Characterization of the complete mitogenomes of two species of Eumolpinae (Coleoptera: Chrysomelidae) and phylogenetic insights

The subfamily Eumolpinae holds substantial economic importance due to their plant-feeding habits. In this study, 2 complete mitochondrial genomes of eumolpine leaf beetles, Macrocoma budura Daccordi & Medvedev and Colasposoma grande grande (Lefèvre), were newly sequenced. Both mitogenomes possess the standard 37 mitochondrial genes and a large noncoding control region, and exhibit a highly conserved gene arrangement except for a diagnostic inversion of trnR (tRNA-Arg) and trnA (tRNA-Ala). The inversion of these 2 tRNAs has been reported previously in Eumolpinae and represents a potential subfamily-level synapomorphy. Most tRNAs adopt the typical cloverleaf conformation, with the exception of C. g. grande trnS1 (tRNA-Ser [AGN]), which lacks the DHU (dihydrouridine [tRNA structural domain]) arm, and the M. budura tRNA-Cys, which has a shortened D-loop, suggesting possible lineage-specific structural variation. Bayesian and maximum likelihood analyses recover C. g. grande within Euryopini, whereas M. budura is placed within Bromiini with an intratribal position that varies by dataset. These new mitogenomes not only contribute to the sparse genomic resources for Eumolpinae from arid regions but also demonstrate the value of mitochondrial gene order and sequence data to resolve species-level relationships and biogeographic histories within Chrysomelidae.