Biosecurity alert - Fall armyworm

Fall armyworm in NSW

Fall armyworm (Spodoptera frugiperda) is an insect pest that was first detected in NSW in 2020. It has since been detected in all key summer cropping regions of NSW, including the North Coast, Northern Tablelands, North West, Hunter, South East, Central West, Riverina and Murray Local Land Services regions.

Populations of fall armyworm have already been established in northern Western Australia, Northern Territory and Queensland since first being identified in Australia in early 2020.

This insect pest is a serious threat to a wide range of industries including grain, rice, cotton, vegetables and sugarcane. Early detection is vital to minimising the spread and impacts of fall armyworm in NSW.

If you think you’ve found the signs of fall armyworm, email clear images with your name, location, crop type and phone number to fallarmyworm@dpi.nsw.gov.au

To find out more about fall armyworm, visit the DPI website.

How to identify fall armyworm

Small larvae will be difficult to identify in the field, but they are often pale green to brown, with a dark head capsule.

Larger larvae have some characteristics that make identification easier, these include similar colouration to other Noctuids, but they have:

• A dark head capsule with a distinct upside down Y shape between the eyes
• Two dark dots with spines on each upper body segment
• Four dark spots arranged in a square on the last abdominal segment
• Three pale lines running the length of the body may be seen on larger larvae.

If you think you’ve found the signs of fall armyworm, email clear images with your name, location, crop type and phone number to fallarmyworm@dpi.nsw.gov.au

Management tips

To assist producers, NSW DPI has compiled a list of top tips for fall armyworm management:

Know if the pest is in your area

Moth surveillance is an important first action in management because it alerts growers the presence of local fall armyworm activity.

Follow up with regular in-crop monitoring for larvae and signs of damage

If in doubt about which species of larvae is in your crop, send clear images of the head and tail to: fallarmyworm@dpi.nsw.gov.au

Optimise control costs by timely application of selective insecticides on above threshold populations

If sprays are warranted, act fast with full-rates of insecticide to target small larvae before they establish in whorls of plants, at which point control will be more difficult to achieve.

Approach control with an IPM focus and take advantage of natural enemies present in crops

Make spray decisions that will conserve beneficial insects which help suppress FAW populations in your crop. Consider biological options such as Bt and virus products as part of an IPM strategy.

Know which chemicals are likely to be MOST effective on FAW

Selective insecticides such spinosyns (Group 5, e.g. Entrust®, SuccessNeo®), emamectin benzoate (Group 6, e.g. Affirm®, Proclaim®) and chlorantraniliprole (Group 28, e.g. Altacor®, Coragen®) are likely to provide effective control if used correctly.

Know which chemicals are NOT effective on FAW

FAW has high levels of resistance to synthetic pyrethroids such as alpha-cypermethrin and growers are advised to avoid these products because they will not control of FAW and they will destroy crop beneficials.

Be mindful of the effect your insecticide sprays could be having on other pests in the crop

Overuse of selective insecticides will increase resistance levels in FAW and Helicoverpa armigera. Use a planned approach to insecticide selection and chemical rotation in maize and sorghum to minimise resistance risk.

For more information, contact  Dr Lisa Bird, Senior Research Scientist at NSW DPI:

• Phone: 0438 623 906
• Email: lisa.bird@dpi.nsw.gov.au

Resources 

• Tips for managing fall armyworm
• Chemical management options
• Primefact: Fall armyworm
• Poster: Fall armyworm
• Poster: Identifying Fall armyworm
• Queensland government information on fall armyworm
• The Beatsheet - Fall armyworm, should you be concerned?
• Australian Government information on fall armyworm
• Cotton Info fall armyworm identification guide.

Find out more about plant, pests and diseases here.