The advice to record and report any finds remains, as the transition to long-term management continues.
Key points:
- Fall armyworm was a hot topic at the International Congress on Biological Invasions hosted in Christchurch at the beginning of May. Delegates from around the world heard more about the response at the FAR-sponsored fall armyworm session. Many thanks to keynote speakers Helen Spafford, Richard Turner, Craig Phillips, Scott Hardwick, Yuan Liu, Yaru Wang, Graham Walker, and Yanling Xu for presenting their research, knowledge, and insights. It was all very informative and constructive, and much appreciated.
- As FAW is unlikely to be eradicated in New Zealand, the response has ended. Since Friday 21 April we have been in a long-term management phase. This is an industry-led management transition.
- This means that the unwanted organism status of FAW has now been revoked, meaning it is not mandatory to report finds. However, it is still important to continue to record and inform us of any significant observations.
- As temperatures get colder, the FAW life-cycle has begun to slow.
- Stay vigilant and scout harvested and any neighbouring paddocks as FAW will continue to target a large variety of crops. They have been previously observed on ryegrass and clover in a harvested maize paddock. Crop residues should not be overlooked either.
- In many areas poor weather around the harvest period has led to large amounts of lodging, shedding/shattering and volunteer maize, which is a potential winter host for FAW.
- Observations of new host plants are important as we try to understand overwintering capabilities and green bridges.
- There have been 139 confirmed reports of FAW across New Zealand.
- The insecticide Sparta™ is on label for aerial and ground applications for controlling fall armyworm on maize and sweetcorn crops. Consult with your advisor.
- 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.
For the latest identification guides click here and MPI Website here, or contact Ivan Lawrie ivan.lawrie@far.org.nz or Ash Mills ashley.mills@far.org.nz
For other useful tools and guides on detection and identification, consult the FAR website.
Thresholds of economic damage:
Photo: Scott Hardwick (AgResearch) presenting at the ICBI2023 FAR-sponsored fall armyworm session.