Global ETD Search

1	Evaluation of potential baculovirus insecticides : studies of the infection process and host susceptibility Hauxwell, Irene Caroline January 1999 (has links) No description available. 579
2	La spéciation hybride : réflexions générales et exploration d'un cas d'étude chez des papillons alpins du genre Coenonympha / Hybrid speciation : reflexions on the process and exploration of a case study in a complex of alpine butterflies. Capblancq, Thibaut 17 October 2016 (has links) L’hybridation interspécifique est un phénomène très étudié ces dernières années et les conséquences qui lui sont attribuées dans l’évolution des espèces sont diverses. Une littérature de plus en plus fournie met notamment en évidence le rôle que peut avoir l’hybridation sur l’émergence de nouveaux taxons. Mon travail de thèse s’attache à comprendre comment des croisements entre espèces peuvent impacter le processus de spéciation d’une nouvelle lignée évolutive et stimuler ainsi la diversification des organismes vivants.Une revue des différents cas d’espèces hybrides animales proposés dans la littérature a permis, dans la première partie de cette thèse, d’identifier les patrons associés de façon redondante au processus de spéciation hybride. Nous observons par exemple que, si l’apport premier de l’hybridation à la spéciation reste toujours la recombinaison de caractéristiques parentales divergentes, cela peut se traduire de manière différente lors de l’émergence de la lignée hybride. Cette synthèse a aussi été l’occasion de discuter des difficultés méthodologiques qui limitent une réelle estimation de la prévalence de ce phénomène dans l’évolution des espèces.Dans la seconde partie de ma thèse j’explore le processus de spéciation hybride chez un complexe d’espèces proches de papillons du genre Coenonympha. Je montre que, parmi les quatre lignées identifiées dans le complexe, deux sont issues de l’hybridation. Leurs caractéristiques génétiques, écologiques et morphologiques permettent de comprendre, en partie, comment leur phénotype recombinant a favorisé leur établissement en tant qu’espèces à part entière et leur isolement vis-à-vis de leurs espèces parentales.L’histoire évolutive de ces papillons est discutée en détail dans la dernière partie de mon travail de thèse. Les résultats obtenus pour ce cas particulier y sont confrontés aux autres exemples de spéciation hybride ainsi qu’aux attendus théoriques associés à ce phénomène. Les spécificités de ce système d’étude viennent ainsi enrichir les connaissances actuelles sur le processus de spéciation hybride et sur les impacts évolutifs de l’hybridation. / Interspecific hybridization is more and more studied these last years and its consequences on species evolution are diverse. The literature especially points out its potential impact on new species emergence and the number of hybrid speciation cases is increasing. My work aims at understanding how interspecific crosses can initiate the rise of a new hybrid lineage and stimulate the diversification of living organisms.Reviewing the examples of animals hybrid species described in the literature allows me, in the first part of this work, to identify the main patterns associated with the process of hybrid speciation. I observe in particular that, if the recombination of parental characteristics is always the main driver of hybrid speciation, it leads to various patterns in hybrid species establishment. I also discuss methodological issues concerning the identification of hybrid species, which limit our capacity to estimate the prevalence of such process in species evolution dynamic.In the second part of this work I investigate the process of hybrid speciation in a complex of closely related butterfly species of the genus Coenonympha. I show that among the four lineages composing the complex, two originated through hybridization events. Their genetic, ecological and morphological characteristics allow us to better understand how their recombinant phenotype led to their emergence and their isolation from parental species.The evolutionary history of these butterflies is discussed in detail in the last part of this work. The results obtained in this particular case are compared with other examples of hybrid species and with theoretical expectations from literature. This example adds its specificities to the current knowledges about hybrid speciation and evolutionary impacts of hybridization. Hybridation Introgression Spéciation Adaptation Lepidoptère Hybridization Introgression Speciation Adaptation Lepidopteran 570
