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Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains vi, 50 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Orientador: Elza Maria Guimarâes Santos / Coorientador: Silvia Rodrigues Machado / Banca: Juliana Hanna leite El Ottra / Banca: Tatiane Maria Rodrigues / Resumo: A família Bignoniaceae é um bom modelo dos tipos de diversificação evolutiva que deram origem à diversidade de comunidades de plantas tropicais, sendo sua interação com os polinizadores um fator determinante para tal. Zeyheria tuberculosa é uma espécie ameaçada de extinção e apresenta características relacionadas à síndrome de melitofilia. Informações sobre a reprodução desta espécie poderão auxiliar na compreensão dos processos ecológicos que podem ter levado esta espécie a ser incluída na lista vermelha das espécies ameaçadas de extinção. Assim, este estudo teve como objetivo central investigar a biologia floral de Z. tuberculosa, enfocando o padrão de secreção de néctar e as características funcionais e estruturais do nectário floral, responsável pela produção do recurso essencial à manutenção da interação com os visitantes florais. Os resultados obtidos foram divididos em dois capítulos que abordam questões específicas e complementares. O primeiro contempla informações sobre os eventos ocorridos durante a antese floral, a ecologia da polinização e o padrão de secreção de néctar em plantas de Z. tuberculosa situadas em fragmentos de floresta estacional semidecídua, imersos em uma paisagem alterada. O segundo aborda a estrutura e o funcionamento do nectário floral desta espécie, com enfoque nas características relacionadas ao tipo de secreção. Para o Capítulo 1, monitoramos flores durante todo o período de antese; fizemos observações focais dos visitantes e os capturamos para examinar a área de deposição de pólen; registramos a porcentagem de grãos de pólen viáveis e verificamos o período de receptividade do estigma; obtivemos dados relativos à morfometria das flores e das abelhas polinizadoras; fizemos testes de autoincompatibilidade para avaliar a dependência de vetores de pólen para a fecundação cruzada; avaliamos a dinâmica de secreção de néctar através dos... / Abstract: The Bignoniaceae family is a good model for studies about evolutionary diversification that gave rise to the diversity of tropical plant communities, and the interaction with pollinators is a determining factor. Zeyheria tuberculosa is an endangered species and has characteristics related to melittophily syndrome. Information on the reproduction of this species may help to understand the ecological processes that may have led this species to be included in the Red List of endangered species. This goal of this study was to investigate the floral biology of Z. tuberculosa, focusing on the pattern of nectar secretion and the functional and structural characteristics of the floral nectary, which is the responsible for producing the essential resource for maintaining the interaction with pollinators. The results were divided into two sections that deal with specific and complementary issues. The first includes information about the events of floral anthesis, the pollination ecology and the pattern of nectar secretion in plants of Z. tuberculosa located in semi-deciduous forest fragments, immersed in a modified landscape. The second deals with the structure and functioning of the floral nectary of this species, focusing on the characteristics related to the type of secretion. For Chapter 1, we monitored flowers throughout anthesis; we performed focal observations of floral visitors and captured them to examine the pollen deposition area; recorded the percentage of viable pollen grains and the period of stigma receptivity; obtained data on the morphometry of flowers and pollinator bees; made self-incompatibility tests to assess the dependence of pollen vectors for cross-fertilization; evaluated the dynamics of nectar secretion through the volume, concentration and total milligrams of sugars parameters, using the latter parameter to calculate the caloric supply available to pollinators by flower and plant, and we carried out analyzes on the ... / Mestre

Made available in DSpace on 2015-10-06T13:03:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-27. Added 1 bitstream(s) on 2015-10-06T13:18:19Z : No. of bitstreams: 1 000847211_20170226.pdf: 465306 bytes, checksum: 77beb7e97042d7dbb1b1e6f120e84104 (MD5) Bitstreams deleted on 2017-03-03T11:01:32Z: 000847211_20170226.pdf,. Added 1 bitstream(s) on 2017-03-03T11:02:41Z : No. of bitstreams: 1 000847211.pdf: 5262734 bytes, checksum: 2f62d3405020ebd2488db18ef74342e7 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A família Bignoniaceae é um bom modelo dos tipos de diversificação evolutiva que deram origem à diversidade de comunidades de plantas tropicais, sendo sua interação com os polinizadores um fator determinante para tal. Zeyheria tuberculosa é uma espécie ameaçada de extinção e apresenta características relacionadas à síndrome de melitofilia. Informações sobre a reprodução desta espécie poderão auxiliar na compreensão dos processos ecológicos que podem ter levado esta espécie a ser incluída na lista vermelha das espécies ameaçadas de extinção. Assim, este estudo teve como objetivo