Can 'bad' years for damage by Prostephanus truncatus be predicted?

Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) is a sporadic, but serious pest of maize and cassava in the tropics. Farmers report that some years are far worse for damage than others and it is also known that the numbers of insects dispersing, as measured in pheromone traps, varies between years. Using purpose-built mini-stores it was shown that flight-trap catches of P. truncatus were a significant predictor of the risk of stores becoming infested in Ghana but not Tanzania. The estimated relationship between these two variables was, however, similar in both countries, and also matched data subsequently obtained from observations of farmers' stores in Ghana. These findings are an important step towards the development of a warning system to decrease the uncertainty of P. truncatus threat to stored maize and cassava.