Captured fruit fly under the microscope

FLY TRAP: The Queensland fruit fly at the centre of a scare in Auckland on display at Assure Quality in New Lynn.
FLY TRAP: The Queensland fruit fly at the centre of a scare in Auckland on display at Assure Quality in New Lynn.

He's seen a lot of flies but David Voice admits seeing this one left him "a little bit surprised".

The bearded and bespectacled entomologist for the Ministry of Primary of Industries was making routine inspections of fly traps on Wednesday night when one from West Auckland drew his attention. 

"They're quite colourful flies, I knew almost straight away," Voice said.

"I was a little bit surprised but we're trained to recognise these things."

He knew the find was significant - Queensland fruit flies could be devastating to the country's multi-million-dollar horticulture industry.  

There was no big red button to push (it was actually an 0800 number to dial) but by Thursday morning an emergency response was in action.

Traps containing the fruit fly attracting pheromone "cue lure" were deployed and fallen fruit was gathered from under trees to check for eggs or larvae.  

Today, the streets of West Auckland have large signs advertising the threat and urging people to be vigilant. A team of officials attended the Avondale market yesterday.

At the Assure Quality lab in Blockhouse Bay residents have been sending in specimens and emailing pictures of suspicious flies 

Traps in the "A zone" - the 200m area around the find - have yielded five possibles. Luckily all have turned out to be just regular flies and no more of the Queensland variety have been detected.

The wet lab, where three men in lab coats sit carving feijoas into 3mm slices and inspecting them under magnifying glasses, has also failed to pick up any further fruit flies.

The find, though potentially serious, has had several fortuitous aspects. The fact the specimen was a male was the first bonus - a female could have represented a breeding possibility and fruit flies are able to reproduce with their siblings.

The other bonus was timing - with autumn setting in and temperatures cooling, fruit flies would not last as long and would possibly defer breeding.

Voice said the single fruit fly caught was at least four or five days old and could have lived for months. 

No further testing has been done on the fly but there was a possible "isotope tracing" test that could track him back to where he came from. 

Although confidence was high that the testing regime was effective, it would be about another fortnight until the all-clear was given, Voice said.

Until then, the search continues.

Auckland Now