A recent study has found that invasive white Italian snails in Australia are developing resistance to pesticides thanks to a mutated enzyme found in their mucus, raising concerns for the country’s farming sector.
Researchers at the University of the Sunshine Coast (UniSC) revealed that the Theba pisana species, commonly known as the white Italian snail, secretes an unusually high amount of an enzyme capable of breaking down toxic pesticide compounds. This biochemical adaptation is enabling the snails to withstand conventional pesticide treatments, making them increasingly difficult to control.
Lead researcher and UniSC PhD candidate Inali Lutschini noted that the enzyme is similar to those found in insects such as ticks and flies—species that have also evolved chemical resistance over time. “Finding this enzyme in land snails, and in such abundance, was unexpected,” she said.
Professor Scott Cummins, a co-author of the study and expert in functional genomics at UniSC, said the team is now working on developing alternative control measures to reduce reliance on chemical pesticides, particularly organophosphates, which pose risks to ecosystems and non-target organisms.
Cummins explained that the snails release this enzyme in significant quantities through their slime, especially during their active mating periods. This mucus-based enzyme essentially forms a chemical shield, neutralizing the pesticides meant to eliminate them.
The economic impact of these snails is substantial. In Australia, invasive snail species are estimated to cost the grain industry approximately AUD 170 million (USD 109 million) each year. Theba pisana, which has expanded its presence across southern parts of the country since the early 1900s, is particularly problematic due to its rapid reproductive rate.
The study, published in the international journal PLOS ONE, warns that the snails’ increasing resistance to molluscicides calls for urgent innovation in pest control strategies.
Researchers are now exploring more sustainable alternatives, including gene-based methods and biological controls such as the use of spider venom, since some spider species naturally prey on snails.
“We’re finding that simply increasing pesticide concentrations isn’t a long-term solution,” Lutschini said. “Snails can adapt quickly, so we need more dynamic and intelligent approaches to pest management.”