Euploea core

Euploea core (Cramer, [1780])
Common Crow or Oleander Butterfly
DANAINAE , NYMPHALIDAE

Don Herbison-Evans ( donherbisonevans@yahoo.com )
and
Stella Crossley & John Stumm

(updated 10 May 2008)

Euploea core
(Photo: courtesy of Russell Yates, Woodgate, Queensland)

This animal is famous for its pupa. The pupa is a shiny metallic silvery gold all over, and is about two centimetres long. It is found hanging from the underside of a leaf of its food plant. The pupa in spite of its appearance is not metallic. The shining effect is the result of of being covered in a number of transparent layers of skin.

(Photo: courtesy of Russell Yates, Woodgate, Queensland)

The Caterpillar has alternating bands or orange, black and white all along the body, and has eight black tentacles in pairs: on the mesothorax, the metathorax, and on abdominal segments two and eight.

(Photo: courtesy of Coralie (aka ferrous angel))

When disturbed, it raises the front of its body, and curls its head underneath.

(Specimen: courtesy Joan Tyson, Bundaberg)

It is usually found on:

Oleander ( Nerium oleander, APOCYNACEAE ).

The Caterpillars have been found for many years on the Oleander bushes along the main street of Newport in the northern suburbs of Sydney, but curiously, not on similar bushes along the adjacent side roads. It is possible that the local Council, in pruning the bushes back each year on the main road, stimulated the growth of more suitable shoots for the Caterpillars to eat, than were available on the less disturbed bushes in the side roads.

It has also been found feeding on:

Morton Bay Fig ( Ficus macrophylla, MORACEAE ), and

Frangipani ( Plumeria alba, APOCYNACEAE ),

as well as a number of other plants in MORACEAE and APOCYNACEAE.

At about mid-larval stage, an interesting feeding habit develops. It is well illustrated at the extreme right-hand side of the photo by Joan Tyson. Before starting to eat a new leaf, the Caterpillar first chews the under surface of its pedicle until the leaf began to sag. It then eats the whole leaf, and the repeats the procedure on subsequent leaves. In summer in Sydney, the larval phase had lasts about 21 days. The Caterpillar grows to a length of about 6 cms.

the pupation process

About twelve hours after pupation, the fully formed pupa is a rich creamy colour. The silver phase occurs about a day later. The pupal stage in summer in Sydney lasts about seven days. On the morning of emergence, the pupa becomes almost black with the pale legs of the adult lying bunched together on the abdomen and some white blotches on the wing outlines. After the adult had emerges, it is able to fly within about eight hours.

The adult butterflies have a wing span around 7 cms. They are black with small white spots on the edges of the wings, and larger spots further in. On the hind wings, these large spots form a marginal row, and some spots are in pairs. On the forewings, the large spots vary in size, and form a less well defined row. In males, the hind margin of the forewing is bowed; in the female it is straight. The adults only have four legs.

(Photo: courtesy of Ian McMillan, Imbil, Queensland)

The eggs are cream coloured and have a height of about 2 mm. They are laid singly on the undersides of young leaves of the foodplant. One of us has a Small-leafed Moreton Bay Fig Bonzai tree and found a small white egg on one of the leaves on the 1st of January one year. It hatched about one week later. By length 8 mm it was recognized as the larva of the Euploea core.

The adult butterflies congregate in groups of thousands at various sheltered coastal valleys from Brisbane to Townsville to pass the winter in a state of hibernation.

(Photo: courtesy of Coralie (aka ferrous angel))

The species is known as various races across south-east Asia, including :

Guam,

Hong Kong,

India,

Sri Lanka,

Thailand, as well as

the race corinna in the northern half of Australia.

It seems to be a species that prefers a tropical climate, but does breed in New South Wales, and occasionally spreads as far south as Victoria and South Australia.

Cocos Islands 1982

The adult butterflies have been quoted as having a lifespan of eleven to thirteen weeks. They have been found overwintering in large crowded congregations in particular places in Queensland. Butterflies of this species may be purchased in Australia for release at weddings etc.