Studies of storage insect pests of maize (Zea Mays L.) in southern Ghana

Abstract

A market survey was carried out between October 2001 and April 2002 to determine insect pests associated with maize sold in the market and the knowledge base of local maize traders on these pests. The persistence of the pests from the field through storage (in cribs) to the markets was also investigated. Two Quality Protein Maize (QPM) and two local maize varieties were used in a further study to determine varietal susceptibilities, under field and laboratory conditions, and moisture content preferences of various SIP. Effort was also made to identify common wild plant seeds that could serve as alternative hosts. Traders purchase and store small quantities for short periods due to lack of capital, fear of destruction by pests and mould growth. Sitophilus sp. was the commonest pest identified by traders and was ranked as the most destructive. The susceptibility of improved maize varieties, as claimed by traders was confirmed by results of common susceptibility parameters conducted with Sitophilus sp. as the test insect. The varieties were however similar in other susceptibility parameters. Most insect pests infested maize from the field but a few persisted through storage to the markets as moisture content fell to 12%. These pests included Ahasverus sp., Catharlus sp., Sitophilus sp., Tribolium sp., Mussidia sp. and Cryptophlebia sp. Seeds of five out of twenty wild plants were found to serve as alternative hosts to only one SIP, Araecerus sp.