Effect of dates of sowing of Brassica juncea on coccinellid beetle of Lipaphis erysimi kalt.

The results indicated that the maximum coccinellids population were observed in the last week of February (when crop was on its maturity) while minimum in the last week of December. The coccinellid beetles observed on crop in the last week of December and sustained up to maturity of the crop. Its population increased with increasing atmospheric temperature. Results also indicated that when coccinellid's population increased significantly, aphids were already in their migration phase. At the peak of aphid population, the coccinellids were present but not capable to keep the aphid population below the economic injury level.