This species occurs only in a very small area of the western Alps on the border of Italy and France. It is distributed in the valleys of Po, Pellice, and Germanasca in Italy, and in the Guil Valley in France. An isolated population was recently discovered in Chisone valley, Italy. It has also been reported to be (or have been) present on the Maritime Alps, in Cuneo Province. This finding is based upon a single specimen housed in Florence Museum, and with a label indicating its provenance as "Antracque", which is a mistake for Entracque, Valdieri (Cuneo), Italy. The species has not been found again at Entracque or nearby sites. Ribéron (2003) concluded that the species' distribution is decreasing, but this assertion is based solely on the Entracque specimen. The altitudinal range is from 1,200m (perhaps less) to around 2,600m asl; the altitude record of 2,800m asl and corresponding locality (Lago delle Forciolline), is most likely erroneous (Andreone and Sindaco 1999; Vences et al. 2003b; Andreone et al. 2004).