PEST MANAGEMENT DECISION GUIDE: GREEN AND YELLOW LIST
Fall armyworm in maize
- Plant early, at start of rains and avoid late and off-season crops as these promote further pest build up
- Avoid planting new crop near infested fields
- Keep field free from weeds as these serve as alternate hosts
- Apply recommended amounts of fertilizers for strong maize plants able to compensate for damage done
- Avoid transporting maize cobs from infested to un-infested areas
- Plough after infested fields are harvested
- Start monitoring maize 2 weeks after germination till harvest, weekly or biweekly
- Use pheromone traps or universal moth traps to catch moths, 1 trap/acre. If > 5 moths are captured in a universal trap per week, or 3 to 5 in a pheromone trap per day, action is considered
- Check for creamy egg masses (100-200 eggs each) mostly located on the underside of leaves
- Search for caterpillars on leaves or in the whorl in early morning or evening hours. Caterpillars have a dark head with a distinct pale, upside-down Y-shape on the front and 4 dark spots forming a square on the second-to-last body segment
- Look for windowing on leaves= "window-pane" damage as well as large ragged and elongated holes
- Check for large amounts of moist sawdust-like frass near the whorl and upper leaves
- 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 consider taking control measures if 40% of whorls are damaged. At tassel and silk stage, do not spray anymore
- Hand-pick caterpillars and crush or place them in hot water
- Feed heavily infested abandoned maize to livestock
- Apply neem based products (biopesticide)
- 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 consult recent list of registered pesticides (ZEMA). Always check label for details and wear appropriate personal protective equipment (PPE)
- If you use chemical pesticides, use a different sort each time to avoid pesticide resistance.
- Always consult recent list of registered pesticides (ZEMA).
Spray with Lufenuron+ Emamectin Benzoate (e.g. Match fit) (insect growth inhibitor)
Lufenuron WHO Class III (slightly acute hazardous). Emamectin Benzoate WHO Class II (moderately hazardous). REI 2 days. PHI 14 days. Toxic to beneficials
Lambda-cyhalothrin – products. Pyrethroid group
WHO Class II (moderately hazardous). Max 2 sprays/season. REI ½ day. PHI 14 days. Toxic to beneficials
Deltamethrin based insecticides. Pyrethroid group.
WHO class II (moderately hazardous). REI 1/2 day. PHI 3 days. Toxic to beneficials
CREATED/UPDATED: July 2017/January 2018
PRODUCED BY: Plantwise
©CAB International. Published under a CC-BY-SA 4.0 licence.