Despite an increasing threat of invasion, a national surveillance program led by the Tasmanian Institute of Agriculture (TIA) has found mainland Australia and Tasmania are still free of an insect pest that has devastated potato crops in New Zealand.

Zebra chip disease, which is caused by a bacteria that produces dark brown stripes in potato tubers and renders them unusable, is carried and spread by a small flying insect called the tomato-potato psyllid (TPP).

Native to North and Central America, TPP was first detected in New Zealand in 2006 and has cost the industry more than $200 million. The risk of an invasion into mainland Australia recently increased after TPP was discovered on Norfolk Island last year.

TIA Research Fellow Dr Robert Tegg says the risk is that the disease could enter Australia either through the accidental importation of infested plant material or by the natural dispersal of psyllids on easterly airflows from New Zealand and/or Norfolk Island.

"The impact of TPP could be potentially devastating to the Australian potato industry and could result in millions of dollars of losses annually through increased pest control and monitoring, reduced yields and disruption to commodity export markets," Dr Tegg said.

"We have been aware of this threat for some time and in 2011 TIA set up a network of yellow sticky traps in the major potato growing regions of eastern Australia, to act as an early warning system to detect incursions of the tomato-potato psyllid.

"These traps are strategically placed in potato crops down the Eastern seaboard of Australia, across five separate states from Queensland to Tasmania.

"In the most recent monitoring for the 2014/2015 season there was no TPP present in Australian potato fields, but we must remain vigilant."

TIA entomologist Dr Paul Walker is also playing a key role in the project by gathering data on what native species of psyllids are present in potato fields.

These could potentially spread the Zebra chip pathogen if it was to become established. The project is also recording the number of major predatory insects present in potato fields which could be important in controlling TPP if it was to arrive in Australia.

Over the last growing season a total of 498 traps were placed in the field. No TPP were detected but more than 3,800 native psyllids and 1,200 beneficial insects were caught.

"Knowledge of what native predators are present in potato fields will be extremely valuable should the TPP arrive in Australia and sustainable management options are needed," Dr Walker said.

Mr Frank Mulcahy, Research and Development Manager at Simplot Australia, says the project plays an important part in the national program to monitor and increase awareness of the insect and pathogens. 

"If TPP came to Australia it could cause high yield losses for us and we would also be looking at major financial costs to control and manage the disease," Mr Mulcahy said.

"We need to be able to act swiftly to take all the necessary precautions and this ongoing monitoring puts us in a good position to do this effectively."

Any suspected cases of TPP or plants suffering from unusual disease/growth symptoms should be reported to your relevant state authority immediately through the Exotic Plant Pest Hotline: 1800 084 881.

The ongoing national psyllid monitoring program is funded by Horticulture Innovation Australia and industry partners Simplot Australia, McCain Foods Australia, Smiths Snackfood Company and Snack Brands Australia.

The project team is led by TIA's Dr Calum Wilson, with TIA team members Dr Paul Walker, Dr Geoff Allen, Dr Robert Tegg and Ms Leonie White.