Comparative mitogenomic analysis of Lygaeoidea (Hemiptera: Heteroptera): insights into genomic features, phylogenetic relationships, and divergence times.

Abstract

Background: Lygaeoidea represents one of the most diverse superfamilies of true bugs. However, the phylogenetic relationships among its major lineages remain to be fully resolved, and the evolutionary history of this group has not been thoroughly investigated, largely due to limited molecular data.

Results: To address this, we sequence 17 complete mitogenomes representing 10 families of Lygaeoidea, including new data for species from Heterogastridae and Cymidae. This study aims to expand mitogenomic resources and explore the evolutionary history of this superfamily. Across all analyzed species, including the 17 newly sequenced mitogenomes, we observed consistently high A + T content, conserved codon usage bias, and purifying selection acting on protein-coding genes (PCGs), with cox1 being the most conserved and atp8 the most variable. Phylogenetic analyses using 12 PCGs from 73 mitogenomes robustly support Lygaeoidea as monophyletic and delineate three clades: Clade I ((Heterogastridae + Pachygronthidae) + Lethaeidae), Clade II (Artheneidae + (Oxycarenidae + Piesmatidae)), and Clade III comprising the remaining families. Divergence time estimation suggests that Lygaeoidea originated in the Early Cretaceous (~ 133.9 Ma), with major familial diversification events occurring from the latest Early Cretaceous through the Paleogene.

Conclusions: This study provides valuable mitogenomic datasets and novel evolutionary insights into Lygaeoidea molecular evolution, phylogeny, and validates the independent familial rank of Lethaeidae. Our findings improve the understanding of evolutionary dynamics in forest-dwelling true bugs and accumulate essential baseline data for subsequent taxonomic and systematic investigations.