The mitochondrial genomes of the Geometroidea (Lepidoptera) and their phylogenetic implications

The Geometroidea is a large superfamily of Lepidoptera in species composition and contains numerous economically important pest species that cause great loss in crop and forest production. However, understanding of mitogenomes remains limited due to relatively fewer mitogenomes previously reported for this megadiverse group. Here, we sequenced and annotated nine mitogenomes for Geometridae and further analyzed the mitogenomic evolution and phylogeny of the whole superfamily. All nine mitogenomes contained 37 mitochondrial genes typical in insects, and gene organization was conserved except for Somatina indicataria. In S. indicataria, the positions of two tRNAs were rearranged. The trnR was located before trnA instead of after trnA typical in Lepidoptera, whereas the trnE was detected rarely on the minority strand (N-strand). This trnR-trnA-trnN-trnS1-trnE-trnF newly recognized in S. indicataria represents the first gene rearrangement reported for Geometroidea and is also unique in Lepidoptera. Besides, nucleotide composition analyses showed little heterogeneity among the four geometrid subfamilies involved herein, and overall, nad6 and atp8 have higher nucleotide diversity and Ka/Ks rate in Geometridae. In addition, the taxonomic assignments of the nine species, historically defined by morphological studies, were confirmed by various phylogenetic analyses based on the hitherto most extensive mitogenomic sampling in Geometroidea.

Automated summary

In this study, nine mitochondrial genomes of Geometridae were sequenced and annotated, and the mitogenomic evolution and phylogeny of the superfamily were analyzed. It was found that gene organization was conserved, except for Somatina indicataria, which showed rearranged tRNA positions. Nucleotide composition analysis showed higher diversity in nad6 and atp8 genes in Geometridae. Overall, this study provides important mitochondrial genomic data for systematic and evolutionary research in Geometridae.