Armyworm 'perfect storm' has Aussie lawns under threat: 'It's exponential'

For Australians who love their lawn, they know how hard it can be to contend with the myriad pests and weeds that are keen to colonise it. And there is an old foe taking over, with homeowners being urged to be on the look out if they notice larges patches of their lawn suddenly eaten away overnight.

Summer rains experienced across much of the east coast in recent weeks have created a "perfect storm" for a familiar backyard bandit – the armyworm.

Commonly referred to as lawn grubs, residents in Queensland have reported infestations ruining their lawns as authorities continue to grapple with how best to deal with a notorious species of the pest which is wreaking havoc after it was first discovered in Australia just four years ago.

Known as Fall armyworms, the pest only reached the Australian mainland in 2020, but given they can turn your lawn from green to brown almost overnight, and cause millions of dollars worth of damage to crops, the little grubs are hard to miss.

"They're rapidly taking over the northern and eastern states of Australia and having a huge effect on the agriculture and turf industry," says Warren Howard from All Grass Solutions, located south of Brisbane.

But as for the common armyworm, their numbers are strong at the moment, thanks to the wet conditions, with workers like him inundated with calls to deal with the grassy invader.

"It's exponential. Every second call is 'Hey my lawn is dying, what am I doing wrong? Help us' ... It's a perfect storm with all the moisture," he told 7News after attending one customer's home to deal with an infestation.

The grubs will tear through a lawn, before marching onto the next food source – hence the name. They come out and feed at night, so residents can often wake up to a rude surprise.

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On social media, other Aussies are also looking for help and offering advice on how to deal with the grubs and sharing tips on the best pesticide options.

One Perth resident pulled dozens and dozens from her lawn after initially mistaking them for harmless caterpillars. "Guess I should be flattered they are attracted to healthy lawns," she joked.

Fall armyworm devastating Queensland growers

Meanwhile those who depend on their backyard for their livelihood are contending with the worst incursion of Fall armyworm (FAW) reported in the country. They're being detected at unprecedented levels in sorghum crops across Central Queensland, the Western and Darling Downs and northern New South Wales.

Queensland Department of Agriculture and Fisheries (DAF) principal entomologist Melina Miles last week urged growers to work with the authorities to best mitigate the scourge.

"We know that FAW can be devastating and we're seeing significant crop damage in southern and Central Queensland," she said.

"In many regions, rain in December has meant later crops, resulting in the coincidence of high FAW activity and susceptible crops. It is also possible that the weather systems associated with the recent cyclones has facilitated the movement of large FAW populations into central Queensland."

According to AgForce Queensland, Central Queensland grower Scott Muller said in previous years he didn't worry too much about the new pest but lamented this season they are at near "plague proportions". "With small crops they can almost decimate it," he said.

The species originated in the Americas and after arriving on the Australian mainland four years ago, they're almost certainly here to stay.

There is plenty farmers can do to fight back, including crop checks, chemical pesticides, and biological controls such as wasps, however there is no panacea. According to the experts, the Fall armyworm has never been eradicated from any country it has invaded.

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