Patterns in flight phenology of a migrant cereal aphid species.
Flight phenologies of the migrant aphid Rhopalosiphum padi, as indicated by suction trap catches throughout France in 1978-88, were compared using multivariate methods. Cluster analysis identified 7 main patterns of flight phenology for this species. Discriminant analysis of patterns using monthly mean temperatures allowed the effect of weather on patterns of flight phenology to be identified. The range of life-cycle strategies displayed by R. padi in France can explain partially the different types of patterns and their variations in space and time. In the regions characterized by a balance between holocycly and anholocycly, the annual variability of patterns in flight phenologies decreased with the increasing prevalence of holocycly. Temperature played a more important role for the prediction of likely patterns when a high proportion of the population was anholocyclic.