From the arid expanses of the Outback to the lush, verdant rainforests, Australia's diverse landscapes have long been the battleground against invasive species, from the infamous cane toad to the destructive European rabbit. Today, a new, prickly enemy threatens to reshape Australia's unique ecosystems: the Hudson pear, a cactus species native to Mexico, known colloquially as the 'jumping cactus'.
A Thorny Threat
The Hudson pear, or Cylindropuntia pallida, is a formidable opponent. Towering up to two meters in height and spreading three meters wide, the plant's long, sharp spines, which can reach up to five centimeters, pose a threat to local wildlife, livestock, and humans alike. Calves are prevented from feeding, dogs suffer injuries, and humans find the spines difficult to remove without the aid of pliers. The cactus's rapid proliferation and adaptability have made it a daunting challenge to control, particularly around the Lightning Ridge area in New South Wales, where local councils have dedicated resources to weed eradication.
An Unchecked Invader
While native to Mexico, the Hudson pear's natural predators – moths, flies, and beetles – are absent in Australia, allowing the plant to spread unimpeded. It has become a problem in countries across the globe, from South Africa to Namibia, and now threatens Australia's Western territories, Queensland, the Northern Territory, and the ranges around Adelaide.
Efforts to control the spread of the Hudson pear have ranged from herbicide sprays to the introduction of a natural predator, the cochineal bug. Native to Mexico and South America, the cochineal bug drains the cactus of nutrients, aiding in its control. Yet, heavy rains in 2021 and 2022 washed the bugs off the plants, hampering the effectiveness of this biocontrol method.
The Battle Continues
In response to the growing threat, the Australian government has allocated significant funds, including a 2.6 million Hudson Pear Control Program. The program plans to reintroduce the cochineal bug, provide free spray for landholders, and oversee the program until 2027. However, some locals have lost faith in the biocontrol method, advocating for more extreme measures, such as flamethrowers or napalm.
The Hudson pear infestation has torn at the fabric of local communities, causing tensions between opal miners and farmers, with miners potentially spreading the cactus while accessing mining claims on farmland. The town of Lightning Ridge, an opal mining hotspot known for its ruggedness and individualism, has become the epicenter of the Hudson pear problem.
As Australia grapples with this tenacious invader, the implications reach far beyond the immediate threat to livestock and wildlife. The Hudson pear's rapid spread and resilience make it a formidable pest, with the potential to reshape Australia's unique ecosystems and the lives of those who call them home.