A new native species of fly has been discovered near Dunedin after a fly expert stumbled upon it while out for a hike.
Entomologist Steve Kerr says the dance fly he discovered near Sullivans Dam can be traced back about 80 million years.
The dance fly is just one of many unique fly species found only in Aotearoa, he tells Jesse Mulligan.
"It's a very small genus with only two previously described species here in New Zealand, and one oddly enough over in southern Chile and that suggests a very ancient linage going back to 80 million years ago, back when New Zealand and South America were almost touching before we all split away.
"One was left behind in Chile and we had two species and now we've got this third one."
With an entomology colleague, Kerr has put together a paper to identify the fly and named it Empidadelpha pokekeao which means 'dark cloud' in te reo Māori.
"It's a small fly, it's about 4mm long, it has beautiful wings with a dark cloud out at the tip, hence its name. It's got incredibly long antennae and a very long proboscis and long spindly longs."
Last year while trying to identify the dance fly, Kerr came across two of the same species, sitting unidentified at Canterbury Museum.
"The morphological features that it has are typical for the genus so it was not too difficult to figure out early on which genus it belonged to.
"The real task was making sure that it had not been previously described somewhere else and when we were sure of that, we went ahead and gave it a new name and put it out for peer review."
Little is known about the dance fly's life cycle and habitat, Kerr says.
"They're probably riparian flies that like watery environments and judging by the very long proboscis with the way it has adapted, it's most likely a pollen feeder.
"The paper was published on the basis of seven male specimens, and no females have yet been seen anywhere, so that remains a mystery."
There are about 2,500 named species of flies in New Zealand, and it's estimated we probably have 2,000 more species yet to be discovered or named, he says.
"New Zealand is unique in that position, we've been separated from other landmasses for 70 million years-plus and have developed a whole ecosystem here."
Steve Kerr is the Otago Museum Honorary Curator of Entomology.
