The latest update of fall armyworm finds and response in New Zealand in the 2023/24 season.
Key points
Since the last update on the 19th of April 2024, there have been two new confirmed finds, both from Northland. In the 2023/24 growing season, there have been 113 confirmed reports from Northland, Westland, Tasman, Bay of Plenty, Auckland, Waikato, Marlborough, and Canterbury.
- Northland FAW moth flights are still being observed in pheromone traps consistently, however moth numbers are falling. Adult FAW have the potential to travel significant distances in one flight, and in the absence of maize they may travel inter-regionally to seek suitable locations to mate and initiate the next generation. If you have been monitoring traps, please keep checking them even after your crop has been harvested.
- Many susceptible crops around the country have been harvested (or are close to harvest) meaning a reduction in FAW’s preferred food source.
- Maize grain crops are still at risk, FAW larvae will typically enter the cob through the side, unlike Corn earworm (Helicoverpa armigera) which enter via the silks and the top of the cob. Observations of population dynamics and kernel damage will be beneficial to help develop NZ-specific economic damage thresholds.
- As temperatures are decreasing, the life cycle has begun to slow, and along with a reduction in surveillance, it is important to stay vigilant and scout harvested and any neighbouring paddocks as FAW will predate a large variety of crops. In NZ they have been observed on ryegrass and clover in a harvested maize paddock. Crop residues should not be overlooked, neither should any volunteer maize that may emerge in the coming weeks or months.
- FAW will feed on a large variety of crops in the absence of maize and sweetcorn, research has shown they will happily travel to an acceptable alternate host.
- The insecticide Sparta® is on label for aerial and ground applications for controlling fall armyworm on maize and sweetcorn crops. Consult your advisor.
At this date last year there were 139 fall armyworm finds nationwide, including Northland, Auckland, Waikato and Taranaki and Canterbury.