Key to the known larvae of Libelloides

1 Abdominal scolus-like processes rounded, unbranched....................... L. lacteus (from Pieper & Willmann 1980)

- Abdominal scolus-like processes elongated, branched......................................................... 2

2 Ventral side of the head capsule with longitudinal pale stripes (Figs. 12,16)........................................ 3

- