INSECTICIDAL ACTIVITIES OF FRUITS OF Xylopia aethiopica (DUNAL) A. RICH AGAINST Callosobruchus maculatus (FAB.) (COLEOPTERA: CHRYSOMELIDAE: BRUCHIDAE)

Abstract

Under laboratory conditions (28±3°C and 70± 5% r.h.) in Akure, Nigeria, powders of different particle sizes (75μm, 150μm, 300μm and 425μm) prepared from dried fruits of Xylopia aethiopica and hexane extract of dried fruits of X. aethiopica were tested for effectiveness as surface protectants against the seed beetle Callosbruchus maculatus (F.), on infected cowpea seeds, Vigna unguiculata (L.) Walp. The powders were evaluated at six rates (0.0, 0.2, 0.4, 0.6, 0.8, 1.0g/20g of seeds), and the oil at four rates (0ml, 1ml, 5mls and 10mls/10g of seeds). Treatments involved introducing freshly emerged beetles onto protected and unprotected cowpea seeds in air-tight glass tubes or plastic plates. Adult mortality, number of egg laid, F1 adult emergence, and seed weight loss were used to determine the effectiveness of treatments. The results showed that the powder and hexane extract of X. aethiopica did not significantly influence mortality of C. maculatus at both 24 and 48 hrs post treatments. Number eggs laid, number of F1 adult emergence and weight loss decreased with increase in the rate of application of both powder and extract. Particle size of powders did not significantly influence