Published online by Cambridge University Press: 25 February 2013
Introduction. Small-scale bananaproducers in Tanzania are facing constraints caused by the destructiveactivities of the banana weevil (Cosmopolites sordidus Germar).Many currently used methods of addressing the problem are ineffective ortoo expensive for local farmers to implement. Materials and methods.A combination of two integrated pest management (IPM) tools (regulartrapping in combination with field sanitation) was tested at twofarmer-managed sites (Bujela and Kyimo) and one researcher-managedsite (SUA-Morogoro). Treated areas were surrounded by untreatedcontrol areas where no trapping and limited sanitation was done.Changes in population densities were estimated by the mark-recaptureprocedure and the Lincoln index. Results and discussion. Aftereight months, weevil populations in the cleaned and trapped areashad been reduced by 33% (Bujela), 33% (Kyimo) and 74% (SUA). Thechange in population sizes in the control areas differed greatly,possibly due to discrepancies in field management between farmers’ andresearchers’ practice. Trap types, areas and sites affected thenumber of weevils captured. Disc-on-stump (DOS) traps captured moreweevils than corm disc (CD) and pseudostem (PS) traps. Weevils respondedmore strongly to traps in the clean area at SUA compared with theother two sites, probably because the more rigid sanitation practicesat SUA meant that volatiles from the traps were less likely to bemasked by volatiles from surrounding residues. Conclusion.Regular trapping with field sanitation can greatly reduce populationsof banana weevils, but strict adherence to method execution is requiredin order to gain favourable results.