September records of Hoverflies (Diptera: Syrphidae) at the Mercantour National Park and its surroundings: a mixture of migratory and resident species

Records of Syrphidae, collected and observed by participants of the 11th International Symposium on Syrphidae are presented. As relatively small numbers of September records exist for many syrphid species from France and Italy, this event made an important contribution to our knowledge of the phenology of many species. A total of 1229 Syrphidae specimens, belonging to 104 species, were recorded in six French departments, together with the Cuneo Province, Italy. Most of the 923 specimens recorded in the upper Ubaye valley (Alpes-de-Haute-Provence) belong to migratory species, which all have predatory larvae. Eristalis tenax and E. arbustorum are the exceptions, with larvae that are aquatic filter-feeders on micro-organisms. The proportion of specimens from migratory species increased with altitude. Ten records are new departmental records for France, and two are new for Cuneo province, Italy.