STUDIES ON THE CAPABILITY OF CHEILOMENES-LUNATA (FABRICIUS) (COLEOPTERA, COCCINELLIDAE) TO PREY ON THE COWPEA APHID, APHIS-CRACCIVORA KOCH (HOMOPTERA, APHIDIDAE) IN NIGERIA

Cheilomenes lunata (F.) is an important predator of Aphis craccivora K och that attacks cowpeas, Vigna unguiculata (L.) Walpers seasonally in Nigeria. Consumption of the various instars of A. craccivora, by firs t and fourth instar larvae and adults of C. lunata was studied in the laboratory. The capability of the predator to suppress aphid populatio ns on caged cowpea plants was determined. Early aphid instars were con sumed in significantly greater numbers than later ones, in no-choice a nd flee-choice trials. The population developing in 1 week from nine a dult apterae of A. craccivora on;three cowpea plants was completely co ntrolled by a pair of C. lunata within the following week, the cowpea plants being infested at the seedling as well as the young pod growth phases.