The hunt is on for the invasive weed stevia in the Ravenshoe and Herberton region.

Stevia ovata, or candyleaf, is in flowering season so now (June) is the best time to identify it.

Terrain NRM is working with Tablelands Regional Council on a project to control this weed and to keep it from spreading any further in Australia than the Atherton Tablelands, the only place it has been found.

Flowering season – May-June – easiest time to identify stevia

Terrain’s Evizel Seymour said stevia, which has the potential to compromise grazing land and natural vegetation, is controllable if everyone works together.

“Research has shown the seed only lives for 18 months and is not as mobile as something like Siam weed,’’ she said. “It was first found in this region in 2007. The growing season is February to May with a flowering season from the end of May through June.

A controllable weed if everyone works together

“We know this is one of the weeds we can get on top of. The best time to control stevia is before it flowers but identifying it is the first step to controlling it.”

Terrain NRM secured funding through the Queensland Government’s Queensland Feral Pest Initiative to follow on from earlier stevia control work by partnering with Tablelands Regional Council to work with landholders and others including Ergon Energy, Powerlink, Clean Co and the Queensland Parks and Wildlife Service.

Control work, with herbicides, is reducing the size of outbreaks on private and public land.

“Getting to stevia before it flowers and sets seeds means there is no seed bank for the future,’’ Evizel said. “By July to August the top of the plant dies off naturally but the bottom can re-shoot with moisture and the problem continues unless it is being controlled.”

Weed warriors are gaining ground on a major threat to the Mossman Gorge area’s world-heritage rainforest.

What is hiptage?

Hiptage is an invasive weed that’s smothering rainforest north of Cairns – and this vine from eastern India and south-east Asia grows so well in the Wet Tropics region that its sheer weight can bring down trees.

Work crews from Douglas Shire Council and the Queensland Parks and Wildlife Service have been targeting the species for almost two decades, with council crews recently extending into new territory for this project thanks to funding from natural resource management organisation Terrain NRM.

Douglas Shire’s Biosecurity Team Leader Brad Everett said crews were hiking up rainforest gullies on a hill known as ‘ground zero’. They take chainsaws, hand saws, secateurs and knapsack sprayers.

“It’s hard work. The whole north side of Butcher’s Hill is infested,’’ he said. “But it’s rewarding work too. We had spots we’d take people, to show them just how bad hiptage gets, where the vine was almost impenetrable.

“Now we go back in there for follow-up work on a biannual basis and there are a few vines and seedlings. The native forest is getting a chance to regenerate and self-seed.”

Where is hiptage found?

Hiptage exists in a 60-hectare section of the Mossman River catchment, with Tara Hills identified as the core infestation area and the gateway for Mossman Gorge National Park infestations.

Tiny beetles could be the answer to an invasive weed that has been found in the Tablelands, Kuranda and Cairns regions.

Terrain NRM and Biosecurity Queensland recently released leaf-mining jewel beetles near Atherton to see if they can stop the spread of cat’s claw creeper – a weed that smothers rainforest and changes the chemistry of soils.

Cat’s claw was introduced to Australia as an ornamental plant. Its spread began in the 1950s and it has since been found from Sydney to Cooktown.

Terrain NRM’s Regional Agricultural Landcare Facilitator Evizel Seymour said a biological control trial using leaf-mining jewel beetles had begun along Priors Creek near Atherton.

She said 1500 beetles were released at three sites.

“If these beetles establish themselves there, the plan is to use these spots as a nursery and release beetles at other known cat’s claw creeper sites on the Atherton Tablelands,’’ Ms Seymour said.

Leaf-mining beetles and their larvae feed on the creeper’s leaves. The South American beetle was introduced to Australia as a biological control in 2012 and is considered a “proven bio-control agent”. Its effectiveness hasn’t been tested yet in Far North Queensland, where there are smaller infestations of cat’s claw creeper.

Ms Seymour encouraged Far Northerners to keep a look-out for cat’s claw.

The creeper has woody climbing stems that cling to tree trunks and it competes with native plants and trees by forming a dense above-ground mat as well as underground reproductive tubers. Its many seeds are spread by the wind and water. Cat’s claw has a yellow flower.