Constraints on Neltumius arizonensis (Coleoptera: Bruchidae) as a biocontrol agent of prosopis in South Africa : the role of parasitoids

dc.contributor.advisorHoffmann, John Hen_ZA
dc.contributor.authorRoberts, Anthonyen_ZA
dc.date.accessioned2017-12-07T09:25:13Z
dc.date.available2017-12-07T09:25:13Z
dc.date.issued2000en_ZA
dc.date.updated2017-02-03T12:44:26Z
dc.description.abstract1. Two species of seed feeding bruchid, Algarobius prosopis and A. bottimeri, were introduced to South Africa in 1987 and 1990 respectively, to curb the spread of the invasive weed Prosopis. Failure of A. bottimeri to establish and reduced effectiveness of A. prosopis due to interference by livestock resulted in the release of a third species, Neltumius arizonensis in 1992. 2. Algarobius prosopis populations have remained high but N. arizonensis has not been as successful. 3. Populations ofboth bruchids showed similar emergence patterns through the sampling period hence there is no temporal partitioning of resources. 4. Percentage emergence of N. arizonensis was low at the start of the season but increased as the season progressed with higher proportions of N. arizonensis emerging from 'tree' pods than 'ground' pods. Regardless of the spatial partitioning of resources by the two bruchids, N. arizonensis emergence numbers are still far lower than those of A. prosopis (approximately 1:4 respectively). 5. Oviposition strategies of N. arizonensis results in high levels of egg parasitism by Uscana sp., Trichogrammatidae, that A. prosopis escapes by ovipositing in concealed places avoiding detection by parasitoids. 6. Egg parasitism is extremely high on N. arizonensis eggs (67%) and has resulted in failure by N. arizonensis to establish large populations and hence its effectiveness as a biocontrol agent is negligible.en_ZA
dc.identifier.apacitationRoberts, A. (2000). <i>Constraints on Neltumius arizonensis (Coleoptera: Bruchidae) as a biocontrol agent of prosopis in South Africa : the role of parasitoids</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/26489en_ZA
dc.identifier.chicagocitationRoberts, Anthony. <i>"Constraints on Neltumius arizonensis (Coleoptera: Bruchidae) as a biocontrol agent of prosopis in South Africa : the role of parasitoids."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2000. http://hdl.handle.net/11427/26489en_ZA
dc.identifier.citationRoberts, A. 2000. Constraints on Neltumius arizonensis (Coleoptera: Bruchidae) as a biocontrol agent of prosopis in South Africa : the role of parasitoids. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Roberts, Anthony AB - 1. Two species of seed feeding bruchid, Algarobius prosopis and A. bottimeri, were introduced to South Africa in 1987 and 1990 respectively, to curb the spread of the invasive weed Prosopis. Failure of A. bottimeri to establish and reduced effectiveness of A. prosopis due to interference by livestock resulted in the release of a third species, Neltumius arizonensis in 1992. 2. Algarobius prosopis populations have remained high but N. arizonensis has not been as successful. 3. Populations ofboth bruchids showed similar emergence patterns through the sampling period hence there is no temporal partitioning of resources. 4. Percentage emergence of N. arizonensis was low at the start of the season but increased as the season progressed with higher proportions of N. arizonensis emerging from 'tree' pods than 'ground' pods. Regardless of the spatial partitioning of resources by the two bruchids, N. arizonensis emergence numbers are still far lower than those of A. prosopis (approximately 1:4 respectively). 5. Oviposition strategies of N. arizonensis results in high levels of egg parasitism by Uscana sp., Trichogrammatidae, that A. prosopis escapes by ovipositing in concealed places avoiding detection by parasitoids. 6. Egg parasitism is extremely high on N. arizonensis eggs (67%) and has resulted in failure by N. arizonensis to establish large populations and hence its effectiveness as a biocontrol agent is negligible. DA - 2000 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2000 T1 - Constraints on Neltumius arizonensis (Coleoptera: Bruchidae) as a biocontrol agent of prosopis in South Africa : the role of parasitoids TI - Constraints on Neltumius arizonensis (Coleoptera: Bruchidae) as a biocontrol agent of prosopis in South Africa : the role of parasitoids UR - http://hdl.handle.net/11427/26489 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/26489
dc.identifier.vancouvercitationRoberts A. Constraints on Neltumius arizonensis (Coleoptera: Bruchidae) as a biocontrol agent of prosopis in South Africa : the role of parasitoids. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2000 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/26489en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherBotanyen_ZA
dc.subject.otherBiological Conservationen_ZA
dc.titleConstraints on Neltumius arizonensis (Coleoptera: Bruchidae) as a biocontrol agent of prosopis in South Africa : the role of parasitoidsen_ZA
dc.typeBachelor Thesis
dc.type.qualificationlevelHonours
dc.type.qualificationnameBSc (Hons)en_ZA
uct.type.filetype
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
Files
Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Roberts_Constraints_on_Neltumius__1.pdf
Size:
591.75 KB
Format:
Adobe Portable Document Format
Description:
License bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
license.txt
Size:
1.72 KB
Format:
Item-specific license agreed upon to submission
Description:
Collections