Molecular phylogeny of the genus Aphis (Homoptera: Aphididae) based on mitochondrial and nuclear EF-1a genes

Abstract: Aphis, is one of the largest genera in the family Aphididae. The accurate identification of these species is of crucial importance because this genus contains many species that are pests of agriculturally important crops. Aphis species are very difficult to discriminate using only morphological characters. Members of this genus have a close association with a wide diversity of plants and the available dichotomous keys were built using host plant association data. A phylogeny of the genus Aphis was reconstructed using the mitochondrial COI and the nuclear EF-1α genes. Individual and combined data sets were analyzed using maximum parsimony and likelihood analysis as implemented in PAUP 4.0b10, and MrBayes v3.1. Our phylogenetic analysis discriminates two main species-groups within Aphis: the gossypii and helianthi groups. In addition it suggests that a revision of some Aphis species is necessary, i.e. A. debilicornis should be placed within the sub-genus Protaphis.