nzButterfly.info > New Zealand Species > Resident Species > Admirals > Yellow Admiral

Yellow Admiral

Kahu Kowhai

Vanessa itea (was Bassaris itea)

Scientific Classification More info

Family

Nymphalidae

SubFamily

Nymphalinae

Tribe

Nymphalini

Genus

Vanessa

Taxon

itea

Also Known As;

Australian Admiral (Aust)

Description

A native butterfly that also occurs in Australia, Norfolk Island & Loyalty Island. The Maori name means Yellow Cloak. This is a long-lived butterfly with individuals known to live over a year. Has larger numbers in years when Painted Lady's are recorded in New Zealand as both species are strong migrants & vagrants. Also, there is no sub-species in it's range, which suggests that migration is common throughout the range. Attracting Yellow Admirals to your garden is fairly easy, just grow some nettles & a plant a few nectar plants. They are the next easiest to raise after the Monarch, but beware, like Monarch larvae, they have big stomachs & will stripe a plant bear in days.

Ovum In English

Usually laid in pairs or trios, but rarely singularly on the foodplant near the tip of the stem where the growth is fresh. Fairly often on the side of one of the stinging hairs & occasionally laid adjacent to the foodplant. Initially pale green, turning to green in colour & dome-shaped with 8 to 10 vertical ribs. Slightly longer in height then width. They hatch in about 8 to 10 days. There are reports that say the shell is eaten by the newly hatched larva for it's first meal & others that say the larva eats a small hole near the top so it can get out, but will leave the rest of the shell behind.

Larvae In English

Upon hatching it's a pale grey, but changes to shades of brown, grey-green or yellow after a few days. They are known to change colour when moulting to provide better camouflage with their immediate enviroment & lighting conditions. It has a hairy head with pale lateral & dorsal stripes along the body which is covered in setae. The larvae live about 4-6 weeks in warmer months & way longer in winter. They have 5 instars. In the first instar it eats fresh tender leaves from underneath. Then from the second instar instar it lives individually in a silken tent which it makes by attaching silken strands to curl the leaf slightly which it is presently eating until there's not much of the leaf left, at which point it moves onto another leaf & repeats the process. The colour changing & leaf-curling is for camouflage & protection from the elements & predators. However to us human's & probably some other predators their 'tents' can be a give-away to their presence in the last 2 instars as they will chew part-way through the stem of the leaf to let it droop, before starting to eat the leaf from the tip. This is to stop the plant 'bleeding' sap & making feeding easier. They also are more likely to feed in the open in the last 2 instars. They generally eat the leaves of the foodplants only. Before pupating, they spend up to 2 days head-down in a 'J' position on a leaf with their anal prolegs attached to a silken pad. Grows up to 40mm when fully grown.

The Admiral caterpillars can be hard to tell apart, the two easiest ways in the field is that the Yellow Admiral has a broader pale patch of colour on abdominal segments 4 & 6 then the Red Admiral. The second being that Yellow Admirals are rarely recorded on Nettle Tree (Ongaonga) (Urtica ferox) in the wild, however they will feed on it in a captive environment. An expert can also notice that the ratios of the setae compared to their bases are different in each species. The Pupae are equally hard to tell apart, but the Yellow Admiral is generally stouter & darker then the Red Admiral.

Pupa In English

Shades of grey, brown, grey-brown with the odd gold spot, they sometimes have a more golden yellow colouration, but this usually indicates the presence of the parasite Echthromorpha intricatoria. The variation in colouration provides camouflage with their immediate environment & lighting conditions. The shape is angular, with a roughened surface. They are approx 20mm in length. They are attached head down by cremaster to some nearby sheltered spot. Pupation lasts between 10-18 days in summer & 25+ in winter. The wing colours show through in the last couple of days before emerging.

Imago In English

The imago has a 45-55mm wingspan. They have a broad yellow band on both sides of front wings. There is a Albino variation that has white bands & paler brown on the remaining parts of the wings. It has a strong & darting flight that sometimes can be direct, however it is not as strong as the Red Admiral. It is a sun worshipper & will align itself with the sun preferring to rest in a head-down position with wings open. It is often encountered sunbathing on walls, rocks, fences etc & can be seen feeding on sap from tree bark, berries, fruit juices, nectar plants like Buddleia & Hebe with Red Admirals. Over winter, Yellow Admirals go into a quiescence, so can be seen on warm winter days on winter flowers. Come spring they are not as common as Red Admirals due to half the population surviving winter as larvae which appear as imagos in late October. If they feel threatened, they will slowly open & close its wings without changing position. Males are territorial & will investigate any other butterfly in the hope of it being a suitable female, especially in the late afternoon when there is more freshly emerged females flying.

Habitat

A open country & garden butterfly that is seen in most types of habitat since it's foodplants grow in most habitats from the foothills to city gardens. Often seen sunning itself on rocks & paths, especially in the afternoon.

Status & Distribution

Widespread Found nationwide where it has a supply of it's foodplants. It is known to be a migratory species, so the native population possibly has a boost with migrants from Australia. It has had a population drop off again despite the slight increase in the 1970's & 80's due to reduced numbers of Nettles (Urtica spp) & since the introduction of the parasites (Ichneumon's & the wasp Pteromalus Puparum) to control the White Butterfly. However, the majority are probably lost to the self-introduced Australian Wasp, Echthromorpha intricatoria. Not present in the Chatham Islands.

Food Plants

It will feed on any of the Nettle species (Urtica spp), but prefers the softer leaved varieties like Small & Scrub Nettle (Urtica urens & Urtica incisa). It will eat the introduced Perennial Nettle (Urtica dioica). It has being recorded on New Zealand pellitory (Parietaria debilis), a stingless plant of the Nettle family.

Lifecycle

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