Figure 4 from: Ståhls G, Barkalov AV (2017) Taxonomic review of the Palaearctic species of the Cheilosia caerulescens-group (Diptera, Syrphidae). ZooKeys 662: 137-171. https://doi.org/10.3897/zookeys.662.11267 - Stahls, Gunilla (2017)