Quantifying the impact of Psylliodes chrysocephala injury on the productivity of oilseed rape.

These data confirm the yield-limiting potential of the larval stages of P. chrysocephala yet suggest that the current action thresholds which trigger insecticide application for both adult and larval stages (25% leaf area loss and five larvae/plant, respectively) are potentially too low as they are below the physiological injury level where plants can fully compensate for damage. Further research in field conditions is needed to define physiological thresholds more accurately as disparity may result in insecticide applications that are unnecessary to protect yield and may in turn exacerbate the development and spread of insecticide resistance in P. chrysocephala. This article is protected by copyright. All rights reserved.