Read here for the latest information on Fall armyworm as of 4 March 2024.
Key points:
The 2023/24 growing season has 100 confirmed reports. These have come from Northland, Westland, Tasman, Bay of Plenty, Auckland, Waikato and Marlborough.
• Northland FAW populations are generally small, with some localised areas of higher damage. Cosmopolitan armyworm (Mythimna separata) and Corn earworm
(Helicoverpa armigera) appear to account for severe crop damage to date.
• In Gisborne, the only confirmed report appears to be under control. The grower and their PGG Wrightson agronomist correctly identified FAW in maize grain crops, deciding that applying Sparta was the correct choice due to observed populations. This appears to have resulted in a successful control of the pest.
• In the South Island, FAW has been found on the West Coast, Tasman and Marlborough. Most larvae have pupated and these are starting to emerge. 22 adult moths and many pupae were found from near Westport down to Harihari recently. Most crops are four to six weeks from harvest.
• In the Bay of Plenty, Auckland and Waikato reports are generally coastal, with low populations of FAW larvae causing serious damage to sweetcorn cobs and some light damage to maize grain crops. Silage crops are generally advanced and there have not been reports of any significant populations or damage.
• Suspect moths from Manawatū-Whanganui will be identified via DNA testing.
• We expect emerging generations to have greater numbers of larvae with the potential to cause significant damage.
• Please scout crops, especially at-risk later planted ones.
• Parasitism of FAW, by the parasitic wasp Cotesia spp, is being observed across the country. Small FAW infestations appear to be kept in check by the wasp.
• Your observations are important. Please record them and inform us; without them, it is hard to validate and develop the modelling work we are doing.
• The insecticide Sparta® is on label for aerial and ground applications for controlling fall armyworm on maize and sweetcorn crops. Consult your advisor.