FAR Research | Fall armyworm update 15 December

The latest Fall armyworm (FAW) update as of 15 December.

Key Points:

The 2023/24 growing season has 17 confirmed reports to date. All in Northland.
Small neonates and early instar larvae have been observed this week, signifying the second generation this season.
Observations of parasitisation of FAW by the parasitic wasp, Cotesia sp have been extremely encouraging.
As surveillance has increased, localised findings of Cosmopolitan armyworm, Greasy cutworm and Tropical armyworm have been observed across the country.
Populations appear to be small and localised, keep crop scouting and liaise with your advisor to seek advice.
Being observant at this early stage is important, the earlier FAW is identified the likelier effective management will be achieved.
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.
Refer to the Davis Scale of Economic Damage and consult with your agronomist when making decisions on Sparta application.

Parasitisation of FAW photo courtesy of Daniel Hawkins, Northland Seed & Supplies.

https://assets.far.org.nz/Cotesia-ruficrus-factsheet.pdf

How are we tracking compared with last year?

On this date last year there were 18 fall armyworm finds nationwide, including Northland, Auckland, Waikato and Taranaki.

There are no confirmed finds this season outside of Northland.
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, enabling constant development of the modelling and has been extremely helpful for ongoing research aiming to develop predictive tools.

Above (top): Photo of 2^nd instar FAW Larvae courtesy of Fleur Scelly, Fonterra.

Neonates and early instars show progression to a second generation.

https://assets.far.org.nz/Fall-Armyworm-identfication-Jan21.pdf

Above (bottom): Photo: Fall armyworm Moth

FAW moths showing characteristic white underwings. They are delicate and easily damaged, any moths found in pheromone traps can be DNA tested.

https://assets.far.org.nz/Distinguishing-moths-in-Fall-Armyworm-FAW-traps.pdf

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)