Thesis (Ph.D.)--York University, 2006. Graduate Programme in Biology. / Typescript. Includes bibliographical references. Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR19860

Thesis (M.A.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains v, 42 p. : ill. (some col.), maps Vita. Includes abstract. Includes bibliographical references (p. 38).

Made available in DSpace on 2014-06-11T19:22:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-07Bitstream added on 2014-06-13T20:10:16Z : No. of bitstreams: 1 souza_tf_me_rcla.pdf: 1237007 bytes, checksum: fe5f2ff0023b2ceaaa9190729308c607 (MD5) / Muitos inseticidas atuam inibindo a ação de neurotransmissores específicos, causando a super atividade dos neurônios, como por exemplo, aqueles ligados ao aprendizado e a memória e, como conseqüência, podem alterar estruturas cerebrais. Atualmente, o inseticida fipronil é muito utilizado como defensivo agrícola, principalmente em culturas como cana-de-açúcar, soja e citrus, sendo que sua pulverização, que visa o controle de insetos-praga, vem causando sérios danos aos insetos não-alvo, como os polinizadores. Embora alguns estudos tenham sido realizados para os efeitos das doses subletais de inseticidas em abelhas A. mellifera, não existe nenhum trabalho documentado sobre esses efeitos para as abelhas africanizadas, híbrido predominante no país. Assim, esse projeto teve como objetivo estabelecer as doses subletais para o inseticida fipronil, administrado oralmente e por contato; os efeitos no comportamento de forrageamento das abelhas; e as possíveis alterações na morfologia do cérebro das abelhas (A. mellifera). Para isso, previamente foi calculado a DL50 oral e por contato, para que posteriormente estabelecesse os valores das doses subletais. Para as abelhas tratadas foram avaliados teste da atividade locomotora durante o forrageamento e de sensibilidade ao alimento, através da metodologia de Resposta e Extensão da Probóscide (REP), que é uma reprodução no que ocorre na interação abelha-planta. Por fim, foram realizados cortes histológicos no cérebro das abelhas tratadas a fim de detectar as possíveis alterações morfológicas destas estruturas e utilizar a técnica de imunohistoquímica para marcar e mapear as regiões cerebrais de atuação do inseticida. Os resultados mostraram-se promissores para as avaliações sobre o efeito de baixas doses do inseticida fipronil para as abelhas africanizadas, embora mais estudos deverão ser realizados e os testes melhores adaptados. / Many pesticides act as an inhibitor of the action of specific neurotransmissors, causing a super activity of neurons, for example, those linked with learning and memory and, as consequence, they can alter cerebral structures. Nowadays, the pesticide fipronil is largely used as an agricultural defense, manly in sugar cane, soy and citrus cultures. Its use that targets the control of plague insects has been causing serious effects on other insects, such as pollinators. Although some studies have been done on the effects of sublethal doses of pesticides on bees Apis mellifera, there are no documented work on those effects on Africanized bees, a hybrid very abundant in this country. Therefore, this project has the objective of establishing the sublethal doses of the pesticide fipronil, administrated orally and by contact; the effects of the foraging behavior of work bees; possible alterations on the brain morphology of Africanized bees (A. mellifera). For that, the oral and by contact DL50 were calculated previously, so that the values of sublethal doses could be established later. For bees treated with sublethal doses of fipronil, tests of dislocation activity during foraging and sensitivity to food were evaluated through the PER methodology, which is a reproduction of what happens in the interaction bee/plant. At last, histological cuts were made in the brains of treated bees to detect possible morphological alterations on these structures and to use the imunehistochemistry technique to mark and map the cerebral regions affected by the pesticide. The results showed themselves very promising for the evaluations of small doses of fipronil pesticide on Africanized bees, although further studies should be made and tests more adapted.

Pesticides, poor nutrition, parasites and diseases work synergistically to contribute to the decline of the honey bee. Heritable sub-lethal behavior/immune effects may also contribute to the decline. Maternal stress is a common source of heritable immune/behavior deficits in many species. A stressed honey bee queen has the potential to pass such deficits on to worker bees. Using a repeated measures design, this study will determine whether the health of worker bee is reduced by a cold stress on the queen by analyzing egg hatch rate and protein content, emergence rate, and adult aggression and immune function for offspring laid before and after the stressor. Results show that queen stress influences egg hatching rate and emergence rate but does not impact egg protein content, adult offspring immune function or aggressive behavior.

