Over a 9-month period, samples of maize and sorghum seeds were purchased monthly from markets located in three contiguous climatic zones of Nigeria; the grain samples were examined and insect pests found on them were recorded. Species of Sitophilus, Rhizopertha and Sitolroga accounted for 57–84% of all insect pests collected from the two grain types. Significantly more insect pests were recorded on grains obtained from the southern guinea savannah zone than from the northern guinea and sudan savannah zones. The relative incidence of the insect pests in the three zones is related to moisture availability reflected in grain moisture content.
