Geographic variation and habitat preference of the italian endemic butterfly Melanargia arge

Melanargia arge is an endemic Italian species occurring in fragmented habitats, ranging from Tuscany to Calabria and Apulia. As other endemic species requiring particular attention, M. arge is included in the Habitats Directive (92/43/EEC) Annex II and Annex IV. Our study aims at elucidating the relationship between patterns of geographic distribution and genetic variation at the species level, and to identify the habitat of this species, as required by the Habitats Directive. Using a phylogeographic approach, we have reconstructed the history of M. arge across the Mediterranean Basin, thus investigating its recent biogeographical past. We have used the bayesian inference to clarify the historical and present demographic trends as well as to estimate the time of the last expansion. We used both a Species Distribution Model (SDM) approach and a fine scale, approach overlaying butterfly occurrence data and vegetation layers. The first was aimed at understanding the present, past and future potential distribution for this species, while the latter to determine the dominant vegetation systems in the localities of the presence of Melanargia arge in comparison with the composition of habitats over the entire Lazio region. M. arge depends on the arid grasslands: this habitat is experiencing a strong reduction due to the abandonment of the rural areas, with deep changes in land use. The results of our study offer a genetic framework for planning future conservation strategy for M. arge.