Unlike other rosaceous fruit crops such as apple and cherry, commercial raspberry cultivars are largely self-fertile and can set fruit in the absence of pollinators. However, their floral morphology often prevents complete self-pollaintion. Incomplete pollination yields unmarketable small or crumbly fruits. Insect visitation is therefore essential to maximizing raspberry yield. Honey bees are typically used to pollinate commercial raspberry; however, escalating prices for hive rentals coupled with increasing acreage encourage evaluation of other manageable pollinators. Bumble bees (Bombus spp.) and several mason bees (Osmia spp.) are promising raspberry pollinators. Five bee species were evaluated and compared for their single-visit pollination efficacies on raspberry. From this a pollinator effectiveness index was created and an estimation of the minimum number of visits required to maximize fruit set was calculated. This estimation was then experimentally verified. Finally, in an attempt to synchronize their brief activity period with raspberry bloom, winter management options aimed at delaying the emergence of the mason bee, O. lignaria, were investigated. All five bee species proved excellent pollinators of raspberry. None of the alternative manageable species greatly outperformed honey bees. For this reason honey bees remain the most economical and practical option for open-field raspberry pollination. The adoption of alternative manageable bees could still be justified in other production systems, such as high-tunnel or greenhouse grown raspberry, which hamper honey bees’ ability to forage effectively. The pollinator effectiveness score for honey bees suggested that as few as two visits can achieve maximum fruit set. This estimate was confirmed through experimentation on three different red raspberry cultivars. For two of these cultivars, just one visit yielded drupelet counts similar to openly-pollinated flowers. This information can be used to help refine stocking density estimates for honey bees on raspberry. Wintering bees at 0° or -3° C rather than 4° C effectively delayed emergence of O. lignaria by more than a month without any impact on post-winter performance. These results suggest winter storage at near freezing temperatures is a viable management option for the use of O. lignaria with later-blooming crops.

Darbo tema: „Bičių šeimos kaip gamybos priemonės tyrimai“. Duomenys rinkti 2012-2013 metais iš 10 bitynų, kurie yra šiaurės rytų Aukštaitijos regione. Apklausti 5 bitininkai profesionalai ir 5 bitininkai mėgėjai. Raktiniai žodžiai: bitės, Varroa destructor erkės. Apie 64 proc. Lietuvos bitininkų savo bitynuose nekeičia bičių motinėlių, todėl sumažėja bičių produktyvumas. Taip pat, didžiausia bitynų problema yra Varroa destructor erkės, kadangi jos ne tik nualina bičių šeimą, bet yra viena iš esminių priežasčių, dėl bičių mirtingumo po žiemojimo. Darbo tikslas yra įvertinti veiksnius, labiausiai įtakojančius bičių populiacijos mažėjimui ir bičių produktyvumui. Taip pat išanalizuoti bitininkų kompetenciją bitininkystės srityje mėgėjų ir profesionaliuose bitynuose. Darbo uždaviniai: įvertinti bičių šeimų produktyvumą profesionaliuose bitynuose ir mėgėjų bitynuose: • Įvertinti Varroa destructor erkių paplitimą bičių šeimose; • Įvertinti Varroa destructor įtaką bičių šeimų produktyvumui; • Palyginti veislinių ir mišrūnių bičių produktyvumą; • Nustatyti, bičių šeimų, kuriose buvo keistos motinėlės produktyvumą ir atsparumą Varroa destructor erkėms; • Įvertinti medaus kokybinius rodiklius tirtuose bitynuose pagal medaus techninio reglamento reikalavimus; Atlikus analizę paaiškėjo, kad: • Produktyviausios bičių šeimos, kuriose bičių motinėlė keičiama kas du metus, ir nesirgo varoze. • Bičių šeimos sergančios varoze yra mažiau produktyvios. Iš sergančios šeimos profesionaliame... [toliau žr. visą tekstą] / Topic of the paper: “Research of a beehive as a mean of production”. Data collected from 10 apiaries in the region of northeast Upper Lithuania in the year 2012-2013. 5 professional and 5 amateur beekeepers were interviewed. Key words: bees, Varroa destructor mites. It is argued that about 64% of Lithuanian beekeepers apiaries does not change the queen bee, which reduces the productivity of the bees. Also, the biggest problem of the apiaries is Varroa destructor mites, which not only exhausts a beehive, but it is one of the most significant reasons for bee mortality after hibernation. Aim of the paper is to evaluate the most influential factors in declining of bee population and productivity. Also to analyze beekeepers competency in the fields of amateur an professional apiaries. Tasks of the paper: evaluate the productivity of bee colonies in professional and amateur apiaries. • Evaluate the spread of Varroa destructor mites in beehives; • Evaluate the influence of Varroa destructor to the beehive productivity; • Compare the productivity of pedigree and hybrid bees; • Identify beehives that productivity and immunity were affected by Varroa destructor mites; • Evaluate qualitative indicators of honey according to honey technical regulation requirements; The analysis shows that: • The most productive beehives are the ones where the queen bee is substituted every two year and never had varroasis; • Beehives that had varroasis are less productive. 35 kg or 27% less honey is... [to full text]

