• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 14
  • 6
  • 4
  • 4
  • 2
  • 2
  • Tagged with
  • 35
  • 35
  • 10
  • 9
  • 9
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • 6
  • 6
  • 5
  • 5
  • 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

Desenvolvimento de diferentes populações de Cydia pomonella (Lepidoptera: Tortricidae) em temperaturas variáveis e consequências na modelagem fenológica /

Scomparin, Ana Luiza Xavier. January 2009 (has links)
Resumo: A maioria dos organismos vivos são ectotérmicos, com exceção de pássaros e mamíferos. A temperatura corporal (Tc) de um ectotérmico é resultado da troca de calor entre o organismo e o meio ambiente e esta afeta a maioria das funções biológicas. Por exemplo, os insetos, para mudarem de estágio de desenvolvimento, requerem um mínimo de energia acumulada (calor). Para as pragas, a maioria dos modelos fenológicos é baseada na relação entre características do de desenvolvimento (ex., crescimento) e a temperatura do ar. Todavia, a utilização destes modelos ainda é limitada em razão da falta de exatidão na estimativa das temperaturas máximas e mínimas de desenvolvimento para a maioria das pragas. O objetivo deste trabalho foi avaliar a importância dos fatores: resistência a inseticidas e termoperíodo, assim como discutir os métodos de modelagem para o inseto endofítico Cydia pomonella. Para tal, se submeteu larvas e pupas de 4 linhagens diferentes desta espécie: sensível (Sv), resistente a diflubenzuron (Rdfb), resistente a deltametrina (Rdelta) e resistente ao granulovírus (Rgv), a 4 termoperíodos (15°C-20°C, 20°C-25°C, 25°C-30°C e 30°C- 35°C). Os parâmetros avaliados foram: taxa de crescimento, mortalidade, razão sexual e temperatura base, mínima e ótima de desenvolvimento do inseto. Com o auxílio dos valores obtidos nestes parâmetros, modelos lineares e curvilineares foram desenvolvidos, comparados entre si e com modelos obtidos por autores a temperaturas constantes. Os resultados mostraram que em condições de temperaturas variáveis a resistência implica em mudanças nos parâmetros biológicos (taxa de crescimento, mortalidade e razão sexual) e que o termoperíodo acelera o crescimento de larvas e pupas de carpocapsa. Com o auxílio dos modelos obtidos, foi realizada uma simulação do período de desenvolvimento de C. pomonella utilizando... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The majority living organisms are ectotherms except birds and mammals. The body temperature (Tb) of an ectotherm results from the energy balance between this the organisms and its environment. The Tb determines most of the biological functions. For instance, a minimum of heat accumulation by insects is needed to pass from a development stage to another during their life cycle. For insect pests, most of phenological models are based on life history trait (e.g., growth) and air temperature. Unfortunately, the use of phenological models is limited since there is a lack of accuracy estimatives in maximum and minimum temperatures. The aim this work was to study the importance of two factors ((i) the insecticide resistance, (ii) the thermoperiod) and the modelling methods to design a phenological model for the the endophyte insect Cydia pomonella. Four strains of C. pomonella: (i) Sv (susceptible strain), (ii) Rdfb (resistant to diflubenzuron), (iii) RD (resistant to deltamethrin), RGv (resistant to C. pomonella granulovirus) and 4 thermoperiods (15°C-20°C, 20°C-25°C, 25°C-30°C e 30°C-35°C) were used. Measured parameters were the development rate, the mortality, the sex ratio, the Toptm, Tmin and Tmax of the development rate. Based on the obtained values for each parameter, linear and curvilinear phenological models were made and compared between them and with those obtained at constant temperature by some authors. Thus, in fluctuating thermal conditions, it was shown that insecticide resistance involved aftereffects on life-history traits as the development rate, the mortality and sex ratio. Also, it was shown that the C. pomonella development rate at larval stage is higher in thermoperiodic conditions. With the models the development of C. pomonella was simulated using air and micro-habitat temperatures for two areas of apple orchards in Europe (e.g., Valais in Switzerland and la Drôme...(Complete abstract click electronic access below) / Orientador: Odair Aparecido Fernandes / Coorientador: Marc Saudreau / Coorientador: David G.Biron / Coorientador: Hervé Sinoquet / Banca: Benoit Sauphanor / Banca: Mario Eidi Sato / Banca: Nilza Maria Martinelli / Banca: Sergio Antonio de Bortoli / Doutor
32

Využití BAC klonů při studiu pohlavního chromosomu W obaleče jablečného \kur{Cydia pomonella} (Lepidoptera: Tortricidae) / BAC clones as a tool for the study of codling moth \kur{Cydia pomonella} (Lepidoptera: Tortricidae) W chromosome

