Ips acuminatus has a Eurasian distribution and overlaps with Ips chinensis in southern China. These species are morphologically similar and taxonomic confusion is possible because of the lack of a recent systematic review of these species. Assembly of specimens throughout the ranges of these species allowed for the examination of species boundaries based on monophyly. A phylogeny was reconstructed with cytochrome oxidase I DNA sequences for 24 individuals plus three outgroups and morphological diagnostic characters typical for Ips species were reviewed. The strict consensus of 16 most parsimonious trees recovered I. acuminatus and I. chinensis reciprocally monophyletic with an above average pairwise sequence difference (9.6% compared to 6.1% for Ips sister species). These clades associated with diagnostic characters of elytral declivity, that is, the position of spine 2. Monophyly, nucleotide differences, and diagnostic characters support the validity of I. chinensis. In addition, high sequence divergence was observed between two clades of I. chinensis which corresponded to northern and southern populations however consistent morphological differences were not found for those clades.

Ips acuminatus has a Eurasian distribution and overlaps with Ips chinensis in southern China. These species are morphologically similar and taxonomic confusion is possible because of the lack of a recent systematic review of these species. Assembly of specimens throughout the ranges of these species allowed for the examination of species boundaries based on monophyly. A phylogeny was reconstructed with cytochrome oxidase I DNA sequences for 24 individuals plus three outgroups and morphological diagnostic characters typical for Ips species were reviewed. The strict consensus of 16 most parsimonious trees recovered I. acuminatus and I. chinensis reciprocally monophyletic with an above average pairwise sequence difference (9.6% compared to 6.1% for Ips sister species). These clades associated with diagnostic characters of elytral declivity, that is, the position of spine 2. Monophyly, nucleotide differences, and diagnostic characters support the validity of I. chinensis. In addition, high sequence divergence was observed between two clades of I. chinensis which corresponded to northern and southern populations however consistent morphological differences were not found for those clades.