Call number: LD2668 .T4 1955 R36 / Master of Science

No description available.

No description available.

A diapausa é um fenômeno amplamente presente nos artrópodes e é considerada como primordial para o sucesso evolutivo da Classe Insecta, pois possibilita a sobrevivência em condições adversas, como estações frias e secas. Sabe-se que durante a diapausa ocorre o silenciamento de muitos genes e que outros são unicamente expressos nesta fase. Embora existam evidências de que o processo da diapausa tenha se mantido conservado durante a evolução das espécies, ainda há lacunas no conhecimento sobre o nível de conservação dos padrões metabólicos. Um bom modelo para se estudar a diapausa é Tetrapedia diversipes, uma espécie bivoltina de abelha solitária. Os indivíduos que nascem na primeira geração seguem o desenvolvimento desde ovo até adulto em tempo bem menor do que aqueles que nascem na segunda geração; estes retardam o desenvolvimento na fase larval. Além disso, essa espécie é de fácil obtenção no seu ambiente natural, pois apresenta alta taxa de nidificação em ninhos-armadilha. O objetivo deste trabalho foi comparar o perfil de expressão de genes entre as larvas da 1ª geração (que não entram em diapausa), larvas da 2ª geração (que entrariam em diapausa) e das larvas em diapausa. Foram identificados 196 genes diferencialmente expressos, destes 87 foram anotados. Muitos destes genes já foram descritos na literatura como relacionados à diapausa em outras espécies, no entanto, o padrão de expressão não é conservado. Os genes aqui identificados foram divididos em cinco grupos: relacionados à desintoxicação celular, cutícula e citoesqueleto, metabolismo de lipídeos e esteróis, ciclo celular e outros genes relacionados à diapausa / The diapause is broadly distributed among the arthropods and has had an important role for the evolutionary success of the Class Insecta, mainly because this process permits insects to explore adverse conditions, such as cold and dry seasons. It is known that there are many genes being silenced and others being uniquely expressed during diapause. And although there are evidences that the diapause process has remained conserved during the evolution of species, it is still not clear how conserved are the metabolic patterns involved in this behavior. Tetrapedia diversipes is a solitary bee and a good model to study diapause. Individuals from the first generation do not enter in diapause and develop faster than individuals from the second generation, which enter in diapause during the winter. Moreover, this species is easy to capture in natural conditions due to the high rate of nesting in trap nests. The aim of this work was to compare the gene expression profile among non-diapause larvae from first and second generation (about to enter diapause) and larvae already in diapause, trough transcriptome data. One hundred ninety-four genes were identified as differentially expressed and 87 of them were annotated. Many of these genes have already been described as related to diapause in others species, but the expression pattern was not conserved. These genes were divided in five groups: related to cellular detoxification, cuticle and cytoskeleton, lipids and steroids metabolism, cell cycle and other genes related to diapause