The cost of a recent fruit fly outbreak in South Australia's Riverland has been estimated by the State Government at $1.7 million, but growers want people to know the cost will be much higher if travellers continue to bring fruit into the region.
The Riverland is one of two internationally-recognised pest-free areas in Australia that support growers with a massive trade advantage when exporting.
In December the town of Loxton had a fruit fly outbreak when seven male Queensland fruit flies were found.
Fifty staff from Primary Industries and Regions (PIRSA) worked for months to clear up the outbreak until last month when quarantines were lifted.
Minister for Primary Industries Tim Whetstone said early estimates of costs to government were $1.7 million, which included strategies to remove the flies.
"It has been quite an extensive campaign, what I would say is that's it been very successful," he said.
The quarantine-free date for the region was pushed back numerous times after flies were discovered, but Mr Whetstone was confident ramped-up biosecurity measures would keep the region pest free.
"We had a number of further of male flies around the Loxton area and what it showed us was there was a large build up of flies in that area," he said.
"We don't know exactly how they [the flies] were introduced, we do have suspicions of contaminated bins coming into the area but that has not been qualified."
During the time of the outbreak Australia's trade partners were watching the region with scrutiny and the Commonwealth Government is yet to reinstate Loxton's pest-free status.
Venus Citrus was one of the biggest exporters in the outbreak zone.
It lost market access to China over the last few months and had extra costs due to further regulation.
"It was purely the end of our season, maybe the impact was $30,000 - $40,000," marketing director Helen Aggeletos said.
Ms Aggeletos said people travelling from the city and across the border needed to understand the importance of the region's pest-free status, which would be impacted by future pest incursions.
"It [the pest free status] can make or break a business. I think that without that status it will probably cost our business over $3 million," she said.
"[You] have to treat the fruit, the impact on the market place, you may lose some markets, also the returns back to the growers would be impacted as well."
Stone fruit grower and Riverland Fruit Fly Committee member Jason Size would be faced with similar challenges.
"For me, for that crop that was destined for export market, it probably wouldn't be viable to grow that product, it just adds a lot of unnecessary cost to a business that they currently don't have," Mr Size said.
Riverland farmers want to stress to people travelling through the region that fruit brought in could lead to future outbreaks, which had high costs to business, industry and the state economy.
The State Government said prior to the recent outbreak, travellers were not taking the region's pest-free status seriously.
"I don't think we saw a decline in the amount of fruit coming into the Riverland or the amount of fruit that was being confiscated," Mr Whetstone said.
Since December the Marshall Government implemented a zero-tolerance approach, including fines of up to $100,000 for people bringing fruit into the area.
Ms Aggeletos said there was a significant strengthening of biosecurity but she was concerned that people in the city needed further education.
"Generally the travellers won't know much about the area," she said.
"We need to have possibly advertisement on television.
"If we have a long weekend coming up or on the Christmas holidays, I think prior to the holiday period, if we go in there and advertise hard on local TV channels I think that's probably the best way."
Mr Size said it was important biosecurity measures did not drop in the months and years following the recent outbreak.