Insects have crawled under doctor’s skin

Dr Nomakholwa Stokwe holds up a bottle of nematodes that are being studied in the hopes that these will help control insect pests.

When Kraaifontein resident Dr Nomakholwa Stokwe matriculated, she had no idea that insects or nematodes could actually be a field of study, let alone a career choice.

This all changed when she started her BSc degree at Fort Hare University, and insects crawled under her skin and became her passion.

These days the 32-year-old lecturer at Stellenbosch University researches natural ways by which to control insect pests such as woolly apple aphids and mealybugs that give fruit producers their fair share of headaches.

Last year she was named as one of the 22 young researchers from across Africa who were part of the 2017 intake of African Academy of Science affiliates.

The AAS Affiliates Programme aims to further the professional growth of young and early-to-mid career professionals and to help them develop into research leaders.

The opportunity stretches into 2021.

In the past few months she has been finding her feet as a lecturer, since being appointed to the staff of Stellenbosch University’s Department of Conservation Ecology and Entomology in August 2016.

As a member of the Department’s Integrated Pest Management research team, she now finds herself among many of her postgraduate lecturers who had helped develop her into an entomologist with a keen interest in nematology (the study of soil-living roundworms).

Previously she worked as a researcher of the Agricultural Research Council at Infruitec Nietvoorbij in Stellenbosch.

There Dr Stokwe was among others responsible for managing projects related to integrated pest management research.

During this time, she also completed her PhD in Entomology.

She studied whether nematodes and fungi that can parasitize on woolly apple aphids (Eriosoma lanigerum) and therefore help to control this pest in South Africa.

These 2mm small insects originated in North America. The management of this pest primarily entails the use of resistant rootstocks, chemical and biological control, or the integration of all three strategies.

There is not yet a one-size-fits-all approach for producers to take.

“They are also called American blight or plant louse of apple,” says Dr Stokwe.

“These insects are now found worldwide in all apple-producing countries, and have been around in South Africa since at least the late 1890s.”

In a recent review article in the journal, African Entomology, that she co-authored with Dr Antoinette Malan, Dr Stokwe states that these insects pose a major threat to apple production in South Africa.

“The aphid forms densely packed colonies covered with white, waxy, filamentous secretions, on the above-ground parts and on the roots of apple trees.”

During the course of her MSc degree studies at Stellenbosch University on biological ways to control the obscure mealybug (Pseudococcus Viburni), she also discovered a new species of nematode found in the soil.

More than 50 nominees were received for the African Academy of Science’s Affiliate Programme’s 2017 intake, from which four representatives from Southern Africa were chosen. Among the AAS 2017-2021 affiliates are also exceptional young scholars from Benin, Cameroon, Egypt, Ghana, Kenya, Morocco, Nigeria, Tanzania, Tunisia, Ugan da and Zambia.

Dr Wesley Doorsamy of the University of Johannesburg’s Department of Engineering Technology and Applied Sciences is the other representative from South Africa.