Weedbusting Weevils to the Rescue

The mission to rid the coast of the waterweed Salvinia molesta continues with the help of a tiny weevil as part of Landcare Week this week.

With the warmer weather approaching, Maroochy Waterwatch will again be helping dozens of landowners in the coming months to fight the spread of salvinia that is choking waterbodies around the coast.

A tiny weevil known as Cyrtobagous salviniae, will be set free on salvinia infestations and monitored closely to determine the beetles success rate at reducing the plant mass.

Cerran Fawns, Manager of Maroochy Waterwatch said, "We used the weevil earlier this year on a number of properties across the coast, with mixed success."

"This time around we have the ability to start the project four months earlier in the hope of increasing the likelihood of sustainable weed control for each waterbody."

Salvinia weed is a weed of National Significance due to its invasiveness, potential to spread and has severe environmental, economic and social impacts.

Ms Fawns added, "Salvinia weed grows rapidly forming thick mats which cover and choke lakes, slow-moving rivers and other waterways. The mats shade out any submerged plant life and impede on oxygen exchange, making the water unsuitable for fish and other animals. The infestation also spoils the natural beauty of a once free flowing water body".

The weevil larvae feed inside the stems, and adults on the buds, eventually destroying the plant and causing the mats to sink. They are safe to use and have been used on Salvinia control for over 30 years.

"Our plan is to work with landowners who have salvinia on their property, by releasing small weevil populations and performing monthly monitoring, looking for the presence of beetles and the amount of damage caused to the weed," she added.

The weevil control is effective however it does not produce instant effects. The beetles need time and favourable conditions to build up populations that will reduce an infestation. The entire process generally takes between one and three years to completely control an infestation.

The program is supported by the Sunshine Coast Regional Council.

Anyone interested in being part of the control program should phone Maroochy Waterwatch on 5476 4777 to register their interest.

Maroochy Waterwatch
6th September 2010

Permanent Link: Weedbusting Weevils to the Rescue
Publish Date: 09 Sep 10