African bollworm (Helicoverpa armigera)
Caterpillars of the African bollworm also known as the corn worm or earworm attack mainly the developing cobs, although they may occasionally feed in the leaf whorl or on tender tassels. Eggs are laid on the silks. Caterpillars invade the cobs and feed on developing grain. Development of secondary infections is common. Local outbreaks of this pest are sometimes severe.
- Conserve natural enemies. Parasitic wasps, ants and predatory bugs are important in natural control of the African bollworm.
- Monitor the crop regularly.
- Use bio-pesticides. Plant extracts (e.g. neem, garlic, chilli,) and Bt are reportedly effective against the African bollworms. However, timing of application is very important. Spraying when caterpillars are inside the cob would be ineffective. For more information on Neem click here.For information on Bt click here
- Handpick and destroy pod borers. This helps when their numbers are low and in small fields.