|Abstract||The phylogenetic significance of morphological characters used to diagnose Bactericera, Rhinopsylla, Paratrioza, Allotrioza, Klimaszewskiella, Eubactericera, Phylloplecta and Sinitrioza is examined. There is no evidence that the genera or subgenera, in any of their present or past definitions, constitute natural units. The six former together, however, form a monophyletic group, defined by a combination of adult, larval and egg characters. Phylloplecta and Sinitrioza, which share similar adult characters with Bactericera, differ in the larval and egg morphology. The following new synonymies are established: Bactericera (= Rhinopsylla pro parte, = Paratrioza, = Allotrioza, = Klimaszewskiella, = Eubactericera pro parte) and Phylloplecta (= Sinitrioza). A list of the 121 species included in Bacerticera is provided and 75 new combinations are introduced (60 in Bactericera, 4 in Phylloplecta, 9 in Trioza and 1 in Kuwayama). Bactericera, equisetifolii sp. n. and B. vellae sp. n. are described from Israel and Spain respectively, and B. loginovae, B, perrisii and B. rossica are redescribed. The following new species level synonymies are proposed: B. perrisii (= B. maritima) and B. gobica (= P, sinica, = P turcamanica). Variation of genal cone length in B. kratochvili is discussed and the presence of two biological races is noted in B. modesta. Keys are provided for the adults of the European species associated with Salix, and the last instar larvae of the West palaerctic species; the latter are also illustrated. Information on life cycles and host plants is summarised and briefly discussed. Differences in the hindwing venation, which were recently used to erect the families Rhinopsyllidae and Rhinocolidae are shown to be trivial. The two families are therefore synonymised with the Triozidae and Psyllidae respectively.