3	The expression of Bt Cry1Ac in transformed cotton Bt Cry1Ac under abiotic stress Martins, Celia Marilia 03 November 2008 (has links) Bacillus thuringiensis (Bt) is a gram-positive common soil bacterium that produces crystals (Cry) containing proteins that are toxic to certain insects, in particular larvae of Lepidoptera and Diptera. The Bt toxin in the past has been widely used as a bioactive compound for the biological control of mainly lepidopteran pests. Most recently a variety of crops, including cotton and maize, have been genetically modified to express a Bt toxin to confer resistance to lepidopteran pests. However, the effect of abiotic environmental stress, such as drought and heat, which are typical for Africa, on Bt toxin expression in a genetically modified crop has so far not been fully evaluated. This study focuses on the expression and stability of the Cry1Ac insecticidal protein from Bacillus thuringiensis in genetically modified cotton plants under drought and heat stress. These include the physiological and biochemical characterization of the expressed Bt toxin gene under drought stress as well as the biological activity against first-instar larvae of the African cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae). Non-genetically modified cotton (Gossypium hirsutum cv. Opal), as well as genetically modified cotton (cv. Nuopal) expressing the Bt toxin Cry1Ac, were exposed to drought and heat stress. Drought stress was induced by withholding watering plants until the soil moisture content reached 25- 30 % of field capacity. Non-stressed control plants were watered and soil moisture content to 80-100 % of field capacity was maintained. For heat stress, plants were grown at 38 to 32 DC during the day and night, respectively, whereas control plants were grown in a growth cabinet at a 28/25 DC day/night cycle. For growth analysis plants were harvested every second week after planting. At each harvest, different parts of the plant were collected and their fresh and dry weight determined. For biochemical analysis and determining biological activity against first-instar larvae of H. armigera, two types of experiments were carried out, the first experiment four weeks after treatment induction and the second experiment eight weeks after treatment induction. Different plant material (leaves, flowers and immature green bolls) were used for Bt detection as well as for determining biological activity against first-instar larvae of H. armigera. Under drought stress conditions a reduction in leaf area and leaf dry weight were found in both Bt toxin expressing and non-expressing cotton plants, but no significant difference in physiological performance between Bt-expressing and non-expressing cotton plants was found. This study shows that the Bt toxin (Cry1Ac) level decreases in senescent plants and that drought stress did not affect the growth and development of genetically modified Bt plants when compared to non-Bt plants. Although the expression of Bt toxin (Cry1Ac) in Bt cotton plants decreased under drought stress no effect on the efficacy of the toxin against H. armigera was observed. In addition, no significant decrease of Bt toxin content was found in Bt cotton leaves after exposure to heat stress when compared to leaves from nonheat stressed plants. / Dissertation (MSc)--University of Pretoria, 2008. / Plant Science / unrestricted Bacillus thuringiensis Gram-positive common soil bacterium Abiotic stress Lepidopteran pests UCTD
4	Subsídios para o manejo integrado de Chrysodeixis includens (WALKER) (LEPIDOPTERA: NOCTUIDAE) em soja para as regiões do Planalto Sul e Meio Oeste de Santa Catarina / Subsidies for the integrated management of Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) in soybeans in the South Plateau and middle west regions of Santa Catarina Wille, Paulo Eduardo 29 February 2016 (has links) Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-26T16:29:32Z No. of bitstreams: 1 PGPV16MA201.pdf: 1766426 bytes, checksum: 690f1c316be4d0c67b20c202af9f3b70 (MD5) / Made available in DSpace on 2018-02-26T16:29:32Z (GMT). No. of bitstreams: 1 PGPV16MA201.pdf: 1766426 bytes, checksum: 690f1c316be4d0c67b20c202af9f3b70 (MD5) Previous issue date: 2016-02-29 / Capes / Soybean is a commodity produced by the United States, Brazil and Argentina countries, which together account for about 70% of the cultivated area. Its use is primarily for soybean meal and cooking oil production. In order to cultivate it, the soybean farmer faces several difficulties, abiotic and biotic factors, among them the need for management of insect pests, which usually is accomplished by the use of chemical control. Excessive use of chemical control brings harm to human and animal health, selection of resistant individuals and environmental degradation, thus, management alternatives should be studied. This work was divided into three chapters, the goal of the 1st chapter was to do a crop scouting, observing the occurrence of lepidopteran pests and their natural enemies in four and eight commercial plantations of soybean in the crops of 2013/14 and 2014/15 respectively located in the South Plateau and Midwest of Santa Catarina. Collected