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
(Photo: courtesy of Cathy Young)

These caterpillars are brown loopers, initially with 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. There is a range of variation in colour at this stage. They develop a small double dark or reddish dorsal horn at the rear.

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

They rest characteristically sitting on their last pairs of legs, with their other prolegs folded into the body. They 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. They 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, MYRTACEAE ),
  • Bursaria ( PITTOSPORACEAE ), and
  • Needlewood ( Hakea, PROTEACEAE ).

    The caterpillars grow to a length of about 4 cms.

    Ectropis excursaria
    (Photo: courtesy of Cathy Young)

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

    Ectropis excursaria
    (Photo: courtesy of Ken Harris, Morwell Park, Victoria)

    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. The undersides are pale brown with a small brown spot in the centre of each wing. Like most geometrids, it 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 windowsills!

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

    The adult female is larger than the male, with a wingspan in the range from 3.0 to 4.5 cms. The antennae is threadlike on the female, and the male has small pectinations giving the antennae a thickened appearance. The adult moth is similar to that of Ectropis bispinaria, but differs in having an incomplete or stepped second submarginal line on each hindwing.

    Ectropis excursaria
    (Photo: courtesy of Cathy Young)

    The eggs are laid singly and are off-white, oval, and covered in microscopic dimples.

    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.

    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.

    Australian Butterflies
    Australian Moths

    (updated 16 September 2013, 7 February 2018)