Mitogenomic Characterization and Phylogenetic Expansion of Tribe Coccinellini (Coleoptera: Coccinellidae)

Coccinellidae (Coleoptera) is a large and ecologically important beetle family, widely recognized for its members' role as natural enemies of agricultural pests. Within this family, the tribe Coccinellini is of particular significance because it includes many dominant predatory species used in biological control programs and exhibits notable ecological and trophic diversity. Despite their ecological and taxonomic importance, evolutionary relationships within Coccinellini remain unresolved because previous studies relied on limited molecular markers or morphology. In this study, we report nine complete mitochondrial genomes of Coccinellini species, estimated divergence time to place to their evolutionary diversification and present a comprehensive analysis of the features of these newly sequenced mitochondrial genomes. The newly sequenced mitogenomes contain the typical 37 genes (13 PCGs, two rRNAs, and 22 tRNAs) and a non-coding control region, and are arranged in the same order as that of the putative ancestor of beetles. The average A + T content of all nine mitogenomes is 78.2%. The calculated values of relative synonymous codon usage (RSCU) determine codons UUA (L), UCU (S2), and CCU (P) have the highest frequency in all nine mitogenomes. Furthermore, combining 58 available mitogenomes, we reconstructed the tribe's phylogeny and resolved the taxonomic status of the studied species. Our phylogenetic analyses confirm the taxonomic placement of all the newly sequenced species within Coccinellini and support the monophyly of Coccinellini (Bootstrap support ≥ 70%, posterior probability ≥ 0.97). The tribe Coccinellini was resolved into four major clades with the following relationship: (Clade D, (Clade C, (Clade B, Clade A))). The mycophagous genera Halyzia, Psyllobora, Illeis, and Vibidia were consistently grouped within Coccinellini. These findings refine current understanding of evolutionary relationships within Coccinellini and provide a useful mitogenomic reference for future systematic related research in Coccinellidae.