Fall armyworm update 29 September 2023

The 2023/24 growing season has 0 confirmed reports to date.

• There was a total of 140 confirmed reports of FAW across NZ during the response period before the industry-led transition to long-term management began on Friday 21^st April 2023.
• Winter trap monitoring and scouting in Northland and West Coast have shown no moths or obvious signs of larvae overwintering.
• Multiple early sweetcorn crops in Northland have been identified, with surveillance ramping up as cloches are removed.
• A decent weather window in Northland should allow some growers to get Maize crops in the ground in the next week. Earlier planted crops are less likely to suffer significant economic loss as early-season FAW populations are yet to build up multi-generational numbers.
• As temperatures increase, the life cycle will begin to speed up with any winter larvae that have survived pupating, and early moths laying egg masses. Being observant at this early stage is important, the earlier FAW is identified the likelier effective management will be achieved. Newly hatched neonates are 1.5mm in length, windowing on leaves showing their presence. As they grow to 1^st instar larvae, they will disperse to surrounding host plants.
• Observations are important, please record them and inform us.
• The insecticide Sparta® is on label for aerial and ground applications for controlling Fall Armyworm on maize and sweetcorn crops. Consult with your advisor and avoid the use of insecticides that are ineffective on Fall Armyworm and potentially harmful to beneficial insects such as parasitic wasp Cotesia sp. which will help contain the numbers.