CanterburyNature

Bassaris gonerilla

Written by Adam Taylor (Lincoln University)

July 2005

Edited by Mike Hudson and Mark Parker, Lincoln University, February 2006

Taxonomy

• Scientific name: Bassaris gonerilla subspecies gonerilla (Fabricus, 1775)
• Popular Common Names: New Zealand red admiral, red admiral, kahukura (‘red garment’)
• Synonyms: Vanessa gonerilla (Fabricius, 1775), Papilio gonerilla (Fabricus, 1775)
• Comment: Bassaris (Hübner, 1821)

• Kingdom: Animalia
• Phylum: Anthropoda
• Class: Insecta
• Order: Lepidoptera (moths and butterflies)
• Family: Nymphalidae (browns, frillaries, admirals and monarchs)
• Subfamily: Nymphalinae

• New Zealand Status: native (endemic)

• Taxonomy sources: Dugdale (1988), Gibbs (1980), Brusca (2003), Braby (2000).

Identification

Species Description

The red admiral is one of New Zealand’s most colourful butterflies. Some New Zealanders will be familiar with its dark brown, red and black wing colour. The wingspan ranges between 50–60mm (Gibbs, 1980). The forewing is black with white marks and has a central crimson band. Below this central band the forewing is orange-brown. The central crimson band displayed on the hindwing encompasses a set of four black spots each with a white centre. The central crimson band is isolated by the remaining orange-brown colouration of the wing. The underside of the hindwing is a matrix of browns which obscurely reflects the pattern on the top (Figure 1). The underside of the forewing boasts an ‘eyespot’; a black spot with a white lining is centred within a larger black spot. A yellow spiral which resembles an outer glow is attached adjacently to the eyespots. The yellow blends to red as the spiral curves around these eyespots (Figure 2).

Similar species

The wing patterns belonging to butterflies are primarily comprised of three basic colours that pigment individual scales. The pattern depends on individually pigmented scales of different concentration and mixture of colours (Scoble, 1992). The red admiral uses black, red and white to colour the wing where as the Australian Bassaris itea uses yellow in place of red (Figure 6). B. itea and B. gonerilla may have become isolated in the Australian and New Zealand regions from travelling the north west winds. B. itea (yellow admiral) subsequently evolved in Australia and B. gonerilla (red admiral) in New Zealand (Gibbs 1980).

The admirals are strong fliers and may have been able to fly the north west winds from Australia to New Zealand. Within New Zealand the red and yellow admirals can be seen flying side by side (Gibbs, 1980). There has been one sighting of the New Zealand red admiral in Australia (Braby, 2000).

The closet relation to the B. gonerilla subsp. gonerilla is B. gonerilla subsp. ida, commonly known as the Chatham Island red admiral. The difference between these two subspecies is the ratio of the brown outer border to the crimson central band on the topside of the hindwing. The Chatham Islands are 620 km east of New Zealand, directly down wind of the prevailing north west winds. With the strong flight of B. gonerilla it is surprising that the B. gonerilla subsp. gonerilla rarely discovers the Chatham Islands on their travels with the wind. The Chatham Islands may once have been part of a continuous New Zealand where the B. gonerilla population split because of sea flooding from glacial melting and consequent evolution in their new environments (otherwise known as vicariance). Another possibility could be that strong winds blew these butterflies from the coast of New Zealand and they were unable to return against the wind. With their strong flight, the red admirals decided to glide on the wind. By doing so they had the chance of discovering the Chatham Islands. Relieved, the red admiral set down to thankfully continue future generations.

Geographic Distribution

Full natural and naturalised range

The species B. gonerilla is present naturally in New Zealand and Chatham Island (Gibbs, 1980). B. gonerilla are not naturalised in any other parts of the world. There are two subspecies of B. gonerilla that are endemic to New Zealand: New Zealand red adrmial (B. gonerilla subsp. gonerilla) and Chatham Island red admiral (B .g.subsp. ida). From this point the subspecies B. gonerilla subsp. gonerilla will be referred to as ‘red admiral’.

