Leucomonia bethia (Kirby, 1877)
(one synonym is Meganoton distinctum Rothschild, 1894)
Don Herbison-Evans
Stella Crossley

Leucomonia bethia
(Photo: courtesy of Paul Kay, Pilbara, Western Australia)

Early instars of this Caterpillar are green with a straight dark brown tail-horn. Later instars caterpillars develop diagonal white stripes on the side of each segment and the horn curves backward. There is a brown mottled form of later instars for which the diagonal stripes are less conspicuous. The caterpillars usually rest by day on the undersides of the leaves of foodplants. The caterpillars have been found feeding on :

  • Lolly Bush ( Clerodendrum floribundum, LAMIACEAE ).

    The caterpillar grows to a length of about 7 cms.

    Pupation occurs in a cell dug in the soil down about 12 cms. The inside of the cell is hardened with regurgitated fluid The pupa is brown with a curved extension for the haustellum of the developing moth.

    Leucomonia bethia
    male, with eroded dorsal scales
    (Photo: courtesy of Paul Kay, Pilbara, Western Australia)

    The adult moths of this species have patchy grey forewings, each with vague broad dark bands, and a dark wavy line across costal bulge near the wing-tip, and also have a dark dot near the middle. The hindwings are dark brown, with variable pale marginal and submarginal bands. The hindwings margins are sinuous near the tornus. The abdomen has a dark dorsal line. The wingspan is of the males is about 11 cms. The wingspan is of the females is about 12 cms.

    The dorsal hairy scales on abdomen are easily lost in flight. revealing a set of dark triangles.

    Leucomonia bethia
    (Photo: courtesy of Paul Kay, Pilbara, Western Australia)

    The eggs are spherical and green, and laid singly on a leaf of a foodplant.

    The species is found inland in

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

    Leucomonia bethia
    drawing by Rothschild, listed as Meganoton distinctum,

    Notes on Sphingidae, with descriptions of new species,
    Novitates Zoologicae, Volume 1, Number 1 (1894), Plate VII, fig. 19,
    image courtesy of Biodiversity Heritage Library,
    digitized by Natural History Museum Library, London.

    Further reading :

    William Forsell Kirby,
    Notes on the new or rare Sphingidae in the Museum of the Royal Dublin Society,
    Transactions of the Entomological Society of London,
    1877, Part 3, pp. 238, 243.

    David A. Lane,
    Life history notes on 'Leucomonia bethia' (Kirby) (Lepidoptera: Sphingidae),
    Australian Entomologist,
    Vol. 33, Part 1 (March 2006), pp. 31-34.

    Max S. Moulds, James P. Tuttle and David A. Lane.
    Hawkmoths of Australia,
    Monographs on Australian Lepidoptera Series, Volume 13 (2020),
    pp. 163-166, Plates 37, 73, 88.

    Lionel Walter Rothschild,
    Notes on Sphingidae, with descriptions of new species,
    Novitates Zoologicae,
    Volume 1, Number 1 (1894), p. 89,, and also Plate 7, fig. 19.

    Australian Butterflies
    Australian Moths

    (written 13 September 2006, updated 2 March 2015, 10 December 2020)