central investigar a biologia floral de Z. tuberculosa, enfocando o padrão de secreção de néctar e as características funcionais e estruturais do nectário floral, responsável pela produção do recurso essencial à manutenção da interação com os visitantes florais. Os resultados obtidos foram divididos em dois capítulos que abordam questões específicas e complementares. O primeiro contempla informações sobre os eventos ocorridos durante a antese floral, a ecologia da polinização e o padrão de secreção de néctar em plantas de Z. tuberculosa situadas em fragmentos de floresta estacional semidecídua, imersos em uma paisagem alterada. O segundo aborda a estrutura e o funcionamento do nectário floral desta espécie, com enfoque nas características relacionadas ao tipo de secreção. Para o Capítulo 1, monitoramos flores durante todo o período de antese; fizemos observações focais dos visitantes e os capturamos para examinar a área de deposição de pólen; registramos a porcentagem de grãos de pólen viáveis e verificamos o período de receptividade do estigma; obtivemos dados relativos à morfometria das flores e das abelhas polinizadoras; fizemos testes de autoincompatibilidade para avaliar a dependência de vetores de pólen para a fecundação cruzada; avaliamos a dinâmica de secreção de néctar através dos... / The Bignoniaceae family is a good model for studies about evolutionary diversification that gave rise to the diversity of tropical plant communities, and the interaction with pollinators is a determining factor. Zeyheria tuberculosa is an endangered species and has characteristics related to melittophily syndrome. Information on the reproduction of this species may help to understand the ecological processes that may have led this species to be included in the Red List of endangered species. This goal of this study was to investigate the floral biology of Z. tuberculosa, focusing on the pattern of nectar secretion and the functional and structural characteristics of the floral nectary, which is the responsible for producing the essential resource for maintaining the interaction with pollinators. The results were divided into two sections that deal with specific and complementary issues. The first includes information about the events of floral anthesis, the pollination ecology and the pattern of nectar secretion in plants of Z. tuberculosa located in semi-deciduous forest fragments, immersed in a modified landscape. The second deals with the structure and functioning of the floral nectary of this species, focusing on the characteristics related to the type of secretion. For Chapter 1, we monitored flowers throughout anthesis; we performed focal observations of floral visitors and captured them to examine the pollen deposition area; recorded the percentage of viable pollen grains and the period of stigma receptivity; obtained data on the morphometry of flowers and pollinator bees; made self-incompatibility tests to assess the dependence of pollen vectors for cross-fertilization; evaluated the dynamics of nectar secretion through the volume, concentration and total milligrams of sugars parameters, using the latter parameter to calculate the caloric supply available to pollinators by flower and plant, and we carried out analyzes on the ... / FAPESP: 2008/55434-7

For over twenty years, flower-visitation networks have been used to assess the effects of pollinator decline, linked to habitat loss, climate change and invasive species, on entire communities. However, most rely on flower visit frequency as a proxy for pollination; very few sample pollen from flower visitor's bodies or from stigmas and so do not include a quantitative measure of pollination success. Here, I add pollinator effectiveness (as single visit pollen deposition) into a traditional flower visitation network, creating a pollinator importance network that better evaluates the flower visitor community from the plant's perspective. Given recent interest in pollination in urban areas, I use an urban garden habitat, and compare visitation, pollen transport and pollinator importance networks, giving several novel conclusions. Firstly, although there are similarities in the structure of my networks, interactions were most specialised in the pollinator importance network, with pollen transport proving to be a better proxy for pollinator importance than visitation alone. Secondly, the specialisation of individual plants and the role of individual flower visitors varied between the networks, suggesting that community-level patterns in simple visitation networks can mask important individual differences. Thirdly, the correlation between flower visit frequency and pollinator importance largely depends on bees, and may not hold in plant-pollinator communities that are not bee-dominated. Fourthly, heterospecific pollen deposition was relatively low, despite the unusually diverse plant community of a garden. Finally, bees (particularly Bombus and non-eusocial halictids) carried the largest pollen loads and were the most effective at depositing pollen on to the stigma during a single visit in this garden habitat. The implications of this thesis highlight the strengths and limitations of each network for future studies, and raise important questions for the future of urban pollination studies.

