Insect Biodiversity in a Prealpine Suburban Hilly Area in Italy

SIMPLE SUMMARY: In the present work, we considered areas located in a park of 4000 ha in northern Italy in a suburban area, with an altitude between 190 and 960 m asl. Our aim was to update the list of insect species and to evaluate the influence of habitat and the locality on the beetle fauna present in the park. We therefore monitored the insects using different collection techniques. A total of 409 different species were collected. Species in Coleoptera were the most abundant, followed by Lepidoptera and Hymenoptera, with other orders in smaller numbers. The analysis showed that the habitat influenced the communities more than the locality. Unfortunately, as there is no detailed historical information on the presence of the species in the area, we cannot hypothesize an effect of the area on the communities. This research, therefore, allowed us to list numerous species for the area, among which some are important, as they were never detected in this area, and constitutes a new starting point for future research on the biodiversity in the prealpine areas. ABSTRACT: Human activities and habitat fragmentation are known to greatly influence biodiversity. The aim of this study was to update an entomological checklist of a prealpine area in Italy, and also to evaluate the influence of different habitats and the proximity to cities on the entomological fauna. This study included different areas of a local park in Northern Italy, covering about 4000 ha, and situated at altitudes between 190 and 960 m asl. The surveys were carried out between 2010 and 2013 using different monitoring techniques (pitfall traps, car mounted nets, light traps, direct catches on soil and vegetation, visual sampling, gall collection). Furthermore, to assess the effect of habitat and locality on the composition of epigeic beetles, pitfall traps were set and inspected from April to September. All captured specimens were classified to species level. A total of 409 species were recorded, belonging to 7 orders and 78 families. A total of 76.1% were represented by Coleoptera, 13% Lepidoptera, 9.4% Hymenoptera, followed by other orders. In particular, some species with peculiar characteristics, or whose presence in the area had not been previously reported, were detected, such as Atheta pseudoelongatula, Ocypus rhaeticus, Tasgius tricinctus, Euplagia quadripunctaria, Scotopteryx angularia, Elachista constitella, Parornix bifurca, Oegoconia huemeri, and Lasius (Lasius) alienus. It seems possible that the habitat affected the community more than the locality. The woods showed a reduced biodiversity, and a simplified community structure. The comparison of the same habitats in different localities did not show significant differences.