Cnaphalocrocis medinalis (Guenée, 1854)
Rice Leaf Folder
(one synonym: Botys nurscialis Walker, 1859)
Don Herbison-Evans
Bart Hacobian & Stella Crossley

Cnaphalocrocis medinalis
(Photo: courtesy of Graeme Cocks, Townsville, Queensland)

The Caterpillar of this species is a translucent brownish green, and has two black spots on each thoracic segment, dark marks on the last two abdominal segments, and a brown head. The caterpillar is a pest throughout south-east Asia, feeding on various crops in POACEAE including:

  • Maize ( Zea mays ),
  • Wheat ( Triticum species ),
  • Sugar Cane ( Saccharum species ),
  • Sorghum, ( Sorghum species ), and
  • Rice ( Oryza sativa ).

    It rolls a leaf up to form a shelter in which it lives. When it feeds, it scrapes the flesh away from the leaf surface.

    Cnaphalocrocis medinalis
    (Specimen: courtesy of the Macleay Museum, University of Sydney)

    The adult female moth is pale brown, with dark margins, and with two dark lines across the each forewing, and one across each hindwing. The males are similar but paler and greenish, and have a thickened region on the costa of each forewing. The wingspan of the moths is about 1.5 cms.

    The moths are known to undertake migrations which makes control of the pest difficult. The pheromones of this species have been identified. Control of the pest is being attempted using :

  • the development of resistent varieties of rice,
  • insecticides,
  • Neem extracts,
  • semiochemicals for mass trapping, and
  • the nematode Steinernema carpocapsae ( STEINERNEMATIDAE ).

    The species is found in Asia, including :

  • Bhutan,
  • Cambodia,
  • China,
  • India, and
  • Indonesia,

    as well as in Australia in

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

    Further reading :

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press, 1990, pl. 9.10, pp. 355,357.

    Achille Guenée,
    Deltoïdes et Pyralites,
    in Boisduval & Guenée: Histoire Naturelle des Insectes; Spécies Général des Lépidoptères,
    Volume 9, Part 8 (1854), p. 201, No. 148.

    Peter Hendry,
    The Night of the Crambidae,
    Butterfly and Other Invertebrates Club Newslettter,
    Issue 49 (June 2008), pp. 26-29.

    Australian Butterflies
    Australian Moths

    (updated 26 January 2013, 30 November 2020, 17 February 2021)