Achaea janata

Achaea janata (Linnaeus, 1758)
(one synonym : Phalaena melicarta)
Croton Caterpillar
CATOCALINAE , NOCTUIDAE

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

(updated 14 August 2008)

These Caterpillars hatch from blue spherical eggs, each about half a millimetre across, laid singly on the food plant.

(Photo: courtesy of Carol Lockyer, Brisbane)

The Caterpillars are initially brown with a black and white head, a red knob on the tail, and a black mark on the back of the second abdominal segment. The spiracles on each side of the abdominal segments are black. In the last instars, the brown turns to bluish-grey, and the point on tail turns black.

(Photo: courtesy of Carol Lockyer, Brisbane)

The first pair of prolegs of the Caterpillars is degenerate, and so the Caterpillars move in a looper fashion.

(Photo: courtesy of Carol Lockyer, Brisbane)

Specimens have been found feeding on a variety of plants including:

Grey Mangrove ( Avicennia marina, ACANTHACEAE ),

Orchid Trees ( Bauhinia species, CAESALPINIACEAE ),

Green Rose ( Aeonium canariense, CRASSULACEAE ),

Soybeans ( Glycine max, FABACEAE ),

Cotton ( Gossypium hirsutum, MALVACEAE ),

Wattles ( Acacia species, MIMOSACEAE ),

Gum Trees ( Eucalyptus species, MYRTACEAE ),

Three Corner Jack ( Emex species, POLYGONACEAE ),

Macadamia Nuts ( Macadamia integrifolia, PROTEACEAE ),

Roses ( Rosa odorata, ROSACEAE ),

Lychee ( Litchi chinensis, SAPINDACEAE ),

Puncture Vine ( Tribulus species, ZYGOPHYLLACEAE ),

and is a pest at times on

Hoop Pine seedlings ( Araucaria cunninghamii, ARAUCARIACEAE ),

Tamarind ( Tamarindus indica, CAESALPINIACEAE ), and

Castor Oil Plants ( Ricinus communis, EUPHORBICEAE ).

(Photo: courtesy of John Moore, Karratha, Western Australia)

The Caterpillars grow to a length of about 5 cms. They pupate in a white cocoon between leaves and stems of the foodplant.

(Photo: courtesy of John Moore, Karratha, Western Australia)

The adult moth has forewings that have a pattern of light and dark brown, and hind wings that are black with three white spots along the margin, and an inner unbroken white band. The moth has a wingspan of about 6 cms. The pheromones of the species have been studied. A number of control measures have been proposed.

(Specimen: courtesy of Dawn Bishop, Bundaberg, and
the Macleay Museum, University of Sydney)

The adult moth is known to feed on fruit juice, and is suspected of piercing fruit to obtain it.

Cocos Islands 1982

The species occurs from south-east Asia to the south Pacific, including :

Thailand, as well as

most of Australia.