The funds for controlling hyacinth on the Hartbeespoort has run out and the Centre for Biological Control at the Rhodes Unversity on Friday had to let go of its mass rearing team.
“We are now relying on our students volunteering their time to maintain the mass rearing facility, and collect agents for release. Our funding is running dry but we are still determined to carry on with our work at Harties.
The most work that needs to be done is rearing and releasing Megamelus scutellaris against water hyacinth,” the CBC said.
The CBC received R22 million for aquatic weed research from the Department of Forestry, Fisheries and Environment (DFFE) for 4 years, from 2018-2021, allowing the CBC to, free of charge: Consult on invasive aquatic plant management Provide biological control agents Set up insect rearing stations Research new agents Conduct post release evaluations Build capacity – students, scholars, courses Conduct community engagement and public relation activities
However, funding which should have come into place on 1 April 2021 has not yet been awarded for the next cycle.
Research and implementation of water weed biological control at Hartbeespoort Dam has cost the CBC approximately R1.8 million per year. This includes salaries, operation and running costs, rearing tunnels, quarantine facilities and rearing of the bugs.
“We have a successful track record of controlling water hyacinth on the dam, since we initiated a mass rearing campaign in 2018. The water hyacinth hopper, Megamelus scutellaris, is our silver bullet for water hyacinth control, and we continue to mass rear it for release when water hyacinth comes back in summer. Since the collapse of water hyacinth in early 2021, a new invader has exploded on the dam, common salvinia (Salvinia minima). We are now focusing our research on developing a new biological control agent for common salvinia, which is safe and damaging. The weevil, Cyrtobagous salviniae is successfully used to control common salvinia in the USA. Furthermore, a relative of the common salvinia, Salvinia molesta or Kariba weed, is no longer a problem in South Africa due to biological control. Given these prospects, we are confident that we can get the common salvinia on Harties under control.”