It prefers decaying banana corm material. Spent stems (cut or left standing), residual corms left after the stem has been cut, underground stubs of corm tissue left after de-suckering, uprooted suckers or stems, and any corm tissues that are large enough to dry slowly are good targets for this pest
Dispersal within a banana field occurs when adult weevils walk from plant to plant or when infested plants containing eggs and larvae are moved.
Injury is caused by grubs (larvae), which tunnel through the corms. Tunnels are circular in cross section, become wider as the grub grows and are filled with dark-coloured debris.
Extensive feeding damage by grubs results in root destruction, slowed plant growth , reduced fruit production, and, sometimes, toppled plants.
The tunneling by the grubs makes the corms susceptible to invasion by secondary decay organisms. Production and growth of suckers reduced when parent plants are heavily damaged.
Affected sucker plants can be recognized by their dull, yellowish-green withered leaves . Relatively little damage is caused by adults( feeding on plant tissues.
The life cycle (egg to adult) of the weevil requires 30 to 40 days.
Eggs are deposited singly in cavities chewed by the adult females in the corm or pseudostem at ground level or between leaf sheath scars on the crown of the banana corm.
The stout, creamy white, legless grubs have reddish-brown heads and fleshy white bodies. The grubs are normally found in the pseudostem upto 2 feet above the ground.
Grubs pupate within chambers that are usually close to the surface of the corms.
The black, hard-shelled weevils are reported to live for as long as 2 years.
The nocturnal adults hide under debris or in the soil around banana plants during the day and are active at night.
Management
Adopt strict field sanitation. Remove crop residues and keep the field clean.
Select only healthy planting materials free from weevil infestation.
Plough or dig the land deep so as to expose the inner soil layer to sun .
Cut and remove the outer layers of rhizome and sundry for 3-4 days after smearing it with cow dung slurry and ash.
Dip suckers in Beauveria bassiana @ 20 g /l for 30 min. before planting.
Prepare traps using pseudostem of approximately 50 cm long, which are split lengthwise and treated with B.bassiana . Keep about 100 traps per ha.
Apply 50 g of powdered neem seed kernel per plant in the baby pits in which suckers are planted.
Apply one kg of neem cake in two equal split doses at one and two month after planting.
Cosmolure (an aggregation pheromone) can be set at the rate of 4 traps per ha. The pheromone will last for 2-3 months. Pit fall trap is a metal basin of 15 cm diameter and 12 cm height filled with detergent water up to 3 cm level from the bottom. This is placed in such a way that the brim of the basin is at the ground level and the remaining part inside a pit. A small wooden stand is kept at the middle of the basin on which cosmolure is suspended. The trap should be placed on a 20 x 100 m grid throughout the area. After a month the trap is moved to 20 m thereby the whole area will be covered with in a cropping season at 4 traps per ha.
Dept of Agriculture Development 
SFAC Kerala
