Smash earth mites early

Red-legged earth mites hit Central West high country

Lee Matthews and wife Stacey on Vale View in their paddock of Tobruk triticale that has recovered from red-legged earth mite attack.

Lee Matthews and wife Stacey on Vale View in their paddock of Tobruk triticale that has recovered from red-legged earth mite attack.


From Mandurama to Borenore, red-legged earth mites are making their presence felt.


WHEN Lee Matthews thought a crop of triticale wasn't preforming as expected, still at the three-leaf stage a month after emerging, he took a closer look.

He found red-legged earth mites munching away on young shoots.

"It took me about a week to twig there was something wrong, because it's so early, we wouldn't normally have a problem with them until late winter or early spring," he said.

Further investigation across the 280-hectare property Vale View, near Blayney, revealed his clovers were also under attack.

"We sprayed the whole place, I've never seen them so bad," he said.

Mr Matthews estimated in a five centimetre square sample there would have been 10 to 15 mites.

But 10 days after spraying his 15-hectare paddock of Tobruk triticale it has turned the corner.

"You wouldn't know it was the same paddock."

Mr Matthews said he always used innoculated seed, which cost him about $100 a tonne for cleaning and innoculation.

Further west Parkes and Forbes seem to have been spared.

AgriWest Forbes-based agronomist Tom Macleay said there had really been only two or three genuine frosts in his region to this point this year.

But in the last three weeks he had been undergoing preventative checks.

Mr Macleay said he wasn't a fan of in-crop sprays, because often beneficial insects took a hard hit too.

People should be looking to innoculated seed, he said.

"Sure the seed might cost a little more first up, and the spray is not expensive, but it's well worth it once you think of labour, chemical and fuel costs of getting a spray rig across your country."

At Borenore, on the Australian National Field Days site, an AusWest pasture trial has also been hit by red-legged earth mites.

Agronomist Kate Labrocque said while it seemed the grasses might survive after the mites were sprayed, she would need to re-seed legumes, such as clovers and medics.

"Because there's so many of them they eat the cotyledon and the plants run out of energy," she said.

She urged farmers to take a good look at newly sown pasture or crop that wasn't performing as well as expected.

"You can actually see them on the ground. But if the plants are more established you can run your hands through it and check your hands to see if there's any hanging on." She said Gippsland, Ballarat and the Western District in Victoria had been hit hard.

Parkes-based AgriWest agronomist Greg Miller said his region has so far been spared.

He said once ambient daytime temperatures decreased to below 21 degrees Celsius it was time to be on watch.

When it came to preventative measures he said there were clover varieties that were tolerant to mites.

Treating seed with insecticide also helped, he said.

At Cowra, Elders agronomist Peter Watt said red-legged earth mites had been found at Hobbys Yards and Mandurama, but there had been low-level impact in the Cowra area, so far.

Department of Primary Industries research entemologist based out of Wagga Wagga Jo Holloway said most crop was vulnerable at the emergent stage, but unless stressed most could cope with an outbreak.

"Canola is vulnerable to three-leaf stage and wheat is most vulnerable at growth stages 10 to 12, but once it is through to 14 it can cope," she said.

"But we must watch spreading resistance," she said. Western Australia, South Australia and Victoria all have signs of emerging resistance.

She said there were two insecticide groups that killed the mites, organophosphates and synthetic pyrethroids.

If repeated spraying was required, the same group should not be used twice running, she said.


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