The Efficacy of the Weevil Cyrtobagous salvinae (Coleoptera: Curculionidae) as a Biological Control on Giant Salvinia (Salvinia molesta) in the Lower Colorado River

Persistent Link:
http://hdl.handle.net/10150/195497
Title:
The Efficacy of the Weevil Cyrtobagous salvinae (Coleoptera: Curculionidae) as a Biological Control on Giant Salvinia (Salvinia molesta) in the Lower Colorado River
Author:
Choi, Sangho
Issue Date:
2006
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The Lower Colorado River Giant Salvinia Task Force has tried a series of physical and chemical activities in an effort to control and eradicate giant salvinia (Salvinia molesta) since 1999. Because these efforts have not produced satisfactory results, biological control using the weevil Cyrtobagous salviniae (Coleoptera: Curculionidae) was applied on the Lower Colorado River by the Animal and Plant Health Inspection Service, United States Department of Agriculture offices in California and Arizona. They released the weevil at four sites in the summer of 2003, four sites in 2004, and eight sites in 2005.We monitored physico-chemical and biological parameters at release and 10 m and 1 km down stream from release sites. Weevils established their colony in the field, but control has not been determined. Integrated pest management (physical, chemical, and biological methods) will be essential for successful management of salvinia in the Lower Colorado River.The low temperature resistance and survival rates of the weevils were tested under three different diurnal temperature regimes (5 to 15 oC , 10 to 20 oC , and 15 to 25 oC ) and two different salvinia densities. At the low temperature range, the survival rate of the weevil was sharply decreased. The relationship between low temperature resistance of weevils and giant salvinia population was tested at the 5 to 15 oC range. The experiment was conducted at three different giant salvinia populations (0, 1, and 3 salvinia per container). The salvinia density had no significant effect on the survival of the weevil.To examine a more efficient method of biological control, we conducted a nitrogen fertilizer experiment on the river. Our goal was to demonstrate that plants fertilized with nitrogen would support a faster growing population of C. salviniae. In the Lower Colorado River, the weevil successfully survived winter and dispersed down the river.
Type:
text; Electronic Dissertation
Keywords:
Soil, Water & Environmental Science
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Soil, Water & Environmental Science; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Fitzsimmons, Kevin

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleThe Efficacy of the Weevil Cyrtobagous salvinae (Coleoptera: Curculionidae) as a Biological Control on Giant Salvinia (Salvinia molesta) in the Lower Colorado Riveren_US
dc.creatorChoi, Sanghoen_US
dc.contributor.authorChoi, Sanghoen_US
dc.date.issued2006en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe Lower Colorado River Giant Salvinia Task Force has tried a series of physical and chemical activities in an effort to control and eradicate giant salvinia (Salvinia molesta) since 1999. Because these efforts have not produced satisfactory results, biological control using the weevil Cyrtobagous salviniae (Coleoptera: Curculionidae) was applied on the Lower Colorado River by the Animal and Plant Health Inspection Service, United States Department of Agriculture offices in California and Arizona. They released the weevil at four sites in the summer of 2003, four sites in 2004, and eight sites in 2005.We monitored physico-chemical and biological parameters at release and 10 m and 1 km down stream from release sites. Weevils established their colony in the field, but control has not been determined. Integrated pest management (physical, chemical, and biological methods) will be essential for successful management of salvinia in the Lower Colorado River.The low temperature resistance and survival rates of the weevils were tested under three different diurnal temperature regimes (5 to 15 oC , 10 to 20 oC , and 15 to 25 oC ) and two different salvinia densities. At the low temperature range, the survival rate of the weevil was sharply decreased. The relationship between low temperature resistance of weevils and giant salvinia population was tested at the 5 to 15 oC range. The experiment was conducted at three different giant salvinia populations (0, 1, and 3 salvinia per container). The salvinia density had no significant effect on the survival of the weevil.To examine a more efficient method of biological control, we conducted a nitrogen fertilizer experiment on the river. Our goal was to demonstrate that plants fertilized with nitrogen would support a faster growing population of C. salviniae. In the Lower Colorado River, the weevil successfully survived winter and dispersed down the river.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectSoil, Water & Environmental Scienceen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineSoil, Water & Environmental Scienceen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairFitzsimmons, Kevinen_US
dc.contributor.committeememberGlenn, Edward P.en_US
dc.contributor.committeememberNelson, Stephen G.en_US
dc.contributor.committeememberRiley, Jamesen_US
dc.contributor.committeememberMatthias, Allenen_US
dc.identifier.proquest1937en_US
dc.identifier.oclc659746573en_US
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