Ectropis bispinaria

Ectropis bispinaria (Guenée, 1857)
(one synonym is Tephrosia subtinctaria Walker, 1860)
Loop-line Bark Moth
BOARMIINI, ENNOMINAE, GEOMETRIDAE, GEOMETROIDEA

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

male caterpillar
(Photo: courtesy of Mike and Pat Coupar, Moths of Victoria: Part 7)

These Caterpillars are brown loopers with a blunt pair of horns on the tail, The males have a black and white mark about halfway along on each side, and the females are plain brown.

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

The caterpillars rest characteristically sitting on their last pairs of legs, with their other prolegs folded into the body. This makes the caterpillar look like a twig, unless it happens to be standing on the edge of a leaf ! If harassed, early instars drop down on a silken thread until danger passes, then they laboriously climb back up it.

The caterpillars have been found feeding on a wide variety of plants, including:

Dahlia ( Dahlia pinnata, ASTERACEAE ),

Avocado ( Persea americana, LAURACEAE ),

Roses ( Rosa odorata, ROSACEAE ),

Lemon ( Citrus limon, RUTACEAE ),

as well as the Australian natives:

Australian mulberry ( Hedycarya angustifolia, MONIMIACEAE ) and

Silky Oak ( Grevillea robusta, PROTEACEAE ).

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

The caterpillars grow to a length of about 4 cms. They have been found to burrow down about 2 cms. into the soil to pupate.

The adult is a variable brownish fawn colour, with wavy dark lines on the wings. Like most Ectropis species, it has a blurry dark blotch near the middle of each forewing, and dark marks on the first abdominal segment. which align with wavy dark lines on the hindwings when the moth is at rest. Like most geometrids, the moth rests with wings outspread.

female
(Photo: courtesy of Marilyn Hewish, Moths of Victoria: Part 7)

The males and females have slightly different patterns. The female moth has a wingspan of about 4 cms. The male has only a span of 3 cms.

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

The antennae are thread-like on the female, but the male has very small pectinations giving the antennae a thickened appearance. The male Ectropis bispinaria moths have shorter pectinations than those of Ectropis excursaria, enabling the latter to be identified if the moth has the pectinations extended.

male
(Photo: courtesy of Marilyn Hewish, Moths of Victoria: Part 7)

The adults are otherwise similar to those of Ectropis excursaria, except Ectropis bispinaria has a smoothly curved dark submarginal arc, often dotted, on each hindwing extending from hind margin to costa, whereas generally Ectropis excursaria has a continuous line with a step by the costa.

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

Specimens have been collected in

Queensland,

New South Wales,

Victoria, and

Tasmania.