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  • 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.
301

Diversité génétique et recherche de facteurs de virulence de Nosema ceranae, parasite de l'abeille mellifère

Roudel, Mathieu 12 December 2013 (has links) (PDF)
Le parasite microsporidien Nosema ceranae est un pathogène émergent de l'abeille européenne (Apis mellifera). Il provoque une maladie appelée nosémose qui peut induire de fortes mortalités dans les colonies. La présence de N. ceranae dans les ruches n'est pas toutefois pas systématiquement associée à des symptômes ou à une dépopulation, ce qui suggère une variabilité de sa virulence. Une hypothèse proposée pour expliquer cette variation repose sur l'existence potentielle de variants parasitaires de niveaux de virulence différents. Ce travail a eu pour objectif d'évaluer le polymorphisme de N. ceranae par une approche multilocus, dans le but de savoir s'il est possible de différencier des isolats parasitaires. La diversité nucléotidique de dix marqueurs génétiques a été évaluée dans des abeilles géographiquement éloignées. L'analyse du polymorphisme de ces gènes a révélé un fort contenu allélique au sein même d'un individu hôte mais une absence de divergence entre les populations parasitaires issues d'hôtes distincts. Ces données montrent que cette approche multilocus ne permet de pas de différencier des isolats de N. ceranae, mais que des populations parasitaires similaires infectent des abeilles géographiquement distantes. Ces données sont en accord avec l'hypothèse d'une colonisation récente d'A. mellifera par N. ceranae mais posent de nombreuses questions quand à l'origine de la diversité parasitaire au sein d'un seul individu. Le second volet de cette thèse a eu pour objectif de rechercher dans le génome de N. ceranae des gènes codant de potentiels facteurs de virulence puis de produire des protéines recombinantes et des anticorps dirigés contre ces facteurs. Ces anticorps devaient permettre de localiser ces protéines d'intérêt au niveau subcellulaire dans des tissus infectés.
302

Impact de la microsporidie Nosema ceranae et d'insecticides neurotoxiques sur la santé de l'abeille domestique (Apis mellifera)

Aufauvre, Julie 19 December 2013 (has links) (PDF)
Apis mellifera est un insecte pollinisateur jouant un rôle économique et écologique majeur. Depuis plus d'une vingtaine d'années, d'importantes pertes de colonies d'abeilles ont été recensées à l'échelle mondiale. L'origine de ce phénomène impliquerait de nombreux facteurs de stress qui pourraient en outre interagir entre eux. Ce travail de thèse a eu pour but d'évaluer l'impact sur la santé de l'abeille de l'association entre un facteur biotique, le parasite microsporidien Nosema ceranae, et un facteur abiotique, des insecticides neurotoxiques à faibles doses. Des études en laboratoire ont montré que l'association N. ceranae-insecticide entraine une surmortalité significative, et plus précisément un effet synergique sur la mortalité des abeilles. Cet effet synergique semble indépendant de l'ordre d'exposition des abeilles aux deux facteurs de stress. De plus, lorsqu'ils ont été appliqués dès l'émergence des abeilles, ces facteurs ont eu un impact plus fort sur la mortalité. La réponse de l'abeille à N. ceranae et aux insecticides a ensuite été analysée à l'échelle transcriptomique. L'analyse du transcriptome de l'intestin a été réalisée en combinant une approche globale de séquençage à haut débit (RNA-Seq) et un suivi de l'expression d'une sélection de gènes par qRT-PCR. L'exposition à N. ceranae et aux insecticides a entraîné des modifications de l'expression de gènes impliqués dans les défenses de l'abeille (immunité, détoxication) et dans les métabolismes du tréhalose et de la chitine. De nombreuses perspectives à ce travail sont envisageables dans le but de mieux appréhender la réponse de l'abeille à différents facteurs de stress, notamment en combinant des expérimentations en laboratoire avec des études de terrain.
303

Avaliação da qualidade do mel e atividade da enzima invertase em Apis mellifera L. africanizadas

Arauco, Elvira Maria Romero [UNESP] 08 1900 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-08Bitstream added on 2014-06-13T19:22:54Z : No. of bitstreams: 1 arauco_emr_dr_botfmvz.pdf: 810943 bytes, checksum: 6acc5913059689bd4615fef648271508 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O néctar é coletado pelas operárias coletoras e transportado em sua vesícula nectarífera para a colméia. Durante a sua transformação em mel, o néctar recebe enzimas provenientes das glândulas hipofaringeanas, as quais atuam em seu processamento. A invertase é uma das enzimas adicionadas ao néctar e promove a inversão da sacarose em frutose e glicose. Com o objetivo de se conhecer o pH ideal dessa enzima nas abelhas operárias foram extraídas as glândulas hipofaringeanas de abelhas com oito dias de idade. O método utilizado para a dosagem da invertase foi o do ácido 3-5þ dinitrosalicílico (DNS) para determinação de açúcares redutores, utilizando-se medida de leitura espectrofotométrica em absorbância da glicose em comprimento de onda (?) igual a 540nm. De acordo com os resultados, verificou-se que a atividade catalítica da enzima foi mais eficiente no pH 5,0 e em 40 minutos de reação em comparação com outros valores de pH e tempos de reação. Não foi possível a reutilização das glândulas. Desta forma, concluiu-se que a enzima invertase aumentou sua eficiência em função do tempo de reação de forma linear e significativa em pH 5,0. / The nectar is collected by the collecting workers that carry it in its nectar gallbladder to the beehive. During its transformation in honey, the nectar receives enzymes proceeding from the hypopharyngeal glands, which act in its processing. Invertase is one of enzymes added to the nectar and promotes the inversion of sacarose in fructose and glucose. With the aim of knowing the ideal pH, in the worker bees, the bee's hypopharyngeal glands with eight days of age had been extracted. The used method, for the dosage of invertase, had been the 3-5 ' dinitrosalisilic acid for determination of reducing sugars, using absorbance spectrophotometry data from the glucose in ? equal to 540nm. According to the results, it had been verified that the enzyme catalytic activity had been more efficient in pH 5,0 and in 40 minutes of reaction, comparing to other pH values and times of reaction. The glands reuse had not been possible. At this way, it was concluded that the invertase enzyme had increased its efficiency by the reaction time at linear and significant way in pH 5,0.
304

Ovarian Regulation of Honey Bee (Apis mellifera) Foraging Division of Labor

January 2011 (has links)
abstract: There is increasing evidence that ovarian status influcences behavioral phenotype in workers of the honey bee Apis mellifera. Honey bee workers demonstrate a complex division of labor. Young workers perform in-hive tasks (e.g. brood care), while older bees perform outside tasks (e.g. foraging for food). This age correlated division of labor is known as temporal polyethism. Foragers demonstrate further division of labor with some bees biasing collection towards protein (pollen) and others towards carbohydrates (nectar). The Reproductive Ground-plan Hypothesis proposes that the ovary plays a regulatory role in foraging division of labor. European honey bee workers that have been selectively bred to store larger amounts of pollen (High strain) also have a higher number of ovarioles per ovary than workers from strains bred to store less pollen (Low strain). High strain bees also initiate foraging earlier than Low strain bees. The relationship between ovariole number and foraging behavior is also observed in wild-type Apis mellifera and Apis cerana: pollen-biased foragers have more ovarioles than nectar-biased foragers. In my first study, I investigated the pre-foraging behavioral patterns of the High and Low strain bees. I found that High strain bees progress through the temporal polyethism at a faster rate than Low strain bees. To ensure that the observed relationship between the ovary and foraging bias is not due to associated separate genes for ovary size and foraging behavior, I investigated foraging behavior of African-European backcross bees. The backcross breeding program was designed to break potential gene associations. The results from this study demonstrated the relationship between the ovary and foraging behavior, supporting the proposed causal linkage between reproductive development and behavioral phenotype. The final study was designed to elucidate a regulatory mechanism that links ovariole number with sucrose sensitivity, and loading decisions. I measured ovariole number, sucrose sensitivity and sucrose solution load size using a rate-controlled sucrose delivery system. I found an interaction effect between ovariole number and sucrose sensitivity for sucrose solution load size. This suggests that the ovary impacts carbohydrate collection through modulation of sucrose sensitivity. Because nectar and pollen collection are not independent, this would also impact protein collection. / Dissertation/Thesis / Ph.D. Biology 2011
305

