In order to prevent pod borers from your cowpeas;
- Do not crop on the same piece of land for more than two seasons (rotate cowpea with maize)
- Deep plough and harrow to kill larvae/pupae or expose them to direct sunlight and predators.
- Remove and destroy volunteer cowpea plants because they may harbor the borer.
- Intercrop cowpea with non-host plant like maize.
- Remove and destroy alternate host e.g soyabean plants and wild leguminous plants.
- Practice good farm sanitation.
- Visit the field every day after flowering to look for signs of damage.
- Check for eggs on flower buds, flowers and terminal shoots.
- Look for presence of young caterpillars among flowers and foliage
- Also look for fecal remains of adults and larvae, frass of larvae and malformed pods
- Damaged flowers and newly formed pods with holes
- Inspect fields to look for the presence of more natural enemies such as ladybird beetle and praying mantis.
As direct control measures;
- Hand pick eggs and larvae from plant and crush them
- Prune some leaves (older leaves) to expose larvae to natural enemies and allow direct penetration of sunlight into the canopy
- Remove and destroy leaves with white silk thread where larvae hide
- Create conducive environment for natural enemies (e.g lady bird beetles, spiders. Praying mantis etc.) to multiply by minimizing spraying and by mulching.
Options with restrictions
These are also methods that you may use. However, use as last resorts and apply lots of caution in its application.
Option 1: Apply cypermethrin (cypercan, fastrack 10SC) at a rate of 40mls/15lits of water. Observe pre harvest interval of 7 days. Apply early morning and or late evening.
Option 2: Lambda-cyhalothrin 25g/l (e.g conquer super 2.5 EC, Aweradlamp 2.5EC, Bonlambda 2.5EC) at 100ml/15lits of water. Observe pre harvest interval (PHI) of 7 days. Apply during early infestation and at early morning or late evening. Always wear protectives when using chemicals.
If you choose chemicals to control pests, do well to read and understand its rate of application and take all precautions to protect yourself and other lives. Possibly, let chemical control be your very last resort.