East Gippsland farmers are being urged to stay alert and ensure they can correctly identify armyworms following multiple reports of native armyworms across Victoria.
Agriculture Victoria Horticulture Program Coordinator for Gippsland, Scott Botten, said native armyworms are often mistaken for the far more destructive Fall armyworm (FAW), a highly invasive pest now present in every Australian state.
“Fall armyworm is native to tropical and subtropical regions of the Americas, but it has spread rapidly around the world and is now established in Australia,” Mr Botten said.
“The species, also known as Spodoptera frugiperda, poses a significant threat to agriculture, feeding on more than 350 plant species.”
Crops at risk include maize, cotton, rice, sorghum, sugarcane, wheat, as well as a wide range of vegetable and fruit crops.
Mr Botten said correct identification is critical, particularly during late summer and early autumn when larvae activity is at its peak.
Key identifying features of Fall armyworm include egg masses of 100 to 300 laid on the underside of leaves, often covered with fine bristles. Newly hatched larvae are around one millimetre long, pale green with a black head, while mature caterpillars can grow up to 40 millimetres in length.
“They are smooth-bodied and can vary in colour from dark yellow through to green, brown or black, with prominent lighter stripes running along the body,” he said.
Adult male moths can also be identified by two distinct white marks on each forewing, while the caterpillars are most reliably identified by an inverted Y-shaped marking on the head — a key feature that distinguishes FAW from other armyworm species commonly found in Victoria.
Mr Botten encouraged farmers who suspect they may have identified Fall armyworm to seek advice promptly.
“If you think you have found Fall armyworm and are unsure about the next steps, contact your local agronomist for guidance,” he said.
Further information on Fall armyworm, including monitoring and identification resources, is available through Agriculture Victoria and the Grains Research and Development Corporation websites.
