Polyura sempronius

Polyura sempronius (Fabricius, 1793)
CHARAXINAE , NYMPHALIDAE
Tailed Emperor

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

(updated 8 May 2008)

Polyura sempronius
early instar
(Photo: courtesy of Sharron Marks)

These Caterpillars are initially yellow with a black head. They change to green in later instars, with a number of yellow crescents distributed along the body, one each on the third and fifth segments, and sometimes on other segments as well.

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Caterpillar with few crescents
(Photo: courtesy of the Macleay Museum, University of Sydney)

The head is frightening, like a large green shield four horns on it, and smaller projections between them. In fact the animal is quite harmless.

Caterpillar with lots of crescents
(Photo: courtesy of Carol Buchanan)

The Caterpillar weaves a loose white cocoon on the leaves on which it is feeding, which is useful for spotting places to search for it. We have found it on various species of Wattle ( Acacia, MIMOSACEAE ) such as:

Cootamundra Wattle ( Acacia baileyana ),

Glory Wattle ( Acacia spectabilis ),

as well as other plants such as:

Poinciana ( Delonix regia, CAESALPINIACEAE ),

Black Locust ( Robinia pseudoacacia, FABACEAE ),

Camphor Laurel ( Cinnamomum camphora, LAURACEAE ),

Crepe Myrtle ( Lagerstroemia indica, LYRTHRACEAE ),

Black Booyong ( Argyrodendron actinophyllum, STERCULIACEAE ), and

Hackberry ( Celtis species, ULMACEAE ).

The caterpillars also commonly feed on the introduced :

Honey Locust ( Gleditsia triacanthos ), , and

Yellow Poinciana ( Peltophorum pterocarpum )

in FABACEAE, which are deciduous and causes fatalities to larvae in autumn when the leaves fall.

Caterpillar with web
(Photo: courtesy of Sharron Marks)

The caterpillar grows to a length of about 8 cms. It pupates dangling by its cremaster from the stem of its food plant, or an adjacent bush. The pupa is green with white bands where the wings develop, and a pair of white dorsal lines on the abdomen.

(Photo: courtesy of the Macleay Museum, University of Sydney)

The adult butterflies have a wing span up to 11 cms. The wings are predominantly cream and black above. The hind wings are extended into two narrow pointed tails on each side. There is an orange patch to the inside of these on each upper surface.

(Photo: courtesy of the Macleay Museum, University of Sydney)

Underneath, the wings are predominatly cream and brown, with orange and rusty brown markings.

(Photo: courtesy of the Macleay Museum, University of Sydney)

The adult butterflies are attracted to fermenting juice such as rotting fruit or sap. When they feed on this, they often become intoxicated and easy to capture.

The eggs are pale green and spherical with a diameter of about 2 mm. They are laid singly on the foodplant.

(Photo: courtesy of Sharron Marks)

The species is known across Australia. It seems to be a species that prefers a tropical or subtropical climate, but sometimes is found in further south, including:

Victoria, and

Butterflies of this species may be purchased for release at weddings etc.