Butterflies make very poor fossils. They have no bones or other solid matter that can be preserved. Therefore, unlike other animals, we can’t use their fossils to trace the history of when they arrived in New Zealand.
There are 5 butterfly families
Butterflies are categorised into 5 families – Papilionidae, Pieridae, Nymphalidae, Riodinidae and Lycaenidae. In New Zealand, our butterfly species fall into 3 of these families, while 2 families are not represented.
| Scientific classification | |
| Kingdom: | Animalia (animals Arthropoda (arthropods) Insecta (insects) Lepidoptera (butterflies and moths) Papilionidae (not represented in New Zealand) Pieridae (white butterfly) Nymphalidae (monarch, admirals, tussocks, ringlets) Lycaenidae (coppers and blues) Riodinidae (not represented in New Zealand) |
New Zealand’s butterfly history
Entomologists once thought we shared many butterflies with Australia before the break up of Gondwana, 60 million years ago, but there is little evidence to support this. It is now believed that New Zealand butterflies are more recent arrivals. They either blew across the Tasman Sea or were able to reach here via New Caledonia.
Living things within New Zealand are classed as endemic, native or introduced. If a species is endemic, it is found nowhere else in the world – it evolved into a new species in New Zealand. Most New Zealand butterflies are both endemic and native. Ringlets are an example of endemic natives. The monarch, yellow admiral and common blue are natives because they arrived without the aid of humans, but the species naturally exist in other countries. The white butterfly is an introduced species because it arrived by accident in a food shipment.
Butterfly specimens were collected and their details recorded by early European entomologists. These reports, combined with local Māori knowledge, helped to identify our endemic and native butterfly species. Knowing what was here helps us to identify more recent butterfly arrivals.
Blown across the oceans
Butterflies can be blown across from Australia. Isn’t it amazing to think that butterflies can survive being blown across the Tasman and arrive here intact? When there has been a food source and favourable climatic conditions, these visitor butterflies have stayed, bred and established themselves here. The monarch butterfly, Danaus plexippus, is a good example of this.
The monarch butterfly is originally from North America. The monarch made its way here using island stopovers and prevailing wind currents. Its establishment in each of these countries was made possible by the planting of its larval food plant, the milkweed. (The fluffy seeds of this plant were an original source of pillow and mattress stuffing.) Monarchs were reliably documented here more than a 130 years ago.
Inadvertent butterfly arrivals
The white butterfly, Pieris rapae rapae, arrived more recently, most likely as an accidental import during the late 1920s or early 1930s. They are thought to have arrived in an imported shipment of refrigerated vegetables. These butterflies quickly gained a foothold here and are a familiar (and often unwelcome) sight in vegetable gardens.
A second member of the Pieridae butterfly family arrived in 2010. The great white butterfly (Pieris brassicae) was first found in a Nelson city garden. Great white butterflies became established in the Nelson area. The Department of Conservation (DOC) led an eradication programme to prevent this butterfly species from spreading. Great white butterflies look similar to the common small white butterfly, but as their name implies, they are about twice the size. DOC requested that the public report any sightings of great white butterflies, caterpillars or eggs.
In a 3 year period, DOC rangers made more than 263,000 searches in the region. The community also played its part. Children were offered a $10 bountry for dead butterflies during the 2013 school holidays. Locals used modified garden ornaments to attract and catch the great whites.
In late 2016, two years after its last sighting, the great white butterfly has been eradicated from New Zealand. Maggie Barry, the Minister of Conservation says, "This is the first eradication of an unwnated butterfly population in the world and is another impressive example of New Zealand's innovation and skill in removing pests." It is estimated the eradication saved the country millions of dollars per year in pest control costs.
Planned introduction
The Honshu white admiral butterfly was deliberately introduced to Aotearoa in 2014 as a biocontrol agent. The caterpillars feed on the leaves of invasive Japanese honeysuckle, potentially stripping the plants of foliage. The butterfly is endemic to a single island in Japan and its release in New Zealand is the first time it has been used for biocontrol. Honshu white admiral butterfles have become established in the Waikato region and have since been introduced to the Taranaki region.
They keep coming
Butterflies can easily cross our borders. Each year, there are sightings of Australian butterflies that are known as visitors to New Zealand. However, these visitors have not become established, as none can survive the cold winters.
From time to time, Customs or Biosecurity officers detect unwelcome butterfly visitors in imported goods. A documented case involved a Japanese swallowtail butterfly. The newly hatched butterfly was found close to vehicles imported from Japan a few weeks earlier. The butterfly was probably imported in its hibernating pupa form and emerged after a few days of warm weather.
Our butterfly history will keep evolving through additions or declines or changes in habitat and climate.
Useful links
This Department of Conservation factsheet explains how to identify the great white butterfly and who to contact with sightings.
Listen to this Radio NZ, Our Changing World interview about the great white butterfly eradication programme.
And read about the successful eradication of the great white butterfly.
For more information about butterflies being blown over from Australia, refer to Learning Media’s Connected 3, 2001.
