Banana Weevil, Cosmopolites sordidus

Cosmopolites sordidus, commonly known as Banana weevil is the most serious pest of banana.

The adult weevil is nocturnal and lays eggs at the base of the pseudostem. Young larvae tunnel through the corm weakens the plant by reducing water and mineral uptake. Therefore, bunch weight and yield reduce substantially. In severe weevil infestations, crop losses of up to 100% have been reported. It also reported infestation of Banana weevil toppled the plant during windstorm. The weevil is native to Malaysia and Indonesia but is found in all banana growing areas of the world. It is distributed in Africa, South East Asia; Middle East (Oman), South America and Caribbean Islands.

Grubs are creamy white, reddish-brown heads and fleshy white bodies. The grubs are normally found in the pseudo stems up to 2 feet above the ground. The larvae pass through 5-8 instars. Larval period completed in 15 to 20 days. Pupation takes place near the surface of the host plant. Pupae are white and about 12 – 15 mm long. Pupal development is completed in about 8-10 days. The black, weevil is about 12-15 mm long with characteristic long snout. Female laid an average of 1 egg per day during their life span. Normally the life cycle of the banana root borer requires 30 to 40 days. Adults are reported to live for as long as 4 years. Banana weevil could survive without feeding for several months in wet condition.

Adult banana weevils, Cosmopolites sordidus are attracted by host plant volatiles. Injury is caused by grubs making tunnel through the corms. Banana weevils are attracted to cut rhizomes, Cosmopolites sordidus attributed invasion decaying organisms by tunnelling in corms. The weevil influenced root initiation very badly, kills existing roots, limit nutrient uptake, slowed plant growth, and reduced fruit production. Yield reductions are caused by both plant loss and lower fruit weights. 40% of the total yield loss of has been reported.