Keeping crop nasties out

Five exotic crop pests we don't want to see here

Dale Grey, Agriculture Victoria, warns that strict protocols must be maintained to stop exotic pests hurting the Aussie grains sector.

Dale Grey, Agriculture Victoria, warns that strict protocols must be maintained to stop exotic pests hurting the Aussie grains sector.


The focus is currently on COVID-19 but Australian grains biosecurity teams continue the fight against other unwanted diseases and pests.


MIRRORING the Australian medical community's lion-hearted attempts to stop the spread of the deadly COVID-19 virus, Australia's grains industry biosecurity teams are also pushing to stop unwanted incursions which could cost the industry millions of dollars.

Dale Grey, Agriculture Victoria, said there were five major exotic pests his organisation had identified as key pests, with four of them not found in Australia and one, lupin anthracnose, limited to Western Australia.

Mr Grey said the Ag Vic coordinated Crop Safe network was particularly concerned with four exotic pests, khapra beetle, Ug 99 stem rust of wheat, barley gall midge and the fungal disease karnal bunt.

All of the pests have different means of impacting the sector.

Khapra beetle has long been a major concern for the Aussie grains sector.

Found throughout the Middle East, Africa and the Indian subcontinent, Khapra is a pest in stored grain and other dry food.

Its eggs can lay dormant for up to two years and once hatched the larvae are the major problem, with a voracious appetite for grain and other dry foodstuffs.

Speaking at a Grains Research and Development Corporation (GRDC) update last month Mr Grey said the beetle also caused contamination issues in the food.

With many countries having strict zero tolerance policies for khapra beetle in exports he said an incursion could have major impacts on export markets.

Karnal bunt is also a pest that influences grain quality, this time in wheat.

Unlike khapra beetle it is a fungal disease.

Mr Grey said grain infected with the disease had a strong, unpleasant fish-like odour which rendered it unusable for milling purposes.

The karnal bunt infection is difficult to spot on the plant, but on the seed it is clearer as a discolouration at the end of the grain.

It was initially discovered in India but has spread to much of the Middle East and parts of North and South America.

Mr Grey said the stem rust Ug 99 had garnered a lot of publicity due to its virtual complete decimation of wheat crops throughout Africa and the Middle East.

While stem rust is already present in Australia Mr Grey said this particular strain was very virulent and not treatable with fungicides registered in Australia.

Barley stem gall midge is a far less known pest but can also cause significant damage.

It is thought to have originated in Tunisia in northern Africa but has spread throughout the world and is found as close to Australia as New Zealand.

The midge causes damage by feeding on the stem of cereal plants.

While it prefers barley, Mr Grey said it could also damage oats and rye in particular.

He said the pest could most easily be identified by the pea sized galls, or swelling of the plant tissue at the base of the host plant between the leaf sheath and the stem.

Locally, he said authorities wanted to keep lupin anthracnose out of SA and the east coast.

South Australia last had the disease in the late 1990s while a small-scale epidemic in NSW in 2016 was contained and the disease declared eradicated.

The disease is devastating for lupin crops, causing lesions on the pods which means no seeds set.

Mr Grey said the disease was part of the reason there were strict protocols about fodder coming across from Western Australia during the drought.

Australia has had some notable pest incursions in recent years, including the discovery of Russian wheat aphid in 2016 and the fall army worm was detected in Queensland earlier in the year.


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