Key to the Palaearctic species of Lasiopa

The following key (based on Rozkošný 1983) is completed by the two new species.

1. Legs entirely black................................................................................... 2

- Legs with largely yellow knees and at least partly pale basitarsi................................................ 9

2. Proboscis slender, without dilated labella; female head always without yellow postocular spots......................... 3

- Proboscis stout, with dilated labella; yellow postocular spots on female head present or absent........................ 6

3. Proboscis short; last 3 antennal flagellomeres not remarkably haired; female head without any yellow spots..................................................................................................... L. calva (Meigen)

- Proboscis long; last three flagellomeres densely haired; female head without pale postocularspots, but small frontal spots may be present............................................................................................ 4

4. Face covered with mainly dark brown or black hairs; abdominal lateral markings often reduced on tergites 3 and 4............................................................................................... L. peleteria Brullé

- Face covered with whitish or greyish hairs; abdominal lateral markings on tergites 2–4 well developed................ 5

5. Anterior veins on wings blackish; male frons broad; female eyes long haired............... L. albanica Dušek & Rozkošný

- Anterior veins on wings brownish; male frons narrow; female eyes short, finely haired................. L balius (Walker)

6. Last two flagellomeres slender and only sparsely haired; yellow frontal and postocular spots on female head present....... 7

- Last two flagellomeres thick and densely haired; yellow spots on female head absent................ L. caucasica (Pleske)

7. Basal antennal segments long, antennal index about 1.2; mid-membrane on medial process of male genital capsule without posterior incision...................................................................... L. villosa (Fabricius)

- Basal antennal segments shorter, antennal index about 1.5; mid-membrane on medial process of male genital capsule with deep incision............................................................................................ 8

8. Male basistylus without protuberance on inner base; postocular band on female head remarkably broad................................................................................................. L. pseudovillosa Rozkošný

- Male basistylus with large rounded protuberance on inner base; postocular band on female head relatively narrow...................................................................................... L. tsacasi Dušek & Rozkošný