Bathytricha truncata (Walker, 1856)
Sugarcane Stem Borer, Maned Moth
(one synonym : Nonagria exitiosa Olliff, 1893)
Don Herbison-Evans
Stella Crossley

(Photo: courtesy of Bureau of Sugar Experiment Stations, Bundaberg, Queensland)

These Caterpillars are pale pink or purple, with black spots. They bore into the stems of their foodplants, leaving smelly messy fecal matter behind in the hole as they go. They move to new stem after they destroy the one on which they were feeding, and this way, they may destroy a whole plant.

The caterpillars are an agricultural pest, attacking a variety of plants from the family POACEAE, including:

  • Rice ( Oryza sativa ),
  • Sugar Cane ( Saccharum officinarum ),
  • Wheat ( Triticum aestivum ),
  • Maize ( Zea mays ),

    as well as various grasses, such as:

  • Rhodes Grass ( Chloris gayana ),
  • Crowsfoot Grass ( Dactyloctenium species ),
  • Red Natal Grass ( Melinis repens ),
  • Guinea Grass ( Panicum maximum ), and
  • Dallisgrass ( Paspalum dilatatum ).

    The caterpillars have even been reported to attack:

  • Gladiolus ( Gladiolus grandiflorus, IRIDACEAE ), and
  • Ginger ( Zingiber officinale, ZINGIBERACEAE ).

    They grow to a length of about 4 cms.

    They pupate in the tunnel they have bored. The pupae have a length of about 2 cms. The pupal stage lasts for about 12 days in summer.

    (Photo: courtesy of Katarina Christenson, Melba, Australian Capital Territory)

    The adult moth is beige, with some dark markings, and a narrow dark line from base to mid-margin on each forewing.

    (Photo: courtesy of CSIRO/BIO Photography Group, Centre for Biodiversity Genomics, University of Guelph)

    The female moths lay about 600 eggs, in clusters under the edges of leaves of foodplants. The eggs hatch in about eight days.

    The species is found over most of Australia, including

  • Queensland,
  • New South Wales,
  • Australian Capital Territory,
  • Victoria,
  • Tasmania, and
  • South Australia.

    Further reading :

    J.R. Agnew (ed.),
    Australian Sugarcane Pests,
    Bureau of the Sugar Experiment Stations,
    Indooroopilly: 1997, pp. 42-43.

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press 1990, p. 462.

    Peter Marriott & Marilyn Hewish,
    Moths of Victoria - Part 9,
    Cutworms and Allies - NOCTUOIDEA (C)
    Entomological Society of Victoria, 2020, pp. 6-7, 12-13.

    Francis Walker,
    Catalogue of Lepidoptera Heterocera,
    List of the Specimens of Lepidopterous Insects in the Collection of the British Museum,
    Part 9 (1856), p. 111, No. 79.

    Australian Butterflies
    Australian Moths

    (updated 1 July 2010, 7 January 2024)