insects were taken to the Entomology Laboratory CAV / UDESC for identification and larval development. In the 2nd chapter, it was verified the natural resistance of the soybean cultivars BR 36, ND 5909RG, BMX TurboRR and Benso 1RR to Chrysodeixis includens, evaluating the antibiosis effect in leaves, consume preference among new leaves, old leaves and soybean pods for 24 hours and larval development in the leaves structures and soybean pods on antibiosis tests. In the 3rd chapter, it was evaluated the susceptibility of three populations of C. includens collected in the crop of 2014/15, which were compared with a susceptible reference collected in the crop of 2013/14, using the active ingredients flubendiamide and methomyl and defined the diagnostic concentrations for monitoring the susceptibility of C. includens. The crop scouting in the commercial areas showed that the Noctuidae family stood out with 67.1% of the total in the South Plateau in the crop of 2013/14, 57.0 and 90.5% in the South Plateau and Midwest respectively in the crop of 2014/15. There was a predominance of Plusiinae subfamily insects, in especial the species C. includens during the two crop years. The natural biological control accounted 69.7% in the South Plateau in the area of Capão Alto, crop of 2013/14. The primary parasitoid collected during the two crop years was Copidosoma sp. In the antibiosis tests, the cultivar Benso 1RR showed a significant effect, providing a longer period for larval development. In the preference test with new leaf, old leaf and soybean pod, the preference of C. includens was the old leaf. The preference test showed that there was a consumption of the soybean pods, however it was the least preferred structure. When pod was provided as the only source of food no larval development was observed. The bioassays showed that there are differences in susceptibility among populations, with resistance ratio up to 15.2 and 12.0 times for flubendiamide and methomyl respectively. The diagnostic concentrations that caused 95% mortality of the susceptible population for susceptibility monitoring were 180 mg /l water for flubendiamide and 3.200 mg /l water for methomyl. In order to make a sustainable management of caterpillars in soybean, there is a necessity to incorporate alternatives to reduce the use of synthetic insecticides and thus minimize the harmful effects of its intrinsic use, among them, the mortality of natural enemies and evolution of insect resistance to insecticides / A soja é uma “commodity” produzida principalmente pelos países Estados Unidos, Brasil e Argentina que juntos são responsáveis por cerca de 70% da área cultivada. A sua utilização é, principalmente, para a produção de farelo de soja e óleo de cozinha. Para o seu cultivo, o sojicultor enfrenta diversas dificuldades, por fatores abióticos e bióticos, dentre elas a necessidade de manejo dos insetos-praga que, geralmente, é realizado pelo uso do controle químico. O uso excessivo do controle químico traz malefícios a saúde humana e animal, seleção de indivíduos resistentes e degradação ambiental, com isto alternativas de manejo devem ser estudadas. Assim este trabalho foi dividido em três capítulos, o objetivo do 1°capítulo foi realizar o levantamento da ocorrência de lepidópteros-praga e seus inimigos naturais em quatro e oito lavouras comerciais de soja nas safras 2013/14 e 2014/15, respectivamente, localizadas no Planalto Sul e Meio Oeste de Santa Catarina. Os insetos coletados foram encaminhados ao Laboratório de Entomologia CAV/UDESC para identificação e desenvolvimento larval. No 2° capítulo foi verificada a resistência natural das cultivares comerciais de soja BR 36, ND 5909RG, BMX TurboRR e Benso 1RR a Chrysodeixis includens, avaliando o efeito de antibiose de folhas, preferência de consumo entre folhas novas, folhas velhas e vagens por 24h e o desenvolvimento larval nas estruturas de folhas e vagens em testes de antibiose. No 3° capítulo foi avaliada a suscetibilidade de três populações de C. includens coletadas na safra 2014/15, comparando com a suscetível de referência, coletada na safra 2013/14, para os princípios ativos flubendiamida e metomil e definida as concentrações diagnósticas para o monitoramento da suscetibilidade de C. includens. No levantamento dos insetos nas lavouras comerciais a família Noctuidae se destacou com 67,1% no Planalto Sul na safra 2013/14, 57,0 e 90,5% no Planalto Sul e Meio Oeste, respectivamente, na safra 2014/15. Houve predominância de insetos da subfamília Plusiinae, com destaque para C. includens durante as duas safras de cultivo. O controle biológico natural representou até 69,7% no Planalto Sul na área de Capão Alto na safra 2013/14, com o Copidosoma sp. sendo o principal parasitoide coletado durante as duas safras. No teste de antibiose, a cultivar Benso 1RR apresentou efeito significativo, proporcionando um maior