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Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa
Thesis (PhDConsEcol)--Stellenbosch University, 2026.
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Stellenbosch : Stellenbosch University
2026
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| _version_ | 1869484186032668672 |
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| access_status_str | Open Access |
| author | Molepo, Dikobe Karen |
| author2 | Veldtman, Ruan |
| author_browse | Molepo, Dikobe Karen Veldtman, Ruan |
| author_facet | Veldtman, Ruan Molepo, Dikobe Karen |
| author_sort | Molepo, Dikobe Karen |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDConsEcol)--Stellenbosch University, 2026. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/136163 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-07-01T04:10:53.146Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/136163 Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa Molepo, Dikobe Karen Veldtman, Ruan Masehela, Tlou Van Asch, Barbara Daly, Derek Addison, Pia Stellenbosch University. Faculty of AgriSciences. Dept. of Conservation Ecology and Entomology. Vespa germanica Introduced organisms -- South Africa -- Western Cape Wasps -- South Africa -- Western Cape Predation (Biology) Climatic changes Biological invasions -- South Africa -- Western Cape DNA barcoding -- Data processing Habitat (Ecology)-- Modification UCTD Thesis (PhDConsEcol)--Stellenbosch University, 2026. Molepo, D. K. 2026. Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/4f0094cf-ef33-4e82-bce5-d125ef5f535b ENGLISH ABSTRACT: Vespula germanica (German wasp) is a highly invasive social wasp species and the most widely distributed worldwide. It presents substantial threats to biodiversity, the economy, and various human social aspects. Vespula germanica preys on and/or competes with native insect species, disrupting ecological food webs and their species’ interactions, listed species, and can also alter the pollination network. Furthermore, the presence of V. germanica leads to increased costs for management and can cause substantial losses in the agricultural sector. Vespula germanica is known for its painful stings with the potential to trigger severe allergic reactions and its aggressive behaviour, especially when defending its nests and it negatively impacts tourism by deterring outdoor activities. In South Africa, within the Western Cape Province where V. germanica has invaded but remain restricted up till now, little is known about some of these factors particularly the predatory pressures it exerts on native biodiversity, especially insect species. To understand the predatory pressures exerted by V. germanica, there was a need to investigate the native insects it preys upon, its temporal abundance and predictions of its potential spread to other regions of the country based on bioclimatic and habitat modelling. To achieve these, prey items of V. germanica were collected using a vacuum sampling method, and identification was carried out both morphologically and molecularly through DNA barcoding. Vespula germanica occurrence records were assessed and the MaxEnt model was used to predict the distribution into other parts of the country under certain bioclimatic variables and habitat parameters. Fisher’s Exact Test, Correspondence Analysis and PERMANOVA were used to explore associations between land use, buffer zones and dependencies between land use, habitat types and dipteran prey families. Pielou’s Evenness and Shannon-Wiener diversity index were used to measure dipteran prey diversity, count, evenness and richness as its major prey type. Vespula germanica was found to prey on a wide range of insect species, mainly members of the dipteran, lepidopteran families and the Apis mellifera species. Vespula germanica occurrence record seem to have increased in areas where V. germanica occurs the past few years and the model predicted V.germanica potential to spread and establish in other parts of the country. This predicted spread wassignificantly influenced by the bioclimatic variable: mean diurnal range in temperature and land use types consisting of trees, crops, built-up and rangeland. Low forest, thicket, dense forest, woodland and open woodland supported the highest dipteran diversity, suggesting that this land use type may offer optimal habitat or prey availability for V. germanica. These findings fill a critical gap in the existing global research by contributing to V. germanica diet variations across different land use and habitat types within the Cape Winelands District Municipality, Western Cape Province of South Africa. The findings will contribute to the understanding of factors influencing the maintenance and spread of V. germanica in invaded regions, as the study predicted the species’ potential future distribution under specific bioclimatic and land use conditions within a Mediterranean climate environment. Ultimately the findings of this study will inform targeted management strategies and eradication plans for V. germanica, in South Africa. AFRIKAANSE OPSOMMING: Vespula germanica (Duitse wesp) is 'n hoogs indringende sosiale wespspesie en die mees wydverspreide wêreldwyd. Dit bied aansienlike bedreigings vir biodiversiteit, die ekonomie en