Conservation genetics of the protected moth "Graellsia isabellae" (Lepidoptera, Saturniidae)

[Abstract] Evolutionary and molecular genetics provides valuable information for the efficient conservation of endangered species. In this thesis, I have used a combination of newly generated genetic and ecological data to assess the conservation status of the protected moth Graellsia isabellae. Firstly, I reconstructed the evolutionary history of this iconic insect by using genetic data obtained from samples obtained across the whole known distribution area: Iberia Peninsula and French Alps. Data from one mitochondrial gene (cox1) and nine nuclear microsatellites revealed a strong phylogeographic pattern represented by six main genetic clusters. The changes in distribution range of its primary host plant, Pinus sylvestris, during the Upper Quaternary climatic oscillations, is likely to have played an important role in the diversification of the moth. Those six clusters were defined as Evolutionary Significant Units, which broadly match the current intraspecific taxonomy of this species. Secondly, I combined molecular (microstaellites) and ecological (mark- release-recapture) data to estimate the contemporary effective and census population size. The comparison of these parameters in two contrasting localities of G. isabellae contributed to reveal the factors that influence the genetic diversity of the moth at population level. Both demographic history and habitat configuration were essential to explain the similarity of census size and the significant difference in effective population size between the two sites. The need for the re-categorisation of this species in national and sub-national red lists is therefore argued for. Lastly, the analysis of population structure at fine-scale in the Pyrenean National Park of Ordesa y Monte Perdido confirmed topography and host plant of source-sink dynamics involving subpopulations located off limits of the National Park highlighted the importance of buffer zones to conserve genetic diversity of endangered populations.