Geography, climate and shifts in host plants distribution explain the genomic variation in the cactus moth

Landscape heterogeneity and the host plant use are factors suggested to play determinant roles in shaping evolutionary history of herbivorous insects. However, role reconfiguration plants distributions linked Quaternary climate oscillations as drivers contemporary population genetic structure is still poorly understood. Here, we formally examine relative contribution such on intraspecific diversification using South American cactus moth, Cactoblastis cactorum , an herbivore insect specialized cacti plants. We assessed genomic variation genome-wide SNPs mitochondrial data populations sampled across a broad geographical gradient where moths feed different species. integrated demographic simulations ecological niche modeling into landscape genomics framework, test alternative hypotheses past current connectivity for both C. its Regions exhibiting higher diversity were evaluated congruence with areas suitable climatic conditions remained stable through time. Our results revealed that spatial configuration habitat shifts better explain diversification. Genomic also supported hypothesis long-term stability served refugia enabling maintenance high levels over Overall, our study highlights importance integrating inter-specific interactions their spatio-temporal dynamics understand abiotic biotic driving processes insects restricted ranges.