1. Eyes; distinctly hairy, setulae longer than width of an ommatidium ………………………….… 2
– Eyes; bare or practically bare ...……………………………………………….…………... 9
2. Anterior genal setae: forming a single row along mouth margin (Fig. H ) …………………………... 3
– Anterior genal setae: in multiple rows or widely spread. (Fig. G ) ………………………………… 4
3. Legs; tarsomeres brownish yellow. Calypteres; fringe dark. Wing; Intercostal section (Fig. P) greatly exceeding maximum width of costal cell, costa bare. Scutellum; disc with ~ 6 setulae, the anterior of these arising slightly anterior of a line joining lateral scutellar setae. Proepimeron; with 4-5 setulae Male terminalia (Fig. 1) Surstylus projecting ventrally beyond shell of epandrium for most of its length, inner surface stoutly spinose, phallus bi-segmented, distiphallus slightly sinuous and ~equal in length to basiphallus. Female aculeus, apical segment without very long setae situated half way along dorsal surface. …………………………………….. hirticeps Zetterstedt
– Legs; all tarsomeres black. Calypteres; fringe pale. Wing; Intercostal section of wing ~ 0.5x maximum width of costal cell, costa usually bearing numerous small black spinules. Male terminalia; Surstylus projecting posteriorly beyond shell of epandrium as a finger-like process, phallus bi-segmented, distiphallus almost straight and longer than basiphallus (Fig.2). Female aculeus, apical segment with a pair of very long setae situated half way along dorsal surface. ………………………………..………… corusca Czerny
4. Legs; all tarsomeres entirely black dorsally AND ventrally … (fraxina group) …..…… 5
– Legs; at least some tarsomeres yellow or brown (Fig. M) (check carefully under t1 of hind leg ) ................................................... 8
5. Male terminalia; inner surface of surstylus with a distinct row of strong setulae parallel to the ventral margin (Figs. 3, 4 ) ..................................................................................... 6
– Male terminalia; Inner surface of surstylus with only scattered setulae (Figs. 5, 6) ........... 7
6. Male terminalia; Inner surface of surstylus; strong setulae forming a single row of ~ 6, a small spiculate rounded process lying anterior to these (Fig. 3). Both sexes - Proepimeron; usually with 2 setae. Scutellum; disc bare. Wing; intercostal space length to depth ratio ~3:1 ..................... angelina MacGowan
– Male terminalia; Inner surface of surstylus, strong setulae forming double or triple row of between 14 and 20, no rounded small spiculate anterior process (Fig. 4). Both sexes - Proepimeron; usually with > 3 setae. Scutellum; disc usually setulose. Wing; intercostal space length to depth ratio in range of 4-6:1 .....................fraxina MacGowan & Rotheray.
7. Male terminalia; Inner surface of surstylus with only a few scattered spinules, without an anterior setulose raised area. Basal section of phallus distinctly broader than apical section (Fig.5). Both sexes - Proepimeron; with 1 or occasionally 2/3 setae. Wing; Intercostal section length to depth ratio in range of 2.8-3.3:1 ...................... iona MacGowan.
– Male terminalia; Inner surface of surstylus with ~ 20-30 scattered spinules, a finely setulose raised area lying anterior to these (Fig. 6). Phallus, basal section only slightly wider than apical section (Fig.). Both sexes - Proepimeron; with 1 or occasionally 2 setae. Wing; Intercostal section length to depth ratio 2 :1. Eyes: can be bare (see couplet 13). ..........................spicata MacGowan.
8. Legs; only t1 orange-yellow ventrally (Fig. M). Proepimeron: ~ 20 setulae. Setulae present in notopleural depression. Postpedicellus; length to depth 1.7 : 1, entirely black. Wing; length 3.8mm.. Face and parafacials intensely silvery-grey. Male terminalia: Surstylus extending posteriorly as two rounded processes. Phallus, basiphallus narrowing from base to apex. (Fig.7)…….. albigena Collin
* Lonchaea mamaevi Kovalev, 1973 fits in here - it has lighter (brownish pollinose) genae (Russian far east).
– Legs; Usually t1-3 yellow, t4 dusky, t5 black. Notopleural depression bare. Wing; length 3.0mm. Postpedicellus; length to depth 1.6 : 1, entirely black. Male terminalia, Surstylus hardly extending posteriorly from shell of epandrium. Phallus; basiphallus parallel sided (Fig. 8). ………….. nitens (Bigot)