Comparative Mitogenomic and Phylogenetic Insights of Three Aulacophora Species (Coleoptera: Chrysomelidae) Associated with Cucurbit Crops

Abstract

This study sequenced and comparatively analyzed the mitochondrial genomes of three agriculturally important Aulacophora pests: the polyphagous A. indica, the oligophagous A. lewisii, and the early-diverging A. nigripennis. All three mitogenomes contained the typical 37 genes with conserved gene order. However, total length varied substantially (15,258–18,766 bp), driven primarily by control region length variation. All species exhibited pronounced AT bias, and relative synonymous codon usage analysis revealed marked interspecific divergence. Phylogenetic analysis based on 13 protein-coding genes resolved A. nigripennis as the basal lineage and A. lewisii and A. indica as closely related sister species. Both widespread species displayed maximum haplotype diversity (Hd = 1.000); however, A. indica exhibited approximately 2.4-fold higher nucleotide diversity (Pi = 0.00478) than A. lewisii (Pi = 0.00198), indicating differential population genetic architectures between the two species. These findings established a comparative mitogenomic framework for Aulacophora and provide baseline data for future phylogenomic and phylogeographic investigations.