verskeie sosiale aspekte. Vespula germanica jag op en/of kompeteer met inheemse insekspesies, wat ekologiese voedselwebbe en hul spesies se interaksies ontwrig, en benadeel bedreigde en ander gelyste spesies, en kan ook die bestuiwingsnetwerke verander. Verder lei die teenwoordigheid van V. germanica tot verhoogde koste vir beheer en bestuur en kan aansienlike verliese in die landbousektor veroorsaak. Laastens is V. germanica bekend vir sy pynlike steke met die potensiaal om ernstige allergiese reaksies te veroorsaak en sy aggressiewe gedrag, veral wanneer sy neste verdedig word, en dit beïnvloed toerisme negatief deur buitelugaktiwiteite te ontmoedig. In Suid-Afrika, binne die Wes-Kaap Provinsie waar V. germanica binnegedring het maar nou nog toe beperk is, is min bekend oor sommige van hierdie faktore, veral die roofdruk wat dit op inheemse biodiversiteit, veral insekspesies, uitoefen. Om die roofdruk wat deur V. germanica uitgeoefen word, te verstaan, was daar 'n behoefte om die inheemse insekte waarop dit jag, die temporale oorvloed en voorspellings van die potensiële verspreiding daarvan na ander streke van die land te ondersoek, gebaseer op bioklimatiese en habitatmodellering. Om dit te bereik, is prooi-items van V. germanica versamel met behulp van 'n vakuummonsternemingsmetode, en identifikasie is beide morfologies en molekulêr uitgevoer deur DNS-streepieskodering. Die verspreidingsrekords van V. germanica is geassesseer en die MaxEnt-model is gebruik om die verspreiding in ander dele van die land onder sekere bioklimatiese veranderlikes en habitatparameters te voorspel. Fisher se presiese toets, korrespondensie-analise en PERMANOVA is gebruik om assosiasies tussen grondgebruik, buffersones en afhanklikhede tussen grondgebruik, habitattipes en diptera-prooifamilies te ondersoek. Pielou se ewigheid en Shannon-Wiener-diversiteitsindeks is gebruik om diptera-prooidiversiteit, -telling, ewigheid en -rykdom as die belangrikste prooitipe te meet. Daar is gevind dat V. germanica op 'n wye reeks insekspesies jag, hoofsaaklik lede van die dipteraan-, lepidoptera-families en die heuningby, Apis mellifera-spesies. Die aantal V. germanica verspreidingsrekords blyk om in die afgelope paar jaar toegeneem het en die model het die potensiaal van V. germanica voorspel om te versprei en in ander dele van die land te vestig. Hierdie voorspelde vergrooting in verspreiding is beduidend beïnvloed deur die bioklimatiese veranderlike: gemiddelde daaglikse reeks in temperatuur en grondgebruiktipes, bestaande uit bome, gewasse, beboude gebiede en weiveld. Lae woude, ruigtes, digte woude, bosveld en oop bosveld het die hoogste dipteraan-diversiteit ondersteun, wat daarop dui dat hierdie grondgebruiktipe optimale habitat- of prooibeskikbaarheid vir V. germanica kan bied. Hierdie bevindinge vul 'n kritieke gaping in bestaande globale navorsing deur by te dra tot V. germanica se dieetvariasies oor verskillende grondgebruik- en habitattipes binne die Kaapse Wynlande-distriksmunisipaliteit, Wes-Kaap Provinsie van Suid-Afrika. Die bevindinge sal bydra tot die begrip van faktore wat die verspreiding van V. germanica in binnegedringde streke beïnvloed, aangesien die studie die spesie se potensiële toekomstige verspreiding onder spesifieke bioklimatiese en grondgebruikstoestande binne 'n Mediterreense klimaatomgewing voorspel het. Uiteindelik sal die bevindinge van hierdie studie geteikende bestuurstrategieë en uitroeiingsplanne vir V. germanica inlig. Doctoral 2026-04-23T13:51:00Z 2026-04-23T13:51:00Z 2026-03 Thesis https://scholar.sun.ac.za/handle/10019.1/136163 en Stellenbosch University ix, 10 unnumbered pages, 185 pages : illustrations (some color), maps application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Vespa germanica Introduced organisms -- South Africa -- Western Cape Wasps -- South Africa -- Western Cape Predation (Biology) Climatic changes Biological invasions -- South Africa -- Western Cape DNA barcoding -- Data processing Habitat (Ecology)-- Modification UCTD Molepo, Dikobe Karen Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa |
| title | Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa |
| title_full | Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa |
| title_fullStr | Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa |
| title_full_unstemmed | Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa |
| title_short | Integrating DNA barcoding, bioclimatic modelling, and habitat analysis to assess the diet and potential spread of Vespula germanica (Fabricius, 1793) in the Western Cape of South Africa |
| title_sort | integrating dna barcoding bioclimatic modelling and habitat analysis to assess the diet and potential spread of vespula germanica fabricius 1793 in the western cape of south africa |
| topic | Vespa germanica Introduced organisms -- South Africa -- Western Cape Wasps -- South Africa -- Western Cape Predation (Biology) Climatic changes Biological invasions -- South Africa -- Western Cape DNA barcoding -- Data processing Habitat (Ecology)-- Modification UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/136163 |
| work_keys_str_mv | AT molepodikobekaren integratingdnabarcodingbioclimaticmodellingandhabitatanalysistoassessthedietandpotentialspreadofvespulagermanicafabricius1793inthewesterncapeofsouthafrica |