156 research outputs found

    Biological control of the two-spotted spider mite in raspberries with the predator mite, Phytoseiulus persimilis

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    Phytoseiuius persimilis was released to control the two-spotted spider mite, Tetranychus urticae, in field raspberries at Agassiz, B.C. The mite predators became established and responded numerically to the prey in the treatment plots. For a period of 8 weeks after release, the numbers of T. urticae were consistently lower in the treatment plots than in the controls. Differences in numbers of T. urticae between the treatments and the controls were significant on two dates.Key words: Tetranychus urticae; Phytoseiulus persimilis; Rubus idaeus; biological control; Fraser Valle

    Compilation of taxonomic catalogues by computer

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    The advantages of using a computer are examined for storing, updating and cross indexing taxonomic collection data in working and published lists

    Movement of Ericaphis fimbriata (Hemiptera: Aphididae) apterae on blueberry

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    Blueberry scorch Virus is a new and important pathogen of blueberry in British Columbia, Canada of which the blueberry-infesting aphid Ericaphis fimbriata is a known Vector. In a study of the movement of apterous E. fimbriata, significantly more aphids fell when one ladybird beetle was added to E. fimbriata infested blueberry branches than when zero, two, or four were added. Similar numbers of aphids fell in the presence or absence of beetles at low aphid density (10-30 aphids per terminal), but more fell in the presence of beetles at high aphid density (50-70 aphids per terminal). The time taken for aphids to move a minimum distance of 60 cm off infested plants onto uninfested plants decreased with increasing aphid density which has important implications for the spread of the Virus

    Inequality, poverty and the privatization of essential services: A "systems of provision" study of water, energy and local buses in the UK

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    This paper is concerned with the distributional effects of the deregulation and privatization of essential services in Britain since the 1980s, based on a cross-sector study of water, energy and local bus transport. Our approach locates end users within the structures and processes, and prevailing narratives that underpin both production and consumption. This framework highlights the ways that the provisioning of these vital services is contested, contradictory and underpinned by power relations. We show that, at one end, investors in these sectors have made generous returns on their investments but their methods of profit maximization are often not in the public interest. Meanwhile these profits are financed by end users’ payments of bills and fares. Many lower-income households face challenges in terms of affording, and even accessing, these essential services. Regulation has failed to provide adequate social protection. We argue that adverse social outcomes emerge from systemic factors embedded in these modes of provision. A narrative of politically-neutral, technocratic solutions belies the underlying contested nature of privatized monopolistic shared essential services. Moreover, a policy preoccupation with markets and competition obscures the inequality embedded in the underlying structures and processes and undermines more collective and equitable forms of provisioning
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