Sökning: "Bombus"
Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet Bombus.
1. Effects of landscape context on populations of bumblebees
Sammanfattning : To investigate recent declines in bumblebee populations, I carried out landscape analyses, made field studies of bumblebees, flowering plants and pollination in an agricultural region in southernmost Sweden. Studies were carried out in landscapes of contrasting agricultural intensity and land-cover configuration; "simple" landscapes highly dominated by large crop fields, and "complex" with mixed farming, grasslands and smaller fields. LÄS MER
2. Understanding the adaptive capacity of the bumblebee Bombus terrestris across native and novel environments
Sammanfattning : Anthropogenic stressors such as agricultural intensification, climate change, andincreased densities of non-native managed bees used for crop pollination arecontributing to bee declines. Understanding how and why bees have responded topast environmental changes is crucial for predicting future ones and enablingmitigation to maintain the functioning of both natural and agricultural ecosystems. LÄS MER
3. Go with the flow : visually mediated flight control in bumblebees
Sammanfattning : Despite their small brains and tiny eyes, flying insects are capable of detecting and avoiding collisions with moving obstacles, and with remarkable precision they navigate through environments of different complexity. For this thesis, I have investigated how bumblebees use the pattern of apparent image motion that is generated in their eyes as they move through the world (known as optic flow), in order to control flight. LÄS MER
4. The Ecology of Floral Signals in Penstemon digitalis
Sammanfattning : In this thesis, I combined field observations and lab experiments to explore the ecological significance of floral signals in a North American wildflower, Penstemon digitalis. More specifically, to determine the potential mechanisms driving selection on floral scent, I studied how scent mediates interactions with pollinators and antagonists by (1) observing spatiotemporal variation in scent emission (2), floral volatile ability to suppress microbes (3) the honest advertisement of nectar, and (4) if scent could aid pollinator learning by reinforcing visual signals. LÄS MER
5. How the sensory ecology of the bumblebee affects their functional traits
Sammanfattning : Morphological traits are important for trait-based ecological studies as they allow for the prediction of biodiversity across the biosphere. Currently, the predictive power of trait-based ecology is not often applied to terrestrial arthropods, even though they provide us with important agricultural, ecological, and cultural value. LÄS MER
