Identification of fall armyworm in Torres Strait and Cape York Peninsula

The exotic pest fall armyworm (Spodoptera frugiperda) has been detected for the first time in Australia, in traps on the northern Torres Strait islands of Saibai and Erub and on the Cape York Peninsula.

Currently there is no evidence that fall armyworm has established either in Torres Strait or on the mainland of Australia.

The Queensland Government Department of Agriculture and Fisheries is working with the Australian Government, state and territory governments, and with industry groups and communities to assess the distribution, host range and threat of the pest and develop a response strategy. The response strategy will help determine the current distribution of fall armyworm in Queensland, while seeking to contain the pest through regulatory measures.

About fall armyworm

Fall armyworm larvae are known to eat and destroy more than 350 plant species, including maize, cotton, rice, sorghum, sugarcane, wheat and many vegetable and fruit crops and have caused significant economic losses overseas. There are two strains of fall army worm, that look identical but can have slightly different host preferences. For cotton this can mean damage may be non-existent to more severe.

Fall armyworm is native to tropical and subtropical regions of the Americas. Since 2016 it has rapidly spread to and throughout Africa, the Indian subcontinent, China and Southeast Asia. Adults can fly long distances and their migration rate is remarkably fast. As well as natural dispersal, they can also be spread through movement of people.

Australia’s climatic conditions are favourable for this pest to establish and spread via numerous suitable hosts. It is prevalent in warm, humid regions and is most active during late summer and early autumn.

Pest species of Spodoptera that look similar to fall armyworm are already present in Australia and include lawn armyworm and day-feeding armyworm. Spodoptera litura (cluster caterpillar) is native to Australia and is considered a minor pest in cotton in Northern Australia.

Likely impact of fall armyworm on cotton

If established, fall armyworm is expected to behave similarly to the native Spodoptera litura and has the potential to become a pest of cotton in Northern Australia. Although fall armyworm prefers warm and humid conditions, it may spread further south under suitable conditions.

Bollgard 3 is not registered for the control of Spodoptera spp.,however from what has been observed in other countries it is expected that there would be a degree of incidental suppression.

The industry is currently investigating chemical control options for emergency permits.

What to look for

Proper identification is important for knowing if the insect in your field is of economic importance.

For more information on identifying fall armyworm, click here: https://www.cottoninfo.com.au/publications/insect-id-guide-endemics-exotics

If you suspect you have detected fall armyworm, contact the Exotic Plant Pest Hotline: 1800 084 881