White snails infest Nhill farmers' grain, costing thousands

Crop and sheep farmers Mr Pilgrim and Mr Bound are calling on the state government to list a snail species as an invasive pest to help manage its "exploding" population.

The Cernuella spp, also known as the common white snails or vineyard snails, came to Australia in 1923 and is currently growing its population in the Wimmera region.

It is considered a prohibited pest in several export countries including China, Chile and Korea, and GrainCorp are unable to accept grain with the species.

The Catchment and Land Protection Act 1994 is the main article of legislation governing the management of invasive animals and plants, however it does not cover the management of invertebrate animals, including snails.

The Cernuella spp is instead declared a pest under the Plant Biosecurity Act 2010.

Mr Pilgrim said they had struggled to manage the white snail population and growers needed more state support to be able to better manage its numbers.

He said he spent $12,000 two years ago to have his grain cleaned after snails were found in his sample.

"Two years ago I had problems with my canola, I wasn't the only person either, there were lots of farmers in the district in the same predicament," he said.

"They look at the sample, if they find a snail in it - it's gone, you need to take it home.

"It ends up being costly when you freight it back home, you have to pay to clean it and then freight it back again and in that timeframe the price has dropped."

A GrainCorp spokesperson said the company used snail baiting and weed control when needed to help reduce its numbers.

"Each country has a sovereign right to list pests they consider to be of quarantine concern and that they do not want introduced," the spokesperson said.

"Therefore, it is important that the Grain Trade Australia maximum limits in our industry commodity standards are met, to ensure we uphold Australia's strong trading partnerships with the countries we export to, and maintain our reputation for excellent quality management."

Applied malacologist Michael Nash, Adelaide, said the common white snails were causing both economic and ecological issues, and he believed the species should be considered invasive.

"They're an invasive species from a very similar climate to what we have here in Australia," he said.

"They're non-Indigenous, they're overtaking native species that are there and from a biosecurity perspective they're a contaminant in our grain.

"All these snails need to be recognised as pests so we can enforce everybody to actually do something to control them."

Dr Nash said specialists were eager to implement on-farm biosecurity plans to help manage the risk to remnant native vegetation and growers' grain.

He said a standard biosecurity practice to help manage the population included a dedicated 18-month program of site clean ups to remove broadleaf weeds and rubbish, and undertake strong baiting programs in ideal conditions.

"Now there's no roadside control so all these snails have moved out into the paddocks, it's opened the floodgates," he said.

"[Burning] is another tool in the toolbox, it is a solution I think if it was done in a traditionally custodian-sensitive way.

"Fire is a way we maintain these open grassland woodland systems."

Mr Pilgrim, who is the First Lieutenant at the Wyndham Vale Fire Brigade, said he hoped to have permission for safe roadside burning to help reduce the snail population.

"We need to be able to deal with the sides of the road," he said.

"They're just spreading and getting further, which is why we have to keep on top of it.

"None of us have any time, but burning is a very cheap, quick exercise to get rid of them; they can't survive the burn."

Mr Pilgrim and his neighbouring farmers are now gearing up to bait the snails with a new product after recent rains caused ideal baiting conditions.

"This is our biggest rain since harvest, so we'll throw the baits out because they're down and active and ready to feed," he said.

Mr Bound said the snails started populating when they would fall from the nearby trains.

He said their populations grew once the Hindmarsh Shire Council used limestone for its roads as part of a flood recovery more than 10 years ago.

The snails prefer limestone soils because of its calcium content.

"It's the roadsides where we get the ingress from still," he said.

"When you get the government to put the snails on the pest list, it'll cover everyone in Victoria if they have a problem."

An Agriculture Victoria spokesperson said under the Plant Biosecurity Act 2010, landholders were obligated to control declared plant pests on the land they were responsible for.

They said landholders were encouraged to contact the relevant road manager to discuss integrated management of declared pests on roadsides.

Stock & Land contacted Hindmarsh Shire Council about its action on roadside management and whether it would support calls for the species to be listed as an invasive, but the council declined to comment.