On-farm analysis of attacks by the pea weevil (Sitona lineatus L.; Col., Curculionidae) and the resulting damage to pea (Pisum sativum L.) crops

Abstract : The study measures intensity of attacks by Sitona lineatus L. on pea crops in farmers’ fields and the resulting damage. Insect attacks were measured on the aerial parts of the plant at the vegetative stages and on roots at the start of flowering of the crop. Attack intensity varied between and within plots. Early sown crops were at greater risk of severe damage. There was a good correlation between leaf damage at the beginning of the crop cycle and damage to nodules at the start of flowering in unsprayed crops. Aerial spraying did not completely prevent nodule damage in crops severely injured by insects at the early vegetative stage. The effects of the attacks on nitrogen nutrition of the pea crop were also assessed; these results are discussed with regard to the consequences for crop management.