período para o desenvolvimento larval. No teste de preferência com folha nova, folha velha e vagem da soja, a preferência de C. includens foi pela folha velha. Para a vagem, houve consumo no teste de preferência, porém sendo a estrutura menos preferida. Quando foi fornecida a vagem como a única fonte de alimento não houve desenvolvimento larval. Para os bioensaios, foi verificado que houve diferenças na suscetibilidade entre as populações avaliadas, apresentando razão de resistência de até 15,2 e 12,0 vezes para flubendiamida e metomil respectivamente. As concentrações diagnósticas que causaram 95% da mortalidade da população suscetível foram 180 mg de flubendiamida/L de água e 3.200 mg de metomil/L de água. Para o manejo sustentável de lagartas na soja, há necessidade de incorporar alternativas para a redução no uso de inseticidas sintéticos, visando minimizar os efeitos maléficos intrínsecos ao seu uso, entre eles a mortalidade de inimigos naturais e a evolução da resistência de insetos a inseticidas 5.00.00.00-4 Ciências Agrárias
5	Avaliação da formulação concentrado emulsionável de indoxacarbe no controle de Helicoverpa armigera (Hübner) e Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) em soja / Evaluation of emulsifiable concentrate formulation of indoxacarb on the control of Helicoverpa armigera (Hübner) and Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) in soybean Silva, Marina Gomes da [UNESP] 06 July 2016 (has links) Submitted by MARINA GOMES DA SILVA null (marinags@hotmail.com.br) on 2016-08-04T16:07:16Z No. of bitstreams: 1 Diss_Agro_05 (002).pdf: 2170011 bytes, checksum: f477b7dc180f664f409a6c5baf8897fb (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-09T14:18:34Z (GMT) No. of bitstreams: 1 silva_mg_me_jabo.pdf: 2170011 bytes, checksum: f477b7dc180f664f409a6c5baf8897fb (MD5) / Made available in DSpace on 2016-08-09T14:18:34Z (GMT). No. of bitstreams: 1 silva_mg_me_jabo.pdf: 2170011 bytes, checksum: f477b7dc180f664f409a6c5baf8897fb (MD5) Previous issue date: 2016-07-06 / Atualmente, insetos praga estão impactando a produção de soja e táticas de controle não estão sendo eficientes, por causa do uso inadequado no campo. Assim opções para manejo de pragas precisam ser desenvolvidas, tais como novos compostos químicos. Devido a disponibilidade de formulação recentemente desenvolvida (concentrado emulsionável – EC) de indoxacarbe, os objetivos com este estudo foram avaliar a eficiência desta formulação no controle de Helicoverpa armigera (Hübner) e Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) em soja. Um experimento a campo foi conduzido usando duas formulações (EC e solução concentrada – SC) de indoxacarbe (30 e 60 g i.a. ha-1) e testemunha. Após a pulverização, folíolos foram coletados das regiões mediana e superior das plantas em diferentes períodos. Os folíolos foram infestados com lagartas de 3°. instar de H. armigera e C. includens. As duas formulações do indoxacarbe foram eficientes no controle de ambas as pragas, independente da região da planta. As maiores dosagens causaram mortalidade > 80% em H. armigera somente 1h após a aplicação e em C. includens até 3 dias. No experimento de laboratório, folíolos recém-coletados de soja cultivada em casa-de-vegetação e imersos em soluções com concentrações crescentes das duas formulações de indoxacarbe para construção das curvas dose-resposta. Após secagem, os folíolos foram infestados com lagartas de 3°. instar de H. armigera e C. includens. As curvas dose-resposta foram similares para ambas as formulações. Para a espécie H. armigera, as formulações EC e SC de indoxacarbe apresentaram CL50 de 0,113 e 0,111 µg i.a. mL-1, enquanto que para a espécie C. includens, elas apresentaram CL50 de 0,065 e 0,127 µg i.a. mL-1, respectivamente. Para avaliar movimento translaminar de indoxacarbe, folíolos de soja foram tratados com as duas formulações de indoxacarbe (30 e 60 g i.a. ha-1) e foram então infestados com lagartas neonatas de C. includens. As formulações do indoxacarbe não apresentaram ação translaminar. A espécie C. includens mostrou ser mais sensível ao indoxacarbe do que H. armigera. De modo geral, a formulação EC é tão eficaz quanto a formulação SC no controle de H. armigera e C. includens em soja e pode ser utilizada como ferramenta no Manejo Integrado de Pragas. / Currently, insect pests are impacting soybean yield and control tactics are not efficient because of their inappropriate use in the field. Therefore, options for pest management ought to be developed, such as new chemical compounds. Because of the availability of recent developed formulation (emulsifiable concentrate - EC) of indoxacarb, the objectives of this study were to evaluate the effectiveness of this formulation for the control of Helicoverpa armigera (Hübner) and Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) in soybean. A field experiment was carried