New Zealand range

Bassaris gonerilla have a wide distribution across New Zealand, inhabiting the North, South and Chatham Islands.

Canterbury range

Red admirals flourish along the Southern Alps and on remote hilltops above 900m. It is possible to view a red admiral along the coastline or in a sunny glade. Banks Peninsula has several sites where they can be found.

Natural History in Canterbury

Habitats

The habitat of the red admiral is unrestricted. A greater abundance of red admirals can be found in alpine conditions and remote hilltops. Forest glades and inner city gardens can also be home to red admirals.

Preferred habitats

Preferred habitats of the red admiral include Nothofagus (beech) forests and Urtica species (nettles). Red admirals are in abundance above 900m (Gibbs, 1980).

Phenology

Red admirals can be found at all times of the year and are most common in summer (Walker, 2000). Generations occur during spring, summer and autumn and those that emerge late in autumn have an expected life of six months. The age of the red admiral can be viewed by loss of pigmentation of the scales (Gibbs, 1980). The species is a strong and rapid flier with the potential to migrate, yet no ‘regular’ flight patterns within New Zealand have been discovered (Gibbs, 1980).

Life Cycle

There are four stages to the red admirals life cycle. The initiation of this life cycle starts with the production of eggs. Eggs are usually laid in the beginning of September until the end of May (Borrow, 2004). Eggs of the red admiral can be laid individually or in pairs upon the preferred host plant of the endemic Urtica ferox or other species of stinging nettle (Braby, 2000). Eggs are laid on the sides of stinging hairs of the Urtica leaves. Each egg is green and barrel like in shape with nine vertical ribs (Gibbs, 1980). Within nine days the egg hatches and the second of the four stages starts. A larva removes itself from the egg by gnawing a lid around the top. Once it has left the egg shell, construction of a new shelter starts. A side of a leaf is folded over and fastened down with silk to produce a protective covering (Braby, 2002). Within 4–6 weeks the larva completes five stages of growth (instars) before pupation (Gibbs, 1980). During the early instars, larvae feed mainly at night on the edges of young leaves. As it feeds voraciously and grows rapidly a new protective shelter will be needed and is made of two leaves joined together rather than the folding of one (Braby, 2000). The larva seems to grow in confidence as it enters the later instars. This change can be seen as it feeds openly during the day and shelters are made much more loosely knit and open (Braby, 2000). The larva suspends itself for 12 hours in a ‘J’ position in preparation of the third stage (Cook, 1976). The third stage is pupation where the larvae undergo complete transformation through metamorphosis. The pupa varies in colour and can be golden if attached to the larval food plant, or brown to reddish-brown if on a wall or tree trunk where it resembles a dead hanging leaf (Braby, 2000). During the summer the pupal stage is 14–18 days and several generations occur during spring, summer and autumn. The adult butterflies are considered long lived, six months for those who emerge late in autumn and spend their days in a dormant state, occasionally flying on warm days (Gibbs, 1980).

Diet

During the larval stage the larvae is dependent on the endemic tree nettle, Urtica ferox. Larvae also feed on the native herbaceous nettle U. incisa (Borrow, 2004). Gibbs has observed several red admirals clustered around the wounds of Nothofagus (beech) tree trunks, feeding on the nectar and fermenting sap. The red admiral also feeds on the blossoms of garden shrubs. The blossom of Buddleia spp. appear to be the preferred blossom of the red admiral (Gaskin, 1966).

Parasites

Research conducted by Barron, Wratton, and Barlow in 2004 on the phenology and parasitism of the red admiral butterfly show that the red admiral is highly susceptible to heavy parasitism. The self introduced wasp Echthromorpha inticatora is a pupal parasite that emerged from 67.5%-82.3% of the pupae collected and a further 3.5%-16.9% were home to Pteromalus paparum, a tiny “non-target” parasitic wasp, which was introduced to control the growing population of small white butterfly (Peris rapae). The decline in the population of red admirals can be attributed to parasitism during pupation.

