Achaea argilla (Swinhoe, 1901)
Plain Looper
Don Herbison-Evans
Stella Crossley

These Caterpillars are initially blue-grey with black spiracles, and a grey and white head. There are raised black and white markings on the second and last abdominal segments.

Achaea argilla

Later the caterpillars become reddish brown with a black and white head, with a pair of red knobs on the tail, and a black mark on the back of the second abdominal segment. The spiracles on each side of the abdominal segments are orange with a black mark above each one. The first pair of prolegs of the caterpillars is degenerate, and so the caterpillars move in a looper fashion.

Achaea argilla

We have found specimens on :

  • Willgar ( Breynia oblongifolia, PHYLLANTHACEAE ), and
  • Spurge ( Euphorbia sp., EUPHORBICEAE ).

    The caterpillars grow to a length of about 5 cms.

    One pupated at the top of the jar in which it was kept, in a sparse cocoon that broke as soon as the jar lid was twisted for removal and inspection, dropping the pupa to the bottom! The pupae are initially dark brown but soon become white.

    Achaea argilla

    The adult moth has forewings that have a subtle brown pattern, and hindwings that are black with three white spots along the margin, and an unbroken white band across the middle. Underneath: the forewings have a white band between two black ones, and the hindwings have a blackspot near the tornus. The moth has a wingspan of about 5 cms.

    Achaea argilla
    (Specimen: courtesy of the Macleay Museum, University of Sydney)

    The caterpillars hatch from blue spherical eggs, each about half a millimetre across, laid in small arrays on the leaf of a food plant.

    Achaea argilla

    The species is found over much of Australia, including

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

    Achaea argilla
    (Photo: courtesy of Graeme Cocks, Townsville, Queensland)

    Further reading :

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press, 1990, fig. 46.11, p. 453.

    Peter Marriott,
    Moths of Victoria - Part 8,
    Night Moths and Allies - NOCTUOIDEA(B)
    Entomological Society of Victoria, 2017, pp. 22-23.

    Charles Swinhoe,
    On Indian and Australian moths,
    The Annals and Magazine of Natural History,
    Series 7, Volume 8 (1901), p. 132.

    Australian Butterflies
    Australian Moths

    (updated 23 June 2011, 26 August 2023)