Fall army worm ( Spodoptera frugiperda).įall armyworm arrived in Queensland in February 2020 and has subsequently been found in the Northern Territory, Western Australia, New South Wales and, as of December 2020, in Victoria.

Inland armyworm ( Persectania dyscrita).

Southern armyworm ( Persectania ewingii).

There are 3 common species of armyworm found in southern Australia:

In the unusual event of extreme food depletion and crowding, they will 'march' out of crops and pastures in search of food, which gives them the name 'armyworm'. The change in feeding habit is caused by depletion of green leaf material or crowding. They are the only caterpillars that growers are likely to encounter in cereal crops, although occasionally native budworm will also attack grain when underlying weed hosts dry out.Īrmyworms mostly feed on leaves, but under certain circumstances will feed on the seed stem, resulting in head loss. The inverted Y is the key distinction between fall armyworms and true armyworms, a different species of armyworm that typically infests wheat and oats in spring before moving to corn later in the season.Armyworms are caterpillar pests of grass pastures and cereal crops. The determining characteristic of fall armyworms is a distinctive inverted “Y” on the head and face, along with four raised bumps in the shape of a square near the end of the abdomen. Young larvae are greenish with a dark head, while older larvae are mottled with red and brown.

Emerging larvae go through six instars (stages of development) before pupation. The rough-looking eggs are covered with gray scales and usually hatch within 4 days of deposit. Eggs are typically laid in masses of 100-200 on light-colored surfaces, such as utility poles, tree limbs and fence posts. Iowa State University entomologists say the pest can arrive in the Midwest in multiple migrations, with moths being driven on strong south winds of late spring and summer.Ī generation takes about 30 days to complete its summer life cycle. Mid-to-late season summer row-crop scouting in no-till and conventional fields usually finds infestations of several species of armyworms, but in some conditions, fall armyworms can become a serious problem, particularly on extremely late-planted corn.Ī native to tropical regions, fall armyworms can only overwinter in south Texas and Florida, but the adults are strong fliers and are capable of long-distance travel into the northern states.

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