Theretra oldenlandiae (Fabricius, 1775)
Impatiens Hawk Moth
(one synonym : Deilephila argentata Stephens, 1828)
Don Herbison-Evans,
Stella Crossley

Theretra oldenlandiae
early instars
(Photo: courtesy of Jan MacDonald, Mackay, Queensland)

These Caterpillars can sometimes be a pest in Sydney gardens on :

  • Busy Lizzie ( Impatiens wallerana, BALSAMINACEAE ), and
  • Fuchsias ( Fuchsia species, ONAGRACEAE ),

    Theretra oldenlandiae
    (Photo: courtesy of Michael Manning)

    The first and second instars of these caterpillars are green with a row of dark-outlined pale spots along each side of the back, and a black tail spike.

    Later instars are black, the rows of spots become yellow, and spike on its tail becomes a thin spine. As they walk, this spine does a cute wiggle. The head and thorax are rather narrower than the abdomen. The last instar develops yellow bands between segments, and the spots can become red.

    Theretra oldenlandiae
    (Photo: courtesy of Clint Siggins, Newcastle, New South Wales)

    The caterpillars have also been found feeding on a wide variety of plants from other familes, including :

  • Arum Lily ( Zantedeschia aethiopica, ARACEAE ),
  • Argentine Trumpet Vine ( Clytostoma callistegioides, BIGNONIACEAE ),
  • Climbing Guinea Flower ( Hibbertia scandens, DILLENIACEAE ),
  • Billy Goat Plum ( Planchonia careya, LECYTHIDACEAE ),
  • Star Cluster ( Pentas lanceolata, RUBIACEAE ),
  • Australian Native Violet ( Viola hederacea, VIOLACEAE ), and
  • Slender Grape ( Cayratia clematidea, VITACEAE ).

    Theretra oldenlandiae
    (Photo: courtesy of Simon Hunt)

    Theretra oldenlandiae
    (Photo: courtesy of Genevieve Schebeck)

    Theretra oldenlandiae
    (Photo: courtesy of David Lewis)

    However, in captivity, the caterpillars quite happily consume and thrive on:

  • Lettuce ( Lactuca sativa, ASTERACEAE ).

    The caterpillars grow to a length of about 7 cms.

    Theretra oldenlandiae
    (Photo: courtesy of Catriona Coote, Sydney, New South Wales)

    Theretra oldenlandiae
    (Photo: copyright Lyn Finn,
    Hunter Region School of Photography in Newcastle,
    Macquarie Hills, New South Wales)

    The caterpillars pupate in a sparse dark cocoon in the leaf litter on the soil near the food plant. The pupa is a variable patchy brown, sometimes with some black spots on the sides, and has a length of about 4 cms.

    Theretra oldenlandiae
    (Photo: courtesy of Merlin Crossley, Melbourne, Victoria)

    The adult moth is brown, with a light stripe edged with dark brown extending from the hind margin to the tip of each forewing. The hind margin is sinuously curved. The moth has a pair of white stripes running along its back from its nose to its tail. The wingspan is about 6 cms.

    The eggs are green and oval, with a length of about 1.6 mm. The eggs are laid singly on the underside of foodplant leaves.

    The species is found as various subspecies across most of south-east Asia, from India to Australia, including :

  • Borneo,
  • China,
  • Japan,
  • Papua,
  • Philippines, and
  • Taiwan.

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

    In Australia, specimens have been taken in :

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

    Further reading :

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press, 1990, pls. 16.9, 29.10, 29.11, p. 415.

    Johan Christian Fabricius,
    Historiae Natvralis Favtoribvs,
    Systema Entomologiae,
    1775, p. 542, No. 21.

    Max S. Moulds, James P. Tuttle and David A. Lane.
    Hawkmoths of Australia,
    Monographs on Australian Lepidoptera Series, Volume 13 (2020),
    pp. 257-260, Plates 67, 81, 92.

    Buck Richardson,
    Tropical Queensland Wildlife from Dusk to Dawn Science and Art,
    LeapFrogOz, Kuranda, 2015, p. 204.

    Australian Butterflies
    Australian Moths

    (written 16 August 1996, updated 29 March 2018, 13 December 2020)