PLANT PEST
Southern armyworm
Southern armyworm (Spodoptera eridania) is exotic to Australia
Features: Larva – fall armyworm either light green or brown with white lengthwise lines; southern armyworm grey–brown with reddish lines underneath
Moth – brown or grey forewings and white hind wings
Where they’re from: Southern armyworm is native to tropical and subtropical regions of the Americas and widely distributed in Africa.
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.
Egg mass of fall armyworm. Ronald Smith, Auburn University, Bugwood.org
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.
Southern armyworm has been recorded to feed on more than 200 plant species causing significant economic losses overseas. Larvae 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.
Importing goods
To keep the southern armyworm 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
Eggs
- greenish and less than 0.5 mm in size
- 100–200 eggs in a ‘mass’ laid on underside or top of leaves
- covered in a pale, felt-like layer of scales.
Larva (early development)
- young larvae black with yellow lengthwise lines
- older larvae grey-brown with a row of paired black triangular spots along its back, and reddish lines underneath.
Moth (adult)
- 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
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.
Importers
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:
- corn
- sugarcane
- rice
- Sorghum and other grasses.
What to do
If you think you have found southern armyworm:
- 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.
Report it
Seen something unusual? Report it. Even if you’re not sure.
