The red admiral (Vanessa gonerilla) is perhaps the most visible native butterfly in New Zealand. It flies most of the year, including sunny days in winter. Photo / Janice McKenna
The red admiral (Vanessa gonerilla) is perhaps the most visible native butterfly in New Zealand. It flies most of the year, including sunny days in winter. Photo / Janice McKenna
New Zealand’s native moths and butterflies are facing mounting challenges, with 60 years of evidence pointing to significant species declines in the eastern South Island, according to a new report.
Their decline matters because moths and butterflies are key pollinators, an important food source for birds, and essential to healthyecosystems.
An independent panel of experts has assessed the conservation status of 498 Lepidoptera (moths and butterflies) species in a new report published by the Department of Conservation (DoC).
Since the previous assessment in 2015, 35 species have deteriorated in status, including six now listed as Threatened – Nationally Critical, the final category before extinction.
Although a further 19 species have improved in status, DoC said this reflected increased knowledge rather than genuine recovery.
The Canterbury decline data came from scientists who sampled moths using a standard light‑trapping method at two mid‑Canterbury sites in 1961–63, 1987–89 and 2020–21.
Panel member and DoC senior science adviser Eric Edwards said the 60 years’ worth of evidence was rare worldwide and provided valuable insights into moth population trends.
“The 60-year record shows an 82% decline of moths in the two Canterbury sites between 1961 and 2021,” he said.
“This result is compelling and is worrying evidence of serious moth declines.
“Unfortunately, this trend of a decline in moth species is likely to be ongoing in many other parts of New Zealand and around the world.”
The panel found the greatest pressures on moths and butterflies came from habitat change, driven by invasive plants and animals, as well as the growing effects of climate change.
“Among more naturally open areas, particularly the eastern South Island, habitats that historically hosted native moths are being outcompeted by exotic grasses, exotic broom and wilding pines,” Edwards said.
“Invasive animals are a problem, too. Wasps are eating moth and butterfly caterpillars.
“More research is needed to better understand the seriousness of wasps and other invasive predators like mice.”
Edwards said it wasn’t all bad news for moths and butterflies, and exciting discoveries were being made.
The frosted phoenix moth (Titanomis sisyrota) is large but secretive, rediscovered after several decades on Rakiura/Stewart Island and then parts of the North Island by keen naturalists posting pictures to the New Zealand iNaturalist platform. Photo / J. Banga
“A Swedish tourist’s rediscovery in 2024 of the large and striking frosted phoenix moth was a sensation.
“Since then, several sightings have been reported in Rakiura, Little Barrier Island and Pureora Forest Park.
“These sightings are largely thanks to the use of ultraviolet LED technology, which works in damp weather when frosted phoenix like to fly.”
There is a community conservation concern for the gradual retreat of the forest ringlet butterfly (Dodonidia helmsii). Photo / Catherine Beard
New Zealand has almost 2000 moth and butterfly species.
Edwards said there were community groups and private landowners taking pest plants seriously, which was vital for moth habitat restoration.
“Citizen scientists are also making a difference,” he said.
“In the last few years, members of the public have used their mobile phones to record and upload vivid and detailed images of secretive and rare moths and butterflies to the iNaturalist app, increasing local knowledge.”
The nationally critical snout moth (Sporophyla oenospora), here in Central Otago, was once found from the Canterbury coast to mid-Canterbury and Central Otago, but is now confined to a very few dry open sites with bare ground and native herbs. It is threatened by exotic weeds and tall exotic grasses. It has been seen only twice in the past 20 years. Photo / R.J.B. Hoare
Edwards said anyone could become a citizen scientist by downloading the iNaturalist NZ app.
“Recording your sightings of moths and butterflies helps scientists, environmental agencies and community groups to better understand New Zealand’s Lepidoptera and plan restoration work.
He said other activities people could do to help included planting nectar species as food for moths and butterflies, getting rid of invasive weeds, and controlling exotic wasps.
Read the report Conservation status of Lepidoptera (moths and butterflies) in Aotearoa New Zealand, 2025here.
