Species-level problems in the Aphis (Bursaphis) complex are reconsidered based on the partial sequences of the mitochondrial cox1 gene together with morphological and ecological data. This indicates that the American species A. oenotherae is a complex of four species (A. oenotherae, A. holoenotherae, A. costalis and A. neomexicana) and the taxonomic status of the species couples A. varians - A. manitobensis and A. epilobii - A. grossulariae require further clarification. Aphis sp. (USA: California, Oregon) of Blackman & Eastop (2006, p. 415) deserves the status of a species provided there is information on its host association and life cycle. Partial cox1 sequences might be misleading when used as standard DNA barcodes of aphid species of the subgenus Bursaphis. and Rimantas Rakauskas, Jurga Turčinavičienė, Jekaterina Bašilova.
Phylogenetic relationships among Palaearctic Ribes and/or Onagraceae inhabiting Aphis species from five countries were examined using mitochondrial gene cytochrome oxidase I (CO-I) and nuclear gene elongation factor 1 α (EF-1α) sequences. There was no major conflict between the trees obtained from two data sets; nodes with strong bootstrap support from one analysis never contradicted those strongly supported by the other analysis. Palaearctic species of the subgenus Bursaphis (= "grossulariae" species group of the genus Aphis) form a monophyletic group within the genus Aphis. All these analyses indicated that Aphis grossulariae and A. schneideri are close relatives, which is supported by the information on experimental and probably also natural hybridisation. Our data indicate the independent colonisation of Ribes spp. by two species groups of the genus Aphis: A. triglochinis (subgenus Aphis s. str.), and A. grossulariae and A. schneideri (subgenus Bursaphis). Once the subgenus Bursaphis (and other subgenera) is accepted, the subgenus Aphis s. str. will require further subdivision.