Plutella xylostella (Linnaeus, 1758)
(one synonym:
Tinea cinerea)
Diamond Back or Cabbage Moth
PLUTELLIDAE
Don Herbison-Evans (
donherbisonevans@yahoo.com )
&
Stella Crossley
(updated 22 August 2004)
(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,
where it is now found in every state.
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 ).
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.
adult moth
(Photo: copyright Lyn Finn,
Hunter Region School of Photography in Newcastle,
Macquarie Hills, New South Wales)
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.
Its
pheromones have been elucidated.
Internationally, it is a pest in:
Australia,
Canada,
France,
Germany,
Hawaii,
India,
Kenya,
Sarawak,
Sweden,
Thailand,
United Kingdom, and
United States America.
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,
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, p. 208.
