Publications by authors named "David J Saville"

An insect's fitness varies on different host plant species, and can be affected by previous host feeding experience. In New Zealand, Bactericera cockerelli (the tomato potato psyllid (TPP)) overwinter on various host species, and later migrate to annually grown crop host plants. How changing host plant species affects the insect's fitness is unknown.

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In Central and North America, Australia and New Zealand, potato () crops are attacked by , the tomato potato psyllid (TPP). 'Mesh crop covers' which are used in Europe and Israel to protect crops from insect pests, have been used experimentally in New Zealand for TPP control. While the covers have been effective for TPP management, the green peach aphid (GPA, ) has been found in large numbers under the mesh crop covers.

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A better understanding of the ecology of the insect pathogenic fungus, Beauveria bassiana, in soil is needed to identify reasons behind the variable efficacy often seen after field application. A transformed strain of a candidate commercial strain of B. bassiana (F418 gfp tr3), expressing the green fluorescent protein and the hygromycin B resistance gene, was used to assess the effects of the larvae of a host insect, Tenebrio molitor L.

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The wheat bug, Nysius huttoni L. is an endemic New Zealand pest. The seedlings of forage brassicas are highly susceptible to direct feeding damage by this insect, and this can reduce plant establishment.

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The efficacy of different combinations of undervine and inter-row treatments for managing a soil-dwelling orthopteran pest, weta (Hemiandrus sp.), in vineyards was investigated over 2 seasons. This insect damages vine buds, thus reducing subsequent grape yield.

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Vineyards worldwide occupy over 7 million hectares and are typically virtual monocultures, with high and costly inputs of water and agro-chemicals. Understanding and enhancing ecosystem services can reduce inputs and their costs and help satisfy market demands for evidence of more sustainable practices. In this New Zealand work, low-growing, endemic plant species were evaluated for their potential benefits as Service Providing Units (SPUs) or Ecosystem Service Providers (ESPs).

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This paper has two main themes. First, the various statistical measures used in this journal are summarized and their interrelationships described by way of a flow chart. These are the pooled standard deviation, the pooled variance or mean square error (MSE), the standard error of each treatment mean (SEM) and of the difference between two treatment means (SED), and the least difference between two means which is significant at (e.

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