Tolerance to virus infections could explain increased winter colony survival observed in Varroa destructor-resistant honey bees

Bouro Wallgren, Sofia January 2018 (has links)
Honey bee colonies all over Europe and North America have been declining dramatically for over three decades and is continuing to do so which is causing significant threats to economy, agriculture and ecosystems. The main reason behind the declining colonies is an ectoparasitic mite known as Varroa destructor and viruses vectored by the mite. In previous studies, it has been suggested that a unique mite-resistant subpopulation of honey bees (Apis mellifera) in Gotland, Sweden have developed adaptive tolerance to these viruses as they have managed to survive high mite infestation through natural selection without any mite control treatment. This indicates that there might be a correlation between resistance to Varroa destructor and virus tolerance. This project examined if a correlation between virus resistance and/or virus tolerance can be observed in Varroa-resistant honey bees from unique subpopulations in Europe covering Sweden, Norway, France and Netherlands. Results showed that no correlation could be established based on the findings in this project. However, significant differences in winter colony survival numbers between mite-resistant and mite-susceptible honey bees suggest that tolerance mechanisms could be present in these subpopulations. Further studies are required to verify this hypothesis.
306

Efeito da insolação na sanidade de abelhas Apis mellifera (africanizadas) no Semiárido Brasileiro / Effects of the insolation on the bee health of Apis mellifera (Africanized bees) in the Brazilian semiarid region

