Invitation to the release of a weevil species to target an invasive alien aquatic plant

The National Research Foundation (NRF), in collaboration with Rhodes University, invites members of the media to the official release of Cyrtobagous salviniae, a weevil species designated for the biological control of an invasive alien aquatic plant which poses a significant threat to South Africa’s freshwater ecosystems.

The DSTI/NRF-SAIAB SARChI Chair in Biological Control and Freshwater Alien Invasive Species Management, Professor Julie Coetzee, will be joined by the Deputy Minister of Water and Sanitation, Mr Isaac Sello Seitlholo and South African Institute for Aquatic Biodiversity (NRF-SAIAB) Acting Managing Director, Prof Albert Chikona at the official release event. The event is scheduled to take place on Monday, 17 March, at Mogi Adventures, situated adjacent to the Crocodile River at the inlet to Hartbeespoort Dam.

The Cyrtobagous salviniae will target Salvinia minima, commonly known as common salvinia, an invasive alien aquatic plant native to South America that presents a substantial threat to South Africa’s freshwater ecosystems. Initially recorded at Hartbeespoort Dam in 2011, the species has since spread across various water bodies in the North West and Gauteng provinces and has extended its range to the Limpopo River, which forms the national border with Botswana.

Rhodes University’s Centre for Biological Control (CBC), where Prof Coetzee serves as the Deputy Director, has conducted extensive research over several years to evaluate the efficacy of Cyrtobagous salviniae (Florida biotype) as a biological control agent for Salvinia minima. Prof Coetzee is also the Principal Scientist at NRF-SAIAB, leading the development of sustainable management strategies for invasive aquatic species.

Prof Coetzee says, “Looking ahead, the CBC in collaboration with community partners, will rear the weevil and facilitate releases at various sites across the country invaded by common salvinia. Additionally, this biological control programme will be monitored by the CBC to record establishment and progress of the weevil, and its impact on common salvinia.”

Event Details:

• Venue: Mogi Adventures, Crocodile Road, Hartbeespoort. Click here for Google Maps Link
• Date: 17 March 2025
• Time: 10:00 – 13:00

Journalists are requested to confirm their attendance with Bongani Nkosi, NRF Media Relations Officer, via mobile at 061 477 3064 or email at b.nkosi@nrf.ac.za.