Invasive white Italian snails in Australia are using mutated mucus enzymes to withstand pesticides, posing a growing threat to the country’s agriculture, a new study has revealed.
Researchers from the University of the Sunshine Coast (UniSC) discovered that trails left by the white Italian snail Theba pisana contained high levels of an enzyme capable of neutralising pesticide toxins, effectively making the pests resistant to conventional control methods.
“This mutated enzyme has previously been found in insects like ticks and flies that developed chemical resistance over time,” said UniSC PhD researcher and lead author Inali Lutschini. “Its abundance in land snails, however, was unexpected.”
Co-author Prof. Scott Cummins, a functional genomics expert at UniSC, said the team is now working on ways to use the discovery to design better control strategies and reduce reliance on organophosphate pesticides, which can harm the environment and non-target species.
According to Cummins, the snails secrete the enzyme in large amounts through their slime, particularly during mating when they are most vulnerable. This secretion acts as a protective barrier against pesticides.
Invasive snails are a global problem, causing severe economic losses. In Australia alone, they cost the grain industry an estimated AUD 170 million (USD 109 million) each year.
Theba pisana, which has spread across southern Australia since the early 20th century, is small but reproduces rapidly, worsening the challenge.
The findings, published in the international science journal PLOS One, underscore the snails’ growing resistance to molluscicides. Researchers now hope alternative measures — including biological or gene-based controls, such as deploying spider venoms from species that prey on snails — could provide long-term solutions.
“Our research suggests that rotating different types of pesticides may be more effective than simply increasing concentrations,” Lutschini said. “Snails can evolve defence mechanisms quickly, so we need smarter, more adaptable approaches.”
(dpa)