New Zealand red admiral

New Zealand Red Admiral
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Nymphalidae
Genus:	Vanessa
Species:	V. gonerilla
Binomial name
Vanessa gonerilla (Fabricius, 1775)
Subspecies
V. g. gonerilla V. g. ida (Alfken, 1899)
Synonyms
Bassaris gonerilla

The New Zealand Red Admiral (Vanessa gonerilla) is a butterfly that is endemic to New Zealand. The Māori name is kahukura which means red cloak. The Red Admiral is a member of the family Nymphalidae, the sub-family Nymphalinae as well as the tribe Nymphalini.

There are two sub-species of Vanessa gonerilla, V. g. gonerilla, which occurs on the mainland of New Zealand, and V. g. ida, which occurs on the Chatham Islands.

Description

A medium sized butterfly with a 50–60mm wingspan ^[1][2]. The top side of the forewings is basically black with a central bright red bar running back from the front edge. There are white spots, fringed with light blue, near the tips. The rear wings are more a dark reddy brown with a red area containing four black circles. The centre of each circle is pale blue. The underside of the rear wings is a mottled collection of shapes and white/brown/black colours – very camouflaged when at rest.

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  Folded camouflaged wings

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  Eyespot

When revealed, the underside of the fore wings display a striking blue eyespot bracketed by white and red arcs.

Distribution and habitat

Red Admirals are relatively common throughout New Zealand where their food plants occur.

Life cycle

Eggs

The green coloured, barrel shaped, ribbed, eggs are generally laid singly on a nettle leaf. Unlike the close relative yellow admiral the larvae only eats enough of the egg shell to get out, whereas the yellow admiral will consume the whole shell ^[2][3].

Larva

Closeup (damaged specimen)

The larvae go through 5 growth stages (called instars). For about 10 days they have a brown body with small white spots and fine hairs (setae). At about 2.5mm they moult and during this stage develop a pale stripe along the body just above the legs. The setae start to develop spikes, usually two or more at this stage. At about 5mm long they moult again and the pale longitudinal lines become more obvious. At about 10mm they moult once more, and the setae develop more spikes.^[2] The last moult is at about 22mm, from where they grow to about 36mm before pupating.^[1].

Ongaonga, Urtica ferox is the main food plant for Red Admiral larvae. The larvae can also eat other Urtica species. Throughout their life they use the leaf to protect them during the day, by rolling the edge around them, or (as they get bigger) folding the leaf over into a 'tent'^[2]

The pupa is about 20mm long^[1].

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  Size approx 36-37mm long

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  Ongaonga, the food plant for the New Zealand Red Admiral

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  Protective 'tent' made from a folded leaf

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  Hiding under folded leaf 'tent'

It is difficult to distinguish between Red Admiral and Yellow Admiral caterpillars. Caterpillars on the Tree Nettle (Ongaonga) (Urtica ferox) are more likely to be Red Admirals than Yellow Admirals. Looking at the 4th and 6th body segments, the Yellow Admiral has a wider light coloured area than the Red Admiral. When compared side by side it may be noted that the pupae of the Red Admiral tends to be thinner and longer than that Yellow Admiral, but otherwise they are very difficult to tell apart.^[2]

Adult

Over-wintered butterfly showing faded colours and extreme wing tip damage.

Red Admirals occur most frequently during summer and may live for several months, they overwinter as adults so can be seen on warm winters days. They are long lived, surviving up to 6 months in the summer, and perhaps 9 months for those who over-winter^[2]. The adults feed on nectar from various plant species (native and introduced) and occasionally on seepage of sap^[1][2].

References

1. ^ ^{a b c d} Leonie Clunie (2001-08-23). "Bug identification - Red admiral". http://www.landcareresearch.co.nz/research/biosystematics/invertebrates/invertid/bug_details.asp?Bu_Id=262. Retrieved 2009-07-16. 
2. ^ ^{a b c d e f g} "NZ Butterfly.Info > Red Admiral". http://homepages.ihug.co.nz/~nzbutterfly.info/resident/red-admiral/. Retrieved 2009-07-16. 
3. ^ "NZ Butterfly.Info > Yellow Admiral". http://homepages.ihug.co.nz/~nzbutterfly.info/resident/yellow-admiral/. Retrieved 2009-07-20.