Made available in DSpace on 2014-08-13T14:51:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-06-13Bitstream added on 2014-08-13T17:59:43Z : No. of bitstreams: 1 000775857.pdf: 960836 bytes, checksum: 8e683a2cad5b9e5d051eb153e3f065d0 (MD5) / As características migratórias e defensivas das abelhas Apis mellifera africanizadas e seu contato com a população podem ocasionar acidentes, em que o tratamento muitas vezes é ineficiente, ressaltando a necessidade do desenvolvimento de um soro antiveneno eficaz e abrangente. Para isso, os fatores que podem resultar em possíveis alterações qualitativas na apitoxina precisam ser avaliados, como é o caso da fonte alimentar das abelhas. Neste estudo verificamos diferenças nas médias da quantidade e intensidade dos picos estudados gerados pela análise da apitoxina por CLAE/FR, proveniente de colmeias mantidas em diferentes recursos florais. A alimentação proveniente da florada de Citrus sp., gerou picos correspondentes a apamina, fosfolipase, isoforma da fosfolipase e melitina com maiores intensidade e maior quantidade total de picos (44); porém, duas amostras não apresentaram a isoforma da melitina, fato este que pode estar associado a genética do enxame. Diferentemente, as abelhas mantidas em vegetação de Eucalyptus sp. apresentaram a apitoxina com menores intensidades para os picos correspondentes a estes compostos, e menor quantidade total de picos (33). A apitoxina das abelhas mantidas em vegetação silvestre associada à alimentação artificial teve a maior intensidade do pico correspondente a isoforma da melitina e aquela proveniente apenas da vegetação silvestre não apresentou picos dominantes. Estas variações sugerem a influência da alimentação na composição da apitoxina, porém as pesquisas precisam ser aprofundadas considerando diferentes recursos florais disponíveis em outras regiões. Estas informações podem contribuir para o futuro desenvolvimento de um soro antiveneno representativo, específico e seguro para o tratamento de ferroadas de abelhas. / The migratory and highly defensive behavior of the africanized honeybees and their close contact with human populations can result in accidents, where treatment is often inefficient, emphasizing the need for the development of an effective honeybee antivenom. For this, the factors that may cause possible qualitative changes in apitoxin need to be evaluated, such as the food source of bees. In this study we verify differences in the mean number and intensity of the studied peaks generated by the HPLC/RF analysis of apitoxin, from hives kept in different floral sources. The feed from the flowering of Citrus sp., generated peaks corresponding to apamin, phospholipase, melittin and phospholipase isoform with higher intensity and higher total amount of peaks, but two samples not presented melittin isoform, a fact that can be associated to the genetic hive. Differently, the bees maintained in the area of Eucalyptus sp. showed the apitoxin with lower intensities for the peaks corresponding to these compounds, and also lower the total amount of peaks. The apitoxin of bees maintained in wild vegetation associated with artificial feeding had the highest peak intensity corresponding to melittin isoform and that originates from wild vegetation showed no dominant peaks. This variations suggest the diet influence in the composition of apitoxin, however the researches need to be deepened considering different floral resources available in other regions. This information can contribute to the future development of a representative, specific and safe antivenom for the treatment of bee’s stings.

