Empis

Key to the Empis subgenera of Iran

(adapted from Chvála (1994))

1 Anal lobe of wing well developed, alular incision acute; in doubtful cases, then antennal stylus long, at least half as long as 3rd segment............................................................................................ 2

- Anal lobe of wing less developed, alular excision obtuse, at least 90° or more; 3rd antennal segment elongate, stylus very short; large yellow species (Xanthempis) with long slender legs and no acrostichal bristles, or small black species (Lissempis) with hind tibiae apically and hind basitarsi very dilated........................................................... 5

2 Veins R4+5 and M1, very diverging at wing-tip, radial fork acute, and vein R4 often S-shaped, usually strongly bristled species, at least hind tibiae spinose and (except Pachymeria Stephens ), abdomen with distinct hind marginal bristles................ 3

- Veins R4+5 and M1, almost parallel towards wing-tip, or at least not very diverging, radial fork not acute, rather open; not very bristly species, legs covered rather with bristly- hairs, and no hind-marginal bristles on abdominal tergites...... Empis s.str.

3 Prosternum completely covered with hairs; dark mesonotal stripes, if present, usually along the lines of bristles.......... 4

- Only sides of prosternum with hairs, central part between fore coxae bare; dark mesonotal stripes between the lines of bristles, or yellow species............................................................................ Polyblepharis

4 Eyes meeting on frons in males, females dichoptic; large to medium-sized strongly bristled species; hind femora not swollen, and hind tibiae spinose; abdomen with distinct hind-marginal bristles...................................... Euempis

- Head broadly dichoptic in both sexes. Medium- sized, rather short but densely pubescent species, legs not distinctly bristled, hind femora often strongly dilated and hind tibiae with a bent knee, no hind-marginal bristles on abdomen..... Pachymeria

5 Generally large (4–8 mm) species with ground-colour yellow. Legs mostly yellow, without black pattern, covered with sparse, minute hairs and bristles, hind tibia and tarsi without dilated; acrostichal bristles usually absent............... Xanthempis

- Smaller (about 4 mm) black species. Legs yellow with a black pattern, covered with long dense pubescence, and hind tibiae and tarsi dilated; acrostichal bristles present.......................................................... Lissempis