GRDC and partners tackle snail project

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

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

In addition, 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.

Lead researcher from the University of Adelaide/SARDI Kym Perry said snail management had 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.

Dr Perry said Mediterranean snails created substantial costs for affected growers and reputational risks for Australian grain that could affect international trade.

"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," Dr Perry said.

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.

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Dr Perry said the project would examine a range of physical, cultural, chemical, and biological tools and technologies with a view to expanding graingrowers' toolkits to combat these pests.

"This project is tackling the snail problem from multiple angles, combining technology development with biological research to inform control and deliver an integrated package of new outputs," he said.

"We have assembled an exciting multi-disciplinary research team to deliver the various components."

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

Additionally, they want to know more about where in paddocks snails reside at key times of year and when controls targeting snails above ground level are typically applied, so that they can adjust or design new tactics accordingly.

The work will also explore the efficacy and cost-benefit ratio of existing snail control tactics, by looking at how well snail populations can bounce back from low numbers.

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

"We hope these technologies will become new tools for monitoring snail activity and densities in near real-time, so that growers can more effectively target their control," Dr Perry said.

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 WA for the first time to help suppress conical snails.

The fly Sarcophaga villeneuveana attacks conical and small pointed snails that are greater than five millimetres in size and requires flowering vegetation to flourish.

Researchers will establish a local breeding population of the fly in WA this summer, following successful work with the same species in South Australia.

GRDC manager - pests Leigh Nelson said snails were highly disruptive and costly for graingrowers 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.

"This investment will develop an integrated package of new biological knowledge, surveillance, and control methods, which will become tools to assist growers to better manage snails on farm."

The project is supported by an advisory group, including direct input from growers, which will help guide planned research and outputs to ensure recommendations can be adopted by growers and identify opportunities to partner with industry.

The project will run until 2026, with extension materials including newsletters and podcasts planned from 2023 onwards.