DALÍKOVÁ, Martina January 2009 (has links)
In the present study, the W sex-chromosome of the codling moth was studied by means of fluorescence in situ hybridization (FISH) with probes prepared from bacterial artificial chromosome (BAC), which were isolated from the codling moth BAC library. The BAC library was screened for clones derived from both the W and Z sex chromosomes using three sets of molecular markers of codling moth sex chromosomes. A total of 54 BAC clones have been obtained. In this work, only 3 W-derived BAC clones and 1 Z-derived BAC clone were further characterized by BAC-FISH mapping on chromosome preparations of pachytene oocytes; the other BAC clones have been retained for next studies. Whereas the Z-BAC probe provided a discrete hybridization signal on the Z chromosome, and surprisingly on the W chromosome, the W-BAC probes showed multiple hybridization signals distributed on the whole W chromosome, suggesting that they are mainly composed of repetitive sequences, which occur in multiple clusters on the W chromosome. The specific pattern of W-BAC hybridization signals along with the discrete signal of the Z-BAC enabled us to discriminate left/right orientation of both the W and Z chromosomes and examine specificity of W-Z pairing during meiotic prophase I.
33

Assessment of Granulovirus, Spinosad, and Mating Disruption for Controlling <i>Cydia Pomonella</i> L. [Lepidoptera: Tortricidae] in Organic Coastal California Apple Orchards

Lukehart, Raven 01 August 2018 (has links) (PDF)
Codling moth, Cydia pomonella[Lepidoptera: Tortricidae], is a major entomological pest of apples, pears, and walnuts cross the world (Pajac et al. 2016). Female codling moths lay eggs on the apple exocarp and larvae burrow within the fruit causing economic losses to fruit growers.Organic apple orchards in San Luis Obispo, CA currently have three codling moth, Cydia pomonella,control options commercially available including granulovirus (CpVG), spinosad, and mating disruption. In field tests on apple (Malus), we compare percent fruit injury between treatments of granulovirus (2.43 oz/ha Cyd-X® organically approved, Certis USA, Columbia MD), spinosad (4.05 oz/ha Entrust® Naturalyte® organically approved WP formation, Dow AgroSciences, Indianapolis IN), and a control. We also compared mating disruption in form of codling moth Codlemone® sex pheromone (257 ties/ha (506 mg)/acre Isomate®-OFM TT organically approved Pacific Biocontrol Corporation Vancouver, WA) against a control. Delta taps and 1 mg pheromone lures were used to trap males and track the degree day (DD) model for the two orchard’s codling moth populations to determine application timing for each treatment. A preliminary DD model was used based on the University of California at Davis Agricultural Extension codling moth DD model. During 2016 trialsno detectible control was provided by spray treatments with an average fruit injury of 26% control, 23% granulovirus, 28% spinosad. During 2016 trialsno detectible control was provided by mating disruption with an average fruit injury of 16% control and 16% pheromone. During 2017 trials there was detectible control provided by the treatments to the crop by both spray treatmentsand pheromone ties. 2017 average fruit injury for spray treatments was 51% control, 20% granulovirus, and 14% spinosad. 2017 average fruit injury for mating disruption was 29% control and 6% pheromone. Data suggest underlying relationship between location specific climate factors, cultivars, codling moth populations, and treatment efficacy.
34

'n Bydrae tot die biologie en beheer van die valskodlingmot Cryptophlebia leucotreta (Meyr.) (Lepidoptera : Eucosmidae) op nawels

Schwartz, A. (Allen) 12 1900 (has links)
Thesis (PhD )--Stellenbosch University, 1981. / EKSERP: Vanwee die voortdurende probleme wat die valskodlingmot, Cryptoph lebia leucotreta (Meyr.), by die verbouing van nawels in die Oos-Transvaalse Laeveld daarstel, is 'n indringende studie van hierdie insekprobleem onderneem. Die biologie van die insek is onder sowel laboratorium as natuurlike toestande nagevors. Daar is bevind dat temperatuur 'n belangrike rol in die ontwikkeling van die insek speel. By 20 tot 30°C het temperatuurstygings die ontwikkeling van die insek laat versnel. By 35°C het die lewensduur van die volwasse motte afgeneem en is geen eiers gelê nie . Die valskodlingmot is deur middle van 'n kunsmatige metode geteel om genoegsame proefmateriaal te verkry. Verskeie verbeteringe is in die bestaande tegniek aangebring.
35

Optimization of a mass-rearing system to produce codling moth, Cydia pomonella, for a Sterile Insect Release programme in South Africa