out using two formulations (EC and suspension concentrate - SC) of indoxacarb (30 and 60 g a.i. ha-1) and an untreated control. After spray, leaflets were collected from mid and upper regions of the plants at different times. The leaflets were infested with 3rd instar larvae of H. armigera and C. includens. The two indoxacarb formulations were effective in controlling both species, regardless of plant region. Higher doses caused > 80% mortality of H. armigera only 1h after application and of C. includens up to 3 days. In a lab experiment, fresh soybean leaflets were collected from greenhouse and immersed in solutions with increasing concentrations of the two indoxacarb formulations to build the dose-response curves. After drying, they were infested with 3rd instar larvae of H. armigera and C. includens. The dose-response curves were similar for both formulations. For H. armigera, the EC and SC indoxacarb formulations showed LC50 of 0.113 and 0.111 µg a.i. mL-1 while for C. includens, they showed LC50 of 0.065 and 0.127 µg a.i. mL-1, respectively. To evaluate translaminar movement of indoxacarb, soybean leaflets were treated with both indoxacarb formulations (30 and 60 g a.i. ha-1) and were then infested with neonate larvae C. includens. No translaminar movement was detected. The species C. includens was more sensitive to indoxacarb than H. armigera. Overall, the EC formulation is as effective as the SC formulation for the control of H. armigera and C. includes on soybean and can be used as a tool in Integrated Pest Management. Concentração letal Curva dose-resposta Inseticidas Lepidópteros-praga da soja Manejo Integrado de pragas Movimento translaminar Lethal concentration Dose-response curve Insecticides Soybean lepidopteran pests Integrated pest management Translaminar movement
6	Birds, bats and arthropods in tropical agroforestry landscapes: Functional diversity, multitrophic interactions and crop yield Maas, Bea 20 November 2013 (has links) No description available. 630 birds bats arthropods multitrophic interactions agroforestry tropical landscape forest margin landscape functional diversity crop yield exclosure experiments experimental exclusion arthropod suppression avian predation ecosystem services mist netting point counts artificial plasticine caterpillar dummy experiment biological control monitoring mapping Lemon-bellied White-eye Grosbeak Starling Zosterops chloris Scissiostrum dubium Theobroma cacao cacao agroforestry cacao diseases cacao harvest cacao pests flying vertebrates aerial insectivores volant vertebrates logging breeding colony flower herbivory mesopredator release predatory insects ants spiders aphids Lepidoptera Coleoptera Lepidopteran larvae sustainable agriculture sustainable agroforestry management implications management recommendations applied managament extensive land use management landscape management conservation biodiversity-friendly dbh distance to forest forest proximity habitat conversion herbivory Indonesia insectivorous bats insectivorous birds invertebrates Central Sulawesi Napu valley leaf gleaning leaf herbivory pests insects phytophagous insects plant productivity remnant forest trees shade tree managament South-east Asia Paleotropics tropical landscape tree height landscape gradient local shade management Cacao Pod Borer Cherelle Wilt fruit abortion Helopeltis sulawesi deforestation habitat fragmentation land use intensification forest margin species critical decline predation experiment species-specific functions Southeast Asia biodiversity conservation mesopredators food security human welfare human well-being poverty alleviation poverty reduction smallholder cacao smallholder plantation cacao farmers sustainable cacao management landscape perspective landscape scale large scale field experiment long term field experiment human wellbeing economic importance economic value valuation ecosystem services landscape matrix yield quality yield quantity fruit productivity species identity species diversity species richness ecosystem functioning pesticide use chemical compounds complex food web tritrophic interactions wildlife-friendly rural livelihoods endangered bird species endangered bat species endemic endemic birds endemic bats beneficial impact IUCN Lore Lindu National Park bioindicator indicator species forest margin agricultural habitat agroforestry systems population density predation activity species activity cacao flower cacao pod Orthoptera linear mixed effect models Tukey Post Hoc Test AICc model selection generalized least squares restricted maximum likelihood model simplification species richness estimator species accumulation linear mixed-effects models Likelihood Ratio Test Maximum Likelihood nocturnal insects diurnal arthropods nocturnal arthropods diurnal insects landscape context Land- und Forstwirtschaft (PPN621302791)

1

Page generated in 0.0678 seconds