Phylomitogenomics supports Actias isabellae (Graells, 1849) as the definitive scientific name of the Spanish Moon Moth (Lepidoptera, Saturniidae)

The taxonomic classification of the Spanish Moon Moth has been contentious for over a century, with debates over its placement within the genera Graellsia and Actias. This study presents a comprehensive analysis of the complete mitochondrial genome (mitogenome) of this iconic insect, revealing a closed circular molecule of 15,252 bp containing 37 genes, consistent with the mitochondrial genomes of other Lepidoptera. Phylomitogenomic analyses confirm that the Spanish Moon Moth clusters monophyletically with Actias dubernardi and the other species of this genus, supporting the assertion that Graellsia is a junior synonym of Actias. Our findings further highlight that the shared ancestry of these species suggests a common evolutionary origin for the pine-feeding trait, challenging previous notions of parallel evolution. The implications of this taxonomic revision are significant, as Actias isabellae is protected under various European conservation laws. This research provides the crucial genetic data necessary for the formal recognition of Actias isabellae, potentially prompting updates to legal classifications and enhancing our understanding of Lepidopteran biodiversity.