Insect Infestation of West African Produce imported into Britain

Abstract

An analysis is made of the records of inspections for infestation by insects of cargoes imported into Britain from West Africa. The exporting territories extend from Angola to Senegal but the bulk of cargoes were produce of the four British colonies.The ready spread of insects from one cargo to another causes infestation to be similar for all cargoes but a few species are especially associated with a particular crop. Groundnuts in shell are normally shipped alone and therefore relatively protected from cross-infestation.The three major cargoes are cocoa, palm kernels and groundnuts which form four-fifths of the inspected shipments. Fifteen other kinds of produce are also considered.Twelve species were found on more than ten per cent. of cargoes of cocoa beans. Of these five were probably acquired from groundnuts and one from palm kernels by cross-infestation. Ephestia cautella (Wlk.), Tribolium castaneum (Hbst.) (from groundnuts), Lasioderma serricorne (F.), Necrobia rufipes (Deg.) (from palm kernels) and Araecerus fasciculatus (Deg.) all infested over 40 per cent. of cargoes.The fluctuations of infestation year by year are examined, and it is shown that these are similar for all the species acquired from groundnuts except T. castaneum. Variations in frequency of other species appear to be unrelated.