Souza, Franklin Amaro de 27 February 2016 (has links)
Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-03-13T13:17:05Z No. of bitstreams: 1 FranklinAS_DISSERT.pdf: 1406892 bytes, checksum: 31ccee360ab84a9af3e75803363344c4 (MD5) / Made available in DSpace on 2017-03-13T13:17:05Z (GMT). No. of bitstreams: 1 FranklinAS_DISSERT.pdf: 1406892 bytes, checksum: 31ccee360ab84a9af3e75803363344c4 (MD5) Previous issue date: 2016-02-27 / Africanized honey bees (Apis mellifera) from the region of the Semiarid Potiguar has two main diseases: varroatose, whose agent is the mite Varroa destructor and, the Nosemosis disease, recently introduced in the state, whose agent was previously identified in the area of our experimental apiaries as being the microsporide Nosema ceranae. The objectives of this study were to evaluate the effects of direct insolation and shading on the hives, in relation to the mite infestation rate in the adult bees and in the worker brood; on hygienic behavior and on the Nosemosis disease. The experiment was conducted in CETAPIS / UFERSA in the Mossoró-RN city. It were used 10 beehives installed under a metallic structure covered by dry leaves of coconut, it was built on the east-west direction, and with a capacity to absorbed about 90% of the direct insolation. Ten other beehives were installed under the direct effect of insolation, about 15 meters in relation to the former group. The results showed that during the dry season period the hives installed in the shade had an average infestation rate (%) in adult bees significantly lower (P <0.01) than in hives installed in the sun. Although the results show a smaller infestation trend on the bee brood of hives installed in the shade, no significant differences were observed (P = 0.253). Already hygienic behavior was very low, considering that the bees were Africanized bees and it were captured in the region during the swarming season. However, there was a significant negative correlation between the hygienic behavior and the mite infestation rate in adult bees. The nosemosis disease showed one prevalence of 100% in the experimental apiary, however, the average number of spores per bee can be considered very low, being significantly higher during the harvest period than in the off season period's, however, this results did not show significant differences between the hives receiving direct insolation and that ones under shade / As abelhas africanizadas (Apis mellifera) da região do Semiárido Potiguar apresentam duas doenças principais: A varroatose cujo agente é o ácaro Varroa destructor, e a nosemose, recentemente introduzida no estado, cujo agente foi identificado anteriormente na região dos apiários experimentais como sendo o microsporídio Nosema ceranae. Os objetivos desta pesquisa foram avaliar os efeitos diretos da insolação e do sombreamento sobre colmeias em relação à taxa de infestação do ácaro em abelhas adultas e nas crias; sobre o comportamento higiênico e sobre a doença nosemose. O experimento foi realizado no CETAPIS/UFERSA em Mossoró, RN, onde, utilizou-se 10 colmeias instaladas sob uma latada construída no sentido leste-oeste, coberta com folhas de coqueiro que absorvia cerca de 90% da insolação e, outras 10 sob efeito direto da insolação. As coletas foram feitas no período da safra (chuvoso), nos dias 30/01, 20/03, 09/4 e 10/05, e no período da entressafra (seca), nos dias 18/08, 23/09, 07/10 e 30/11. Os resultados mostraram que durante o período de entressafra as colmeias instaladas na sombra apresentaram uma taxa de infestação média (%) (6,54 ± 0,59) em abelhas adultas menor (P<0.01) do que nas colmeias instaladas no sol (9,71 ± 1,02). Embora os resultados tenham mostrado uma tendência de infestação menor nas crias em colmeias instaladas na sombra, em relação as instaladas no sol, não foram observadas diferenças significativas (P=0.253). Já o comportamento higiênico (%) foi muito baixo para as colmeias na sombra e no sol (57, 61 ± 6,44 e 57,33 ± 7,96) respectivamente. No entanto, observou-se uma correlação negativa significativa entre este comportamento e a taxa de infestação do ácaro em abelhas adultas. Quanto à nosemose, foram encontrados esporos em todas as colmeias tanto no sol quando na sombra, mas no entanto, o número médio de esporos por abelha pode ser considerado muito baixo, sendo significativamente maior no período de safra (200.000 ± 40. 869) do que na entressafra (31.250 ± 3.900), no entanto, não se obteve diferenças significativas entre as colmeias na sombra e no sol / 2017-03-13
307

Parâmetros genéticos para características produtivas e comportamentais em abelhas africanizadas Apis mellifera via abordagem bayesiana

