FIELD DENSITY OF APHIS GOSSYPII GLOVER ON BRINJAL IN RELATION TO PREDATORY AND BIOTIC FACTORS

Field density of aphid. Aphis gossypii Glover on brinjal var. "Pusa Purple Round' were recorded for two consecutive cropping seasons 1999 and 2000. The study revealed that the incidence of the aphid began from second week of March and continued till the fourth week of June. The population reached its peak during May with the maximum abundance of 365.39 and 330.44 aphids/sampling unit during 1999 and 2000 respectively. The average mean temperature and relative humidity recorded were 25.15°C and 70.71% respectively. The correlation coefficient between the pest and related abiotic and biotic parameters were calculated. The results showed positive correlation between the pest and temperature, relative humidity, wind speed and Sunshine whereas negative relationship with the rainfall. Nine species of aphidophagous predators belonging to Coleoptera, Diptera and Neuroptera were recorded and found to be prey density dependent.