Orientador: Ricardo de Oliveira Orsi / Coorientador: Rui Seabra Ferreira Junior / Banca: Daniel Nicodemo / Banca: Nabor Veiga / Resumo: As características migratórias e defensivas das abelhas Apis mellifera africanizadas e seu contato com a população podem ocasionar acidentes, em que o tratamento muitas vezes é ineficiente, ressaltando a necessidade do desenvolvimento de um soro antiveneno eficaz e abrangente. Para isso, os fatores que podem resultar em possíveis alterações qualitativas na apitoxina precisam ser avaliados, como é o caso da fonte alimentar das abelhas. Neste estudo verificamos diferenças nas médias da quantidade e intensidade dos picos estudados gerados pela análise da apitoxina por CLAE/FR, proveniente de colmeias mantidas em diferentes recursos florais. A alimentação proveniente da florada de Citrus sp., gerou picos correspondentes a apamina, fosfolipase, isoforma da fosfolipase e melitina com maiores intensidade e maior quantidade total de picos (44); porém, duas amostras não apresentaram a isoforma da melitina, fato este que pode estar associado a genética do enxame. Diferentemente, as abelhas mantidas em vegetação de Eucalyptus sp. apresentaram a apitoxina com menores intensidades para os picos correspondentes a estes compostos, e menor quantidade total de picos (33). A apitoxina das abelhas mantidas em vegetação silvestre associada à alimentação artificial teve a maior intensidade do pico correspondente a isoforma da melitina e aquela proveniente apenas da vegetação silvestre não apresentou picos dominantes. Estas variações sugerem a influência da alimentação na composição da apitoxina, porém as pesquisas precisam ser aprofundadas considerando diferentes recursos florais disponíveis em outras regiões. Estas informações podem contribuir para o futuro desenvolvimento de um soro antiveneno representativo, específico e seguro para o tratamento de ferroadas de abelhas. / Abstract: The migratory and highly defensive behavior of the africanized honeybees and their close contact with human populations can result in accidents, where treatment is often inefficient, emphasizing the need for the development of an effective honeybee antivenom. For this, the factors that may cause possible qualitative changes in apitoxin need to be evaluated, such as the food source of bees. In this study we verify differences in the mean number and intensity of the studied peaks generated by the HPLC/RF analysis of apitoxin, from hives kept in different floral sources. The feed from the flowering of Citrus sp., generated peaks corresponding to apamin, phospholipase, melittin and phospholipase isoform with higher intensity and higher total amount of peaks, but two samples not presented melittin isoform, a fact that can be associated to the genetic hive. Differently, the bees maintained in the area of Eucalyptus sp. showed the apitoxin with lower intensities for the peaks corresponding to these compounds, and also lower the total amount of peaks. The apitoxin of bees maintained in wild vegetation associated with artificial feeding had the highest peak intensity corresponding to melittin isoform and that originates from wild vegetation showed no dominant peaks. This variations suggest the diet influence in the composition of apitoxin, however the researches need to be deepened considering different floral resources available in other regions. This information can contribute to the future development of a representative, specific and safe antivenom for the treatment of bee's stings. / Mestre

Over 80% of wild angiosperms are reliant upon animal pollination for fruit and seed set and bees and other insects provide a vital pollination service to around a third of the crops we produce. Habitat loss, climate change and disease spread all threaten pollinator populations, with local declines and range contractions in honeybees and bumblebees leading to concerns that crop production may suffer as a result of pollinator shortages. Whilst agriculture and wildlife are often presented as being at odds with one another, the relationship between farmers growing pollination dependent crops, and the bees and insects that service them could be mutualistic. Flowering crops planted by farmers can provide an important source of forage to wild bees, whilst in return wild bees can contribute to ensuring farmers achieve adequate yields of marketable crops. The potential of this mutualistic relationship can be maximised by farmers by adopting management practices that reduce harm to, and enhance the wellbeing of, the wild bees around their farm. A group of common pesticides (neonicotinoids) used by farmers have recently been linked to pollinator ill health. Sub-lethal effects resulting from exposure to the neonicotinoid imidacloprid have been reported in honeybees and bumblebees, with bumblebee reproductive success found to diminish as a result of exposure to field realistic doses of this agrochemical. Here, the mechanism behind the reduced queen production in bumblebee colonies is suggested, with bees exposed to imidacloprid showing reduced efficiency in foraging for pollen. Farmers dependent upon pollinating insects for crop production can opt to avoid the use of pesticides known to harm these insects, however future studies are needed to identify safer alternatives that can be use in their place. Farmers can choose to increase the number of bees at their farms by utilising domesticated honeybees and purchasing commercially reared bumblebees. The use of these pollinators can ensure a minimum number of bees in the vicinity of a crop, and facilitate the production of crops at times when wild bee numbers are low. Concerns have been raised, however, regarding the use of commercially reared bees, mostly in regard to pathogen and parasite transmission, but also in respect to the possibility of outcompeting native species. Here the