The hunt for a natural predator to take down a rampant cactus in western NSW is over.
After years of research and breeding, biocontrol experts are ready to release a tiny insect to destroy the thorny Hudson pear near Lightning Ridge.
Landcare cactus coordinator Jo-Anna Skewes said the tiny insect, Dactylopius tomentosus, belonged to the cochineal family.
"Our trial work shows the insect distributes really well in the wind, which is what we want to see," Ms Skews said.
In recent years the cactus has spread to completely blanket 100,000 hectares of grazing land in the area, rendering it unusable for pastoral activity.
If left unchecked the cactus could take over 300,000ha of the Murray-Darling basin within the next 10 years.
"It's very brittle and segments fall off the parent plant easily and re-root wherever they fall," she said.
Driven cactus mad at Cumborah
Land manager Tina Lawrence has seen firsthand the destruction wreaked by the Hudson pear — an invasive pest native to Mexico.
A property she manages at Cumborah near Lightning Ridge was once infested by the cactus — it covered 99 per cent of the land mass.
"It was pretty much impassable. You can't run sheep, cattle, or goats on paddocks like that," Ms Lawrence said.
"It's got a hook-shaped barb so you can't pull it out. It gets into animals and maims them."
Since 2017 Ms Lawrence has helped spray chemicals around the region to stop the weed's spread.
Now, help has arrived.
"I've seen the biocontrol working on multiple sites; it's going great guns," she said.
"We're actually running out of patches to spray because the bug is working so well."
Infected cacti ready to go
Landholders battling with the cactus can now register to pick up infested cactus segments, called cladodes, from a facility near Lightning Ridge that was built to mass rear the insects.
Ms Skewes hoped the insect would help landholders reclaim lost ground but said there was more work to be done.
"Biocontrol isn't a silver bullet but it does help us destroy the highly dense areas and hold it where it is," she said.
"Landholders still need to manage outliers, which are causing it to spread."
