Banana weevil
A black weevil whose grubs tunnel in the corm of banana plants, weakening them so that they topple over in wind and yield small bunches.
Also known as: Banana corm borer, Banana root borer
Symptoms and identification
Plants are stunted and yellow, leaves are small, and bunches are small or fail to emerge. Plants may fall over in wind, and the corm shows dark tunnels full of creamy white grubs with brown heads when cut.
Causes
Adult weevils hide in old pseudostems and crop residue and lay eggs on the corm near ground level. They are attracted to the smell of banana tissue, and they spread mainly through infested suckers.
Organic treatment
Make traps of split pseudostem pieces laid cut-side down on the soil, and collect and kill weevils underneath every few days. Remove and destroy badly infested plants.
Prevention
Plant clean suckers or tissue-culture plants, and pare off the outer layer of suckers to remove tunnels and eggs. Clear old pseudostems and crop residue from around plants.
Chemical treatment (use with care)
Use an insecticide labelled for banana weevil, applied to the base of the plant as the label directs, and follow local agricultural advice.