Morphological and molecular analysis of Bachycaudus, subgenus Appelia-complex (Rhynchota Aphididae)

A taxonomic investigation is developed on aphids of the genus Brachycaudus v.d.G. subgenus Appelia Börner, commonly known as B. prunicola complex. To date the group composition is not entirely clear because of the morphological similarity of its different members. Biometric multivariate analysis and genetic analysis which included both mitochondrial and nuclear DNA sequencing as well as allozyme analysis were used. All analytical methods highlighted a convergence of results which recognise three separate species (B. prunicola, B. tragopogonis and B. cerinthis);a forth taxon however, B. schwartzi, proved to be closely allied either morphologically and genetically to B.prunicola, hence considered as B. prunicola ssp. schwartzi. Finally, a synoptic morphological description including a key to separate apterous and alate viviparous females of the different taxa is included.