Attractiveness of host banana leaf materials to the banana weevil Cosmopolites sordidus in Ghana for development of field management strategies

摘要

BACKGROUNDThe banana weevil, Cosmopolites sordidus, has been frequently cited as the most challenging constraint to banana and plantain production, particularly in small‐scale (smallholder) farming. For the development of a new, low‐cost weevil management technology based on attractive host plant material, we previously identified (2R,5S)‐theaspirane as the active component of attractive senesced banana leaves. In this new study, we used behavioural (olfactometer) bioassays with adult weevils to compare the attractiveness of four different developmental stages of banana leaves, i.e. unfolding (pale green), matured green (deep green), matured yellowing and senesced, to determine which leaf developmental stage would be most appropriate for use in weevil management. We also investigated the attractiveness of senesced leaf extracts prepared using different solvents to determine which solvent would be most appropriate for local production of leaf extracts. Coupled gas chromatography–electroantennography (GC–EAG) was then used with adult weevils to confirm the presence of (2R,5S)‐theaspirane in attractive leaf extracts.