“We did tests where we placed the weevil near both cabomba and other similar Australian plants, and the weevil only ate the cabomba.”
After being convinced that the weevil itself will not become a pest, scientists have now released them into Lake Kurwongbah, a small artificial lake in the Moreton Bay region used for recreation and additional drinking water supply.
David Roberts, senior researcher at Seqwater, said the weed had caused significant problems over the years and they were glad they finally had something to address it head on.
“Cabomba is so thick that recreational activities such as swimming, fishing and canoeing are both difficult and dangerous,” he said.
“The weeds also reduce the water holding capacity of dams and contribute significantly to the cost of drinking water treatment.”
The weevil is not expected to completely eradicate cabomba, but it is expected to significantly control its spread, eliminating many of the problems associated with it.
Removing cabomba is also expected to help native wildlife, with platypus and water rats recording lower populations in areas where cabomba had taken over.
Seqwater has also established a weevil “nursery” at Lake Kurwongbah to continue supplying weevils for future releases.
Nagalingam said releases were planned for Lake Macdonald, near Noosa, and could potentially be expanded to releases in central Queensland, northern NSW and some locations in the Northern Territory.
“It’s been great working with Seqwater to help us develop natural solutions to problems like invasive weeds,” he said.