frequency and severity of attacks on commercial Bombus terrestris colonies, by the wax moth, an understudied bumblebee pest, are examined. Wax moths were found to infest almost half of the bumblebee nests deployed at fruit farms, with around a third of infestations resulting in nest destruction. Farmers investing in commercial bees will want to reduce the impact of harmful pests that may result in a reduced pollination service being delivered. Wax moth infestation rates at the study farms using commercial bees were high and the potential of a ‘spill- back’ effect on wild bees was examined. No evidence was found to suggest that nests in close proximity to these farms were any more or less likely to suffer from an attack than nests situated further away. Nest size was found to be the most significant predictor of an infestation, with larger nests more prone to wax moth attacks. Whilst farmers can utilise domesticated and commercially reared bees, relying on one source of pollination is inherently risky, and the most robust service will likely be provided by a range of pollinators. As well as reducing the use of chemicals known to harm beneficial insects, farmers can improve the habitat around their farms to help encourage and sustain wild pollinator populations. Sowing flower strips has been found to increase the abundance and diversity of pollinating insects, however, studies linking the use of these strips to crop production are lacking. Here we demonstrate for the first time that sowing small flower strips, adjacent to strawberry crops serviced by both wild and managed bees, can increase the overall number of pollinators foraging on the crop. This thesis contributes to our understanding of the implications of farm management decisions on pollinator health. It provides experimentally based evidence to guide farmers in making informed decisions regarding the future of crop pollination services and highlights the need for an integrated approach to managing pollination services for sustainability.

Bumblebees are ecologically and economically important as pollinators, but some species are suffering severe declines and range contractions. In this thesis, three cryptic bumblebee species are studied to elucidate differences in their distribution, ecology and population genetics. As a result of their high morphological similarity, very little is known about the lucorum complex species: B. lucorum, B, cryptarum and B. magnus. In this study, their distributions across Great Britain were assessed using molecular methods, revealing that B. lucorum was the most abundant and most generalist of the three species, whereas B. magnus was the rarest and most specialised, occurring almost exclusively on heathland. Additionally, both B. magnus and B. cryptarum were more likely to be present at sites with cooler summer temperatures. Cryptic species represent interesting models to investigate the levels of niche differentiation required to avoid competitive exclusion. Characterising the niches of these species at a single site across the flight season revealed differences along three niche dimensions: temporal activity, weather sensitivity and forage-resource use. These species exhibited asymmetric niche overlap; a combination of ecological divergence and spatio-temporal heterogeneity may contribute to maintaining them in sympatry. Population genetic studies can be highly informative for understanding species ecology and for conservation management. The differences in habitat specialisation exhibited by these bumblebee species provide the opportunity to test conflicting hypotheses about links between dispersal and ecological specialisation: are habitat specialists selected to have low or high dispersal ability? Based on microsatellite analysis, the generalist B. lucorum had high levels of genetic diversity and little population structure across large spatial scales. The habitat specialist B. magnus had the lowest genetic diversity but similar levels of population differentiation to the moderate generalist, B. cryptarum. However, unlike B. cryptarum, B. magnus population differentiation was not affected by geographic distance, suggesting that this specialist species may maintain effective dispersal across large scales despite being restricted to a fragmented habitat. Bergmann’s rule is a well-known ecogeographic rule describing geographical patterns of body size variation, whereby larger endothermic species are found more commonly at higher latitudes. Ectotherms, including insects, have been suggested to follow converse Bergmann’s gradients, but the facultatively endothermic nature of bumblebees makes it unclear which pattern they should adhere to. This thesis reports caste-specific differences in body size between the three lucorum complex species in agreement with Bergmann’s rule: queens and males of B. cryptarum and B. magnus, which were found more commonly at higher latitudes and at sites with cooler temperatures, were larger than those of B. lucorum. Population genetic studies of invertebrates generally require the destruction of large numbers of individuals, which is often undesirable. Testing a variety of faecal collection and DNA extraction methods demonstrated that it is possible to obtain DNA of sufficient quality for genotyping from bumblebee faeces, without harming the individuals. This method would be valuable for studies of rare or declining bee species, for queens in reintroduction projects, and may be applicable to other arthropods. Overall this thesis contributes substantially to our knowledge of the ecology and population genetics of three important pollinator species. It provides data to inform species conservation, as well as understanding of ecosystem functioning and population dynamics. Furthermore, it successfully uses these cryptic species as a model to test several fundamental ecological theories.

