Distribution, abundance and genetic structure of Parnassius apollo in Sierra Nevada

Abstract

Butterflies have been traditionally studied due to their sensitivity to climate and even more nowadays because of their vulnerability to climate change. Parnassius apollo (Linnaeus, 1758) is a papilionid (Lepidoptera) with a patchy distribution in the Palearctic ; it normally inhabits cold meadows and in the South of its distribution we found it isolated in mountain habitats. As a glacial relict it is even more sensitive to global warming, and in the last decades its populations have shown changes in their distribution, decline in their abundance and even extinction. The populations of Parnassius apollo are locally small, and in the case of the iberian subspecies that inhabit in high mountain habitat, there is a documented elevation in their distribution range as a response to the increase of temperatures, that could be restricting the gene flow between patches. Small and isolated populations are typically characterized by low genetic diversity, as a result of the combined action of processes such as genetic drift and inbreeding that would deteriorate the evolutionary potential and long-term viability of the species. Parnassius apollo nevadensis is the perfect example of a glacial relict isolated in high mountain habitat, and a perfect model to study the effects of habitat fragmentation and climate change.