South Perth, Western Australia
March 5, 2008
The Department of
Agriculture and Food is proposing new measures to protect
the Kimberley region from silverleaf whitefly, a serious pest of
vegetable and cotton crops.
A set of proposed restrictions on the movement of nursery stock,
cutflowers and leafy vegetable hosts to the Kimberley from other
parts of Western Australia has been developed and is available
for public comment until 4 April 2008.
Department Kununurra district manager Noel Wilson said
silverleaf whitefly was first detected in Australia in Darwin in
1994. By 1995, it was found to be widespread in Queensland and
northern New South Wales.
“The pest has more recently been detected in the Perth and
Carnarvon areas of Western Australia, but has not been recorded
in the Kimberley region,” Mr Wilson said.
“To prevent the spread of silverleaf whitefly to the Ord
production areas from within Western Australia, the department
has proposed restrictions that are similar to those already in
place for interstate imports.”
Silverleaf whitefly is a small sap-sucking insect, related to
mealybugs and aphids. It can cause premature leaf drop, the
development of sooty mould, and reduced yield. Plants and plant
products can become disfigured and be unmarketable.
Mr Wilson said it had an extensive host range of over 500
species including cotton, avocado, beans, cabbage, capsicum,
cucumber, egg plant, melon, tomato, lettuce, papaw, potato,
pumpkin, squash,
sweet potato, begonia and poinsettia.
Both nymph and adult whitefly cause direct feeding damage by
piercing and sucking sap containing nutrients from the leaves.
The feeding adults and nymphs cause spots to appear on the
surface of leaves and depending on the level of infestation, the
spots may cause the whole leaf to turn yellow or silver.
The honeydew produced by the feeding nymphs covers the underside
of leaves, leading to the development of sooty moulds.
Honeydew can also disfigure flowers and, in cotton, cause
problems in lint processing.
Mr Wilson said the proposed restrictions included six options
for the importation of host nursery stock, cut flowers/foliage
and leafy vegetables.
“These proposed import conditions provide alternative options
for exporters to safely send host products to the Kimberley
ranging from certification to pre-shipment and arrival
inspections or fumigation,” he said.
“They include specific importation and treatment requirements
for host plants and parts of plants, in addition to standard
general quarantine requirements.”
Copies of the Proposed restrictions on nursery stock, cut
flowers/foliage and leafy vegetable hosts of silverleaf whitefly
can be downloaded from the Department’s website at
www.agric.wa.gov.au
Comments can be forwarded to Graeme Lukeis at the Department of
Agriculture and Food Locked Bag No. 4 Bentley Delivery Centre WA
6983. Email
glukeis@agric.wa.gov.au; phone 9368 3859. |
|