Made available in DSpace on 2014-06-11T19:22:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-04-25Bitstream added on 2014-06-13T20:10:19Z : No. of bitstreams: 1 jacob_cro_me_rcla.pdf: 1789232 bytes, checksum: 4d1aeb62cf1a6763869b8890da8b652a (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Recentemente as abelhas têm sido devidamente valorizadas como importantes polinizadoras de flores silvestres e cultivadas. A densidade populacional de muitos polinizadores tem diminuído devido, principalmente, à intensificação agrícola e ao uso de pesticidas, prejudicando os serviços de polinização. A metodologia clássica para estimar a toxicidade dos produtos químicos para insetos é determinar a dose letal média (DL50) ou a concentração letal média (CL50), podendo então estabelecer doses que sejam mais seguras aos organismos não-alvo ou benéficos. Além dos efeitos de toxicidade aguda, levando a morte das abelhas, doses subletais dos inseticidas podem provocar alterações comportamentais e fisiológicas nos indivíduos, que ao longo do tempo acarretarão em sérios prejuízos na manutenção da colônia. Um dos inseticidas amplamente utilizado é o fipronil, este atua ligando-se aos receptores do ácido gama-aminobutírico (GABA), interrompendo os canais de cloro, resultando na perda de sinalização inibitória neural. Na literatura pode-se encontrar diversos trabalhos que utilizam como modelo principal a abelha Apis mellifera, porém, é importante ressaltar a diversidade existente entre as abelhas nativas no Brasil, os meliponíneos, e sua participação na conservação da biodiversidade, assim como na polinização de áreas de cultivo, o que torna extremamente importante estudos com essa abelha. Com a finalidade de entender como o fipronil interfere morfo e fisiologicamente em abelhas sem ferrão, a região de interesse deste estudo foram os corpos pedunculados, já que estes são centros cerebrais complexos e tidos como local de convergência multisensorial. Para auxiliar no mapeamento metabólico, utilizou-se como marcador a enzima citocromo oxidase e a enzima caspase-3, técnicas utilizadas na observação de atividade neural... / A few decades the bees are considered an important indicator of high environmental sensitivity, and appreciated as important pollinators of wildflowers and cultivated. The population density of many pollinators have declined to harmful levels to pollination services manly due to agricultural intensification and the use of pesticides. The classic methodology of estimating the effects of chemicals for insects is to determine the median lethal dose (LD50) or median lethal concentration (LC50) that can then establish doses that do not harm non-target organisms or beneficial. Besides the effects of acute toxicity, leading to death bees, sublethal doses of insecticides can cause physiological and behavior changes of individuals over time, resulting in serious harm to maintain the colony. One of the widely used insecticides is fipronil, its acts by binding to gamma-aminobutyric acid (GABA) disrupting chloride channels, resulting in loss of inhibitory neural signaling. In the literature one can find several works using as main bee model Apis mellifera, however, it is important to highlight the diversity of Brazilian native bees, the stingless bees, and their participation in biodiversity conversation, as well as in the pollination of cultivated land. In order to understand how fipronil affect morpho and physiologically the stingless bee S. postica, the region of interest in this study were the mushroom bodies, since these are complex brain centers and used as a place of multisensory convergence. This work established the contact LD50 and Ingestion LC50 to the fipronil insecticide for foragers workers stingless bee Scaptotrigona postica in 0.54ng/bee and 0.24ng/μL of the food after 24 hours, respectively, confirming the high toxicity of this phenylpyrazole, in the groups submitted to contact contamination, were identify morphological... (Complete abstract click electronic access below)