Farmers urged to keep an eye out for armyworms

22 December 2025

Following multiple reports of the native armyworms across Victoria, farmers are encouraged to learn how to correctly identify them.

Agriculture Victoria horticulture program coordinator for Gippsland Scott Botten said often, native armyworms can be mistaken for fall armyworm (FAW).

‘FAW are native to tropical and subtropical regions of the Americas but have quickly spread across the world, including to Australia after being found in every state.

‘The fall armyworm, also known as Spodoptera frugiperda, is a highly invasive and destructive caterpillar that poses a significant threat to plant species.

‘They are known to feed on more than 350 plant species, including maize, cotton, rice, sorghum, sugarcane, wheat and other vegetable and fruit crops.’ Mr Botten said.

He said when identifying FAW, there are a number of key signs to look out for:

• Eggs are laid on the underside of leaves in masses of 100 to 300, usually with a protective cover of fine bristles.
• Newly hatched larvae (caterpillars) are 1 mm long, pale greenish with a black head.
• Mature caterpillars are smooth bodied and grow up to 40 mm in length.
• They range in colour from dark yellow to green, brown and black with prominent lighter stripes running the length of the body.
• Males have 2 distinct white marks on each of the forewings.

Mr Botten said while having a similar appearance to other armyworm species commonly found in Victoria, FAW can be distinguished by the inverted Y shape on the head.

‘Correctly identifying FAW is especially vital during the late summer and early autumn months, with the larvae being most active around this time.

‘If you think you have identified a FAW and aren’t sure of next steps, contact your local agronomist for advice,’ he said.

Further information on fall armyworm, including monitoring and how to identify it, can be found on the Agriculture Victoria website and on the Grains Research & Development Corporation (GRDC) website.

Media contact: media@deeca.vic.gov.au