Another green monster takes over

“Just when we thought we had some breathing room, common salvinia is back,” the Centre for Biological Control at the Rhodes University said this week.

Salvinia invasion on the dam

“We knew that this would happen once the water hyacinth cover reduced, as this is what happened last year. The common salvinia cover is likely to increase over winter in the absence of water hyacinth to similar levels that we saw last year. The Centre for Biological Control – CBC is working on a biological control agent for the weed, but given our funding issues, we had to put the work on hold, and have not yet completed the testing that we have to do in order to get permission to release it.”

The CBC said the bad news is that because the water quality of the dam remains so very bad, the common salvinia will be a problem throughout this winter. “We do expect another water hyacinth germination event, which appears to then compete with the salvinia, and we have a Master’s student working on understanding the dynamics between these two invasive plants. We are also working very hard with local stakeholders to ensure we have rearing facilities up and running to rear the hopper, Megamelus scutellaris, over winter so that we can introduce them as soon as water hyacinth starts to reappear.”