Genetic diversity of edible Lepidoptera in Southern Africa and implications for sustainable use of wild populations

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dc.contributor.advisorVan Asch, Barbaraen_ZA
dc.contributor.advisorVeldtman, Ruanen_ZA
dc.contributor.authorNethavhani, Zwanndaen_ZA
dc.contributor.otherStellenbosch University. Faculty of Agrisciences. Dept. of Genetics.en_ZA
dc.date.accessioned2024-03-04T14:14:25Z
dc.date.accessioned2024-04-26T16:37:58Z
dc.date.available2024-03-04T14:14:25Z
dc.date.available2024-04-26T16:37:58Z
dc.date.issued2024-03
dc.descriptionThesis (PhDAgric)--Stellenbosch University, 2024. en_ZA
dc.description.abstractENGLISH ABSTRACT: The African Saturniidae encompass 400 species, some of which contribute significantly to the nutrition and income of many rural livelihoods across the continent. Due to their significance, species such Gonimbrasia belina are subjected to unregulated harvesting and hostplant destruction which threaten their populations. The taxonomic classification of Saturniidae is challenging, impeding accurate documentation of the biodiversity in this family. Additionally, genetic data that could guide conservation and management efforts of Saturniidae in the wild is largely unavailable. Our study aimed to address these knowledge gaps by pursuing four primary objectives. Firstly, we generated DNA barcode (COX1) data for 17 species to contribute to cataloguing the biodiversity of African Saturniidae. The genetic diversity of 170 specimens representing 17 species across 12 genera was assessed in the context of 1586 DNA barcodes publicly available for those genera. Results show that the current taxonomy of African Saturniidae for the 12 genera is affected by taxonomic inconsistencies and clerical errors resulting in 56% of cases of non-monophyly. Integrating alpha taxonomy and genetic data resolved 87% of these cases, thus demonstrating the importance of combining the two disciplines. Secondly, in the context of the mitochondrial phylogeny of the family, Africa was represented by only two species (Gonimbrasia belina and Gynanisa maja), a small number relative to the Asian counterparts. We generated complete mitochondrial genomes for 12 African Saturniidae from five tribes, including the first representatives of the tribes Eochroini and Micragonini. We performed comparative mitogenomics and phylogenetic reconstruction of the family, which strongly supported the monophyletic tribal structure in Attacini, Bunaeini, Micragonini and Saturniini, the sister relationship between Saturniini and Attacini, and the placement of Eochroa trimenii in the tribe Eochroini. Thirdly, despite the extensive harvesting of edible caterpillars of Saturniidae across southern Africa, genetic data for informing conservation and management of these species is largely lacking. We assessed the phylogeography, genetic diversity and historical demography of Gynanisa maja in northwestern Namibia based on sequence data for the standard DNA barcoding region (COX1) and two mitochondrial polymorphic (ND6 and Cytb). This baseline data showed that Gy. maja in northwestern Namibia is genetically diverse and panmictic, indicating healthy levels of genetic diversity and demographic status. Lastly, we evaluated the phylogeography, genetic diversity and demographics of Gonimbrasia belina using a multi-marker approach (mitochondrial sequences and nuclear RADseq data). Gonimbrasia belina exhibited high overall genetic diversity and showed large scale phylogeographical structure between Namibia and the South Africa/Botswana region. Some level phylogeographic structure was also apparent at the fine scale, with a large proportion of haplotypes exclusive to Botswana or South Africa, and shared haplotypes present at the border between the two countries. Furthermore, G. belina showed signs of strong population structure, low genetic diversity, small effective population size and recent bottlenecks across individual sampling sites in Botswana and South Africa, raising conservation concerns. Overall, our study offers important baseline contributions for species identification, genetic characterization, and conservation strategies of African Saturniidae, particular the edible species G. belina and Gy. maja.en_ZA
dc.description.versionDoctorateen_ZA
dc.format.extent291 pages : illustrations (some color), mapsen_ZA
dc.identifier.urihttps://scholar.sun.ac.za/handle/10019.1/130411
dc.language.isoen_ZAen_ZA
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch Universityen_ZA
dc.rights.holderStellenbosch Universityen_ZA
dc.subject.lcshEdible insects -- Africa, Southern en_ZA
dc.subject.lcshSaturniidae -- Africa -- Classificationen_ZA
dc.subject.lcshInsects -- Phylogeny -- Molecular aspectsen_ZA
dc.subject.lcshDNA -- Geneticsen_ZA
dc.subject.lcshPhylogeography -- Africa, Southernen_ZA
dc.subject.lcshLepidoptera -- Genetic aspectsen_ZA
dc.subject.lcshSpecies diversityen_ZA
dc.subject.nameUCTDen_ZA
dc.titleGenetic diversity of edible Lepidoptera in Southern Africa and implications for sustainable use of wild populationsen_ZA
dc.typeThesisen_ZA
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