Nanna multisetosa
Originally described by Hackman (1956)[1] (as Amaurosoma multisetosum) he describes it as similar in size and general appearance to N. flavipes. Frons not projecting, black except for a yellow front spot which tapers backwards and reaches the ocellar triangle. Antennae black, third joint broad and with a sharp angled upper corner. Arista as in N. flavipes thickened to about the middle of its length. Face yellowish, jowls yellow with whitish pollinosity. Palps yellow. Mesonotum, pleurae and scutellum grey and evenly dusted. Bristles of head and thorax black. Wings normal. Halteres pale. Legs yellow, only the second and third coxa darkened. The tarsi look dark because they are covered in dense dark dusting. Front femora with 10-14 black anterior-ventral spines (the main distinction from N. flavipes which has 7-8). Mid-femur with 8-10 ventral spines. Third femora with a less regular anterior-dorsal row of black spines. Abdomen dark grey with whitish dusting above. Male genitalia similar to N. flavipes. Wing length: ♀ 4.1 - 4.6 - 5.0 mm (2).
References
Recently discovered in Ireland by Speight (1995)[1] from a Malaise trap operated in the Connemara National Park, Galway in 1994. Speight checked material from Surrey and found it to be true N. flavipes. However, following this publication, material from southern England which he had previously determined as N. flavipes was exhibited at Dipterists Day by Peter Chandler who, based on limited material, believed that these two species may be equally frequent.
World distribution: Palaearctic: Ireland, Sweden