Population structure of Cicada barbara Stål (Hemiptera, Cicadoidea) from the Iberian Peninsula and Morocco based on mitochondrial DNA analysis

We assess the genetic history and population structure of Cicada barbara in Morocco and the Iberian Peninsula, based on analysis of the mitochondrial cytochrome b gene. The divergence between Morocco and the Iberian Peninsula populations was strongly corroborated by the molecular data, suggesting genetically isolated populations with a low level of gene flow. The Ceuta population from Spanish North Africa was more similar to the Iberian populations than the surrounding Moroccan populations, suggesting that the Strait of Gibraltar has not been acting as a strict barrier to dispersal while the Rif Mountains have. The Iberian Peninsula specimens showed a signature of demographic expansion before that which occurred in Morocco, but some of the assumptions related to the demographic parameters should be considered with caution due to the small genetic variation found. The high haplotype diversity found in Morocco implies higher demographic stability than in the Iberian Peninsula populations. These results do not, however, suggest a Moroccan origin for Iberian cicadas; but the most northwest region in Africa, such as Ceuta, might have acted as a southern refuge for Iberian cicadas during the most severe climatic conditions, from where they could expand north when climate improved. The separation of two subspecies within C. barbara (C. barbara lusitanica and C. barbara barbara) finds support with these results.