Dozens of New Zealand's giant weta were relocated to a pest-free island home today.

About 150 of the nationally endangered weta punga were released on Motuora Island in the Hauraki Gulf following a successful breeding programme, Auckland Zoo said.

The weta punga is one of the world's heaviest insects, with some weighing as much as a sparrow.

Another 150 of the invertebrates will be released on the Hauraki Gulf's Tiritiri Matangi island next month, followed by a further 200 later this year.


The successful breeding programme saw six male and six female weta punga transferred from Little Barrier Island, the only place they are now naturally found, to Auckland Zoo in May 2012.

The zoo's curator of ectotherms and birds, Richard Gibson, said new techniques involving rearing the insects in groups as well as individually, were trialled within the zoo's temperature controlled weta facility for the first time.

"It's been a pretty intense period of work for the team, but an absolute privilege to be helping such an iconic threatened species.

"We're delighted to have achieved a 95 per cent success rate in rearing animals individually, and around 50 per cent success rate with the groups - significantly higher than we expected."

The 150 weta released today are close to adulthood, and it is expected they will soon begin to breed.