Loxocera aristata
Identification: This species differs externally from all other Palaearctic species of the genus by the entirely black face and the whitish-yellow, or brownish-yellow, triangular spot below the eye. It is also characterized by the specific structure of the terminalia (Friedberg & Shatalkin 2008).
Face below antennae black
Frons - (dorsal surface of head) black, may have a small dark orange spot anterior to the ocellar triangle
Head profile - black except for a small yellow patch below and adjoining the eye (this area is the gena); adjoining this patch posteriorly (on the occiput) and running from the eye to the mouth is a "shimmering stripe" (view obliquely from behind) comprising white hairs (which exhibit a good deal of variation in size in the specimens examined, ranging from just a shimmer hinting of white hairs to fairly long, clearly defined white hairs) Termed "postgenal stripe" (see Malcolm Storey's image)
(Sumner, 2008)
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
Essentially, Loxocera species are associated with Juncaceae and Luzula. Chandler (1975) reports that early stages have been found in the stems of Juncus effusus