Estimation of crop losses due to major insect pests of grass pea (Lathyrus sativus L.) in Gangetic plains of Eastern India

At vegetative stage grass pea crop, was found infested mostly by a sucking pest viz., black pulse aphid (Aphis craccivora), while, gram pod borer, Helicoverpa armigera was an important pod boring insect during reproductive stage. The results revealed that the fully protected plot which was treated with Thiamethoxam 25 WG @ 0.2 g/l of water and Indoxacarb 14.5 SC @ 0.5 ml/l of water during vegetative stage and reproductive stage of the crop, respectively, had resulted the highest pod yield, avoidable crop loss and increase in yield over control. The results also suggested that if two rounds of spraying are allowed to control the pests, the crop should be sprayed with Thiamethoxam and Indoxacarb at aforementioned doses during both vegetative and reproductive stages, respectively. Otherwise, if single spraying would be allowed, the crop should be managed during vegetative stage to control aphids which had more damaging ability than pod borers.