The wild bees (Hymenoptera, Apoidea, Anthophila) of the urban nature reserves of Rome (Italy, Latium): a preliminary survey.

Background: Urbanisation is a global phenomenon responsible for negative processes in natural ecosystems, such as degradation, loss of habitat and fragmentation. Large urban green areas could, however, represent shelter for animal species, promoting biodiversity conservation. Urban green spaces can also provide useful habitats for threatened species. Wild bees are amongst the most important and efficient pollinating insects and play an indispensable role in ecosystem functioning. Approximately half of the European wild bee species have been reported from Italy, making it a biodiversity hotspot for this group of insects. Many studies have been conducted on pollinating insects in recent years, but few data and incomplete knowledge on wild bee faunas in strictly urban environments exist. Georeferenced faunal data would be important for conservation efforts and understanding the effects that large cities such as Rome may have on the diversity of wild bee communities. New information: This work focused on the diversity of wild bees in nature reserves belonging to the RomaNatura network within the urban area of Rome, Italy. A total of 208 wild bee species belonging to 36 genera and six families were identified. Amongst the species surveyed, one species was classified as Endangered (EN) and seven species were classified as Near Threatened (NT) by the European Red List of wild bees. Twenty-four species are new reports for the urban area of Rome. Sampling took place from April to September 2022. The most represented family in terms of abundance was Halictidae, accounting for 36% of all bees collected, followed by Apidae (24% of samples), Andrenidae (17% of samples), Megachilidae (15% of samples), Colletidae (7% of samples) and Melittidae (1% of samples). The Megachilidae family was the richest in terms of the number of species, accounting for 25% of the total species sampled. This research aimed to provide a set of standardised and georeferenced wild bee occurrences that constitute the baseline for any faunistic, ecological and conservation activity of Rome's nature reserves. In addition, the research aims to demonstrate the importance of large urban green areas in one of the largest European cities as biodiversity reservoirs for wild bees.