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Contents > Butterflies > Resident > Coppers > Boulder Copper

Boulder Copper

Pepe Para Riki

Lycaena (Boldenaria) boldenarum (was Lycaena boldenarum and Chrysophanus boldenarum)

Distribution & Status Boulder Copper Distrubtion Map

Widespread Found throughout the South Island and central areas of the North Island, but is more commonly encountered in the upland areas like the Southern Alps and the central plateau.

NatureWatch NZ
Observations map for
Boulder Copper (L boldenarum)


NatureWatch NZ
Observations map for
Canterbury Alpine Boulder Copper (L tama)

Scientific Classification More info

Family

Lycaenidae

SubFamily

Lycaeninae

Tribe

Lycaenini

Genus

Lycaena

SubGenus

Boldenaria

Taxon

boldenarum

Also Known As;

The Small Copper

Classification changes

All the Copper Butterflies are under debate as to their classification. Presently nzButterfly.info is using George Gibbs classifications. But there is merit in the Brian and Hamish Patrick’s reclassification in 2012. nzbutterfly.info will be adopting the Patrick’s classification in the present website overhaul. This will increase the number of Copper species from 4 to 7.

The Common Copper is split into the Coastal Copper and Maui’s Copper. The Glade Copper has the ‘enysii’ variation becoming the North Island Glade Copper. The Boulder Copper is also split in two with the introduction of the Canterbury Alpine Boulder Copper. Finally the Rauparaha’s Copper is unchanged.

Notes: All links are to the relevant NatureWatch NZ observation page. These pages have the scientific names which are omitted here.
Description

A native Butterfly that is one of New Zealand's smallest butterflies running a close second to the Southern Blue. It is certainly the smallest Copper, add its small size and flight close to the ground, it becomes a very overlooked Butterfly, even when they are in plentiful supply. To see them, it is best to look for them along a river or gravel path on a sunny day when they rest with their wings open showing their bright colours, otherwise they become almost invisible when they close their wings. The male has a striking purple, whereas the female is more like the average Copper colour. It was split from the genus Lycaena in 1995 after much ongoing discussion regarding it's status for many years. Like the Glade and Rauparaha's Copper, the Boulder Copper doesn't travel much more the 10-50 metres from areas of the larval foodplant. All the coppers are all suffering from Wasp predation, especially paper wasps, as they are a good source of protein for the wasp's developing larvae. Attracting Boulder Coppers to your garden is fairly easy, just grow some Creeping Pohuehue (Muehlenbeckia axillaris) in a rock garden including local stones or shingle as they will land on this to sunbathe.

Ovum  In English

Laid singularly on the foodplant, either side of leaves or the stem. Olive-Green in colour and dome-shaped which is pitted all over with ridges. They hatch in about 8 days.

Larvae  In English

Colour varies from olive-green, through yellow-green, through yellow-pink to reddish-brown with a white edged dorsal stripe and oblique segmental stripes. In the South Island the green variation is predominant. Unlike the other Coppers, they have shorter and straighter setae plus they are brighter in colour in the 4th instar. Their distinctive feature from other Coppers is a prominent diamond shaped that is white with brown margins on its prothorax. It has it's legs and head covered by fleshy side flanges (giving it a Woodlouse shape), it appears to have a slow slug-like movement, especially in the 4th instar. In the first instar they only feed beneath the leaves, grazing the lower tissues in oval patterns. From the second instar they begin to eat notches from the side of the leaves. They prefer to eat new growth and in flowering season, November and December, they will eat the flower clusters. They can be often found beneath loose stones under the foodplant. There is also a high chance that the native Southern Ant (Chelaner antarcticus) will be present, however there has being no proven link between them and the larvae of the Boulder Copper as suspected in the past. This suspicion came about because lots of Lycaenidae Butterflies do have such links with Ants. However the larvae do have thick skins that reduce the risk posed by nearby Ants causing injury. Since the foodplant is partly deciduous, the over-wintering larvae move to a sheltered spot near the base of the foodplant and spend the winter in a quiescence. These overwintering larvae go on to pupate in September or October. Grows up to 10mm when fully grown.

