The surprise discovery of a tiny insect in Kahurangi National Park may help solve the mystery of a cricket and tell scientists more about New Zealand’s separation from other lands.
Conservation Minister Poto Williams said Department of Conservation (DOC) staff discovered an unnamed species of flightless and songless cricket when they surveyed the Heaphy River catchment in 2022. Three individuals were found at the same place.
“Until now it has been understood that most crickets in NZ came here from Australia and none of those had ever been seen in Kahurangi beech forest. There are some native crickets but their habitat is open areas,” she said.
Crickets belong to a group of insects called Orthoptera, which includes grasshoppers, katydids, wētā, cave wētā and mole crickets.
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“The Kahurangi finds appear to be the same as a 1990s record in the Canterbury Museum of an almost completely forgotten bush cricket. All that was known about it was that it was found somewhere in the north-western South Island,” Williams said.
The find meant scientists now had a chance to study them in the wild and name them with a genus and species name. Mana whenua Ngāti Waewae would also be able to choose to gift a common name to replace the current listing Gryllidae species A, she said.
“For me, this discovery reinforces the importance of the Aotearoa New Zealand biodiversity strategy, which we are using to address the biodiversity crisis. We have around 4000 species threatened or at risk of extinction. It’s exciting that we’ve been able to rediscover an insect we know little about and take steps to find out more.”
The three crickets found at Kahurangi appeared to be mature females as they all had an egg laying spike. They were less than 1cm long, had powerful back legs and, as they are flightless, their main means of escape from predators was jumping.
“Unearthing a species unique to Aotearoa adds to the story of our ancient separation from other lands,” Williams said.
The bush crickets were likely to inform scientists of new ecological associations, but a great deal more work was required to accurately describe those connections.
DOC’s insect expert and science adviser, Eric Edwards, said DOC’s Buller office had monitoring biodiversity in the area to see how pest animal and plant control had affected it.
“We looked at bird life and forest health – monitoring plants, birds, insects. We started with some pitfall traps,” he said.
Pitfall traps are like coffee cups dug into the dirt that the insects fall into.
“We got some samples and were working through them and when we saw the crickets that got us scratching our heads.
“When I looked I thought it looks like a wētā, but it’s not a wētā.”
It was different to other crickets because they lived in the bush and did not have any sound or wings.
“I had never seen anything like it so that was the intriguing thing. New Zealand’s native frogs don’t croak and our native crickets don’t sing,” Edwards said.
He consulted New Zealand experts who had heard about chance encounters with an unknown type of cricket, but their habitats were not known.
“In this case we have now got a geographical location and that’s exciting.”
He also consulted Australian experts who confirmed it was not a recent arrival from there.
“We are still learning about it. It’s an undescribed species. Experts have interpreted it as belonging to a group of crickets not usually known in New Zealand.”
Edwards said Ngāti Waewae had been consulted to give it a “good New Zealand name” but for now DOC staff were calling it the Kahurangi cricket.
Staff had sought funding to be able to study the species in the wild, he said.
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