Padilha, Alessandro Haiduck January 2011 (has links)
O objetivo desse estudo foi estimar parâmetros genéticos para características produtivas e comportamentais em uma população de abelhas Apis mellifera africanizadas por meio de inferência Bayesiana. Os dados foram submetidos a análises uni e bicaracterística utilizando o programa MTGSAM. Os modelos consideraram os efeitos (fixos) de local do apiário, mês-ano ou estação-ano e o número de caixilhos com abelhas aderentes como covariável linear. As estimativas de herdabilidade apresentaram magnitudes de moderada a alta para comportamento higiênico (0,81 ± 0,17), produção de própolis (0,83 ± 0,16), produção de mel (0,37 ± 0,22) e taxa de coleta de xarope (0,39 ± 0,22) e magnitude baixa para a percentagem de ácaros em abelhas adultas (0,12 ± 0,13). A rapidez de coleta de xarope apresentou correlação genética de 0,21 ± 0,51 com produção de mel, de 0,45 ± 0,33 com produção de própolis, e de 0,05 ± 0,43 com comportamento higiênico. As correlações genéticas entre produção de mel, produção de própolis e comportamento higiênico foram de 0,20 ± 0,43, de -0,11 ± 0,41 e de 0,23 ± 0,31, respectivamente. As correlações genéticas foram negativas entre percentagem de ácaros em abelhas adultas e as características produção de mel (-0,63 ± 0,39), produção de própolis (-0,07 ± 0,50), comportamento higiênico (-0,19 ± 0,51) e rapidez de coleta de xarope (- 0,41 ± 0,51). As características produção de mel, produção de própolis e comportamento higiênico apresentam potencial para seleção genética. A menor percentagem de ácaros em abelhas adultas está relacionado a maior produção de mel e maior comportamento higiênico, mas não deve ser usado como único critério de seleção devido a baixa herdabilidade. A seleção de abelhas que coletam xarope mais rapidamente, prevendo maior produção de mel, promoverá pequeno ganho genético. Ao selecionar abelhas que produzem mais própolis haverá pequenos ganhos genéticos para comportamento higiênico ou maior produção de mel. / This study was carried out to estimate genetic parameters for productive and behavioural traits in Africanized honey bees Apis mellifera. The data were submitted uni and bicharacter analysis using the software MTGSAM. The fixed effects considered in the models were localization of the hive, month-year or season-year and number of frames covered with bees as covariate. The heritability estimates were moderate to high for hygienic behaviour (0,81 ± 0,17), propolis production (0,83 ± 0,16), honey production (0,37 ± 0,22) and syrup-collection rate (0,39 ± 0,22) and lower for percentage of mites on adult bees (0,12 ± 0,13). Syrup-collection rate showed genetic correlation values of 0,21 ± 0,51 with honey production, 0,45 ± 0,33 with propolis production and 0,05 ± 0,43 with hygienic behaviour. Genetic correlation between honey and propolis was 0,20 ± 0,43, between honey production and hygienic behaviour was -0,11 ± 0,41 and between propolis production and hygienic behaviour was 0,23 ± 0,31. Genetic correlations were negative between percentage of mites on adult bees and other traits honey production (-0,63 ± 0,39), propolis production (-0,07 ± 0,50), hygienic behaviour (-0,19 ± 0,51) and syrup-collection rate. Honey production, propolis production and hygienic behavior traits have potential for genetic selection. The lower percentage of mites on adult bees increase honey production or hygienic behaviour, but it is not recommended as the only criterion for selection, due to its low heritability. Selection for syrupcollection rate will promote small genetic gain for honey production. Propolis production is positively correlated to hygienic behaviour or honey production.
308

Óleos essenciais no controle de praga e seletividade a organismos não alvos / Essential oils in pest control and selectivity to non-target organisms

