War declared on exotic pests – Researchers on snail trail

A NEW $4.6 million national research project is set to provide Australian grain growers with new tools and management techniques to combat snails.

The aim is to minimise losses and improve market opportunities for affected crops.

Exotic snail species established in Australia as early as the 1920s and have become major pests of grain crops.

In addition to attacking crops, snails climb crop plants in spring and contaminate harvested grain, resulting in substantial management costs, grain yield and value losses, opportunity costs, and market risks.

The four-year project has investment from the Grains Research and Development Corporation and is led by the University of Adelaide in collaboration with the South Australian Research and Development Institute, working with University of South Australia, CSIRO, the Western Australian Department of Primary Industries and Regional Development and other research partners.

Lead researcher from the University of Adelaide, Dr Kym Perry, said that snail management has improved over the years through the concerted efforts of growers, researchers, and funding bodies working together, but snails remain a costly and difficult target for management.

Crop damage, harvest delays, and grain value downgrades at delivery, are common occurrences for growers in affected areas.

“Mediterranean snails create substantial pre- and post-farm gate costs for affected growers and reputational risks for Australian grain that can affect international trade,” Dr Perry said.

“Snails are particularly abundant in some coastal regions but occur in a wide range of cropping environments where they have spread by hitchhiking on vehicles and fodder.”

The project will target four species of Mediterranean pest snails: the vineyard snail, the white Italian snail, the conical snail, and the small pointed snail.

Conical snails are a focus of the project because their habit of sheltering in cryptic places, small size, and large populations, make them particularly difficult for growers to manage using existing control methods.

Dr Perry said the project would examine a range of physical, cultural, chemical, and biological tools and technologies with a view to expanding grain growers’ toolkit to combat these pests.

“Field and laboratory work will investigate the effects of feeding preferences, crop rotations, migration habits, and snail barriers and attractants on snail populations,” Dr Perry said.

Several new prototype technologies for snail monitoring and control are being developed and tested.

In addition, the project will explore tools to assist with the mechanical destruction of snails in paddocks in summer, and electrostatic separation of snails and grain post-harvest.

In the area of biological control, a parasitoid fly will be released in Western Australia for the first time to help suppress conical snails.

GRDC Manager – Pests, Leigh Nelson, said that snails are highly disruptive and costly for grain growers in affected areas, particularly during harvest when grain can be contaminated and cause value downgrades at receival points.

“Despite significant changes in farming practices and technology, it has been more than 20 years since engineering, cultural practices and other technological solutions for snail control have been assessed holistically,” Ms Nelson said.