Studies on the distribution and ecology of snow flies Chionea lutescens and Chionea alpina(Diptera, Limoniidae) in Italy

We report here the results of studies on two species of Chionea (subgenus Sphaeconophilus), based on 328 specimens of C. alpina and 242 of C. lutescens collected in Italy. The insects were collected using different methods during the period 1969–2006. Sampling was mainly carried out in the Alps, although some records from the Apennines were also obtained. Specimens of C. lutescens were collected for the first time in the regions Lazio and Abruzzo (Central Italy) and these records represent the southern distribution limits of this species in Italy. Samples collected in the Apennines, in the region Emilia Romagna, represent the southern limits of C. alpina. For both species, most specimens were found on snow, in different ecosystems, both in habitats rich of vegetation (beech forest, spruce forest, Pinus mugo ecosystem, alpine meadow) and at higher altitude on stony ground in glacier retreat zones. However, several samples were obtained in caves or using subnivean pitfall traps. No specimens of C. lutescens were collected in caves, whereas c. 19% of the collected C. alpina came from this environment. The obtained data highlight that C. alpina is active in an altitudinal range between 1100 and 2500 m a.s.l. whereas C. lutescens were collected between 800 and 2000 m a.s.l. Considering the ecological (e.g. microclimate, presence inside caves) and geographical (e.g. limits of distribution) data, it is possible to assert that the distribution of the subgenus Sphaeconophilus is related to the glacial events which occurred during the Pleistocene period.