Silva, Isabel Moreira da 26 July 2016 (has links)
Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-09-01T18:45:18Z No. of bitstreams: 1 texto completo.pdf: 1150084 bytes, checksum: cb8a662b7c1be28ab3c004268003e13e (MD5) / Made available in DSpace on 2017-09-01T18:45:18Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1150084 bytes, checksum: cb8a662b7c1be28ab3c004268003e13e (MD5) Previous issue date: 2016-07-26 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Diaphania hyalinata (Linnaeus, 1767) (Lepidoptera: Crambidae) é praga chave de Cucurbitaceae e danifica folhas, ramos, brotos e frutos, causando desfolha total da planta em altas populações . Seu controle ocorre basicamente com inseticidas químicos, mas o uso indiscriminado desses produtos pode causar a contaminação ambiental e a morte de organismos benéficos, como inimigos naturais e polinizadores, importantes na agricultura, pelo controle de insetos-praga e pela polinização de plantas cultivadas e silvestres, respectivamente . Alternativas como os inseticidas botânicos e o controle biológico vêm ganhando importância no Manejo Integrado de Pragas (MIP). Inseticidas botânicos são usados, principalmente, por produtores agroecológicos, porém, a toxidade em organismos não alvo é pouco estudada. O objetivo deste trabalho foi verificar a eficiência de óleos essenciais sobre imaturos de D. hyalinata e a seletividade ao parasitoide Trichospilus pupivorus Ferrière, 1930 (Hymenoptera: Eulophidae) e aos polinizadores, Apis mellifera Linnaeus, 1758 e Trigona hyalinata (Lepeletier, 1836) (Hymenoptera: Apidae). No primeiro experimento, a toxicidade dos óleos essenciais de gengibre, menta, orégano e tomilho sobre ovos, lagartas (contato, tópico, ingestão) e pupas de D. hyalinata e a seletividade a T. pupivorus foram avaliadas em diferentes concentrações para a determinação das CL 50 e CL 90 e o índice de seletividade relativa (ISR 50 ). A fase de ovo de D. hyalinata foi a mais sensível aos produtos aplicados com maior toxidade para o orégano e tomilho. A aplicação tópica foi a menos tóxica para as lagartas de D. hyalinata, principalmente, o óleo de gengibre . Os óleos de gengibre, menta e tomilho foram mais tóxicos por ingestão e o orégano por contato a D. hyalinata. A fase de pupa foi a menos sensível aos produtos botânicos, em D. hyalinata necessitando de maiores concentrações para inviabilizar a emergência de adultos. Os óleos essenciais de gengibre, menta, tomilho e orégano foram seletivos a T. pupivorus (ISR 50 > 1). A toxidade desses óleos, a pelo menos, uma fase do ciclo de D. hyalinata e a seletividade ao parasitoide T. pupivorus possibilita o uso combinado ou sequencial dessas práticas de controle no MIP. No segundo experimento, concentrações subletais dos óleos essenciais de gengibre, menta, orégano e tomilho foram utilizadas para avaliar o desenvolvimento, deterrência alimentar e atividade em grupo de lagartas de D. hyalinata. A sobrevivência, viabilidade larval e pupal e o peso das pupas reduziram e a duração do período larval e pupal aumentaram após D. hyalinata ingerir folhas tratadas com os óleos de gengibre, menta e tomilho. As lagartas alimentadas com folhas tratadas com orégano não completaram o estádio larval. O óleo de orégano apresentou forte ação antialimentar (IDA>80%) e os de gengibre, menta e tomilho efeito moderado (50< IDA <80%) no teste com e sem escolha. A atividade em grupo de D. hyalinata não variou em contato com óleos essenciais. O terceiro experimento avaliou a toxidade dos óleos de gengibre, menta, orégano e tomilho para A. mellifera e T. hyalinata e a locomoção desses polinizadores em superfície tratada com esses produtos. Os óleos de orégano e tomilho foram mais tóxicos, principalmente, para A. mellifera e os de gengibre e menta apresentaram baixa toxidade para esses polinizadores. Os óleos foram mais seletivos a T. hyalinata que A. mellifera. No teste de locomoção, arenas foram tratadas (total ou parcial) com as concentrações CL 50 dos óleos. No bioensaio com área totalmente tratada, o orégano reduziu a distância percorrida e a velocidade de movimentação e aumentou o tempo de parada para A. mellifera, já para T. hyalinata estes efeitos foram observados também para o tomilho. Em arena parcialmente tratada, observou irritabilidade para os óleos de gengibre, menta e tomilho para A. mellifera e gengibre e tomilho para T. hyalinata pelo menor tempo de permanência na área tratada. Os óleos essenciais de gengibre e menta foram mais seletivos para o parasitoide e para ambos polinizadores e com