PEST MANAGEMENT DECISION GUIDE: GREEN AND YELLOW LIST
Fall armyworm on maize
Spodoptera frugiperda Fall armyworm
- Avoid late or off-season planting and avoid planting new crop near infested fields
- Ensure optimum use of fertilizer for strong maize plants able to compensate for damage done and apply at the right time
- Keep the surrounding of the plot free of grass weeds
- Conserve shelters and flowering plants on the edges for beneficial insects such as ground beetles and parasitoids
- Intercrop maize with less susceptible crops such as legumes
- Avoid spraying broad spectrum insecticides which might kill beneficial enemies
- Do not move infested maize materials from one area to another; instead feed to livestock
- Start monitoring for the pest one week after germination, continue weekly or every second week.
- Monitor 10 consecutive plants in 10 locations of the field
- Look for creamy/grey egg masses covered in silk located on the underside or top of the leaves and on the stems
- Look for light green/dark brown caterpillars with longitudinal stripes, dark head with an upside down pate Y-shaped. The second-to-last body segment has 4 dark spots forming a square. Do so in early morning or evening hours
- Look for light coloured patches (“window panes”) to large ragged and elongated holes in the leaves emerging from the whorl
- Look for caterpillars and accumulation of frass in the whorl or burrowed into the side of the cobs
- At early whorl stage, take action if >20% of plants are damaged or infested with larvae. At late whorl stage, if small larvae can be found then take action if >40% of whorls are damaged. At tassel and silk stage, do not spray anymore
- On small-scale farms, handpick and destroy the egg masses and larvae
- If available, spray young caterpillars with neem-based products before they enter the ears or whorl
- Insecticides are most effective on young larvae and before they enter the funnel and ears. Spray early morning or late afternoon when larvae are active.
- Spray only according to needs identified by monitoring (including decision for a second application)
- Minimise usage of WHO class II chemicals for own safety and protection of natural enemies which will help in pest control. Always check label for details and wear appropriate PPE
- If you use chemical pesticides, use a different sort each time to avoid pesticide resistance.
WHO Class II (moderately hazardous). REI: 1 day. PHI: 21 days (grazing 42 days).
Do not apply more than three applications in one growing season. Toxic to beneficial organisms.
CREATED/UPDATED: October 2017
PRODUCED BY: Plantwise
©CAB International. Published under a CC-BY-SA 4.0 licence.