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 156 for “"nectar"”.
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The Evolution and Development of Nectar Spurs
Nectar spurs are tubular structures usually borne from perianth tissue, which contain, or appear to contain, a floral reward such as nectar or oil. Nectar spurs have convergently evolved in many disparate angiosperm lineages, often in association with long-proboscid pollinators. The spur provides a …
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The Evolution and Development of Nectar Spurs
Nectar spurs (tubular outgrowths of a floral organ which contain or give the appearance of containing nectar) are hypothesized to be a ‘key innovation’ which can lead to rapid speciation within a lineage, because they are involved in pollinator specificity. However, given that there are no …
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Pheromones, nectar, and computer vision: investigating large-scale patterns of chemodiversity.
… I investigate the role of specialized nectar chemistry under several existing hypotheses, generate and test novel hypotheses regarding global patterns of insect semiochemical diversity, and discuss methods for rapidly and scalably monitoring insect biodiversity using machine learning. …
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Elucidating the molecular basis of dihydroxyacetone (DHA) production in Leptospermum nectar
Mānuka (Leptospermum scoparium) nectar contains variable amounts of dihydroxyacetone (DHA), a triose sugar that is the precursor to methylglyoxal (MGO), the antimicrobial compound underpinning the high value of mānuka honey and forming the basis of the Aotearoa-New Zealand honey industry. This …
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Dynamics and Communication Structures of Nectar Foraging in Honey Bees (Apis mellifera)
In this thesis, I examined honey bee nectar foraging with emphasis on the communication system. To document how a honey bee colony adjusts its daily nectar foraging effort, I observed a random sample of individually marked workers during the entire day, and then estimated the number and activity of …
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Facultative butterfly-ant interactions - the role of variation in composition of nectar secretions
The significance of variation in nectar secretions of facultatively ant-associated lycaenid butterfly larvae was investigated. The strongly myrmecophilous European Polyommatus coridon, and two moderately myrmecophilous species, the Palaearctic P. icarus and the subtropical Zizeeria knysna were …
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Characteristics of Nectar Production and Standing Crop in <em>Campsis radicans</em> (Bignoniaceae).
<p>We examined several aspects of nectar production in <em>Campsis radicans</em> to better understand how standing crop is affected and how production affects pollinator visitation. In all experiments, nectar and concentration of flowers were measured and total sugar was calculated. Flowers do not …
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Role of KNOX genes in the evolution and development of floral nectar spurs
… produce new morphologies during evolution. The nectar spur is an evolutionarily labile structure known to influence speciation in a broad range of angiosperm taxa. Here, the genetic basis of nectar spur development, and the evolution of differences in nectar spur morphology, is investigated in …
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How availability and quality of nectar and honeydew shape an Australian rainforest ant community
Ant communities visiting nectar and honeydew sources were studied in a tropical lowland rainforest in North Queensland, Australia. The study focused on the hypothesis whether the distribution and composition of nectar and honeydew diets influence resource partitioning and competition in the ant …
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The effect of supplementary nectar feeders on bird-plant mutualisms in the Cape Fynbos, South Africa
… to target a broad bird community. Attracting nectarivorous birds to gardens using supplementary nectar feeders is a popular human activity across the globe, but few studies have explored its effects on birds and the plants they pollinate. Nectar feeders may have positive effects, facilitating …
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The effects of structured variation in nectar standing crop on currency choice and optimal foraging by bumble bees
… foraging animals are unclear. A survey of nectar abundance in five plant species revealed the spectrum from only within- to solely among-plant variation. Captive bumble bees (Bombus impatiens) confronted with an increasing component of among-inflorescence nectar variation departed …
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Investigating Nectar Rhythms in Squash (<em>Cucurbita pepo</em>): Effects on Honey Bee (<em>Apis mellifera</em>) Foraging Behavior.
… of water availability on the diel patterns of nectar secretion (volume, concentration, sugar production) in male squash flowers as well as to discover what physical component of nectar honey bees use to trigger their time-memory. Squash plants were grown in the greenhouse and in the field under …
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Role of Flagellar Motility in Apple Blossom Invasion and Tactic Response to Various Plant Nectar Extracts by Erwinia Amylovora
… ml. The chemotactic response of E. amylovora to nectar extracts from 24 plant species with varying degrees of resistance or susceptibility to the pathogen was determined by capillary assay. Plants that were immune to E. amylovora infection had nectar extracts that were weakly attractive while …
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Silene otites (Caryophyllaceae): Attraction of nectar-seeking mosquitoes to inflorescence odours, and temporal variation of flower scent and flower visitors
… are known to visit diverse flowers for nectaring, S. otites is one of only two plant species world-wide in which mosquitoes have been described as pollinators. In several investigations flower odours were described as effective attractants for mosquitoes, however, in none of the studies …
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An investigation into the effects of homopteran honeydew sugars versus floral nectar sugars on black fly longevity, flight performance and digestion /
Floral nectar is thought to be the primary carbohydrate source for most dipteran species. However, it has been shown that black flies (Burgin & Hunter 1997 a,b,c), mosquitoes (Foster 1995; Burkett et al. 1999; Russell & Hunter 2002), deer flies (Magnarelli & Burger 1984; Janzen & Hunter 1998; …
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The Taste of Blood
<p>Human blood and floral nectar are both appetizing meals to a hungry female mosquito, yet each meal fulfills a distinct nutritional requirement. While protein obtained from blood is required for females to develop eggs and successfully reproduce, carbohydrates supplied from plant nectar are …
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Impact of novel thermal and non-thermal processing on nutritional value and overall quality of papaya and strawberry nectars and their respective blends
… of fruits, such as papaya and strawberry nectar blends, can result in an even greater synergistic impact on human health. Availability of these fruits, however, is limited; both have extremely short shelf lives and tend to be seasonal fruits, resulting in over 50% of fruit not reaching …
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