Loxocera maculata
Identification: In external characters L. maculata differs from L. aristata by its almost black thorax including the scutellum. On the other hand, no clear differences in the structure of the male terminalia have yet been found. Therefore, additional specimens from various localities are necessary in order to clarify the taxonomy of the two taxa. For the time being they are treated as distinct species. (Shatalkin & Merz, 2010)
A photograph of a specimen from the Orkneys by Ian Andrews fits this description. If it does prove to be a distinct species then it is in the UK too.
Added to the UKSI (UK Species Index) with a TVK code of NHMSYS0021236775 on 23/4/2019
Distribution
Europe: Countries (published), online at Fauna Europaea, Occurrences at GBIF
[UK: Recording Scheme map of occurrences 2016 (verified.) Online (NBN Atlas) via Easy maps or Interactive Atlas] awaiting further work