmediation occurring during host-fruit location is needed to improve the management of this pest. The aim of this thesis is to characterize the olfactory stimuli involved in the location by females of B. cucurbitae, of awide range of wild and cultivated host fruits of Cucurbitaceae in Reunion Island. A multidisciplinary approach (behavioural and chemical) was adopted to identify volatile compounds responsible for the attraction of females to their oviposition sites in 27 host fruits. The results highlight that within the range of host plants the female response to fruit odours is very heterogeneous(attraction rates from 1% to 74%). These levels of female response vary according to the plant species and the varietyand the stage of fruit maturity. Meanwhile, the study of the chemical composition of fruit odours reveals aconsiderable inter- and intraspecific chemodiversity: 280 volatile compounds identified in total, with differentemission profiles from one fruit to another. These results, complemented by coupled gas chromatographyelectroantennographic detection, have identified 34 compounds potentially involved in female attraction. In addition, ablend of two synthetic compounds as attractive as fresh fruit odour was identified by measuring attractiveness of 10 ofthe 34 compounds presented individually or in combination. The roles of volatiles in oviposition sites location and ecological specialization of this pest are discussed. Moreover,the association of these results with data on female preference and larval performance represents a promising researchdirection, which would contribute to a better understanding of the phenomenon of host specialization. Finally, theintegration of a simple two-component blend in a trapping system for females into an agroecological management scheme for B. cucurbitae populations is proposed.
37

Resposta de genótipos de soja ao ataque de Euschistus heros (Hemiptera : Pentatomidae) /

Victor, Vinícius Suárez January 2020 (has links)
Orientador: Edson Luiz Lopes Baldin / Resumo: A soja, [Glycine max (L.) (Merrill)] é um dos principais grãos produzidos mundialmente, com o Brasil apresentando grande destaque em produtividade e exportação. Diversos fatores podem comprometer a produção desta leguminosa, no qual o ataque de insetos fitófagos possui grande relevância. Dentre os insetos-praga para a cultura da soja, Euschistus heros (Fabricius) possui grande importância pela alta incidência no campo e elevado danos ocasionados. Como alternativa à baixa eficiência dos métodos de controle e aplicações indevidas de defensivos químicos, este trabalho procurou avaliar a tolerância de quatro genótipos de soja frente ao ataque de E. heros (3 percevejos/planta) em diferentes fases fenológicas (R3, R5, R7, R3 até o final do ciclo e controle) a campo em duas safras, e respostas enzimáticas, analisadas em laboratório, após o ataque de E. heros em casa de vegetação durante a fase fenológica R5 por diferentes períodos de infestação (7, 14, 21 dias). Para isto, foi avaliado a campo a produtividade, peso de 100 grãos, número de vagens/ 10 plantas, número de grãos/10 plantas, retenção foliar e nível de danos ocasionados. Em casa de vegetação avaliou-se produtividade da linha central, número de vagens e número de grãos. Posteriormente, em análises químicas realizadas em laboratório, foram avaliadas as atividades das enzimas peroxidase, polifenol oxidase, catalase, superóxido dismutase e proteínas totais solúveis. Os genótipos ‘Conquista’ infestado em R3, ‘IAC 100’ infestado... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
38

Effects of host plants, temperature regimes, and mating scenarios on the population dynamics of the cabbage whitefly Aleyrodes proletella L. (Hemiptera: Aleyrodidae)

Askoul, Khaldon 20 June 2017 (has links)
No description available.
39

Molecular interactions among soybean aphids and aphid-resistant soybean

Stewart, Ashley January 2019 (has links)
No description available.
40

Evaluation and Management of Neonicotinoid Resistant Tobacco Thrips (Frankliniella Fusca) (Hinds) in Cotton

Darnell, Chelsie Hope 11 August 2017 (has links)
Research was conducted 2014-2016 to determine how tobacco thrips (Frankliniella fusca) (Hinds) resistance to neonicotinoid insecticides impact thrips resistance to neonicotinoid insecticides in cotton, Gossypium hirsutum (L.).Studies included bioassays to determine severity and mechanism of resistance and evaluation of host plant characteristics in multiple cotton varieties. Another aspect of research focused on the neonicotinoid insecticide clothianidin and its leaching ability as a seed treatment on corn by evaluating soil type, water regime, and amount found in tissue.

Page generated in 0.0642 seconds