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 42 for “"Bumble"”.
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Inferring rare bumble bee species occurrences from nontarget bumble bee assemblages
… and the success of wild plant communities. Bumble bees are some of the most effective pollinators in temperate climates thanks to their cold hardiness, ability to buzz pollinate, and generalist foraging tendencies, but many species are experiencing sharp declines. The endangered rusty …
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Population ecology and parasitism in bumble bees (Hymenoptera: apidae)
… caste determination. Rates of parasitization of bumble bee queens at three sites in Southwestern Virginia were studied. Endoparasites of spring queens included Locustacarus buchneri (Stammer) (Acarina: Podapolipidae), a mite infesting the abdominal air sacs; the nematode Sphaerularia bombi Dufour …
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Natural and Anthropogenic Drivers of Variation in Bumble Bee Gut Microbiotas
Bumble bees are key pollinators in natural and agricultural ecosystems. Like all social bees, their health is supported by a core gut microbiota consisting of a few, specialized bacterial phylotypes. The composition and community structure of bumble bee gut microbiotas can vary in response to …
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Connecting above- and belowground effects of climate warming on bumble bee health
… One of the most at-risk groups of pollinators is bumble bees (<em>Bombus</em> spp.). Bumble bees are common, widespread, and key pollinators of a wide range of crops and wild plants. Although studies have examined the thermal physiological traits of individual bumble bees to understand how they …
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Hiding in plain sight: unveiling cryptic diversity and patterns in bumble bees
Bumble bee research has a rich history that spans more than three centuries. The distributions and the vibrant color patterns of nearly all species of bumble bees are well mapped and described. In addition, the natural history, colony structure and social behavior of bumble bees are well documented …
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Colony Life History in the Bumble Bee Bombus terrestris: Interactions, Timing and Control.
… thesis, I use laboratory experiments with the bumble bee Bombus terrestris to investigate the control of eusocial insect colony life history, with a focus on the interactions that bring about control over timing. Specifically, I reveal queen control over the onset of male production; show that …
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How to design a bumble bee, or a Curl Code Editor that will fly ...
The Curl language is a new web development language being written in the Computer Architecture Group at the MIT Laboratory for Computer Science. This thesis describes my design considerations for writing a code editor expressly for the language Curl. The motivation, design philosophy and process, …
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Avian diet and visual perception suggests avian predation selects for color pattern mimicry in bumble bees
… used to explain numerous other mimicry systems. Bumble bees can be found in throughout the temperate parts of the word, as well as the high mountains and polar regions. In any given area, the local bumble bee species tend to share the same color patterns. Statistical confirmation of these trends …
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PATTERNS OF AMERICAN BUMBLE BEE (BOMBUS PENSYLVANICUS) ABUNDANCE ACROSS RESTORED HABITATS IN EAST TEXAS ECOSYSTEMS
<p>Many bumble bee species (<em>Bombus</em> spp.), are declining, yet drivers of their abundance remain partially understood. In the southeastern United States, historically open habitats have shifted towards closed-canopy conditions via fire suppression, deforestation and afforestation, altering …
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Landscape effects on bumble bee (Hymenoptera: Apidae) colony performance and fitness in New York State
Pollinators such as bumble bees are in decline as a result of many factors, including loss of habitat. Initiatives to improve and restore pollinator habitat have become increasingly popular. However, to most effectively conserve pollinators, we need a better understanding of which habitats are …
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Bumble Bees (Apidae: Bombus) Through the Ages: Historical Biogeography and the Evolution of Color Diversity
In the final chapter, I add the rare obligate social parasite Bombus inexspectatus to the phylogeny to assess the evolution of social parasitism. B. inexspectatus is not the sister taxon to its host B. ruderarius, but a close relative, and therefore adheres to the loose version of Emery's rule.
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Competitive Effects of Honey Bee (Apis melifera) Hives on Morphology and Morphology-Based Abundance of Bumble Bees (Apidae: Bombus) in an Urban Prairie Landscape (City of Red Deer, Alberta)
… effects of managed honey bees (Apis melifera) on bumble bee (Bombus) populations in the City of Red Deer, with an intent to aid wild bee conservation in the area as well as decision-making regarding possible legislation of honey bee keeping within the city. A growing body of research has …
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The role of small RNAs in caste determination and differentiation in the bumble bee, Bombus terrestris
… caste determination and differentiation in the bumble bee Bombus terrestris. In Chapter 2, I used deep sequencing (miRNA-seq) and bioinformatics to annotate miRNAs in B. terrestris and a second Bombus species, B. impatiens. I found that B. terrestris yielded 131 miRNAs and B. impatiens yielded …
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Phylogeny and color pattern evolution in a New World bumble bee (Hymenoptera: Apidae: Bombus: Pyrobombus) species complex
… is one of the most common and widespread bumble bee species throughout Mexico and Central America. This robust and charismatic species possesses a highly variable color pattern throughout its wide distribution across montane and lowland regions, which raises the question of whether or not …
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The effects of structured variation in nectar standing crop on currency choice and optimal foraging by bumble bees
… within- to solely among-plant variation. Captive bumble bees (Bombus impatiens) confronted with an increasing component of among-inflorescence nectar variation departed inflorescences in manners that diverged increasingly from expectations of the Marginal Value Theorem (MVT). Bees apparently …
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Landscape composition and configuration affect nest founding but not success of bumble bee colonies in agroecosystems in the Lower Mainland of British Columbia, Canada.
… Columbia, I assessed demographic responses of bumble bees to the availability of resources as inferred from landscape structure (i.e., landscape composition and configuration), and examined the spatial scale that best explained responses to the landscape. I used mixed model regression analysis …
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The Effects of Temporal Cold Exposure and Caste Differences on Gene Expression and Epigenetics of Common Bumble Bee Species
… the cold-induced molecular responses of bumble bees, a genus common across North America with morphological and physiological characteristics adapted for cooler environments. I first investigated cold-induced temporal gene expression changes in a common eastern species, Bombus impatiens. …
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Developmental timing of pupation and analysis of color pattern response to thermal stress in Bombus impatiens (Hymenoptera: Apidae)
Bumble bees comprise a genus of approximately 250 species that exhibit high diversity in color pattern phenotypes, colony sizes, and habitats across the globe. Nearly two centuries of research have investigated the biological factors leading to their widespread distribution and ecological …
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