Stenekamp, Daleen 03 1900 (has links)
Thesis (PhD (Conservation Ecology and Entomology))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Codling moth, Cydia pomonella, is a worldwide pest and of major economic importance to the South African pome fruit industry. Sterile insect release is applied as a component of area-wide integrated pest management and includes the mass-rearing, sterilization and the release of the sterile insects. For sterile insect release, the improvements of rearing methods in terms of the quality of the diet ingredients and the economical aspect of the rearing method are examined. The effect of genetically modified maize meal, containing the Bacillus thuringiensis gene, in an artificial medium for codling moth rearing, is determined. The use of even a small amount of Bacillus thuringiensis resulted in larval mortality and prolonged development. These results are detrimental to a mass-rearing facility and must be considered by any rearing facility that uses genetically modified maize meal if the insect is sensitive to the gene. An alternative to maize meal in the artificial medium was tested and whole wheat flour was considered to be a suitable replacement. Agar agar is an expensive gelling agent used in the artificial medium. An alternative for agar agar (Kelcogel, Elastigel and carrageenen) is tested and the biological effect on codling moth is determined. Factors such as mortality, pupal and moth weight, longevity, fecundity and development time were used as quality parameters. Results showed that Elastigel was a suitable replacement for agar agar, with bigger pupae and moths, higher fecundity and increased longevity. The economical advantage of the replacement is a 40.91% reduction of the diet cost. The other gelling agents tested also gave acceptable results and can be considered if shortages of agar agar or Elastigel occur. A new method of mass-rearing codling moth larvae in a closed rearing system using large trays placed in a ventilated box is designed. This method is more cost and space effective as a smaller area is needed to rear a large number of moths. The risk of diet contamination is less because of the closed environment and more economical and effective air handling. This is the first report of its kind to describe the mass-rearing of codling moth in a closed environment and the risks involved in using genetically modified maize meal in an artificial diet for the codling moth. These results should be incorporated into existing mass-rearing facilities or taking into consideration when designing new mass-rearing facilities. / AFRIKAANSE OPSOMMING: Die kodlingmot, Cydia pomonella, is van ekonomiese belang vir die Suid-Afrikaanse kernvrugte bedryf. Die steriele insek tegniek word gebruik as ‘n komponent in area-wye geïntegreerde plaagbeheer en sluit in die massa-aanteel, sterilisering en vrylaat van steriele insekte. Vir die steriele insek tegniek is die verbetering van die massa-aanteel van die kodlingmot in terme van kwaliteit van die dieet en die ekonomiese aspek van die aanteel metode ondersoek. Die effek van genetiese gemanipuleerde mieliemeel wat die Bacillus thuringiensis geen bevat, in ‘n kunsmatige voedselmedium vir die aanteel van kodlingmot, is bepaal. Daar is gevind dat die gebruik van selfs ‘n klein persentasie Bacillus thuringiensis in die mieliemeel, mortaliteit en ‘n verlengde lewenssiklus in kodlingmot veroorsaak. Die gevolge is nadelig vir ‘n massa-aanteel fasiliteit en behoort in ag geneem te word vir enige insek wat op ‘n kunsmatige medium, wat mieliemeel bevat, geteel word, mits die insek sensitief is vir Bacillus thuringiensis. ‘n Alternatiewe bestanddeel vir mieliemeel, volkoringmeel, word aanbeveel. Agar agar is ‘n duur verdikkingsagent wat in kunsmatige mediums gebruik word. ‘n Alternatief vir agar agar (Kelcogel, Elastigel en carrageenen) is getoets en die biologiese effek op die kodlingmot is bepaal. Faktore soos mortaliteit, papie en mot gewig, langlewendheid, vrugbaarheid en lengte van lewenssiklus was gebruik as kwaliteit parameters. Resultate het getoon dat Elastigel ‘n geskikte plaasvevanger is van agar agar, met groter papies en motte, groter vrugbaarheid en langlewendheid. Die ekonomiese gevolg van die plaasvervanger, is ‘n vermindering van 40.91% van die dieetkoste. Die ander verdikkingagente wat is getoets is, het aanvaarbare resultate gelewer wat noodsaaklik is indien daar ‘n tekort van Elastigel of agar agar ontwikkel. ‘n Nuwe metode van massa-aanteel van kodlingmot larwes is bepaal. Die metode behels ‘n geslote sisteem, waar groter aanteel bakke in ‘n geslote, geventileerde boks geplaas word. Die metode is koste en spasie effektief en ‘n kleiner area word benodig om ‘n groter aantal motte te lewer. Die risiko van kontaminasie van die dieet word verminder as gevolg van die geslote sisteem wat gebruik word en meer ekonomiese en effektiewe lugversorging word gebruik. Hierdie is die eerste verslag van sy soort wat die massa-aanteel van kodlingmot in ‘n geslote sisteem beskryf en wat die risiko aandui van geneties gemanipuleerde mieliemeel in ‘n kunsmatige medium vir die kodlingmot. Hierdie resultate behoort in ag geneem te word vir reeds bestaande massa-aanteel fasiliteite of met die ontwerp van nuwe massa-aanteel fasiliteite.

Page generated in 0.1127 seconds