What plants are affected?
The fall armyworm larvae has a particularly damaging impact on crops including maize, cotton, rice, sorghum, sugarcane, wheat and many vegetable and fruit crops. It is known to eat more than 350 plant species.
What do I look for?
- Larvae are most active during late summer and early autumn months, and are expected to be more active in the northern wet season.
- Evidence of the pest could include egg masses, plant leaf damage or fruit or vegetable damage.
- There are species of Spodoptera already present in Australia which can look similar to fall armyworm. These include lawn armyworm and dayfeeding armyworm.
- Fall armyworm eggs are pale yellow in colour and clustered together in a mass, which often contain 100–200 eggs. Egg masses are usually attached to foliage with a layer of mould or silk-like furry substance.
- The larvae are light coloured with a larger darker head. As they develop, they become darker with white lengthwise stripes. They also develop dark spots with spines.
- The adult moths are 32 to 40 mm in length wing tip to wing tip, with a brown or grey forewing and a white hind wing. Male fall armyworms have more patterns and a distinct white spot on each of their forewings.
How does the pest spread?
Adults moths can fly long distances and their migration is remarkably fast. As well as natural dispersal, they can also be spread through movement of people.
Since 2016 fall armyworm has rapidly spread to and throughout Africa, the Indian subcontinent, and in June 2019 was reported in China and Southeast Asia.
What damage can this pest cause?
Fall armyworm has caused significant economic losses overseas, where destruction of crops can happen almost overnight when population levels are high and in the absence of control measures.
Status in Western Australia
Spodoptera frugiperda Smith & Abbot 1797 is absent from Western Australia and is a declared pest.
A person who finds or suspects the presence of fall armyworm must report it to the department.