Hot-water treatment for the control of the banana weevil, Cosmopolites sordidus Germar (Coleoptera: Curculionidae), in Uganda.

Paring and hot-water treatment of banana suckers have been recommended to prevent the spread of banana weevil, Cosmopolites sordidus Germar, into new banana plantations. Mortality of banana weevil eggs and larvae were recorded after immersion of infested banana suckers in four hot-water regimes: 43C for 2 hours, 43 C for 3 hours, 54 C for 20 minutes and 60 C for 15 minutes. Paring removed 90 % of banana weevil eggs, while all hot-water treatments resulted in 100 % mortality of eggs. However, only hot-water baths of 43C for 3 h resulted in high mortality (94 %) of weevil larvae. Larval mortality in other treatments ranged from 26-32 %. It is unlikely that Ugandan farmers will implement three-hour hot-water baths for banana weevil control. Also, the hot-water treatment that is most effective for nematode control (54 C for 20 min) provided limited control of banana weevil The data suggest that paring alone may be the most appropriate measure for resource-poor farmers to eliminate banana weevil from planting material.