Evidence for the presence of chemicals attractive to the banana weevil, Cosmopolites sordidus (Coleoptera : Curculionidae) in dead banana leaves

The effects of host and non-host plant odours on the foraging responses of the banana weevil, Cosmopolites sordidus (Germar), were investigated in the laboratory through arena and olfactometer bioassays. Contrary to previous reports that banana rhizome and pseudostem were the most attractive parts t o the weevil, dead leaves were most preferred. Comparison of dead banana le aves with dead leaves of other plants showed that attractant odours were pr esent in yam, cocoyam and dead grasses but absent in cocoa and soybean leav es. Complete leaf senescence while the leaf was attached to the mother plan t proved necessary for the development of the dead-leaf-based odours but th e involvement of microbial organisms could not be demonstrated. It is possi ble that dead-leaf-based attractants could be used in combination with micr obials such as entomogenous fungi and nematodes in integrated management of C. sordidus.