Identification, distribution, and genetic diversity of olive lace bugs and olive flea beetles in the Western Cape province of South Africa

Date
2021-12
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: South Africa is a minor contributor to the olive industry globally. However, that has not stopped the country from making a mark in the industry by achieving several awards for producing the world’s finest olive oil. Although the production of olives in South Africa is still new compared to Europe, it has created employment for many and has alleviated poverty in surrounding communities. The production of olives has its fair share of challenges, which include stress from insect pests and diseases. Olive lace bugs and olive flea beetles are considered pests of the olive industry in South Africa, but little is known about these pests and their impact on the production of olives. The similarity between wild African olive trees and cultivated olive suggests that these pests, along with other species associated with olives, jumped from wild olive trees to cultivated olive trees. The study aimed to contribute to the catalogue of entomofauna associated with wild and cultivated olives in South Africa by identifying olive lace bug and olive flea beetle species using morphological and DNA-based methods in which four olive lace bug species (Cysteochila lineata, Neoplerochila paliatseasi, Neoplerochila sp., and Plerochila australis) and two olive flea beetles (Argopistes capensis and Argopistes sexvitattus) were identified. Phylogenetic analyses and estimates of intra- and inter-specific genetic divergences were determined using novel and publicly available DNA barcodes for the family Tingidae for olive lace bugs, and the tribe Alticini for olive flea beetles. Novel mitochondrial genomes for olive lace bugs and olive flea beetles were generated and the phylogenetic position of olive lace bugs and olive flea beetles within their respective family or tribe. In addition, a survey was conducted for the purpose of identifying olive lace bug and olive flea beetle species distributed in olive orchards farms in the Western Cape. Phylogenetic analysis and genetic divergence supported the morphological identification of olive lace bugs and olive flea beetles. The complete mitogenomes of olive lace bugs and olive flea beetle species in South Africa were sequenced. The phylogenetic position of olive lace bugs and olive flea beetles was inferred in context of other complete and partial mitogenomes available within their family/tribe. The four olive lace bugs and two olive flea beetles formed clusters of closely related species in their respective phylogenetic trees. These results show that the group of olive lace bugs and the group of olive flea beetles have a recent common mitochondrial ancestor and indicate that adaptation to feeding on Olea may have a common ancestral evolutionary origin.
AFRIKAANSE OPSOMMING: Suid Afrika lewer wêreldwyd 'n geringe bydrae tot die olyfbedryf. Dit het die land egter nie gekeer om 'n merk in die bedryf te maak deur verskeie toekennings te behaal vir die vervaardiging van die beste olyfolie in die wêreld nie. Alhoewel die produksie van olywe in Suid -Afrika nog nuut is in vergelyking met Europa, het dit vir baie werksgeleenthede geskep en armoede in omliggende gemeenskappe verlig. Die produksie van olywe het baie uitdagings wat stres van insekplae en siektes insluit. Olyf kantgoggas en olyf vlooikewers word beskou as plae in die olyfbedryf in Suid Afrika; min is egter bekend oor hierdie plae en die impak daarvan op die produksie van olywe. Die ooreenkoms tussen die wilde Afrika-olyfbome en gekweekte olyf dui daarop dat hierdie plae saam met ander spesies wat met olywe verband hou, van wilde olyfbome na gekweekte olyfbome spring. Die doel van die studie was om by te dra tot die katalogus van entomofauna wat verband hou met wilde en gekweekte olywe in Suid Afrika deur die identiteit en die bevestiging van die identiteit van die olyf kantgoggas en die olyf vlooikewer te identifiseer en te bevestig met behulp van morfologiese en DNS-gebaseerde metodes waarin vier olyf kantgoggas (Cysteochila lineata, Neoplerochila paliatseasi, Neoplerochila sp. en Plerochila australis) en twee olyf vlooikruie (Argopistes capensis en Argopistes sexvitattus) geïdentifiseer is. Filogenetiese ontledings en ramings van intra- en interspesifieke genetiese afwykings is bepaal met behulp van nuwe en in die openbaar beskikbare DNS-strepieskodes vir die familie Tingidae vir die olyf kantgogga, en die stam Alticini vir olyf vlooikewers. Nuwe mitochondriale genome vir olyfkantbesies en olyfvlooikewers is gegenereer en die filogenetiese posisie van olyfkantbesies en olyfvlooikewers binne hul onderskeie familie of stam. Daarby, is 'n opname gedoen met die oog op die identifisering van spesies van olyf kantgogga en olyf vlooikewers wat op olyfboorde in die Wes Kaap provinsie versprei word. Filogenetiese groepering en p-afstande ondersteun die morfologiese identifikasie van olyf kantgogga en olyf vlooikewers. Die volledige mitogenome van olyf kantgogga en spesies olyf vlooikewer in Suid Afrika is opgestel. Die filogenetiese posisie van olyf kantgogga en olyf vlooikewers is afgelei in verband met ander volledige en gedeeltelike mitogenome wat binne hul familie/stam beskikbaar is. Die vier olyf kantgoggas en twee olyf vlooikewers het 'n groep naverwante spesies in hul onderskeie filogenetiese bome gevorm. Hierdie resultate toon aan dat die groep olyf kantgogga en die groep olyf vlooikewers 'n onlangse algemene mitochondriale voorouer het en dui aan dat aanpassing by die voeding van Olea 'n gemeenskaplike evolusionêre oorsprong kan hê.
Description
Thesis (MScAgric)--Stellenbosch University, 2021.
Keywords
Mitogenomics, Olive industry and trade -- South Africa -- Western Cape, DNA barcoding, Olive -- Diseases and pests -- Identification, UCTD
Citation