Plutella xylostella (Linnaeus, 1758)
Diamond Back or Cabbage Moth
(one synonym : Tinea cinerea Geoffroy, 1785)
Don Herbison-Evans
Stella Crossley

Plutella xylostella
(Photo: courtesy of Michael Keller,
School of Agriculture and Wine,
University of Adelaide,
South Australia.)

This Caterpillar is a worldwide pest, and was unfortunately introduced into Australia by accident.

It is an agricultural pest on plants from the family BRASSICACEAE :

  • Chinese broccoli ( Brassica oleracea var. alboglabra ),
  • Cauliflower ( Brassica oleracea var. botrytis ),
  • Cabbage ( Brassica oleracea var. capitata ),
  • Brussel Sprouts, ( Brassica oleracea var. gemmifera ),
  • Broccoli ( Brassica oleracea var. italica ),
  • Chinese cabbage ( Brassica rapa var. pekinensis ),
  • Radish ( Raphanus sativus ),
  • Watercress ( Rorippa nasturtium-aquaticum ), and
  • Mustard ( Sinapsis alba ).

    Host plants also include several ornamentals, such as :

  • Wallflower ( Cheiranthus cheiri ),
  • Candytuft ( Iberis umbellata ),
  • Alyssum ( Lobularia maritima ), and
  • Stocks ( Matthiola longipetala ).

    An important reservoir for the species are various weeds, such as :

  • Wild mustard ( Brassica kaber ).

    Plutella xylostella
    cocoon and pupa
    (Photo: copyright Lyn Finn,
    Hunter Region School of Photography in Newcastle,
    Macquarie Hills, New South Wales)

    The caterpillar grows to a length of about 2 cms. It then pupates in an open mesh cocoon on a leaf of the foodplant.

    Plutella xylostella
    adult moth
    (Photo: courtesy of Donald Hobern, Aranda)

    The adult moth is brown with a pale zig-zag mark along the trailing edge of the fore wings. When the wings are closed, these create a series of diamond shapes along the back. It has a wingspan of about 1.5 cms. The pheromones of this species have been identified.

    Plutella xylostella
    (Photo: copyright Lyn Finn,
    Hunter Region School of Photography in Newcastle,
    Macquarie Hills, New South Wales)

    Internationally, it is a pest in:

  • France,
  • Hawaii,
  • India,
  • Japan,
  • Kenya,
  • United Kingdom, and
  • United States of America,

    as well as being occurring in Australia, including:

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

    This tiny moth is well-known for its migratory tendencies. Thousands have been counted in a single night crossing coastlines. Attempts to control this pest have included:

  • use of acylurea growth regulators,
  • luring them with pheromones,
  • the bacterium Bacillus thuringiensis ( BACILLACEAE ),
  • toxins from Bacillus thuringiensis,
  • natural virus diseases,
  • extract of Neem seeds,
  • the larval-parasitoid wasp Diadegma insulare ( BRACONIDAE ),
  • the egg-parasitoid wasp Trichogramma chilonis ( TRICHOGRAMMATIDAE ),
  • the fungus Beauveria bassiana ( CLAVICIPITACAEAE ), and
  • breeding transgenic plants that are resistant.

    Further reading :

    Ian F.B. Common,
    Moths of Australia, Melbourne University Press, 1990, fig. 21.7, p. 208.

    Paul Zborowski and Ted Edwards,
    A Guide to Australian Moths, CSIRO Publishing, 2007, pp. 24, 61.

    Australian Butterflies
    Australian Moths

    (updated 31 October 2012, 18 January 2014)