There are now 24 positive FAW detections since 1 September 2022 of a total 393 submissions. The spread of detection now ranges from Kaitaia down to Whanganui.
Key Points:
- There are now 24 positive FAW detections since 1 September 2022 of a total 393 submissions. The spread of detection now ranges from Kaitaia down to Whanganui.
- There are ongoing reports of FAW damage to crops, with some caterpillars found in the whorl.
- The models indicate that we can expect moths to be detected in larger numbers closer to Christmas.
- 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.
- 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. As this is still an unwanted organism all findings 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.
- Chemicals which are effective for FAW control are now going through the process of approval to be on label. International evidence suggest that a range of actives, including spinetoram, chlorantraniliprole and emamectin benzoate among others are effective on fall armyworm and less harmful to beneficials. When considering multiple applications, rotation is key to avoiding resistance.
- We have already had reports of sprays with synthetic pyrethroids (which are on label for other pests on maize) having very limited or no effect on fall armyworm. This aligns with the information from Australia and other parts of the world that indicate FAW is resistant to this group of chemicals, so these are not advised. Consult with your advisors. If you are supplying crops for human or animal consumption, these must meet the standards of residue levels set by those industries.
- 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 available here.
- We have received questions about thresholds of economic damage for use of insecticides. Plant Health Australia provides useful guidance for this:
More detail on this can be found 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 FAR website for the latest identification guides here and MPI Website here, or contact Ivan Lawrie ivan.lawrie@far.org.nz