• Genomic and transcriptomic analysis unveils population evolution and development of pesticide resistance in fall armyworm Spodoptera frugiperda

• Maize Lepidoptera Research at FABI
• Maize Stalk Borer sampling at the University of Limpopo Experimental Farm

My BScHons at Rhodes University: 

I obtained a BSc in Microbiology and Biochemistry in 2017 at Rhodes University. In 2018, I also completed a BScHons in Biotechnology at Rhodes University. My Honours project involved optimising a multiplex PCR assay for use in the detection of two baculoviruses, Cryptophlebia leucotreta granulovirus and Cryptophlebia peltastica nucleopolyhedrovirus, which are being used for the control of the False Codling Moth, Thaumatotibia leucotreta - a huge pest to the South African citrus industry. From this research,  I developed a prototype for a testing kit, which can be used to detect these baculoviruses in the field and within rearing facilities. My honours project inspired me to continue pursuing my studies in agricultural biotechnology.   

My MSc at FABI:

I am now completing my MSc. in Genetics at FABI. I worked on the population genetics of the Fall Armyworm, Spodoptera frugiperda - a polyphagous pest native to the Americas, which has recently invaded Africa. I used microsatellite markers to understand the genetic variation and population structure of the Fall Armyworm in Africa.

Currently, in South Africa, the Fall Armyworm is being controlled by the use of genetically-modified crops. Although resistance by the Fall Armyworm towards GM crops has yet to be identified in South Africa, it may only be a matter of time before this occurs. If deleterious resistance alleles are to arrive in South Africa from the Americas, or if they are to develop through mutation, it is important to understand which regions these traits could spread to, and how rapidly they may spread through populations.

Population genetics could provide insight into the ecological and evolutionary processes of the Fall Armyworm, such as its migratory patterns and mutations, as well as sites of introduction. If this is understood, the necessary control strategies can be implemented to minimise the spread of resistance alleles. 

As part of this project, I also used CRISPR/Cas9 to target specific genes involved in pigmentation and segment formation within S. frugiperda in order to help establish the technology at FABI. Gene-editing of these easily-identifiable phenotypic traits would allow for easier identification of successful alteration. Establishing this technology forms the basis from which we can target other genes in the Fall Armyworm using CRISPR/Cas9. For instance, genes involved in resistance against genetically modified crops could be targeted as part of a control strategy against this pest. We will also be developing a rapid identification protocol for Spodoptera frugiperda, using CRISPR/Cas which will streamline time-consuming identification methods.

I worked under the supervision of Prof. Bernard Slippers and the co-supervision of Prof. Brett Hurley and Prof. Kerstin Krüger. I also work very closely with Ms Phophi Nethononda and Mrs Pfano Mbedzi-Williams, who are both completing their PhDs at FABI, and are involved in projects on the Fall Armyworm and African Maize Stalk Borer at the Lepidopteran rearing facility at FABI. I am honoured and excited to be a part of such a wonderful group of  dynamic and diverse scientists at FABI and look forward to learning and progressing further in this field!

The Grain Research Programme (GRP):

I am currently working as a technical research assistant for the Grain Research Programme (GRP) at FABI. This programme encompasses a group of grain researchers from numerous disciplines and institutes across the country. My work focuses on the monitoring and management of important maize Lepidopteran pests including the African maize stalk borer (Busseola fusca), the Fall Armyworm (Spodoptera frugiperda) and the Spotted Stem Borer (Chilo partellus). As part of this, I conduct various research trips across South Africa, where we collect these species from maize farms and sentinel plots which we have established in key locations. The collected populations are then established as rearing colonies at the FABI Biocontrol Centre, where we are conducting Bt resistance screening trials on these pests.