Biosecurity experts from Government, research and industry outlined options and challenges for strengthening biosecurity to protect the state’s valuable pest free area status to growers at the annual Fruit Growers Tasmania conference.
Fruit coming into Tasmania will come under much greater surveillance as industry and Government work together to ensure the state’s prized pest free area status, once restored, is protected.
Biosecurity Tasmania General Manager Dr Lloyd Klumpp told a well-attended Biosecurity Day at the 2018 Fruit Growers Tasmania Conference in Devonport last week that a renewed national Code of Practice, and a more flexible Biosecurity Act would all strengthen the ability of Government to maintain biosecurity.
Other steps put forward by industry included the need for data on “who is growing what where” similar to the property identification codes (PICs) operating in the livestock industry, to facilitate a rapid targeted-response to any future detection.
Fruit Growers Tasmania (FGT) called for a state-based fruit fly expert, a horticultural liaison officer within Biosecurity Tasmania and more staff to check commercial fruit shipments.
“We need to lift the lid on commercial fruit coming in in containers from the mainland,” said FGT President Nic Hansen.
FGT also called for access to a full suite of end point phytosanitary treatments as a safety net to allow the establishment of protocols for fruit to trade should there be a future biosecurity breach.
Path to restoring PFA status
Dr Klumpp said despite no detections of Queensland Fruit Fly (Qfly) since April 2, it was too early to put a precise date on when the northern control zones would be lifted and PFA status restored across the entire state.
“We are pushing as hard as we can to get the minimum time to reinstatement,” he said. “But we don’t have a date yet.”
He said moving into the winter period, when adult flies were inactive, made quantifying the one generation plus 28 days period required to demonstrate eradication difficult.
But visits by Indonesian and Taiwanese delegations to view the eradication process had been positive.
“The reinstatement process is not in our control,” he said. Once eradication was established, the Commonwealth Government would negotiate with trading partners on reinstating pest free area (PFA) status.
“First we need to make sure we have eradicated them. They are not active when it is below 16 degrees, so there is no point going in looking for them. We are very confident that we are winning the game, but we are not relying on winter, we do need to plan for the possibility of re emergence.”
He said trapping would continue in the 1.5km control zones until January 2019 to confirm eradication.
Dr Klumpp said it was most likely that the Qfly had come into the state in mangoes from Queensland, with similar infested fruit found in South Australia around the same time traced back to that source.
He praised the response from Tasmanian growers and said the fact the outbreaks had been contained to a very small area was due to the hard work and support given by growers to authorities.
Growers were told winter temperatures should not be solely relied upon to kill off Qfly and the survival of the adult fly depended more on the length of the cold winter spell than the low temperature.
Although adult flies would need to survive far longer in Tasmania to over-winter – up to 250 days in the south of the state, compared to 60 days in Mildura and 150 days in Shepparton – this could not be ruled out.
Hort Innovation’s R&D Manager for Biosecurity and Market Access Dr Penny Measham told growers that Victorian research conducted in the 1980s, in a region where flies were established, had shown a small percentage of adult flies emerging in Autumn had survived the winter as adults and remained alive until the following Spring.
“This has implications for late Autumn post-harvest management,” she said. “Every tree and every bit of fruit is capable of hosting a new population.”
Dr Measham commended the continued efforts and activities of Biosecurity Tasmania, industry and the wider community.
“Managing Fruit Fly requires an effort from all stakeholders,” she said.
Dr Measham said some growers in south eastern parts of the mainland were spending $400-700/ha/year on Qfly management.
The SIT factory in South Australia was officially opened in 2016 and has the capacity to produce 50 million ‘healthy, competitive’ flies a week and sterile flies were particularly suited to targeting outbreaks, large isolated production areas and urban areas, she said.
Releases as part of an area wide management approach would start this year with bi-sex lines and male lines to follow.
Industry collaboration imperative
Susie Green, Chief Executive Officer of the Apple and Pear Growers Association of South Australia (APGASA), said a coordinated national approach was need to push back Qfly and Medfly.
“If we work together to push back fruit fly in Australia rather than just relying on individual states to carry the load we will all be better off.”
“One of the national challenges is also to identify who is growing what where,” she said. “The quicker we get a response in place to a biosecurity incursion, the quicker we can get on top of it.”
Key to South Australia’s maintenance of its pest free status despite occasional outbreaks, has been fruit movement controls, ongoing community awareness, vigilance in periods of no detection, a robust trapping grid and a strong Government and industry partnership.
A grid of more than 3,500 trap sites is serviced weekly in high risk periods and fortnightly in winter, and simulation response exercises held. Collaboration between industry and Government is important.
“Industry plays a really important role,” she said. “There is only so much Government can do if there is a single detection, but industry can get in there and play a role in awareness – it is much better coming from one grower to another.”
“We have had a 100 per cent success rate in eradicating fruit fly,” she said. “You can take heart, it can be done.”
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