The Fence
Fast Facts

Horticulture growers urged to monitor crops for voracious pest

Fall armyworm

Horticulture and turf growers in the Gingin and north Wanneroo production areas have been urged to monitor crops for the plant pest, fall armyworm, after larvae were detected in a local crop.

While moths have been found in traps in the area before, as part of Department of Primary Industries and Regional Development surveillance, this is the first time fall armyworm larvae have been confirmed in a horticulture crop near Gingin.

Department senior research scientist Helen Spafford said it was important for growers to monitor their crops carefully for larvae, or caterpillars, to confirm presence of the pest and to make informed management decisions.

Dr Spafford said young fall armyworm larvae could be difficult to identify, as they looked similar and caused the same damage as related pests.

“As fall armyworm grow their characteristics become much easier to distinguish, as they develop white, lengthwise stripes and dark spots – the pattern of which is important for identification,” she said.

“If growers are uncertain, the best way to confirm the pest is to report it to the department for scientific identification, then growers will know what they are dealing with.

“The department also has resources online to assist with fall armyworm identification.”

Dr Spafford said controlling fall armyworm could be a challenge, as they were prone to developing resistance.

“In Australia, the pest carries the genes that confer resistance to Group 1 insecticides,” she said.

“It is important to apply controls for fall armyworm and other pests judiciously to manage the risk of potential treatment issues with fall armyworm.”

Fall armyworm is a moth that is native to the American tropics, which has a wide range of host plants, including corn and grass crops, turf grass, brassicas, beans, melons and tomatoes.

The pest was first confirmed in the Torres Strait islands in January 2020 and has since spread to Queensland, the Northern Territory, New South Wales, Victoria and Western Australia, including detections at Kununurra, Broome, the Pilbara, Carnarvon and Geraldton.

The Consultative Committee on Emergency Plant Pests concluded it is not technically feasible to eradicate fall armyworm from Australia.

The department maintains a surveillance trapping network and undertakes field scouting for the presence of eggs or larvae to confirm establishment and provide an early warning advice to industry as the pest migrates further south.

Dr Spafford advised grain growers and broadacre farmers to incorporate fall armyworm crop monitoring into their autumn pest surveillance program.

“While the pest has been detected in grains, fodder and horticulture crops north of the Grainbelt to date, southern growers should remain observant and report any suspect caterpillars to the department and seek control advice,” she said.

Observations and photographs of suspect fall armyworm larvae and crop damage can be sent to the department via its MyPestGuide Reporter app or its Pest and Disease Information Service on +61 (0)8 9368 3080 or email

For more monitoring and management information on fall armyworm visit the department’s website.

Picture caption: Horticulture growers in the Gingin area and surrounds have been urged to monitor crops for the new crop pest, fall armyworm.

Source: WA DPIRD

Most Popular

Newsletter Signup

The Fence
To Top