toxidade a pelo menos uma fase de D. hyalinata tendo potencial para o MIP. Devido a toxidade moderada dos óleos de orégano e tomilho, principalmente, a A. mellifera devem ser usados em horário de baixo forrageamento. / Diaphania hyalinata (Linnaeus, 1767) (Lepidoptera: Crambidae) is a key pest of Cucurbitaceae due to the damage caused on leaves, twigs, buds and fruits, which may cause complete plant defoliation in high densities. This pest is controlled mainly with chemical insecticides but the indiscriminate use of these products may cause environmental contamination and death of beneficial organisms, such as natural enemies and pollinators, important for biological control and pollination of crops and wild plants. Alternatives techniques such as botanical insecticides and biological control is becoming more important in Integrated Pest Management (IPM). Botanical insecticides are used mainly by agroecological farmers, but their toxicity to non-target organisms needs further studies. The objective of this work was to verify the effectiveness of essential oils to control D. hyalinata of immatures and their selectivity to the parasitoid Trichospilus pupivorus Ferriere, 1930 (Hymenoptera: Eulophidae) and the pollinators Apis mellifera Linnaeus, 1758 and Trigona hyalinata (Lepeletier, 1836) (Hymenoptera: Apidae). In the first experiment, the toxicity of ginger, mint, oregano and thyme essential oils on D. hyalinata eggs, larvae (contact, topic, ingestion) and pupae and their selectivity to T. pupivorus were evaluated at different concentrations to determine the CL 50 and CL 90 and their relative selectivity index (ISR 50 ). The egg stage was the most sensitive to the essential oils with those of oregano and thyme being the most toxics. Topical application was less toxic to the D. hyalinata larvae especially for the ginger oil. This oil and those of mint and thyme were more toxic to D. hyalinata by ingestion while oregano oil was by contact. Pupae of D. hyalinata were less sensitive to the essential oils requiring higher concentrations to prevent adult emergence of this pest. Ginger, mint, thyme and oregano essential oils were selective to T. pupivorus (ISR 50 > 1). The toxicity of these oils to at least one immature stage of D. hyalinata and its selectivity to the parasitoid T. pupivorus, make them feasible for combined or sequential use in IPM of this pest. The second experiment had the use of sub-lethal concentrations of ginger, mint, oregano and thyme essential oils to evaluate the development, feeding deterrence index (FDI) and group activity of D. hyalinata. Survival, larva and pupa viability and weight of pupae were reduced while larva and pupa duration of D. hyalinata increased with ginger, mint and thyme essential oils. Caterpillars of this pest fed leaves treated with oregano oil did not complete their cycle. The oregano oil showed strong anti-feeding action (FDI> 80%) and the ginger, mint and thyme moderate effects (50 < FDI <80%) in the tests with and without choice. Group activity of D. hyalinata did not change in contact with essential oils. The third experiment evaluated the toxicity of ginger, mint, oregano and thyme oils on A. mellifera and T. hyalinata and the locomotion behavior of these pollinators in contact with the oils. The oregano and thyme oils were more toxic, especially to A. mellifera while the ginger and mint showed lower toxicity to these pollinators. The oils were more selective to T. hyalinata than A. mellifera. In locomotion test had arenas treated (totally or partially) with LC 50 concentrations of the oils. In the fully treated area bioassay, oregano reduced the distance walked and the movement speed and increased the periods without movements for A. mellifera and these were also observed with thyme oil for T. hyalinata. In partially treated arena, irritability of A. mellifera was observed with ginger, mint and thyme oils and for T. hyalinata with those of ginger and thyme due the shorter period of time they remained on the arena. Ginger and mint oils were more selective for the parasitoid and both pollinators, showing toxicity to at least one life stage of D. hyalinata demonstrating their potential for IPM programs. Due to moderate toxicity of oregano and thyme oils, mainly, to A. mellifera they should be used when foraging activities of this pollinator is low.
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Polinização por abelhas na produção de tomate destinado à indústria / Pollination by bees in production of tomatoes for industry

