Plantwise Factsheets for Farmers
Planting material clean from banana weevil
Recognize the problem
production in Tanzania is threatened by an insect pest called the banana
weevil. This 1 cm beetle is black, has malt-grey wings, and a long nose. The
first attack symptom is death of the outermost leaf-sheath at the base of the
banana tree. You may also find small feeding holes and feeding tunnels on the
banana base. The plant grows slowly then the pest feeding leads to yellowing
and wilting of banana leaves, and finally rotting of the stem.
banana weevils can live 2 or more years. Adults don’t fly but walk short
distances over the soil between banana plants. They lay eggs in small pits
made into the stem of the banana. They particularly like to lay eggs into any
cut stems, rhizomes or other banana residues. The eggs hatch into larvae. The
larvae are white, legless grubs that are ½ to 1 cm long. For 3 weeks, the
larvae feed and bore tunnels in the rhizome, stem, suckers and roots. Larvae
develop into pupae which are white with no cocoon. In serious cases larvae can cause splitting or snapping of the banana
tree at ground level resulting in total yield loss. Detached suckers for
planting material are especially vulnerable for weevil attack. Therefore,
cleaning of planting materials is important.
Use planting material from
plantation blocks or nurseries that are free of the weevil
- Clean plant materials by paring
(cutting off) the plant layers to search for infestation symptoms. Remove plant
layers by peeling them off with a knife/panga.
- Avoid using dirty knives/pangas
that have been used to chop off infested plant parts because you may transfer
use planting materials that have been grown by tissue cultures in institutes.
Please contact Horticultural Unit at Sokoine University of Agriculture in
The recommendations in this factsheet are relevant to:
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