Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"insect pollinators"”.
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The role of cone volatiles and thermogenesis in the pollination of Encephalartos cycads with particular reference to E.villosus
… the cycad taxa depend on between one and three insect pollinators. Generally, the pollination periods of many cycad taxa are characterised by odour emissions in pollen shedding (male) and receptive (female) cones usually accompanied by heat production. The emission of cone odours and heat …
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The biology of Rosa multiflora (Rosaceae) and two of its biotic mortality factors
… to successfully invade new environments. Insect pollination is an example of a mutualism that is required for seed set in the invasive species, Rosa multiflora Thunb. (Rosaceae), an obligate outcrosser. We determined that the insect pollinators visiting R. multiflora flowers in Iowa were …
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The Effects of Wildfire Burn Severity on Bee and Wasp Communities Two Decades Post-Fire
… conflicted about whether fire harms or benefits insect pollinators. We investigated the lasting effects of wildfire burn severity on wild bee communities and floral resource availability across different burn severities in two-mixed severity fires that burned >20 years ago. We found that high …
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Is local plant extinction a product of mutualism breakdown? A case study of the Namaqualand spring flora
… are vulnerable to extinction in the absence of insect pollinators. The predictions of this model were then compared with actual plant species compositions between adjacent disturbed and undisturbed sites in a Namaqualand flowering community. It was found that autogamous annuals were at the …
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Honey Bee (Apis Mellifera) Foraging Preferences are Negatively Correlated with Alfalfa Leafcutting Bee (Megachile Rotundata) Productivity in Virginian Landscapes
… of habitat quality for themselves and also other insect pollinators because we can observe, decode, map, and analyze the information encoded in the waggle dance communication behavior, which allows us to know where and when bees are collecting high quality forage. Previously we measured honey bee …
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Pollination Biology of <i>Ailanthus altissima</i> (Mill.) Swingle (Tree-of-Heaven) in the Mid-Atlantic United States
… U.S. This study was conducted to determine the insect pollinator fauna visiting <i>A. altissima</i> and to study general pollinator visitation patterns associated with the tree's nectar profile. A list of taxa visiting trees within each of three sites was developed from collected insects. …
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A proteomic and cytological characterisation of the buff-tailed bumblebee (Bombus terrestris) fat body and haemolymph -An immune perspective
… and social, native and managed, are vital insect pollinators that provide essential ecosystem services. Bombus terrestris (Linnaeus) is a widespread and important bumblebee pollinator of wild and cultivated crops and although found commonly across Europe, is available commercially to …
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Petal cell shape and flower-pollinator interaction in Nicotiana
… Conical epidermal cells may increase grip for insect pollinators and enhance flower colouration compared to non-conical cells. Nicotiana (Solanaceae) presents a diverse range of petal cell shapes. Interestingly, sister species in at least two phylogenetically distinct clades of the genus have …
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Effects of temperature and pollinator availability on plant reproductive success in the Indiana spring ephemeral community
… is a key driver of phenology in both plants and insects, and even small changes in temperature can impact the reproductive success of insect-pollinated plants by influencing access to pollinator services. While it is well-established that temperature variation directly impacts the flowering …
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The pollination biology of Haskap (Lonicera caerulea L.: Caprifoliaceae): floral traits and pollinator performance of a new Saskatchewan fruit crop.
… America. It is self-incompatible, and requires insect pollinators in order to set fruit; however, very little is currently known about its pollination biology, including associated pollinators and important floral characteristics. My research compared the pollinating performance of three groups …
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Assessing risk to native ecosystems: using exotic ants as a model
… ants may be competitively excluding important pollinators. I found trophic position varied between native and invasive ant species; although two invasive species represented the two lowest trophic positions, most other species reflected trophic positions similar to predators. There was evidence …
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Molecular phylogenetics, systematics, reproductive safeguarding and chromosome evolution of the genus Lachenalia (Asparagaceae: Scilloideae)
… limitation, resulting from a low abundance of insect pollinators, promotes the evolution of reproductive safeguarding traits (self compatibility, autonomous selfing, bird pollination and clonal propagation) in low insect abundance contexts (i.e., infertile fynbos heathland, and species which …
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The birds, the bees and Erica: vulnerability of plant-pollinator communities in fragmented fynbos landscapes
… not be enough to attract essential bird and insect pollinators. Insect-pollinated species were more impacted by reduced patch size than the bird-pollinated ones. Further investigation using Erica discolor showed that for this widespread ornithophilous species, pollination mutualism still …
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Landscape-scale habitat requirements of flower-visiting insects in the Nene Valley Nature Improvement Area
Recorded population declines of flower visiting insects are a cause for concern. The presence of an abundant and diverse community of insects is essential for ecosystem stability and continued agricultural prosperity. As human populations continue to increase so do the pressures on the natural …
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Bees, Bombs, and Burns: Disturbance and the Native Bee Communities of Military and Other Public Lands in Virginia
Physical and ecological disturbances caused by military land use can create and maintain early successional habitats, which can support diverse communities of native plants and animals. These lands may serve as refugia, protecting rare, threatened, and endangered species that may have disappeared …
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Consequences of plant population size for pollinator visitation and plant reproductive success
… size on plant reproductive success and insect visitation in 8 populations of two common species in the island of Lesvos, Greece (Mediterranean Sea), Echium plantagineum and Ballota acetabulosa, and of a rare perennial shrub endemic to north-central Italy, Ononis masquillierii. All the …
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THERE IS NO PLANET B(EE): AN INTEGRATED APPROACH TO UNDERSTANDING DRIVERS OF POTENTIAL DECLINES IN BUMBLEBEE COMMUNITIES
… Earth’s biotic systems. Of those core functions, pollinators, particularly insect pollinators, are key to the functioning of most terrestrial ecosystems. Bumblebees (Hymenoptera: Apidae: Bombus) represent important agricultural and urban pollinator species as they are tolerant of the high …
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Isolation in Tragopogon (Compositae)
… among the Tragopogon taxa studied. (5) Finally, insect pollinators which frequent the three Tragopogon taxa were collected and identified to investigate whether there is a commonality of insects visiting the Tragopogon flowers.The data indicate that the three taxa have a lower seed set and lower …
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Toxicity and detoxification of imidacloprid in mouse ovarian follicles
… species such as humans, birds, fish, and insect pollinators. Although neonicotinoids are considered insect selective, they can be activated in the environment and within mammals into more toxic metabolites. Imidacloprid (IMI) was the first neonicotinoid synthesized and continues to be the …