Study the seasonal activity of insect pests in pea crop

Abstract

Population of Aphis craccivora was first observed in SMW # 1 (1.37 aphids per plant). Peak population of Aphis craccivora was recorded during SMW # 4 (62.30 aphids per plant) and there after its population decline gradually. Its population remained high till the maturity of the crop in SMW # 8 (21.4 aphids per plant). Acyrthosiphon pisum appeared at a low level for the first time in SMW # 1 (0.47 aphids per plant) and the population remained low throughout the crop season (below 4.07 aphids per plant). The peaks population of Acyrthosiphon pisum was observed in SMW # 4 (4.02 aphids per plant) and in SMW # 6 (4.07 aphids per plant). Leaf infestation by Liriomyza trifolii was recorded to be 10% during SMW # 1. Its incidence increased gradually with peak infestation of 39.34% infested leaves in SMW #5. Thysanoplusia orichalcea was observed in pea crop at a very low level (below 1.0 individual per plant). Its mean population was 0.15, 0.32, 0.45, 0.30, 0.12 and 0.10 individuals per plant observed between SMW # 51 (2016) and SMW # 4 (2017). Helicoverpa armigera was recorded in pea crop at very low level between SMW # 50 and SMW # 4 with peak population of 0.65 larvae per plant in SMW # 1.