Evolutionary insights from complete mitochondrial genomes of Aedes albopictus and Culex pipiens molestus (Diptera: Culicidae)

Mitochondrial genomes (mitogenomes) are powerful molecular tools for exploring phylogenetic relationships, deciphering adaptation and divergence, as well as disease transmission potential among insects. In this study, we performed a comparative mitogenomic and phylogenetic analysis of two major mosquito vectors – Aedes albopictus and Culex pipiens molestus – collected from South Korea, together with mitogenome data from 18 additional mosquito species representing three Culicidae genera (Aedes, Anopheles, and Culex) retrieved from GenBank. The assembled mitogenomes, each comprising 13 protein-coding genes, 22 tRNAs, and two rRNAs, revealed conserved gene order and structural features typical of Diptera. Comparative analyses with multiple species representing the three genera uncovered lineage-specific patterns in codon usage, base composition, and control region variability. Phylogenetic relationships inferred using maximum likelihood and Bayesian methods based on concatenated mitochondrial protein-coding genes robustly resolved genus-level relationships and supported the monophyly of the two major Culicidae clades, Aedes (tribe Aedini) and Culex (tribe Culicini), with Anopheles sinensis and Anopheles gambiae serving as outgroups. Time-calibrated Bayesian analyses indicated a deep divergence between Anopheles and the Aedes–Culex clade during the Paleogene (∼51.8 Mya), followed by the separation of Aedes and Culex around ∼39.7 Mya. Notably, Ae. albopictus diverged from its congeners ∼11.7 Mya, while Cx. p. molestus exhibited a much more recent divergence (∼2.35 Mya), suggesting distinct evolutionary pressures and histories. This study demonstrates the utility of mitogenomic data for reconstructing mosquito evolutionary history and provides insights relevant to vector biology, ecology, and public health.