Tiracola plagiata (Walker, 1857)
Cacao Armyworm
(one synonym : Agrotis plagifera Walker, 1857)
Don Herbison-Evans
Stella Crossley

Tiracola plagiata
early instar
(Photo: courtesy of Ian Common, from Moths of Australia)

Early instars of this Caterpillar are smooth and mottled black, with pale yellow patches on the sides of the abdomen near the front and the back.

Tiracola plagiata
late instar
(Photo: courtesy of Harold McQueen, Goodna, Queensland)

Late instars are brown or green with faint diagonal markings along the sides, forming a series of vague chevrons along the back pointing to the tail. The tail segment is enlarged.

Tiracola plagiata
late instar
(Photo: courtesy of Harold McQueen, Goodna, Queensland)

The caterpillars are an international pest, attacking fruit, particularly:

  • Cacao ( Theobroma cacao, MALVACEAE ), and
  • Banana ( Musa acuminata, MUSACEAE ),

    and they also feed on other agricultural crops and weeds, including :

  • Richmond Birdwing Vine ( Pararistolochia praevenosa, ARISTOLOCHIACEAE ),
  • Striped Cucumber ( Diplocyclos palmatus, CUCURBITACEAE ),
  • Yam ( Dioscorea species, DIOSCOREACEAE ),
  • Red Cedar ( Toona australis, MELIACEAE ),
  • Gum Tree young sucker growth ( Eucalyptus, MYRTACEAE ),
  • Inkweed ( Phytolacca octandra, PHYTOLACCACEAE ),
  • Greater Plantain ( Plantago major, PLANTAGINACEAE ),
  • Purslane ( Portulaca oleracea, PORTULACACEAE ),
  • Coffee ( Coffea arabica, RUBIACEAE ), and
  • Tomatillo ( Physalis ixocarpa, SOLANACEAE ).

    Tiracola plagiata
    late instar head and thorax close-up
    (Photo: courtesy of Harold McQueen, Goodna, Queensland)

    The caterpillar grows to a length of about 5 cms.

    Tiracola plagiata
    (Photo: courtesy of Ann Peach, Maryborough, Queensland)

    It pupates in a sparse cocoon in the soil. The pupa is brown with four spines at the tip of the abdomen, and has a length of about 3 cms.

    Tiracola plagiata
    (Photo: courtesy of Donald Hobern, Blackheath, New South Wales)

    The adult moths have brown forewings, each with a variable pattern including a dark roundish patch in the middle often extending to the middle of the costa. The hindwings that are plain brown fading toward the bases. The moths have a wingspan up to 5 cms.

    Tiracola plagiata
    (Photo: courtesy of the Photography Group, Centre for Biodiversity Genomics, University of Guelph)

    This species may be found mainly in south-east Asia and the south Pacific, including

  • Borneo,
  • Cook Islands,
  • India,
  • Malaysia,
  • Mexico,
  • New Guinea,
  • Sri Lanka,
  • Taiwan,

    and the northern two-thirds of Australia including

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

    Tiracola plagiata
    Norfolk Island, 1976

    Further reading :

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press, 1990, fig. 49.17, p. 465.

    Ron May,
    A recent noctuid to Toowoomba, Qld- the Banana Fruit Caterpillar Tiracola plagiata (Lepidoptera: Noctuidae),
    Butterflies and Other Invertebrates Club,
    Metamorphosis Australia,
    Issue 60 (March 2011), p. 12.

    Peter Marriott & Marilyn Hewish,
    Moths of Victoria - Part 9,
    Cutworms and Allies - NOCTUOIDEA (C)
    Entomological Society of Victoria, 2020, pp. 28-29.

    M.E. Temperley,
    Life history notes on the banana fruit eating caterpillar (Tiracola plagiata Walk.),
    Queensland Agricultural Journal,
    Volume XXXIII, part 4 (April 1930), pp. 551-561.

    E.L. Todd and R.W. Poole,
    The American species of the Tiracola plagiata Walker complex,
    Proceedings of the Entomological Society of Washington,
    Volume 82, pp 396-400.

    Francis Walker,
    List of the Specimens of Lepidopterous Insects in the Collection of the British Museum,
    Part 11 (1857), pp. 740-741, 'page' 347.

    Australian Butterflies
    Australian Moths

    (updated 14 April 2013, 11 July 2019, 7 November 2020, 21 April 2022)