Higher-level phylogeny of Chrysomelidae based on expanded sampling of mitogenomes

Chrysomelidae is one of the most diverse lineages of beetles. The classification and phylogeny of Chrysomelidae have been contentious. In this study, we obtained 16 new mitogenome sequences by using next-generation sequencing. Combined with the published mitogenomes, we inferred the phylogenetic relationships of Chrysomelidae. Different data recoding strategies and substitution models were applied to phylogenetic reconstruction. In the Maximum likelihood analyses under the homogeneous model, Dayhoff recoding allowed for the improved phylogenetic resolution due to the decreased level of heterogeneous sequence divergence. Bayesian inference under the heterogeneous model yielded generally well resolved subfamily relationships. The present mitogenome data strongly supported Chrysomelidae as a monophyletic group. Consistent with previous work, we found three major subfamily clades within Chrysomelidae. However, the pattern of the "sagrine" clade plus the "eumolpine" clade being sister to the "chrysomeline" clade contrasted with the prior study. The placement of the genus Syneta with regards to these three clades was ambiguous. Relationships recovered suggested several major chrysomelid lineages, including: (1) Bruchinae in the "sagrine" clade; (2) Donaciinae + Criocerinae; (3) Spilopyrinae + (Cassidinae + (Eumolpinae + (Lamprosomatinae + Cryptocephalinae))); (4) Chrysomelinae + (Alticinae + Galerucinae). Results also suggested the placement of Timarcha outside the major Chrysomelinae.