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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Plant diversity and its effects on populations of cucumber beetles and their natural enemies in a cucurbit agroecosystem

Walker, Jason 22 August 2008 (has links)
Populations of striped cucumber beetles (<i>Acalymma vittatum</i> Fabr.), spotted cucumber beetles (<i>Diabrotica undecimpunctata howardi</i> Barber), western cucumber beetles (<i>Acalymma trivittatum</i> Mann.), Pennsylvania leatherwings (<i>Chauliognathus pennsylvanicus</i> DeGeer), Diptera (Order: Diptera), lady beetles (Order: Coleoptera, Family: Coccinellidae), hymenoptera (Order: Hymenoptera), and spiders (Order: Araneae) in a cucumber field and a bordering field of uncultivated vegetation were assessed using yellow sticky traps to determine: 1) the relative abundances of target insects across the uncultivated vegetation and the crop field, 2) relationships between target insects and plant species. In both years populations striped and spotted cucumber beetles and Pennsylvania leatherwings (only in 1995) increased significantly and Diptera decreased significantly in the direction of the crop. The strength of these relationships increased over the season to a peak in August in 1995 and July in 1996 and then decreased in September in both years. There were significant correlations between Diptera and sweet-vernal grass in 1995. In 1996, cucumber beetles were correlated with wild violet (<i>Viola</i> spp.) and white clover (<i>Trifolium repens</i>); Diptera with wild violets; and the lady beetle <i>Coleomegilla maculata</i> with goldenrod (<i>Solidago</i> spp.), English plantain (<i>Plantago lanceolata</i>), and marjoram (<i>Origanum</i> spp.) in 1996. This study demonstrated the potential value of increasing the diversity of a cucumber field to control insect pests (and thus reduce pesticide useage) as well as suggested specific plants that influenced insect populations. / Master of Science

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