Farmers released hundreds of beetles into the Queensland and New South Wales hinterlands today, in a bid to destroy a major weed infested thousands of hectares of pastures and crops.

So far, herbicides have had limited success in curbing the spread of blue heliotrope, and if the beetles are successful, they could save landowners up to A$100,000 (US$50,000) in herbicide control.

The beetles, called Deuterocampta quadrijuga, have been trialled in a contained facility in Canberra over the last year, where researchers from the Commonwealth Scientific & Industrial Research Organisation (CSIRO) tested their effect on other plants.

CSIRO entomology project leader David Briese said in a statement: "This day has been a long time coming […] Ten years ago CSIRO conducted surveys in South America which identified some insect species as potential biological control agents.

"However, at the time blue heliotrope didn't attract sufficient industry funding so no further work was done and the plant continued to spread."