Grainguard co-ordinator and Department of Agriculture and Food grains biosecurity officer Jeff Russell has urged growers to ensure pest surveillance is a priority during harvest.
Mr Russell said the harvest season was very busy for growers, but it was vital that growers kept an eye out for exotic pests.
“Pest management at harvest is more than cleaning out your silos in the lead up to rolling out the harvester into the crop,” Mr Russell said.
“Phosphine resistance is a big threat to our grains industry, and growers should do all they can to avoid developing phosphine-resistant insects in their grain.
“Growers should check that silos are properly sealed, so that the correct level of gas fumigation can be maintained for at least seven days.
“As well as ensuring grain is kept free of the endemic grain storage pests, it is also important that growers keep an eye out for high-priority exotic pests, especially any not known to be in Australia.
“Two such stored grain pests are khapra beetle (Trogoderma granarium) – one of the world’s most serious pests of stored grain and dry foodstuffs – and karnal bunt (Tilletia indica) a disease of wheat, durum and triticale. If detected in Australia, these pests could significantly impact on access to some of our export markets.
“Khapra beetle adults are small (2-3 mm long and 1-2 mm wide), brownish in colour with a smooth oval-shaped body. There are three transverse bands (markings) of pale coloured hairs on the wing covers.
“Eggs hatch into small hairy larvae that can grow up to seven millimetres long, are reddish-brown in colour and darken as they mature. Larvae have characteristic long hairs over their body, especially at the rear end, and can survive without food for more than 12 months.”
Mr Russel said khapra beetle was difficult to distinguish from warehouse beetle, which is found in Australian grain.
“Karnal bunt, which is exotic to Australia, is often difficult to see in the crop, but more noticeable in grain samples at harvest,” he said.
“Symptoms can range from pin point sized spots to thick black spore masses running the length of the groove in the grain. Usually only part of each grain is affected, although occasionally the whole seed will be blackened with a sooty appearance.
“Infected parts of each grain will crush easily, producing a black powder between the thumb and forefinger. Often the grain will have a rotten fish smell.”
Mr Russell said his message was simple.
“If growers find any hairy larvae or beetles in their grain, they should report them to ensure they are properly identified,” he said. “We have our experts on hand, and it’s far better to be safe than sorry.”
For more information on farm biosecurity and exotic pests visit Plant Health Australia (PHA) at www.phau.com.au or call the exotic plant pest hotline on 1800 084 881.