A single male fruit fly was detected this week in Launceston in one of the 1000 traps set up across the state by Biosecurity Tasmania, who have now set additional traps for any further possible detections.

No larvae was detected.

The discovery follows a fruit-fly detection in Devonport by Biosecurity Tasmania on January 1, where fruit fly larvae was found in a mango.

Tasmanian Fruit Growers Tasmania chief executive Peter Cornish said the latest incident did serve as a reminder to remain vigilant.

"Indirectly it shows us that the systems put in place by Biosecurity Tasmania are working, the the frontline efforts, pre and post border, are working, and that is what detection is all about," he said.

"The fact that it has been found in a surburban garden means we need to be mindful about what we do and how we do it, and look at how the fruit fly was allowed to enter the state, at some stage, which could of been in a number of forms."

Mr Cornish said the trapping was a third line of defence against the pest.

A majority of the prevention methods were held at the places of export, while other methods in Tasmania such as checking and clearance of all fruit at the borders, as well as checking by handlers and dogs of passengers entering Tasmania in the airports, were also great biosecurity measures.

Mr Cornish said one fruit fly did not have an impact on Tasmania's pest-free status.

The states's fruit-fry free status resumed in February 2019 after a 2018 outbreak of the pest, where at the height of the outbreak authorities received 330 reports of potential fruit flies, and also trapped 23 adult flies.

Adult fruit flies or larvae were detected on Flinders Island, Lady Barron Island, Spreyton and George Town.

The outbreak caused huge financial losses to growers in the quarantine area, where Tasmanian fruit could not leave the state unless treated with methyl bromide or stored in cold storage for weeks.

Countries such as Indonesia, Taiwan, Japan, South Korea and New Zealand refused to accept some Tasmanian fruit.

Indonesia and China have still not formally accepted Tasmania's fruit-fly free status, but trading continues.

The Tasmanian government spent $5.5 million by the end of April 2019 to fight against the fruit fly in Tasmania's north and protect the state's fruit-fly free status.

A further $8 million was allocated in this year's state budget.

The federal government also pledged $20 million to eradicate the threat.