New species of South Island wētā found
Scientists have described and named seven new species of South Island cave wētā , including one named after veteran nature photographer Rod Morris.
Pleioplectron rodmorrisi isa medium-sized cave wētā that inhabits sub-alpine and low alpine regions of the Kaikō ura Ranges and North Canterbury up to about 1500 metres above sea level.
It’s a ‘‘strikingly beautiful and unmistakeable animal [that] stands out for its unusually long legs, red-orange legs and antennae, purple-black back and a bold dorsal yellow median line’’, said Professor Steve Trewick of the Wildlife and Ecology Group at Massey University.
Morris was the first person to record the rare cave wētā in 1993.
‘‘I consider it a great honour to have my name attached to such a lovely creature,’’ Morris wrote in an email.
While South Island wētā have been known to science since 1896, Trewick and colleagues Danilo Hegg and Mary Morgan-Richards used classic taxonomy and DNA sampling to distinguish the high diversity of South Island wētā in the genus Pleioplectron.
They are everywhere in the South Island except Fiordland, but the territories of the South Island species (nine in total) don’t overlap much.
Three species are on the West Coast, but only one in Canterbury-Christchurch, a different one in South Canterbury-Queenstown Lakes and a third in Tasman, for example. There’s one example of the genus on the North Island.
It’s not clear why so many species evolved and Trewick hoped further DNA research would provide insight.
The animals inhabit a broad range of ecologies – everything from the wet West Coast to the dry Canterbury plains and the cold high alpine.
Most prefer forest and leaf litter and some are found in caves. They are known as cave wētā because they were often first found in caves. Overseas, the critters are known as cave crickets or sometimes camel crickets.
Several species seem happy enough in cities, and residents of Christchurch and Dunedin could probably find them under their houses and in woodpiles, especially near the water table, Trewick said in an interview.
They are small – body lengths of 8.5 millimetres to 20mm, but with much longer legs and antennae.
They’re also nocturnal, very sensitive to light, and nimble.
As a result they are not often seen and many South Islanders wouldn’t know they were nearby, he said.
They eat lichen and fungi and scavenge other insects and dead birds. When available, they eat human food such as porridge oats.
Naming species is one of the delights of biology, Trewick said. There are rules and it’s considered a no-no to name something after yourself or something offensive.
The names of people still alive can be used, especially with their permission, and where they had some relationship with the species.
‘‘I’ve always felt that a lack of any real government support for taxonomic work on the yet-to-be described biodiversity of this country plays a complicit role in our biodiversity loss,’’ said Morris.
‘‘Without so much as even a name, much of our flora and fauna is rendered ‘invisible’ to the public, and plays into the very hands of all who seek to develop and destroy biodiversity on public lands,’’ he said.
Trewick and MorganRichards have published extensively on New Zealand biology and collected much of their research in a 287-page book called Wild Life New Zealand.