Notorious tiger pear cactus targeted in biological operation

The operation involves introducing a sap-sucking insect, cochineal (Dactylopius austrinus), to manage an invasive cactus species known as tiger pear (Opuntia aurantiaca), a South American native believed to have been introduced in the late 1800s.

The Central West is a hot spot for tiger pear, which is a low-spreading cactus with sharp, barbed spines that can injure people and animals, and in extreme cases render areas of farmland inaccessible.

WaterNSW, in collaboration with the Department of Primary Industry and Regional Development (DPIRD) Weeds Research Unit, and their biocontrol rearing facilities in Orange, will release the tiger pear cochineal insect over 4,000 hectares of WaterNSW land around Burrendong Dam from 25 November.

The release of the tiger pear cochineal involves introducing tiger pear cladodes, or plant segments,  infected with cochineal into affected areas to manage the cactus infestation in an environmentally-friendly and self-sustaining manner, without using herbicides.

Tiger pear spines are strong enough to pierce heavy work boots and very difficult to extract. The presence of tiger pear in large infestations poses a potential risk to campers, domestic animals and native fauna. The spines are not only painful, but are difficult to remove, and animals may get them stuck in their mouths in attempting to do so.

The three-day operation will  involve local landholders who lease WaterNSW land, along with weed control staff from neighbouring local councils, according to WaterNSW Executive Manager Operations, Ronan Magaharan.

“As responsible land managers and good neighbours, WaterNSW is using biocontrol as an effective, low-cost environmentally-friendly tactic for weed control measures,” Mr Magaharan said. “By using cochineal, we are not only reducing chemical use, but also working towards a long-term solution that benefits both the environment and the communities that rely on these landscapes.

“Biocontrol ensures sustainable management of tiger pear, allowing landholders to focus on other aspects of land productivity and reducing herbicide treatments to manage tiger pear.

“This collaboration with DPIRD’s Weeds Research Unit, and their biocontrol rearing facilities in Orange, demonstrates WaterNSW’s ongoing commitment to adopting research-backed, innovative solutions for weed control, working in conjunction with state partners to deliver results.”