Read the latest Fall armyworm update as of 26 January 2024.
Key Points:
- The 2023/24 growing season has 57 confirmed reports in Northland, Westland and now Tasman.
- There is one unconfirmed case in Bay Of Plenty and also near Gisborne.
- In Northland the anticipated 2nd generation moth flight has been recorded. There have also been newly hatched neonates observed since, these are the 3rd Generation for the 2023/24 season.
- There is a potential that these moths will have travelled further south than Northland, Crop Scouting will be the most effective way to identify the pest.
- FAW has been found at five locations in the West Coast Region. Larvae have progressed through to late instar stages of their lifecycle.
- In general, FAW populations appear to be small and localised, and well below economic thresholds, some 3rd generation populations have been identified in Northland, and have larger populations with the potential for a greater economic threat. Keep crop scouting and liaise with your advisor to seek advice.
- Being observant at this stage is important, the earlier FAW is identified the likelier effective management will be achieved.
- Observations of parasitisation of FAW by the parasitic wasp, Cotesia sp are still being observed. Small infestations have appeared to be kept in check by the wasp.
- Corn earworm populations have been observed more frequently across the country, eggs are being laid in the tassels and larvae make their home at the top of the forming cob.
- Observations are important, please record them and inform us, without them it is hard to validate 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 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
FAW Adult Moths
Observed late evening and active through the night, adult moths are strong fliers and can travel long distances, especially when assisted by the wind.
Northland has just seen a moth flight, these have the potential to spread to other regions of NZ. When the larvae hatch they will cause damage to multiple plants adjacent to each other with tiny windows/dots or scratches. This is a key time to scout and identify the pest as young the larvae are not entrenched in the whorl or the cob and are much more susceptible to parasitism or if necessary insecticide application.
At this date last year there were 93 Fall armyworm finds nationwide, including Northland, Auckland, Waikato and Taranaki
- To date, confirmed finds this season are in Northland, Westland and now in Tasman.
- Average temperatures were considerably lower in regions compared to winter and spring last year.
- Marginal areas may have seen FAW populations unable to overwinter and depend on migration from more favourable areas.
- If you are scouting your crops inform us even if you do not find FAW, THIS POPULATION DATA IS USEFUL. The data provided has been fantastic, it will enable the development of the modelling and has been extremely helpful for ongoing research aiming to develop predictive tools.
What to do if you think you find Fall Armyworm
Photograph it: It can be easily mistaken for other species, so if you suspect Fall armyworm, take a good quality photo, and be sure to include the head, body and rear of the larvae. This can be in multiple photos if necessary. This great guide from the Queensland Department of Agriculture and Fisheries will help How to take a photo of FAW_24Mar20 (thebeatsheet.com.au)
Catch it: Samples will be welcomed and are important for positive identification and testing.
Contact us: Contact the Foundation for Arable Research at FAR@far.or.nz or Biosecurity Officer Ash Mills at ashley.mills@far.org.nz
- Trap network and active scouting and reporting have been fantastic throughout the winter and spring and are much appreciated.
- All data recorded (even zero finds) are valuable for the validation of modelling platforms and for understanding the pest in New Zealand.
- If you are keen to monitor a trap and share scouting information please get in touch
- Data and observations of parasitism as well as potential relationships with other pest species would also be welcomed.
Consult the FAR website for the latest resources and identification guides
FAR Research | Welcome to the Foundation for Arable Research
Listed below are useful updates, tools and guides on detection and identification
FAR Research | Fall armyworm identification and background
For advice around Sparta, FAW information and requesting a great FAW glovebox guide - Fall Armyworm (corteva.co.nz)
Useful insight from over the ditch - https://www.planthealthaustralia.com.au/fall-armyworm/
SGRR Davis Scale Guide - 86d44eb4-7d19-5ce5-befe-4dd32eeca38c.pdf (far.org.nz)
A farm Biosecurity Register is a great way of reducing the risk of unwanted weeds, pests and diseases arriving on your doorstep. Do you have one? Find out more here FAR Research | Arable Biosecurity Risk Register
Thresholds of economic damage
Plant Health Australia provides useful guidance for this:
