The EU conservation priority dragonfly Oxygastra curtisii in the Italian Lake District: a review and new data (Insecta: Odonata)

Abstract

Oxygastra curtisii (Dale, 1834) is an Odonate species of EU conservation priority (‘Habitat’ directive Annex II and IV). In Italy, knowledge about its distribution is fragmentary. We updated and reviewed data on its distribution (geographic and altitudinal) and ecology (habitat preferences and phenology) in the Italian Lake District (an area of >5000 km2 in NW Italy) and evaluated the adequacy of the Natura 2000 Network in protecting the species. We found the species to be present and rather widespread at the main pre-Alpine lakes (Lakes Maggiore, Lugano, Orta, Como, and Iseo, with the exclusion of Lake Garda), and several other smaller lakes. Based on current knowledge, a line running roughly north to south from Lake Moro to Lake Iseo is the easternmost limit of the species’ range in northern Italy. While the flight period runs from the last decade of May to the second decade of August, it peaks between the second decade of June and the second decade of July. Our study showed the importance of two habitats whose significance for O. curtisii had been previously overlooked: lakes, which are an important habitat for reproduction, and grassland on the mountain slopes surrounding the lakes, which serve as an important pre-breeding and foraging habitat for immatures. Only 40% of known breeding localities are included in the Natura 2000 network, highlighting the potential vulnerability of this localized species in the area. In light of this, we believe it is essential to expand the Natura 2000 network to include more sites where this species is present, including foraging and pre-breeding areas, and to begin as soon as possible monitoring efforts to better assess the size of the O. curtisii population in the Italian Lake District.