Predicting susceptibility of non-target species to different insecticide applications in winter wheat.
The exposure of any insect species to a pesticide application depends on the intrinsic properties, behaviour and distribution of both insect species and pesticide. The short term pesticide exposure of several important cereal-dwelling natural enemy species was predicted and used to rank them in order of susceptibility to field applications of insecticide using different application systems. Individual susceptibility indices were attributed to individual beneficial insect species when subjected to an insecticide treatment applied by different nozzle types mounted on a boom sprayer. These indices were derived from a formula incorporating the distribution of insecticide and insect species within the crop, chemical toxicity, varying toxicity of insecticide at different crop strata and insect behaviour. From these indices, insect species were ranked in order of susceptibility to an insecticide application made under field conditions.