Influence of abiotic and biotic factors on seasonal abundance of brinjal shoot and fruit borer (Leucinodes orbonalis Guenee)

Both abiotic and biotic factors influence the seasonal abundance of Leucinodes orbonalis by significantly affecting its survival, rate of multiplication and feeding behavior. Two years study showed that L. orbonalis infestation on brinjal shoots peaked in the second week of September while infestation on fruits peaked in the third week of October. Significant positive correlation was recorded between shoot infestations of L. orbonalis and maximum temperature during both experimental years. With regard to the L. orbonalis infestation on the brinjal shoot in 1st year, a non-significant positive correlation was found with total rainfall while a significant negative correlation was found during 2nd year. Although, the fruit infestations had a significant positive correlation with maximum temperature during both study years. The fruit infestation and average relative humidity had a non-significant negative correlation in 1st year; but a significant negative correlation in 2nd year. The correlation between population of Bracon spp. and infestation caused by L. orbonalis was significant and positive during both years.