Population dynamics of major insect-pests of cowpea and their correlation to abiotic parameters

During the crop season, the Epilachna, jassid and blister beetles were recorded in the last week of July (31 SMW) with a mean population of 2.90 epilachna beetles/plant, 6.30 jassids/3 leaves and 2.70 blister beetles/plant and reached to its peak (9.20 epilachna beetle/plant, 13.70 jassids/3 leaves and 7.20 blister beetles/plant) during the fourth week of August (35 SMW). During this period, the maximum and minimum temperature and relative humidity ranged from 35 to 27°C and 83 to 59%, respectively. The epilachna, jassid and blister beetles show positive correlations with all-weather parameters, viz., maximum and minimum (temperature & relative humidity), rainfall and wind velocity.