How to find a red admiral

Red admirals are widespread yet “less than common”. You can come across a red admiral anywhere at anytime within Canterbury. Red admirals have been sighted at Prices Valley, Orton Bradley Park and Ahuriri Valley. All of these sites are on Banks Peninsula which is located near Christchurch (Barron, 2004). Red admirals can be found where there are stinging nettles because of the dependence their larvae have upon this host plant. Red admirals can also be found in the vicinity of beech forests, for the nectar and sap that exudes from these trees are a favourite (Gibbs, 1980). The red admiral is most common during summer and may be seen as a flicker of red across the viewers’ peripheral vision. The red admiral will perform a few aerobatic movements through the air to let you know of its existence, before setting back down again to bask in the glorious warmth of the sun.

Abundance and Conservation Status

• New Zealand: abundant
• Canterbury: abundant

Hudson (1928) labels the red admiral as being ‘very common’ yet it is thought that the population is in decline (Gibbs, 1980). Evidence from research taken of the parasitism of B. gonerilla pupae show a large percentage being attacked by parasitic wasps. This parasitism can be held accountable for the dwindling population of red admirals in New Zealand. Stinging nettles are viewed by individuals as a weed that warrants destruction. The removal of this larvae host plant could be a factor for the limited amount of sightings within the city (Gibbs, 1980).

Significance for people

Traditional Māori significance and uses

Māori named the red admiral ‘Kahukura’, which translated to English can mean ‘red garment’. The name of Kahukura appears in Māori mythology as the god of travellers; life, death, and disease (NZETC). Red admirals are known to be strong fliers and fit the label of ‘traveller’.

Modern Uses

The English name of red admiral was derived from old English word ‘admirable’ (Gibbs, 1980). The word admirable refers to the gracious flutter and flight. This is emphasised by the genus name Bassaris. Bassaris worshipped the Greek god of wine and were known as dancing nymphs (Gibbs, 1980). The image of drunken dancing nymphs alludes to the red admirals flight pattern and love for fermenting sap. People enjoy watching the red admiral for its spectacular and confident style of travelling.

Summary

The red admiral is a large orange brown butterfly that appears to be wearing red garment. It is a triumphant flier and sun bather. The larvae of this airborne admiral are dependant upon stinging nettles as a food supply when hatched. Larvae living upon the host plant, will make shelter by using silk to fold over the leaves. During pupation the red admiral has a high chance of being attacked by parasitic wasps and never gets the chance to travel. The Bassaris gonerilla subsp. gonerilla is wide spread through out the length of New Zealand and can appear at anytime. Travelling the Banks Peninsula on a hot summer’s day, one may converge paths with a venturing red admiral and watch in awe as it moves around the landscape.

References

Barron, M. C., & Wratton, S. D., & Barlow, N. D (2004). Phenology and parasitism of the red admiral butterfly Bassaris gonerilla (Lepidoptera: Nymphalidae). New Zealand Journal of Ecology, 28(1), 105–111.

Braby, M. F (2000). Butterflies of Australia: their identification, biology and distribution. Victoria, Australia: CSIRO Publishing.

Brusca, R.C (2003). Invertebrates. Sunderland, Mass: Sinauer Associates.

Cook, E.M (1976). Life cycle of the red admiral butterfly and absorbing study. Forest and Bird, 202, 23–24.

Dugdale, J.S (1988). Lepidoptera: annotated catalogue, and keys to family-group taxa. Fauna of New Zealand, 14.

Gibbs, G. W (1980). New Zealand butterflies: identification and natural history. Auckland, New Zealand: Collins.

Gaskin, D. E (1966). The butterflies and common moths of New Zealand. Christchurch, New Zealand: Whitcombe and Tombs.

Scoble, M. J (1992). Lepidoptera : form, function, and diversity. Oxford, NY: Oxford University Press.

Victoria University of Wellington (2005). New Zealand Electronic Text Centre: Māori-Polynesian Comparative Dictionary. Retrieved September 5, 2005, from http://www.nzetc.org/tm/scholarly/tei-TreMaor.html.

Walker, A. K (2000). The Reed handbook of common New Zealand insects. Auckland, New Zealand: Reed.

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