A double celebration for Agil as she completes her PhD 2021-12-03
It was a double celebration for Agil Katumanyane when she successfully defended het PhD on 30 November as she had also received the L’Oréal-UNESCO For Women in Science Award for Sub-Saharan Africa Young Talents at an awards ceremony in Kigali, Rwanda on 25 November. Her Prestige Seminar “Entomopathogenic nematode interactions with white grubs from forest and sugarcane plantations” was presented as a hybrid online event. Agil’s degree was completed under the supervision of Prof.Brett Hurley, Prof. Bernard Slippers, Dr Mesfin Gossa and Prof. Antoinette Malan of Stellenbosch University. The external examiners for her thesis were Prof. Mary Barbercheck from Penn State University (USA) and Prof. Mieke Daneel of the ARC, Tropical and Subtropical Crops division in South Africa while Prof. Fanus Venter was the internal examiner.
Brett praised her tenacity and courage in completing a challenging PhD that has made a massive contribution in Africa and globally. He also thanked her for the massive contribution she has made to FABI during this time.
Agil’s study focused on the interactions of entomopathogenic nematodes (EPNs) with white grubs, to evaluate the use of these nematodes as biological control agents in forestry and agricultural systems. In South Africa, white grubs are important pests of sugarcane and wattle. There is need for a sustainable management alternative since their control has mainly been through the use of chemical insecticides. EPNs offer a viable alternative as the literature shows them providing a higher percentage control of white grubs, when compared to chemical insecticides. Locally isolated EPNs are better adapted to local environmental conditions with a greater expected success in combatting white grubs.
Agil examined EPN associations with white grubs collected from wattle and sugarcane plantations in the Mpumalanga and KwaZulu-Natal provinces of South Africa. Using bioassays, EPN pathogenicity towards white grubs as well as the white grub resistance mechanisms to EPN infection were evaluated using eleven locally isolated EPNs. The results indicated that the mortality percentage of the white grubs varied significantly but was low for most of the EPN species tested, except for the EPN Heterorhabditis zealandica MJ2C.
This study is the first report of locally occurring EPNs found naturally associated with white grub species in South Africa and this project also resulted in the description of a new EPN species from South Africa, described as Steinernema bertusi Katumanyane, Malan, Tiedt & Hurley (Rhabditida: Steinernematidae). The newly described EPN species was the fifth species to be included in the Cameroonense-clade, the 12th Steinernema species described from South Africa, of which only 100 species are currently described in the world.