Insufficient power of mitogenomic data in resolving the auchenorrhynchan monophyly

The hemipteran suborder Auchenorrhyncha consists of four superfamily rank taxa (i.e. Cicadoidea, Membracoidea, Cercopoidea and Fulgoroidea), with more than 42 000 described species worldwide. The monophyly of Auchenorrhyncha and the higher-level relationships within this group remain questionable, despite recent research using morphological and molecular data. In this study, we sequenced 18 mitogenomes of representatives of Membracoidea, three of Cercopoidea and one of Psylloidea and conducted phylogenetic analyses together with 35 existing mitogenomes of Hemiptera, with special emphasis on the auchenorrhynchan monophyly. The phylogenetic inferences from the mitogenomic data are strongly affected by increased rates of sequence substitution associated with several lineages, which leads to the significant long-branch attraction. Under these conditions, the monophyly ofAuchenorrhyncha is not supported even with the comprehensive data coding schemes. This shows the limitations of the mitogenome in resolving the higher-level phylogeny of Auchenorrhyncha. In addition, the removal of fast-evolving sites using a pattern sorting method (OV-sorting) significantly improves phylogenetic estimates under both homogeneous and heterogeneous models. Moreover, data sets with a higher proportion of conserved sites recover the monophyly of Auchenorrhyncha and support a superfamily relationship of [Fulgoroidea + ((Cicadoidea + Cercopoidea) + Membracoidea)].