Araújo, Priscila de Cássia Souza 02 June 2016 (has links)
Submitted by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2017-10-03T11:21:42Z No. of bitstreams: 1 texto completo.pdf: 525806 bytes, checksum: 85b3f5c96e64ac1cc45967fdadafe377 (MD5) / Made available in DSpace on 2017-10-03T11:21:42Z (GMT). No. of bitstreams: 1 texto completo.pdf: 525806 bytes, checksum: 85b3f5c96e64ac1cc45967fdadafe377 (MD5) Previous issue date: 2016-06-02 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Este estudo teve como objetivo descrever a fauna das abelhas visitantes do tomate tipo indústria, avaliar o efeito na polinização pelas espécies mais abundantes, e mensurar a importância delas na produção e qualidade dos frutos. Para avaliar o efeito da presença de abelhas foram definidos dois tratamentos: autopolinização espontânea (AU) e polinização aberta (PA), cada tratamento consistiu de 33 plantas. No tratamento de AU as flores foram protegidas na pré-antese e permaneceram assim até o início do desenvolvimento do fruto. Na PA as flores permaneceram todo o tempo abertas para a visitação. As abelhas que estavam visitando as flores foram coletadas com rede entomológica. Após a maturação, todos os frutos foram colhidos, pesados, contados e avaliados quanto à firmeza, ao pH da polpa e à cor. Para averiguar a eficiência entre diferentes espécies de abelhas, foi feito o teste de primeira visita com as duas espécies mais abundantes, Exomalopsis (Exomalopsis) analis Spinola, 1853 e Apis mellifera Linnaeus, 1758, e o número de sementes dos frutos obtidos no teste foi comparado com o dos frutos formados a partir de flores autopolinizadas espontaneamente. A presença das abelhas foi responsável pelo aumento de 27% na produtividade do tomateiro. A polinização das abelhas aumentou a massa, número de frutos e sementes, mas não foi constatada diferença na firmeza, pH e cor dos frutos. Mesmo não tendo a capacidade de vibrar as flores, A. mellifera é um polinizador mais eficiente que E. analis e o processo de autopolinização. / This study aimed to describe the fauna of bees of visitors tomato type industry, evaluate the effect on pollination by the most abundant species, and measure their importance in the production and quality of fruit. To evaluate the effect of the presence of bees defined two treatments: spontaneous self-pollination (AU) and open pollination (AP), each treatment consisted of 33 plants. In AU treatment the flowers were protected in the pre- anthesis and remained so until the early development of the fruit. In PA, the flowers remain open all the time for the visitation. The bees were visiting the flowers were collected with entomological net. After maturation, all the fruits were harvested, weighed, counted and evaluated for firmness, the pH of the pulp and color. To determine the efficiency among different species of bees, was made the first visit test with the two most abundant species, Exomalopsis (Exomalopsis) analis Spinola, 1853 and Apis mellifera Linnaeus, 1758, and the number of seeds of fruits obtained in the test was compared to the fruits formed from spontaneously self-pollinated flowers. The presence of bees was responsible for 27% increase in tomato yield. The pollination of bees increased mass, number of fruits and seeds, but no difference was found in the firmness, pH and fruit color. Although not having the capability of vibrating the flowers, A. mellifera is more efficient as a pollinator E. analis and spontaneous self- pollination.
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Molekulární epidemiologie druhů Crithidia mellificae a Lotmaria passim v populaci včelstev

VOČADLOVÁ, Kateřina January 2018 (has links)
The increased honey bee colony losses in the last decade gain a considerable attention of scientists and public. The causes of these losses include a wide range of biotic and abiotic factors, but pathogens and parasites are probably the main ones. Monoxenous trypanosomatids in honey bee gut Lotmaria passim and Crithidia mellificae were neglected for a long time but according to recent studies they seem to participate in those colony declines. Trypanosomatids are widespread parasites, including also the causes of some human illnesses, such as sleeping sickness, Chagas disease and leishmaniasis. The mechanism of the effect on honey bee health is not well understood so far. The aim of this thesis was to verify the occurrence of the trypanosomatids in honey bee samples from two regions in Czech Republic. The methods, based on detection of specific DNA loci, confirm the high prevalence of L. passim, which was founded in majority (71 %) of the samples. On the contrary, no samples were positive to C. mellificae.

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