Theretra silhetensis (Walker, 1856)
Brown-banded Hunter Hawkmoth
(one synonym : Chaerocampa bisecta Moore, 1857)
Don Herbison-Evans,
Stella Crossley

Theretra silhetensis
early instar
(Photo: courtesy of Tom and David Sleep, Queensland)

Early instars of this species are green with a pale yellow lateral line each side of the body, and a dark tail spike.

Theretra silhetensis
late instar, green form
(Photo: courtesy of Tom and David Sleep, Queensland)

Later instars of these caterpillars have a row of seven half-eyespots along each side of the body. The spots consist of a round black spot half surrounded by a white semicircle, and this outlined by a black semicircular line.

Theretra silhetensis
late instar, brown form
(Photo: courtesy of Tom and David Sleep, Queensland)

The mature caterpillar has two forms: green and brown. For both forms: the lateral yellow lines run along each side just under the row of eyespots. The the tail spike of the mature caterpillar is short, backward curving, and may be red, cream, brown, and/or black.

Theretra silhetensis
(Photo: courtesy of Todd Burrows, South Stradbroke Island)

Although many food plants have been recorded, the illustrated specimens were found feeding on :

  • Water Primrose ( Ludwigia octovalis, ONAGRACEAE ).

    Theretra silhetensis
    (Photo: courtesy of Tom and David Sleep, Queensland)

    The caterpillar grows to a length of about 7 cms. The pupa is formed in a silk cocoon amongst the ground debris The pupa is elongated, and has dark and light brown striations. It has a length of about 4.5 cms.

    Theretra silhetensis
    (Photo: courtesy of Tom and David Sleep, Queensland)

    The adult moths of this species have light brown forewings each a dark dot near the middle, and with a dark stripe from base to apex separating a pale area on hind-margin side. The moths have brown hindwings, each with a broad indistinct pale submarginal band. A single white dorsal line runs over the thorax to the tip of the abdomen. The moths have a wingspan of about 6 cms.

    Theretra silhetensis
    (Photo: courtesy of Tom and David Sleep, Queensland)

    The eggs are laid singly under foodplant leaves or on flower heads. The eggs are oval and smooth, and pale green, with a length of about 1.4 mm.

    Theretra silhetensis
    an egg, magnified
    (Photo: courtesy of Tom and David Sleep, Queensland)

    The species is found as several subspecies over south-east Asia, including :

  • Borneo,
  • China,
  • India,
  • Indonesia, and
  • Sri Lanka.

    The subspecies intersecta (Butler, 1876) is found in

  • Fiji,
  • Papua,
  • Solomons,
  • Vanuatu,

    as well as in Australia in

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

    Theretra silhetensis
    (Photo: courtesy of Scott Gavins, Fraser Coast, Queensland)

    Further reading:

    Arthur G. Butler,
    Descriptions of several new species of Sphingidae,
    Proceedings of the Zoological Society of London,
    1875, p. 623.

    Maxwell S. Moulds, James P. Tuttle and David A. Lane.
    Hawkmoths of Australia,
    Monographs on Australian Lepidoptera Series, Volume 13 (2020),
    pp. 263-266, Plates 69, 81, 92.

    Buck Richardson,
    Tropical Queensland Wildlife from Dusk to Dawn Science and Art,
    LeapFrogOz, Kuranda, 2015, p. 205.

    Francis Walker,
    List of the Specimens of Lepidopterous Insects in the Collection of the British Museum,
    Volume 8 (1856), p. 143.

    Australian Butterflies
    Australian Moths

    (updated 22 April 2013, 7 May 2020)