Search for dissertations about: "hoverflies"

Showing result 1 - 5 of 8 swedish dissertations containing the word hoverflies.

  2. 1. A behavioural investigation into Eristalis tenax : Pursuit, approach estimation, locomotor activity and rearing

    Author : Malin Thyselius; Karin Nordström; Anna Rostedt Punga; Yuri Ogawa; Emily Baird; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; NATURVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; NATURAL SCIENCES; MEDICAL AND HEALTH SCIENCES; Eristalis tenax; Insect rearing; Hoverflies; Pollinators; Circadian rhythm; Target detection; Motion vision; Pursuit; LAMS; Flight arena;

    Abstract : Hoverflies are suggested to be the 2nd most important pollinator group after bees and bumblebees, and with the changing climate and dwindling numbers of pollinators it might never have been more important understanding our pollinators. Given the hoverflies’ small brains, beautiful aerial acrobatics, good temporal resolution, but limited spatial resolution, these flies make interesting study animals for flight behaviour and vision research. READ MORE

  4. 2. The processing of natural images in the visual system

    Author : Olga Dyakova; Karin Nordström; Dan Larhammar; Eric Warrant; Uppsala universitet; []
    Keywords : MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; natural scenes; image statistics; hoverflies; optomotor response; cSIFE neuron; sleep deprivation;

    Abstract : Any image can be described in terms of its statistics (i.e. quantitative parameters calculated from the image, for example RMS-contrast, the skewness of image brightness distribution, and slope constant of an average amplitude spectrum). READ MORE

  5. 3. Motion Vision Processing in Fly Lobula Plate Tangential Cells

    Author : Yu-Jen Lee; Karin Nordström; Holger Kraap; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; hoverflies; EMD; higher order motion; octopamine; cSIFE; figure-ground discrimination; motion vision; lobula plate tangential cells;

    Abstract : Flies are highly visually guided animals. In this thesis, I have used hoverflies as a model for studying motion vision. Flies process motion vision in three visual ganglia: the lamina, the medulla, and the lobula complex. In the posterior part of lobula complex, there are around 60 lobula plate tangential cells (LPTCs). READ MORE

  6. 4. Small biotopes: Landscape and management effects on pollinators

    Author : Annika Söderman; Biodiversitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Agri-environmnetal scheme; management; agriculture; landscape complexity; heterogeneity; landscape scale; mall biotopes; field boundaries; pollinating insects; pollination; bumblebees; solitary bees; hoverflies;

    Abstract : The intensification of agriculture during the second half of the twentieth century, has caused sever declines of farmland biodiversity, where loss of semi-natural habitats is one of the major drivers. To halt further loss of habitat and biodiversity, agri-environmental schemes (AES) are used to compensate farmers to use methods less harmful to the environment. READ MORE

  7. 5. Effects of Farming Practice on Pollinators and Pollination across Space and Time

    Author : Georg Andersson; Biodiversitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Several studies have found that organic farms support higher biodiversity, but results vary between studies such that some also show no or even negative effects. There can be many reasons why studies comparing organic and conventional farming show conflicting results. READ MORE