This weevil, resembling the rhizome weevil of banana, has become a serious pest in recent years.
Adult female weevil punctures and inserts eggs into the pseudostem. Grubs emerging out feed extensively on the pseudostem(Image2) and thereby the entire plant collapse. Colourless jelly like plant sap oozes out of from minute boreholes on the pseudostem or leaf bases.
This is the first symptom. The ooze later turns deep violet in colour. Chewed up material will also be pushed out through the holes .
Leaves turn yellow, dry up and finally, the plant collapses.
Management
Keep the garden clean by properly disposing pseudostem and rhizome after harvest as this is the most important factor in the prophylactic and curative control of the pest.
During cropping, periodically remove the dried leaves and leaf sheath.
Remove side suckers up to 8 months to prevent harbouring of adult weevils.
Remove the affected plants beyond cure along with the rhizome and destroy them by burning the life stages using kerosene or by burying the same in deep pits
Fill the leaf axils with neem seed kernel powder @ 50 g per plant when the plant attains 135 days after planting.
Beauvria bassiana and Metarrhizium anisopliae have shown efficacy as control agent of the pest. Spray either of this at 20 g per lit of water or 5 ml /l covering the leaf axil and pseudostem at 5 months after planting.
Cowdung ash slurry can be brushed on the pseudostem
Prepare traps using pseudostem of approximately 50.cm long, which are split lengthwise and treated with B.bassiana . Keep about 100 traps per ha.
The disc on stump trap swabbed with B.bassiana can also be used to monitor and reduce weevil population. This is more effective due to higher exudation of plant fluid.
In endemic areas use any of the recommended insecticide viz quinalphos 0.05 %,chlorpyriphos 0.05%,. The spry fluid should reach the leaf axil ,rhizome, surrounding soil and all round the entire pseudostem inserting the nozzle through bore holes made by the larvae, if any, and also within the outer sheath raising the same at different spots. Before spraying remove the dry outer sheath of the pseudostem of all infested and uninfested plants. Repeat the treatments after 3 weeks if infestation persists.
Nanma and Menma (a tapioca leaf based organic pesticide) developed by CTCRI have been found to be very effective in managing the pest. Spray Nanma 5 % (50 ml/l) covering leaf axil and pseudostem when the plant attains 4-5 months after planting. Nearly 100 ml of spray fluid will be required per plant. Before spraying clean the pseudostem of the dried and drooping leaves. Once the infestation is noticed inject undiluted Menma just below the bore hole made by the weevil. Injections are to be made at 3 locations around the pseudostem near the infestation point @ 5 ml per injection.
Dept of Agriculture Development 
SFAC Kerala