Pupa  In English

Variable in colouration depending on the larva colour. A red larva will produce a dark-brown pupa with a reddish abdomen, whereas a greenish larva will produce a light-brown pupa. Both forms have a speckled black abdomen. They hide amongst dry litter or stones on the ground usually protected by a dried leaf which they attach themselves to by a small cremaster and has some silken strands in place of a girdle over it's thorax to help secure it. The odd one has being recorded as pupating in the foodplant like the Glade Copper, but they can be told apart as the Glade Copper has a rough texture due to setae. The pupa is about 6-7mm long.

Imago  In English

The imago has a 17-27mm wingspan, the average being 20-23mm. The male has a iridescent mauve or purple sheen on the upperwings with pronounced veins. Whereas the female has orange-brown upperwings with purple-blue spots around edge of wing. Both genders have black spotting on the upperwings. The underside is similar on both genders and is blue-grey to brown-grey with brown markings which vary to match local rock types, so will be lighter in the Taupo area where there is lots of Pumice and darker in the Southern Alps where there is greywackle, this allows the butterfly to rest almost invisibly on boulders and shingle (see variations page). To aid this disguise, it holds its wings against or over a stones, making it almost invisible (as in the ovipositing picture). The males flight is generally rapid, and darting near to the ground, whereas the females is more fluttery. Their jerky flight can make them very hard to follow as they disappear into 'thin air'. They rarely fly or settle over 1 metre high. They are a sun worshipper and often rest on stones or shingle with their wings open at about 30-40° with its head away from the sun. Just like the Black Mountain Ringlet, they absorb the radiated warmth from the stones. They will quickly close their wings if a cloud passes or a gust of wind disturbs them. I observed when they feel there is a presence of danger, they will rotate themselves until side on to the danger, then close the wings and press them against the rock to disappear or look like a small stone (see this picture). If they feel this isn't working, then they have a short wing flap and hop. This gave the impression that it was just a leaf being blown along in the wind. Depending on the habitat and location, they can seen flying with seen flying with the Common Copper, Common Blue or the Southern Blue. They appear darker in flight then the Blues. But may need following until settling to know for sure, however the undersides are similar at first glace. Males appear more common especially early in the season, but is probably due to them spending more time on the wing and sunbathing then females that take their time ovipositing. There is said to be 2 generations per year, however it is suspected that there is 3 or more generations in some localities in favourable years. They appear to have a constant cycle of all lifestages from November to March similar to the Red and Yellow Admirals.

Variations

There is numerous variations around the country that could technically become sub-species, but haven't yet due to the small areas they inhabit. In 1946 JT Salmon did make a start with the two sub-species listed below. It is generally considered that there is local variations. I wouldn't be surprised if there is developments with more sub-species being described in future since the genus was changed from Lycaena to the sub-genus Boldenaria in 1996.
Presently all Coppers are being reviewed for re-classification. Regarding the Boulder Copper, it is likely to become split in to several sub-species and maybe even species.
However since the Boulder Copper is fairly consistent Copper species, I suspect that only sub-species will be described based on their underside markings that resemble the local type of rock.
Boulder Copper pictures of variations

Sub-species

There is presently 2 sub-species described, both from the Fiordland area. B B caerulea is found in the Upper Hollyford valley which has a mainly grey underside with a thin dark line across the centre and B B ianthina which is found in Milford Sound. It has a thick dark centre of the underside. Both existing and any new sub-species will be variations of the underside that is only found in one area.

Habitat

Found in areas of Tussock and shingle. Also along watercourses (especially braided rivers) and roadsides where their larval foodplant is present. It is generally found from sea level up to 2000m, but is less common above 1300m.

Food Plants

Only recorded on Creeping Pohuehue (Muehlenbeckia axillaris) and Maori Dock - Runa (Rumex flexuosus) in the wild, but in captivity they have fed on other varieties of Pohuehue (Muehlenbeckia spp).

Lifecycle
Lifecycle of the Boulder Copper

Contents > Butterflies > Resident > Coppers > Boulder Copper