The major insect pest of banana is the rhizome weevil. All varieties are susceptible to this insect. The root grubs and pathogenic fungi enter the plant through holes made.
Plants affected by the rhizome weevil show stunted growth, leaves show yellowing and the plant becomes drier. The fingers in the bunch will not grow and lose market value. Adult weevils cannot fly for long distances and can not drill the rhizome. They hide under moist materials in the daytime and are active during night hours. The female weevil lays eggs on the rhizome at the soil level throughout the year and to add up, the lifecycle of the weevil is 3 months.
Management of weevils
Select suckers from weevil free plantations since they enter new gardens with the rhizomes. Adult weevils can be destroyed manually from their hideouts. Draining severe water logged gardens helps control the weevils.
Uprooting affected rhizomes and destroying them at a distance helps in control. It is also advisable to dip the rhizomes in 0.1% chlorophyta solution before planting.
More measures
Smearing of phorate granules on the rhizomes also helps control the weevils. 10 grams of phorate is per plant is used for 4 months. All these measures together will control rhizome weevil effectively.
The stem borer usually results in breaking down of the shear stem. The control measures taken for the rhizome weevil helps in controlling this insect too.
