Scientists Prepare Fungal Biocontrol to Combat Australia's Invasive Lantana Weed

Scientists are preparing to release a plant pathogen, Puccinia lantanae, to combat Lantana camara, a noxious weed in Australia. Lantana camara, introduced in the 1840s, now infests about 5 million hectares, smothering native habitats and harming livestock. The rust weakens the weed by damaging its leaves and stems, with final government approval pending for its release.

Under strict biosecurity measures in Brisbane, scientists are cultivating Puccinia lantanae, a fungal biocontrol agent, in a laboratory. This imported plant pathogen is one approval away from being deployed against Lantana camara, considered one of Australia's most problematic weeds. The rust works by infecting the weed's leaves, shoot tips, and stems, causing dead tissue spots and stem dieback.

Lantana camara, a poisonous and prolific flowering shrub originally from the Americas, was introduced to Australia in the 1840s. It has since escaped cultivation and spread across approximately 5 million hectares of land in New South Wales, Queensland, Victoria, Western Australia, and the Northern Territory. The plant forms dense thickets that overwhelm native vegetation, can poison livestock unfamiliar with its toxicity, and acts as dangerous fuel for bushfires.

Beyond herbicides and manual removal, Australia has previously imported and released over 30 biological controls for lantana since 1914, with 17 becoming established. However, seed dispersal by birds and the sensitivity of insect biocontrols to seasonal conditions have not kept pace with the weed's spread. A 2007 report estimated that lantana cost the grazing industry alone over $100 million annually in lost productivity. Weeds Australia also warns that all parts of the plant are poisonous to humans, potentially causing severe symptoms and even death.

In April, federal authorities recommended approving the Queensland Department of Primary Industries' application to release the South American blister-leaf rust. Scientist Jason Callander expressed optimism, stating, "We're really optimistic that it's going to get in and be very damaging to the young plants, to the regrowth, to the seedlings." The team has submitted a "release from quarantine protocol" request, awaiting the final approval from the federal government's plant imports operations team to commence the program.

“

We're really optimistic that it's going to get in and be very damaging to the young plants, to the regrowth, to the seedlings.