Ectropis excursaria (Guenée, 1857)
Twig Looper or Common Bark Moth
(one synonym is : Tephrosia exportaria Guenée, 1857)
Don Herbison-Evans
Stella Crossley

Ectropis excursaria
early instar, magnified
(Photo: courtesy of Cathy Byrne)

These caterpillars are loopers come in a range of colours, from greenish grey through brown to red. Early instars have a dark mark about half way along each side, on the second abdominal somite. Later this becomes black and white.

Ectropis excursaria
(Photo: courtesy of Peter Marriott, Moths of Victoria: Part 7)

Final instars may lose these marks and may develop other marks or have no marks at all. They develop a small pair of dark or reddish dorsal horns at the rear.

Ectropis excursaria
late instar
(Photo: courtesy of Merlin Crossley, Melbourne, Victoria)

The caterpillars rest characteristically sitting on their last pairs of legs, with their other true legs folded into the body. The caterpillars lay a silken thread wherever they travel, and if harassed, will drop down on the thread until danger passes, then they laboriously climb back up it.

Ectropis excursaria
another late instar
(Photo: courtesy of Harold McQueen, Goodna, Queensland)

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

  • Ivy ( Hedera helix, ARALIACEAE ),
  • Geranium ( Pelargonium x zonale, GERANIACEAE ),
  • Walnut ( Juglans regia, JUGLANACEAE ),
  • Sage ( Salvia officinalis, LAMIACEAE ),
  • Monterey Pine ( Pinus radiata, PINACEAE ),
  • Roses ( Rosa odorata, ROSACEAE ),
  • Gardenia ( Gardenia jasminoides, RUBIACEAE ), and
  • Lemon ( Citrus limon, RUTACEAE ),

    as well as the Australian native plants:

  • Senna ( Cassia species, CAESALPINIACEAE ),
  • Purple Coral Pea (Hardenbergia violacea, FABACEAE ),
  • Wattle ( Acacia species, MIMOSACEAE ),
  • Gum Trees ( Eucalyptus species, MYRTACEAE ),
  • Bursaria ( Bursaria species, PITTOSPORACEAE ), and
  • Needlewood ( Hakea species, PROTEACEAE ).

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

    The caterpillars grow to a length of about 4 cms.

    Ectropis excursaria
    (Photo: courtesy of Cathy Byrne)

    Pupation occurs in a soil cell, and in summer the adult moth emerges about two weeks later.

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

    The adult is grey to light brown, with a wavy lines of various shades of grey and brown. 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 double wavy dark lines on the wings when the moth is at rest.

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

    The undersides are pale brown with a small brown spot in the centre of each wing. Like most geometrids, the moth rests with wings outspread. The adults blend in well with the bark of many trees. However, the moths show little preference for resting on such material, and are frequently found on plain walls and window-sills! The wingspan is about 3 cms.

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

    The antennae is threadlike on the female, and the male has pectinations about twice the width of the filament. This is different from Ectropis bispinaria, the male of which has shorter pectinations. But the male Ectropis excursaria may fold the pectinations at times, so merely giving the antennae a thickened appearance.

    The adult Ectropis excursaria moth has a large kink in the forewing central black transverse line by the central dark mark, which is similar to that of Ectropis bispinaria, but Ectropis excursaria differs in having a dark curved submarginal line on each hindwing that is incomplete or stepped at the costal end.

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

    The eggs are laid in untidy clusters, and are pale green, oval, and covered in microscopic dimples.

    Ectropis excursaria
    (Photo: courtesy of Cathy Byrne)

    The species occurs all over Australia, including

  • Queensland,
  • New South Wales,
  • Australian Capital Territory,
  • Victoria,
  • Tasmania,
  • South Australia, and
  • Western Australia.

    The moths and caterpillars are found throughout the year in suburban gardens of Sydney and Melbourne.

    Ectropis excursaria
    (Photo: courtesy of Tim Leach, Evatt, Australian Capital Territory)

    Further reading :

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press, 1990, fig. 36.2, pp. 67, 367.

    Achille Guenée,
    Uranides et Phalénites,
    in Boisduval & Guenée: Histoire naturelle des insectes; spécies général des lépidoptères,
    Volume 9, Part 9 (1857), pp. 267-268, No. 416.

    Marilyn Hewish,
    Moths of Victoria: Part 7,
    Bark Moths and Allies - GEOMETROIDEA (D)
    Entomological Society of Victoria, 2016, pp. 30-31.

    Peter B. McQuillan, Jan A. Forrest, David Keane, & Roger Grund,
    Caterpillars, moths, and their plants of Southern Australia,
    Butterfly Conservation South Australia Inc., Adelaide (2019), p. 117.

    Australian Butterflies
    Australian Moths

    (updated 16 September 2013, 16 May 2023)