Last month, gorse shoot moth larvae was released into Pipers River in an attempt to combat the rapid spread of the weed, which has taken hold of rural properties in recent years.

When the gorse shoot moths come of age, they destroy gorse plantations without affecting the rest of the surrounding ecosystem.

Tamar NRM chief executive Craig Williams said there was no guarantee the insects would destroy Northern gorse plantations completely, but Tamar NRM would monitor the moths' progress.

"It's not a silver bullet, but it's one of the tools available to help get rid of the weed," he said.

"We won't see a noticeable difference for about three to five years, just because it takes that long for the moth to make an impact in an area.

"At the moment, we've done the initial release and we'll monitor those sites year to year.

"We'll go back in a year's time and check. It's a very slow process."

Mr Williams said other strategies were also in place to tackle the weed.

Spider mites are another biological tool being used around the state, and Tamar NRM believes it will be a mix of factors that determine how successful the state is in controlling gorse.

"There are other bio-controllers out there, like the spider mite. It's a combination with other things, along with an integrated land management approach," Mr Williams said.

"Over time, it will all have an influence."

- CHRIS CLARKE