Nehalennia speciosa (Charpentier): una specie a rischio di estinzione sul territorio italiano (Odonata, Coenagrionidae)

Nehalennia speciosa (Charpentier): a species at risk of extinction on the Italian territory (Odonata, Coenagrionidae). The pygmy damselfl y Nehalennia speciosa (Charpentier) (Odonata, Coenagrionidae) is a rare species considered threatened in several European countries. In 2009 in Italy, the species was detected only in four peat bogs of the Tilaventinum morainal amphitheatre and in one swamp in the Carnic area in the Friuli Venezia Giulia region, while the populations of two sites in the Lombardia region are considered extinct. In the period 2010-2013, as part of the Project “Odonata Atlas of Friuli Venezia Giulia”, periodic samplings were conducted in the five Friulian sites, where the species had already been found. In the morainal area, adults and exuviae of N. speciosa were observed only in the peat bog of Lazzacco (Pagnacco municipality, UD). In the nearby peat bogs of Brazzacco and Chialcinat (Moruzzo municipality, UD), individuals of the species were not detected, while a single adult male was found in 2012 in the peat bog of Modoletto (Pagnacco municipality, UD). In the Carnic area, adults were never detected in the swamp of Cima Corso (Ampezzo municipality, UD). Possible causes for the decline of the species are the progressive burial of some peat bogs, almost completely overgrown with marsh vegetation, and the occurrence of non-native fi sh fauna. The situation of N. speciosa in Italy is very critical, since a viable population is only present in the peat bog of Lazzacco, characterized by a very small area. Therefore, it is urgent to start an environmental restoration program to create or recreate suitable habitats for the reproduction of N. speciosa.