An imported weevil released in forestry blocks in the Bay of Plenty several years ago is finally starting to chew its way through a major weed.
The Chinese weevil was released in 2006 by the Crown Research Institute, Scion, as a biological control agent for buddleia.
Buddleia is one of the country's worst forestry weeds, costing the industry about $3 million a year in lost production and control costs.
Scion scientist Michelle Watson says the weevil is finally spreading naturally through the Bay of Plenty, reducing large patches of buddleia to bare stems.
She says the success of the Chinese weevil is good news for other primary groups currently look at using imported biological control agents for other difficult weeds and pests.