Grain injury models for Prostephnaus truncatus (Coleoptera : Bostrichidae)and Sitophilus zeamais (Coleoptera : Curculionidae) in rural maize stores in West Africa

Prostephanus truncatus (Horn) and Sitophilus zeamais Motschulsky have been reported as the two most serious pests of stored maize in sub-Saharan Afric a and smallholder farmers are in urgent need of guidelines for their proper management. In this article we investigate the injury rates attributable t o these two species in terms of percentage weight loss and percentage grain damage, and we derive functional response models for the two species on ma ize. The models successfully described the progression of grain injury in a n extensive data set compiled from previously published studies, comprising 46 time series of data relating maize injury and insect pest density. The grain injury models can be used in conjunction with predictive models of pe st population dynamics to guide the development of integrated management st rategies for postharvest maize pests in West Africa and comparable regions elsewhere.