Adjustments to the Palaearctic Chrysotoxum key
Refinements to couplets in the key to the Palaearctic Chrysotoxum in Violovitsh (1974) are provided below, based on the results presented here, as well as those in Nedeljković et al. (2013). Chrysotoxum montanum sp. nov., C. vernale and specimens of C. orthostylum sp. nov. with femora black basally would key out to C. vernale (sensu lato) in Violovitsh (1974); specimens of C. orthostylum sp. nov. with femora wholly yellow would key out to Chrysotoxum festivum (Linnaeus, 1758) (s. l.). Chrysotoxum festivum and Chrysotoxum tomentosum Giglio-Tos, 1890, which also have yellow fasciae on terga 2-4 not reaching the lateral margins of tergum, would key out to C. festivum (s. l.).