Fall armyworm and other exotic armyworms
Fall armyworm and other exotic
Exotic to Australia
Features: Larva – either light green or brown with white lengthwise lines
Moth – brown or grey forewing and white hind wing
Where they’re from: Fall armyworm is native to tropical and subtropical
regions of the Americas. It is widely distributed in Africa and parts of Asia
How they spread: Adults can fly long distances and they can also be
spread through movement of people
At risk: alfalfa, barley, buckwheat, clover, cotton, maize, millet, peanut,
sugarbeet, soybean, sugarcane, tobacco, wheat, apple, grape, orange,
papaya, peach, strawberry and a number of flowers, weeds and grasses
Keep it out/stop the spread
It’s everyone’s responsibility to watch out for this destructive pest and protect Australia’s agricultural industries and environment.
Fall armyworm larvae is known to feed on more than 350 plant species, and they have caused significant economic losses overseas. Larvae of the fall armyworm are most active during late summer and early autumn months.
The adult moth can fly long distances and its migration rate is remarkably fast. As well as natural dispersal, it can also be spread through movement of people.
Fall armyworm has been detected in the Torres Strait, Queensland, Western Australia, the Northern Territory, New South Wales and Victoria.
To keep exotic armyworms out of Australia, never ignore Australia’s strict biosecurity rules.
Import shipments may need to be treated and certified, so before you import, check our Biosecurity Import Conditions system (BICON).
What to look for
- Pale yellow and less than 0.5 mm in size.
- 100–200 eggs in a ‘mass’.
- Covered in a pale mould-like furry substance.
Larva (early development)
- Light green to brown in colour.
- White lengthwise lines.
- Dark spots with spines develop as larvae mature.
- Distinctive pattern of four spots on second to last body segment.
- Inverted ‘Y’ shape pattern on its head.
- 32–40 mm from wing tip to wing tip.
- Brown or grey forewing.
- White hind wing.
- Males have more patterns with a distinct white spot on forewings.
Where to look
Fall armyworm are likely to be found in warm, moist regions.
- In areas with little forest cover.
- Hitchhiking on fresh vegetables or fruit.
In these areas, look for the following:
- egg masses
- plant leaf damage
- fruit or vegetable damage.
Keep an eye on all cargo, containers or parcels arriving through airports, seaports and in international mail. If you see something unusual or unexpected on imported plant material, secure it and report it to us immediately.
Growers and home gardeners
Look out for significant and unusually high levels of damage by caterpillars to foliage of:
- Sorghum and other grasses.
What to do
If you think you have found fall armyworm or other exotic armyworms:
- do not disturb the material or insect (this may be as simple as closing the doors on a shipping container or covering infested plant material with plastic)
- take a photo and collect a sample if possible without disturbing them.
Read the detail
- Food and Agriculture Organization of the United Nations
- Centre for Agriculture and Bioscience International (CABI) – Invasive Species Compendium
- Centre for Agriculture and Bioscience International (CABI) – Crop Protection Compendium
- An identification guide in relation to other common caterpillars, a South African perspective
- Fall Armyworm – Food and Agriculture Organisation of the United Nations
- Queensland Department of Agriculture and Fisheries – Fall armyworm