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dc.contributor.authorScarratt, Samantha L.en
dc.date.accessioned2010-05-12T01:37:16Z
dc.date.issued2005en
dc.identifier.urihttps://hdl.handle.net/10182/1836
dc.description.abstractIn this thesis, experiments were conducted in both the laboratory and the field to determine whether the provision of floral resources to Dolichogenidea tasmanica Cameron (Hymenoptera: Braconidae) could enhance the biological control of leafrollers (Lepidoptera: Tortricidae) in an organic vineyard in Marlborough, New Zealand. Laboratory experiments were conducted to find a selective floral resource that could enhance the 'fitness' of the parasitoid, D. tasmanica without enhancing that of its host, the lightbrown apple moth, Epiphyas postvittana Walker (Lepidoptera: Tortricidae). From these experiments it was found that the longevity of adult female and male D. tasmanica could be enhanced significantly from 2.8 and 3.8 days, respectively, with water to 18.4 and 12.4 days, respectively, with buckwheat, Fagopyrum esculentum Moench, cv. Katowase. Also, adult E. postvittana 'fitness' was not enhanced when exposed to buckwheat and first-instar E. postvittana larvae 'preferred' grapevine to buckwheat leaves. Therefore, buckwheat was tested for its ability to enhance the biological control of E. postvittana in the vineyard. In field experiments in 2003, leafroller parasitoids were more abundant in areas of the vineyard planted with buckwheat and greater parasitism rates of naturally-occurring leafroller larvae were recorded in vineyard plots with buckwheat compared with control areas. In 2004, field experiments showed that rubidium chloride could be used to mark parasitoids feeding on buckwheat nectar and that D. tasmanica dispersed at least 30 m from buckwheat plants within a seven-day sampling period following feeding. Also, parasitism rates of leafroller larvae were greater adjacent to the buckwheat (41 %) than at 10 m from it (19 %). In a large-scale field experiment conducted in 2005, parasitism rates of naturally-occurring leafroller larvae were again found to be greater in areas of the vineyard planted with buckwheat and there were fewer larvae in grape bunches at harvest time in buckwheat compared with control areas. Therefore, the results of this work indicate that buckwheat may be used as a "selective food plant" to enhance the biological control of leafrollers in New Zealand vineyards. Future work could further explore whether buckwheat can reduce leafroller larvae in grape bunches to below economic thresholds, as this result is more likely to encourage grapegrower uptake of this technology.en
dc.format.extent1-120en
dc.language.isoenen
dc.publisherLincoln Universityen
dc.subjectDolichogenidea tasmanicaen
dc.subjectleafrolleren
dc.subjectbuckwheaten
dc.subjectfloral resource subsidiesen
dc.subjectconservation biological controlen
dc.subjecthabitat manipulationen
dc.subjectEpiphyas postvittanaen
dc.subjectgrapesen
dc.titleEnhancing the biological control of leafrollers (Lepidoptera: Tortricidae) using floral resource subsidies in an organic vineyard in Marlborough, New Zealanden
dc.typeThesis
thesis.degree.grantorLincoln Universityen
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen
dc.subject.marsdenFields of Research::270000 Biological Sciences::270500 Zoology::270505 Entomologyen
dc.subject.marsdenFields of Research::300000 Agricultural, Veterinary and Environmental Sciences::300300 Horticulture::300303 Plant protection (pests, diseases and weeds)en
dc.subject.marsdenFields of Research::300000 Agricultural, Veterinary and Environmental Sciences::300300 Horticulture::300305 Oenology and viticultureen
lu.contributor.unitLincoln Universityen
lu.contributor.unitFaculty of Agriculture and Life Sciencesen
lu.contributor.unitDepartment of Pest Management and Conservationen
lu.contributor.unitSoil, Plants and Ecological Sciencesen
pubs.organisational-group/LU
pubs.organisational-group/LU/Agriculture and Life Sciences
pubs.organisational-group/LU/Agriculture and Life Sciences/ECOL
pubs.organisational-group/LU/SPES
pubs.publication-statusPublisheden
dc.publisher.placeCanterburyen


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