Orgyia anartoides

Orgyia anartoides (Walker, 1855)
Painted Apple Moth (PAM)
(one synonym: Orgyia phineus Herrich-Schäffer, [1858])
LYMANTRIINAE, EREBIDAE, NOCTUOIDEA

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

early instars
(Photo: courtesy of David Akers, Won Wron, Victoria)

Ealy instars of this Caterpillar are usually dark brown and hairy, with a pair of hair pencils sticking out diagonally from each side of its head, and two yellow patches on the back. The young caterpillars eat the flesh only from one side of the leaf they are feeding on.

orange body, white tufts, brown head
(Photo: courtesy of Merlin Crossley, Melbourne, Victoria)

Later instars nibble from the edges of leaves, eating whole leaves. The body colour of later instars can vary from yellow to black, with several broken white lines running along the body.

black body, white tufts, black head
(Photo: courtesy of Merlin Crossley, Melbourne, Victoria)

The caterpillar has four tufts of hair on the backs of the first four abdominal segments. The colours of these four dorsal tufts vary from white through yellow or brown to black.

black body, white tufts and black tufts
(Photo: courtesy of Frances Mackay, Hobart, Tasmania)

There is also also a hair tuft on its tail, and also two black-tipped tufts on its head pointing diagonally left and right like a pair of horns.

dorsal view, black body, black tufts, black head
(Photo: courtesy of Mathew Haycock)

The colour of the head varies from pale brown to black. The thorax has two or four orange marks. There is an enigmatic dorsal yellow or red gland on each of the two or three penultimate abdominal segments, the function of which is unclear.

close-up of head of yellow form
(Photo: courtesy of David Akers, Won Wron, Victoria)

close-up of head of black form
(Photo: courtesy of Elaine McDonald, Nicholls Rivulet, Tasmania)

young caterpillars ballooning
(Photo: courtesy of Rudie Kuiter, Aquatic Photographics, Victoria) The hairs can cause skin irritation (urticaria) in people with sensitive skin.
The caterpillars have been found feeding on a variety of plants in suburban gardens including :

Dahlia ( Dahlia pinnata, ASTERACEAE ),
Cypress ( Cupressus, CUPRESSACEAE ),
Lupins ( Lupinus, FABACEAE ),
Geranium ( Pelargonium x zonale, GERANIACEAE ),
Gladiola ( Gladiolus byzantinus, IRIDACEAE ),
Albizia ( Albizia species, MIMOSACEAE ),
Banana Fruit ( Musa acuminata, MUSACEAE ),
Passionfruit ( Passiflora edulis, PASSIFLORACEAE ),
Primrose ( Primula, PRIMULACEAE ),
Roses ( Rosa odorata, ROSACEAE ),
Gardenia ( Gardenia jasminoides, RUBIACEAE ),
( Gardenia jasminoides, RUTACEAE ),
Willow ( Salix, SALICACEAE ),
Native Cherry ( Exocarpus cupressiformis, SANTALACEAE ),
Lantana ( Lantana camara, VERBENACEAE ).
In plantation forests, they are a pest on :

Monterey Pine ( Pinus radiata, PINACEAE ).
In the wild they feed on plants such as:

Coral Pea ( Hardenbergia species, FABACEAE ),
Wattles ( Acacia species, MIMOSACEAE ),
Bottlebrush ( Callistemon species, MYRTACEAE ),
Ferns ( POLYPODIOPHYTA ), and
Spider Flowers ( Grevillea species, PROTEACEAE ).
Perhaps because the females are flightless, the newly hatched caterpillars have a special way of dispersing by spinning threads of silk which are caught in the wind ("ballooning").
The male caterpillars grow to a length of about 2 cms.
The females grow to about 3 cms.

pupa in cocoon
(Photo : courtesy of Lorraine Jenkins, Port Lincoln Junior Primary School, South Australia)

They pupate amongst the leaves of the foodplant in a sparse cocoon that they decorate with hairs from their larval skin, making these cocoons likely to cause urticaria too. The adults emerge after a few days.

flightless female, close-up
(Photo: courtesy of Elaine McDonald, Nicholls Rivulet, Tasmania)

The female adult is dull brown with intersegmental fringes of pale hairs, and a band of pale hairs along each side. She is fat and flightless. She stays beside her cocoon emitting a pheromone to attract males. She has a length of about 1 cm.

eggs
(Photo: courtesy of Elaine McDonald, Nicholls Rivulet, Tasmania)

She lays eggs on and around her cocoon after fertilisation. The eggs are white and spherical.

The male has light and dark brown forewings with the various areas outlined in white. The hindwings are yellow with broad black margins. He has a wing span of about 2 cms.

male

The male undersides are fawn with a vague dark diagonal mark under each wingtip..

male, undersides
(Photo: courtesy of Dick Whitford, Mt Molloy, Queensland)

The species is found over most of Australia, including

Queensland,

New South Wales,

Australian Capital Territory,

Victoria,

Tasmania,

South Australia, and

Western Australia.

They seem to have ballooned their way across the Tasman Sea because the species has appeared in

New Zealand.

So far this species has not spread beyond Australasia, although related and similar species occur in America.

male
(Specimen: courtesy of the Macleay Museum, University of Sydney)

The sex pheromone components of this species has been determined by an international research team of Dr. Gerhard Gries (Simon Fraser Univ., Burnaby, B.C., Canada), Dr. John Clearwater (Clearwater Research & Consulting, Auckland, NZ) and Dr. Paul W. Schaefer (U.S. Dept. of Agric., Beneficial Insect Introd. Lab., Newark, USA). In December 2003, John Clearwater and Paul Schaefer completed the final field confirmation trapping in Campbelltown, NSW, using a completely synthetic lure, which proved to be very effective at attracting the males into traps. Therefore, there is now a powerful field sampling tool for population assessment, clarification of distribution or habitat preference, or behavior studies. This research was supported in part by Global Forest, an international research institute based in Banff, Alberta, Canada.

mating pair
(Photo: courtesy of Elaine McDonald, Nicholls Rivulet, Tasmania)

Control of the species is being attempted using:

extracts from the bacterium Bacillus thuringiensis

the release of irradiated (infertile) males, and

natural fly and wasp predators.

pale and dark males attracted to the same female
(Photo: courtesy of Rudie Kuiter, Aquatic Photographics, Victoria)