Read here for the latest update on Fall armyworm as of the 8th of March
Key points:
There have been 106 confirmed reports in the 2023/24 growing season. 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. Reports of some larger FAW infestations have been received and will be confirmed soon.
• One FAW moth was caught in a pheromone trap in Gisborne this week. This is the second confirmed report in the region. A previous find appears to be under control with Sparta application deemed necessary.
• 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. 16 adult moths and many pupae were caught near Hokitika this week. Most crops are four to six weeks from harvest.
• Reports from Bay of Plenty, Auckland and Waikato are generally coastal, with low populations of FAW larvae causing serious damage to sweetcorn cobs and some light damage to maize grain crops. Most silage crops are being harvested 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.