The problem of insect infestation of stored export food commodities in southern Nigeria is discussed, and a list of insects is given. At the ports there is considerable cross-infestation between commodities produced in northern and southern Nigeria awaiting shipment.
Old sacks used for the storage and transit of groundnuts are responsible for the spread of insects to palm kernel and cocoa marketing centres in the south. After bulk shipments of a portion of the groundnut crop, sacks are repaired and distributed for the shipment of palm kernels and some of them may be used by fanners and brokers as service bags for the marketing of cocoa and local food commodities. The importance of disinfestation before distribution is realised, and a small fumigation plant is in operation at port.
Ephestia cautella and Lasioderma serricorne are the major pests of stored cocoa beans. Both originate in farmers' and brokers' stores which are rarely cleaned, and in which small parcels of low-grade beans may be retained for mixing with a following crop to conform with an exportable grade. Ephestia cautella also infests palm kernels, and the early abundance of adult moths in cocoa stores up country during the marketing season is considered to be largely due to the storage of palm kernels in the vicinity. The development of Ephestia larvae can be completed on the outside of cocoa beans, only germinated or damaged beans being penetrated.