There are now 18 confirmed findings of fall armyworm in sweetcorn and maize in the North Island.
Key Points:
- There are now 18 confirmed findings of fall armyworm in sweetcorn and maize in the past few weeks in Northland, Auckland, Waikato and also north Taranaki regions.
- FAW Caterpillar damage has been found, with some insects already inside the whorl.
- FAW moths have been confirmed through DNA testing from an early finding in one site in Northland. The models indicate that we can expect moths to be detected in larger numbers in the next ten days.
- There are over 200 traps across the growing regions of maize and sweetcorn, they include monitor sites from the previous season’s findings and others are spread wider to understand the movements of the pest across the country.
- Early detection and early control will prevent a rapid multiplication of the pest.
- It is time to act: growers and reps should be actively scouting for caterpillars at the early stages of the crop, do not rely only on the moth catches from traps.
- We are still in a response, any suspected findings of caterpillars or moths must be reported to MPI here or using the app here, by email to FAW@mpi.govt.nz or by freephone 0800 80 99 66.
- There are no negative consequences to growers for reporting, as this pest will not be controlled by removing crops.
- There are no insecticides on label yet for FAW on maize. Some international data suggests that spinetoram 120g provides good early control of larvae at 200-400 ml per hectare. This has already been seen to be effective in initial applications in New Zealand in the past week. In order to reach larvae under leaves or in the whorl, high volumes of water are recommended. There are actions under way to fast track the use of this and other chemicals to be used in rotation to avoid resistance for the long term-management of the pest. Consult with your advisors on chemical options that will avoid resistance and minimise impacts on beneficial insects.
- Cosmopolitan armyworm and corn earworm (both present in NZ) have also been found in maize crops in Northland and Waikato in the past days, the differences can be seen on the identification cards provided by Plant and Food Research which you can find here.
It is also of key importance to report any negative finds. If you are scouting your crops and not finding any FAW, it is valuable too. Send this in at faw@mpi.govt.nz .
For useful tools and guides on detection and identification consult the FAR website for the latest identification guides here and the MPI Website here.
Images: FAW damage on leaf and into the whorl. Courtesy of Daniel Sutton (PGGW)