A Survey of the Build-Up of Infestation in Bagged Cocoa Beans in Store in western Nigeria

Abstract

Two tons of cocoa, in 32 bags, stacked in a typical cocoa store in Ibadan, Nigeria, were sampled from December 1953 to the end of April 1954. The weekly catches on “ até “ strands hung round the stack suggested that Ephestia cautella (Wlk.) was the most numerous insect on cocoa, but spear samples of the beans, taken from the sacks every two weeks, showed that the actual population of this species in the beans was small throughout the season, with no sign of build-up. Lasioderma serricorne (F.), on the other hand, was shown to be the most serious pest, the population in the beans increasing steadily from an extremely low level. It is estimated that on the average it is not safe to store initially good cocoa for more than 25 weeks in the main crop season.