Coequosa triangularis (Donovan, 1805)
Double Headed Hawk Moth
(one synonym : Sphynx[sic] castaneus Perry, 1811)
Don Herbison-Evans,
Stella Crossley

Coequosa triangularis
plain green form
(Photo: Don Herbison-Evans, Sydney, New South Wales)

This Caterpillar presents a puzzle : deciding which end is the head ?

Coequosa triangularis
striped green form
(Photo: courtesy of Brian Lewin, Bermagui, New South Wales)

Its real head is an orange conical structure, but on its tail are two large raised black knobs.

Coequosa triangularis
tail: showing one of the false eyes
(Photo: courtesy of Kell Nielsen, Gold Coast)

These look like a pair of large eyes, so that an observer (and presumably a predator) finds it difficult to determine which end is actually the head, hence its common name.

Coequosa triangularis
true head showing real eyes
(Photo: courtesy of Kell Nielsen, Gold Coast)

The rest of the caterpillar is green or yellow, often with yellow diagonal stripes, sometimes with purplish lateral markings, and is covered in soft short pale spines.

Coequosa triangularis
plain yellow form
(Photo: courtesy of Judy and David Addleton, Kempsey)

The caterpillar feeds on various plants in PROTEACEAE, such as :

  • Candle Flowers ( Banksia ericifolia ),
  • Silky Oak ( Grevillea robusta ),
  • Finger Hakea ( Hakea dactyloides ),
  • Macadamia ( Macadamia integrifolia ),
  • Broad Leaf Geebung ( Persoonia levis ), and
  • Firewheel Tree ( Stenocarpus sinuatus ).

    Coequosa triangularis
    (Specimen: courtesy of the The Australian Museum)

    The caterpillar grows to a length of about 10 cms. To pupate it burrows into the soil to a depth down to 4 cms. The pupa is brown, with a length of about 7 cms.

    Coequosa triangularis
    (Photo: courtesy of Ros Runciman of Yeranda at Barrington Tops)

    The adult moth is yellow and brown with broad wavy markings, and is large, with a wingspan of about 13 cms.

    Coequosa triangularis
    (Photo: courtesy of Paul Kay, New South Wales)

    The species occurs in

  • Queensland,
  • New South Wales, and
  • Victoria.

    The eggs are green and oval, with a length of about 3 mm. As they near hatching, they become yellow, and develop a red encircling band. The eggs are laid singly on the underside of a leaf of a foodplant.

    Coequosa triangularis
    (Specimen: courtesy of Steven Dodge, Nowra, New South Wales)

    Further reading :

    David Carter,
    Butterflies and Moths,
    Collins Eyewitness Handbooks, Sydney 1992, p. 240.

    Glen Cleminson,
    Life History Notes on the Moth Coequosa triangularis (Donovan),
    Metamorphosis Australia,
    Issue 55 (December 2009), pp. 19-20,
    Butterflies and Other Invertebrates Club.

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press, 1990, pl. 16.1, p. 412.

    Edward Donovan,
    General Illustration of Entomology,
    An Epitome of the Natural History of the Insects of New Holland, New Zealand, New Guinea, Otaheite and other Islands in the Indian, Southern and Pacific Oceans,
    London (1803), Part 1, p. 138, and also Plate 33, fig. 2

    Peter Hendry,
    Coequosa triangularis,
    Butterflies and Other Invertebrates Club,
    Newsletter, Issue 49 (June 2008).

    Peter Marriott,
    Moths of Victoria - Part 1,
    Silk Moths and Allies - BOMBYCOIDEA
    Entomological Society of Victoria, 2008, pp. 30-31.

    Maxwell S. Moulds, James P. Tuttle and David A. Lane.
    Hawkmoths of Australia,
    Monographs on Australian Lepidoptera Series, Volume 13 (2020),
    pp. 103-108, Plates 20, 75, 86.

    Paul Zborowski and Ted Edwards,
    A Guide to Australian Moths,
    CSIRO Publishing, 2007, p. 31.

    Australian Butterflies
    Australian Moths

    (updated 15 June2010, 15 December 2013, 15 July 2020, 6 September 2022)