European gall-forming Pemphigus (Aphidoidea: Eriosomatidae)

The paper presents the aphid species occurring in Europe which belong to the genus Pemphigus Hartig, 1839 of the family Eriosomatidae (Hemiptera: Sternorrhyncha: Aphidomorpha). Some of these species can become a serious threat for agricultural and horticultural crops and can be deemed pests of economic importance. Information on the harmfulness of some species was provided. The genus was characterised along with the features that differentiate Pemphigus s. str. from the subgenus Pemphiginus Börner, 1930. The most significant biological features were compared and described (type of life cycle, host plants) as well as the distribution of particular species and their probable area of origin. For the species that occur in Europe (also the introduced ones) an original key was included to identify them on the basis of galls they form on poplars.