Phylogenetic signal in elevational distribution and range size of a Satyrinae butterfly genus in the Himalaya

In this study, we investigate the elevational distribution patterns of butterflies by incorporating a phylogenetic and ecological approach, using the genus Lethe Hübner, [1819] as a model taxon in the Himalaya. We obtained COI sequences from butterflies primarily collected during the study and supplemented them with sequence data from various gene repository. Using this data, we first constructed a phylogenetic tree of 20 species using a Bayesian approach and tested for phylogenetic signals in their elevational distribution. We then assessed the influence of range size and climatic variables on distribution patterns using phylogenetic generalized least squares (PGLS). The phylogenetic analysis revealed that Lethe is a monophyletic group consisting of two clades. We found that closely related species cluster along elevation gradients. Species in Clade I, primarily restricted to temperate regions, exhibited larger range sizes and greater thermal variability. In contrast, species in Clade II, mostly found in tropical-subtropical regions, had smaller range sizes and occurred in areas with lower climatic variability.