Hyacinth cover on the Hartbeespoort Dam is currently about 2% and role players around the dam is doing their utmost to remove the remaining dead plants.
According to Dr. Kelby English of the Centre for Biological Control of the Rhodes University, the hyacinth planthopper count reached about 10000 per m2 on Hartbeespoort Dam. They caused significant damage to the water hyacinth and started swarming lights around the dam in search for more nutritious water hyacinth to eat.
The remaining plants are severely damaged from the biocontrol agents eating them. The plants are brown and in poor condition and currently only cover about 2% of the dam.
“Some plants will remain over winter and they create a safe harbour for some of the biocontrol agents to survive. In spring, seeds in the seedbank (which remain viable for up to 20 years) will germinate. The ten biocontrol rearing stations have begun their preparations for winter and as soon as the water hyacinth starts to regrow in spring, large amounts of the planthoppers will be ready for release,” English said.