Phytophagous hoverflies (Diptera: Syrphidae) as indicators of changing landscapes

Spatial and temporal differences in landscape patterns are of considerable interest for understanding ecological processes. In this study, we assessed habitat quality by using the Syrph The Net database and data on decreasing species richness over a 25-year period for the two largest phytophagous hoverfly genera (Merodon and Cheilosia). Furthermore, within this time frame, we explored congruence between ecological responses (species richness and Biodiversity Maintenance Function for these two genera) and landscape structural changes through correlation analysis. Our results indicate that landscapes have experienced changes in aggregation, isolation/connectivity and landscape diversity, with these parameters being significantly correlated with Cheilosia species richness loss and habitat quality. We conclude that the genus Cheilosia is a good bioindicator that can highlight not only the current quality of an area but also temporal changes in landscape patterns.