2. Mesonotum yellow, usually slightly shining, without pollen ... 3

– Mesonotum matt, covered with yellowish-grey or brownish-grey pollen ... 4

3. Abdominal tergite V moderately long, without lateral lobe; fore tarsus short, 1/4 shorter than fore tibia; abdominal tergites with dark transverse bands along anterior margin; hypopygium sessile, shining black; 4.0-4.5 ... erichsoni (Zetterstedt)

– Abdominal 5^th tergite short, with distinct lateral lobe directed downward; hypopygium distinctly pedunculate; III and IV tergites with lobelike lateral widenings; V tergite having lobes black at apex; 6.0 ... pallida (Fallén)

4. 3^rd and 4^th segments of fore tarsus black, black plumose; 5^th segment of the same tarsus white; abdominal tergites along anterior margin with strongly pronounced dark transverse bands having deep emargination posteriorly; hypopygium pedunculate; 3.5-5.0 ... quadrifasciata (Fabricius)

– Fore tarsus simple ... 5

5. ?₁₊₂ straight or nearly straight; R₄₊₅ ? ?₁₊₂ almost parallel; wing darkened, darker along anterior margin; 5^th segment of fore tarsus weakly modified; 4.0-5.0 ... suturalis (Fallén)

– ?₁₊₂ strongly curved at middle of distal part; R₄₊₅ ? ?₁₊₂ converging; fore tarsus with very long anterior and short posterior claws; 5^th segment of the same tarsus with strong curved ventral setae; 4.0-5.0... abdominalis (Fallén)

6. Mesonotum yellow ... 7

– Mesonotum dark, grey pollinose, matt ... 9

7. Mesonotum brilliant; black transversal bands on abdomen are narrow and distinct; 5^th segment yellow; 3.5 ... erichsoni (Zetterstedt)

– Mesonotum matt ... 8

8. 6 dorsocentrals; abdominal tergites along anterior margin with black transverse bands having deep median emargination posteriorly; segment V black with yellow apex; smaller species, 3.5-4 ... quadrifasciata (Fabricius)

– 7 dorsocentrals; abdomen including segment V entirely yellow; larger species, 6 ... pallida (Fallén)

9. ?₁₊₂ straight or nearly straight; R₄₊₅ ? ?₁₊₂ almost parallel; hind tibia more or less darkened ... suturalis (Fallén)

– ?₁₊₂ strongly curved at middle of distal part; R₄₊₅ ? ?₁₊₂ converging; hind tibia-yellow ... abdominalis (Fallén)