Bumblebees in natural and agro-ecosystems at different altitudes from Mount Etna, Sicily (Hymenoptera Apidae Bombinae): long-term faunistic and ecological observations.

The results of a ten-years study on bumblebee species of Mount Etna in eastern Sicily are given. The observations were carried out in natural and anthropized ecosystems at different altitudes in the Mediterranean Basal plan (0-1450 m a.s.l.) and Mountain-Mediterranean plan (1450-2100 m a.s.l.). Twelve species belonging to Bombus (2 spp.), Melanobombus (1 sp.), Megabombus (2 spp.), Thoracobombus (3 spp.) and Psithyrus (4 spp.) subgenera are recorded. In the Mountain-Mediterranean plan, rich in endemic plants from Etna and Sicily, 11 species have been recorded on plants characterised by the highest honey potential like Astragalus, Rubus, and Senecio. The most abundant species in this level are B. lapidarius decipiens and B. lucorum lucorum. In the Mediterranean Basal plan 12 species have been recorded. Among them, Bombus terrestris terrestris is always present, and B. terrestris calabricus has been recorded only at 1900 m a.s.l. Data are given on surveyed bumblebee species and subspecies, their presence in Italy, the spread in Sicily, and the plants on which the bees were observed. These data are placed in relation to the altitudinal levels and the ecological quality of the areas where the specimens were found