Neria longiceps
Identification: Head: Occiput very wide, ocellar triangle positioned behind the eyes.Thorax: Scutellum with scutellar hairs positioned in the middle (rather than at the apex). Legs: Hind femur with two black rings Wings: Veins Sc & R1 very close together Male: Lacking the metathoracic process (thus distinguishing it from Cnodacophora)
Size: 5-6 mm
Distribution
Europe: Countries (published), online at Fauna Europaea, Occurrences at GBIF
Extremely scarce. Arnold reports only 5 specimens ever recorded, Séguy places it in his French key but only mentions a Bavarian record, presumably including it in his French list on the expectation that it might turn up in France. Chvála lists it as present in the Czech and Slovak Republics and Roháček & Barták detail those locations based upon 15 specimens (including 3 males). Ozerov reports it in the Caucasus.
Seguy: Espace interoculairo noir, rougeâtre ou jaune orange antérieurement, à pruinosité blanchâtre latéralement. Face et gènes à reflets blanchâtres. Trompe d'un brun jaune : palpes blanchâtres. Antennes d'un jaune d'ocre, : chète noir à l'apex. Corps entièrement d'un noir brillant: mesonotum a pruinosite blanchâtre. Paltes jaunes: fémurs III avec deux anneaux noirs. Balanciers blanchâtres. Oviscapte noir.
Interocular space black, reddish or orange-yellow anteriorly, with whitish pruinosity laterally. Face and genae with whitish reflections. Proboscis yellow brown: whitish palps. Antennae of an ocher yellow, black bard at the apex. Body entirely of a brilliant black: mesonotum has whitish pruinosite. Yellow leaves: femurs III with two black rings. Whitish halteres. Oviscapte black.
Part of Roháček key::
9(8) Wing with large areas without microtrichiae basally (Fig. 13); mesonotum largely reddish yellow, at most its fore part and scutellum blackish . Neria - N. ephlppium (Fabricius)
Wing basally uniformly microtrichose, rarely basal cells (br, hm) partly bare; mesonotum blackish, at most humeral and postalar calli and sides of scutellum yellowish . 10
10(9) Palpus very short, not reaching facial margin (Fig. 14) ; Sc and Rl ending at C close to each other (Fig. 11); no strong stpl present Compsobata 11
Palpus long, almost reaching facial margin (Fig. 15); distance between apices of Sc and Rl long or strong black stpl present 13
13(10) stpl strong, black (Fig. 5) ; scutellum with scutellars in the middle (Fig. 6) ; Sc and Rl ending at C close to each other (Fig. 11); male without metathoracic process Calobatella C. longiceps (Loew )
Largely unknown. The species appears to be thermophilous and prefers lower altitudes in Czechoslovakia. (Roháček, 1990)
Conversely Walter Pfliegler reports his Hungarian specimen from "mountain region, near a pond" (precise location not given)