EFFECT OF FOOD TYPE ON TOLERANCE OF Callosobruchus maculatus FROM DIFFERENT GEOGRAPHICAL LOCATIONS TO THE OIL EXTRACT OF Fagara zanthoxyloides

Both biotic and abiotic factors have been noted to have effect on response of insects to insecticides. This study therefore evaluated the effect of food type and geographical locations on the tolerance of Callosobruchus maculatus to oil extract of Fagara zanthoxyloides under laboratory temperature of 28±2°C and 75±5% relative humidity. The insects were collected from four different states within the south-western region of Nigeria and they were fed with Ife-Brown and IT96-610 cowpea variety. The effect of the oil extract on survival, oviposition rate and emergence of the adult insect varied with type of food and geographical locations. The insect fed with IT96-610 appeared to significantly tolerance to the oil of F. zanthoxyloides (P = 0.05) while insect from Osun state also showed more tolerance to the oil extract than those from other three locations. Regression analysis showed that the amount of oil extract required to 50 and 95% mortality of the C. maculatus varied with the types of food and geographical locations.