A SMALL beetle could be the answer to controlling an exotic weed damaging native vegetation in riparian, rainforest and other natural areas along the east coast.
Biosecurity Queensland general manager for invasive plants and animals, Dr Gabrielle Vivian-Smith, said efforts between the Department of Em-ployment, Economic Development and Innovation (DEEDI) and overseas authorities, with funding from local councils and state governments, had resulted in the discovery, collection, quarantine and release of the South American beetle.
"The beetle feeds on madeira vine leaves. It is expected it will defoliate the vine, which means the vine will be less competitive against other plants," Dr Vivian-Smith said.
"Biosecurity Queen-sland first released the beetle in May this year and so far it has been successful with early in dications showing severe damage to leaves on the Madeira vine and egg batches being laid."
Further releases had been made at Kenmore, Upper Brookfield, Sherwood and Numin-bah Valley. Beetles have also been sent to NSW to start a breeding pro-gram there.
The South American madeira vine (Anredera cordifolia) smothers and destroys trees and shrubs by growing over the top of them and causing them to collapse.
It spreads rapidly into new areas and produces thousands of small potato-like tubers along its stems which fall to the ground and sprout.
Madeira vine has been nominated for consideration as a Weed of National Significance to recognise its threat.
Dr Vivian-Smith said regular hand-pulling and herbicide applications had been the only control options so far, but they were ineffective and costly.
She said herbicide use was also problematic in sensitive natural areas and near creeks where madeira vine was often found.
"The beetle is a sustainable, safe alternative to control the weed and has been tested against 37 closely related plant species.
"It could only breed on madeira vine and did not harm any non-target plants," she said.
Over the next two years, authorities aim to release the beetle in batches of 100 to 500 throughout the whole area infested with madeira vine.
The madeira vine has distinct wide, fleshy light green heart-shaped leaves about 4-5cm long.
It produces dense blankets of creamy flower spikes resembling a lamb tails, between December to April. The vine is declared as a Class 3 species under the Land Protection (Pest and Stock Route Management) Act 2002.
The release of the beetle was approved by the Australian Quarantine and Inspection Service and the Department of Sustainability, Environment, Water, Population and Communities this year.
Dr Vivian-Smith said Biosecurity Queensland would monitor the beetle's effectiveness over several years.
