The existence of two species ofEuceraphis(Homoptera: Aphididae) on birch in Western Europe, and a key to European and North American species of the genus

摘要

Abstract.Aphids formerly regarded asEuceraphis punctipennis(Zetterstedt) are distinguished as two species,E.punctipennisandE.betulae(Koch), on the basis of cytological and morphological differences.E.punctipennisis primarily associated withBetula pubescensEhrh., andE. betulaewithB.pendulaRoth. Seasonal variations in morphometrics, pigmentation and development of wax glands in the two species are described and compared. A key to European and North American species ofEuceraphisis provided.