Grain growers in New South Wales are advised to check and monitor crops for fall armyworm (FAW), with the pest being detected as far south as the Lower Namoi region.
The first detection of FAW (Spodoptera frugiperda) in northern NSW was on September 23 in a pheromone trap between Moree and Boggabilla, and additional moths were found in traps east of Narrabri and west of Wee Waa last week.
Fall armyworm have a high reproductive rate and dispersive capability. Some estimates suggest the pest can travel around 100 kilometres in a night and 500km in a generation.
Grain growers, agronomists and advisers across the state are now advised to inspect and monitor establishing summer crops for signs of fall armyworm damage and the presence of larvae.
Early symptoms include ‘windowing’ of leaves where larvae have hatched, and small ‘shot holes’ in leaves as the larvae start to grow.
Identification of recently emerged larvae can be difficult in the field, but by the time larvae reach the second to third instar stages the features that allow diagnosis become more obvious.
For small larvae, the NSW Department of Primary Industries (DPI) recommends retaining FAW samples along with food sources, such as host crop leaves, and allowing them to grow to enable photographs to be taken. In most cases, identification will be possible from clear photographs.
Images of suspected FAW can be sent to NSW DPI Biosecurity for assistance with identification: