South Australia has strengthened its import requirements, following the discovery of fruit fly larvae in four consignments of Queensland mangoes sent to South Australia during the summer harvest, which threatened its fruit fly-free status.

The reforms include a ban on fruit that has been heat-treated as well as stronger conditions for the use of a fumigation chemical treatment.

One of the infested mango consignments had been subjected to a hot-water treatment and another to methyl-bromide fumigation.

Geoff Raven, the manager for plant and food standards at Biosecurity South Australia, said investigations found both treatments had met existing protocols for interstate certification.

“They found that the chemical fumigators actually complied with the protocols and with the heat treatment, again there was no non-conformance.

“So the protocols were followed to the letter, which tells us that there’s a problem with the protocols,” he said.

The resulting suspension of heat treatments has virtually banned the trade of organic fruit to South Australia.

Fruit treated by methyl-bromide must now have a temperature of 16 degrees Celsius, up from 12 degrees, during the fumigation process.

The higher temperature causes the larvae to become more active, which makes the pest more likely to ingest the chemical and die.

Supply chain takes biosecurity out of growers’ hands

Biosecurity Queensland has revealed the consignment of infested mangoes treated by methyl-bromide had not originally been destined for South Australia but Victoria.

Its general manager for plant biosecurity, Mike Ashton, said fruit fly treatment rules did not apply to mangoes sent to Victoria, because the pest was already in abundance in that state.

The Victorian fumigation facility involved was also under investigation this year over the detection of live fruit fly in nectarines sent to Tasmania, which also enjoys fruit fly-free status.

Quarantine standards breached

Mr Ashton said dipping and flood spraying, rather than methyl-bromide fumigation, was used during on-farm treatments for mangoes destined for South Australia and Tasmania.

Investigations by Biosecurity Queensland have revealed two of the growers whose infested mango consignments were rejected by South Australia had breached quality assurance standards.

“With the second business, the non-conformance was in relation to the post-treatment inspection for freedom from fruit fly and the business was found to be not undertaking those inspections in the way it’s required,” Mr Ashton said.

All fruit fly host produce subject to new requirements

South Australia’s new import requirements affect all produce that are host to either Queensland fruit fly or Mediterranean fruit fly, which is found in Western Australia.

Recently, fruit fly larvae was also discovered in trays of strawberries sent from Queensland to South Australia.

Fruit flies can also infect citrus fruits, bananas, tomatoes, papayas, berries, grapes, apples, pears, apricots, olives and almonds.

Article Source: ABC News

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