Survey of insect pests on pigeonpea in Nigeria.
Survey of pigeonpea growing areas in Nigeria comprising Imo, Abia, Enugu, Anambra, Delta, Kogi and Benue states was carried out in February 2007 and repeated in February 2008 basically to establish pest incidence and level of damage caused by insect pests in farmers' fields. Questionnaires and discussions with agriculturists from state agricultural extension agencies, universities, staff of Ministries of Agriculture and farmers were carried out. From 103 sample sites, 100 pigeonpea pods were selected at random and analyzed for percentage pod damage by pod borers and pod sucking bugs. The cropping systems in which pigeonpea was growing were noted and percentage seed losses due to pests from each system were analyzed and recorded. From the results, major insect pests encountered during the field visits were: foliage beetles, ants, termites, flower pests [thrips (Megalurothrips usitatus) and blister beetle (Mylabris pustulata)], pod borers (Helicoverpa armigera, Maruca testulalis, Etiella zinckenella), pod sucking bugs (Anoplocnemis curvipes, Riptortus dentipes, Clavigralla tomentosicollis, Nezara viridula), aphids (Aphis craccivora), and leaf damaging weevils (Myllocerus undecimpustulatus). Results also revealed that mean damage by pod sucking bugs was highest in Imo (78%), Kogi (73%) and Benue states (71%) and least in Enugu state (44%) than the damage by pod borers in all the states visited. Among the cropping systems observed in the areas, pigeonpea/maize intercrop recorded greater damage by pod borers than pod sucking bugs while pigeonpea/rice intercrop had the least damage by pod borers and pod sucking bugs followed by pigeonpea/cocoyam intercrop.