Key to the genera of larvae of European Ascalaphidae

1 Head one and a half times wider than long; ocular tubercles flattened; scolus-like processes very large and flattened: 3 main pairs of thoracic scolus-like processes and 8 pairs of dorsal abdominal scolus-like processes; ventral series of abdominal processes absent (Fig. 5)................................................................................ Puer

- Head as wide as long; ocular tubercles cylindrical; 4 pairs of thoracic scolus-like processes and 8 pairs of dorsal abdominal scolus-like processes; ventral series of abdominal processes present but mostly tubercle-like (Figs. 4, 6–16).............. 2

2 Base of the mandible covered with white dolichasters; mandibular teeth relatively small, distance between the base of the mandible and the basal tooth noticeably longer than that between the basal and apical teeth; ocular tubercles with a distinct apical bump; ventral series of abdominal processes composed by scoli-like processes on the four anterior segments and tubercle-like ones on the following segments (Figs. 6–7)........................................................... Bubopsis

- Base of the mandible not covered with white dolichasters; teeth relatively large; distance between the base of the mandible and the basal tooth similar to that between the basal and the apical teeth; ocular tubercles without a distinct apical bump; ventral series of abdominal processes composed by scoli-like processes on the first two anterior segments and tubercle-like ones on the following segments (Figs. 4, 8–16)..................................................................... 3

3 Dorsal posterior depression of the head capsule very deep, reaching the middle of the head; ocular tubercles large, wider than long; first pair of abdominal scoli-like processes of the dorsal series and first pair of abdominal spiracles disposed on the dorsal side (Fig. 4).................................................................................. Ascalaphus

- Dorsal posterior depression of the head capsule shallow, not reaching half of the head length; ocular tubercles longer than wide or as long as wide; first pair of abdominal scoli-like processes of the dorsal series and first pair of abdominal spiracles disposed on the lateral sides (Figs. 8–16)..........................................................................4

4 Head dilated posteriorly, body covered by short goblet- and stick-shaped dolichasters (Figs. 3E, 10–16)......... Libelloides

- Head not dilated posteriorly; body exclusively covered by stick-shaped dolichasters (Figs. 3D, 8–9)....... Deleproctophylla