The NSW Government is unleashing biological control agents to help manage outbreaks of invasive weeds across reserves in Far West NSW.
Crown Lands has been propagating cochineal, a tiny scale insect, to attack invasive cactus species, including Hudson pear, common pear and devil’s rope in the Cobar, Walgett and Wentworth districts.
Cochineal insects, native to South and North America, are effective in controlling the various cactus species.
At a trial at Tallebung Reserve, near Condobolin, a colony of the cochineal species (Dactylopius tomentosus) has eliminated about 90 per cent of a large outbreak of devil’s rope (Cylindropuntia imbricata), which if left untreated can form dense thickets that impact agriculture, hinder livestock, compete with native vegetation, and have sharp spines that can harm people, livestock, and wildlife.
Hudson pear (Cylindropuntia pallida), Common prickly pear (Opuntia stricta) and devil’s rope weeds are extremely prickly cacti that spread easily and have similar impacts on the health and use of land.
Releasing cochineal onto these weeds has proven to be an effective control treatment, especially in difficult to reach and environmentally sensitive areas.
Supporting chemical treatment, biological control is a long-term, environmentally friendly strategy which is less expensive than chemicals. The insects self-propagate, attaching to nearby cactus plants, killing off large swathes of plants.
Due to the size of most cactus outbreaks, cochineal colonies alone will not eradicate infestations but can reduce their size considerably ensuring weed control programs are manageable and effective.
