The ban was announced by the Australian Pesticides and Veterinary Medicines Authority last year because it contained the chemical omethoate.
The APVMA’s Omethoate regulatory decision report found Le-Mat posed unacceptable risks to workers and the public, including all uses on food producing crops.
Yorke Peninsula independent agronomist Craig Wissell said Le-Mat was commonly used in most SA crops and pastures to control RLEM and lucerne flea.
But when the ban kicks in, Mr Wissell said producers’ choice of products would be severely impacted.
“Dimethoate (a systemic insecticide) would be the next most common one with a wide registration of crops, but in pasture its withholding period is 14 days for livestock.”
Mr Wissell said recent weather conditions had encouraged a build up of RLEM and lucerne flea.
“Good stubble cover in the paddocks, cold, frosty nights and mornings followed by sunny days and no rainfall have proved favourable,” he said.
But RLEM and lucerne flea could increase further next year if a suitable replacement product is not identified.
The ban of Le-Mat has some producers concerned, including Farrell Flat farmer Daniel Neill.
"We had a couple of issues this year, one paddock in particular we had a fair bit of strife with lucerne flea," he said.
"It held the crop back, but it was sprayed with Le-Mat and that fixed the problem.”
Mr Neill said the insecticide was commonly used across his 1300-hectare operation and was a popular tool for most farmers.
"It will be a shame if it is banned because it's a good, cost-effective product that works really well," he said.
Besides RLEM and lucerne flea, farmers had found an increase in slaters in the Clare and Maitland areas, affecting lentil crops.
Mr Wissell said slaters were frustrating as there was no insecticide registered for use on lentil crops in SA.
Less pests for Mid North crop
DESPITE farming in a pest-prone area, Bill Piggott, Farrell Flat, has had a successful season with few pests to-date.
While he uses insecticides pre-sowing, Mr Piggott said he had “snuck through” the season without using them.
“The (pests) we are most concerned about are lucerne flea and red legged earth mites,” he said.
“If we can sneak through without using them (insecticides), I think it helps maintain a bit of a natural balance with the pests.”
Mr Piggott’s 809-hectare mixed operation includes wheat, barley, peas, oats for hay, lucerne and canola, plus a Merino-Suffolk lamb production.
He said despite minimal rainfall for the season, the crops were “just hanging on”.
“Some years we get hit with pests harder than others,” he said.