The use of multivariate morphometric methods in the separation of alate morphs of the rose-grain aphid, Metopolophium dirhodum

A preliminary morphometric analysis of alate Metopolophium dirhodum was carried out. The alate morphs studied were: gynoparae and alate emigrants (collected from Rosa), summer exules (collected from maize in the field and from wheat in the laboratory) and winter exules (collected from grasses). Comparing the different morphs using canonical discriminant function analysis gave good separations (always in excess of 80% and often 100%). If this result is found to hold for specimens from a wider temporal and geographical range, it may be used to determine the sources of flying alatae, particularly spring colonists.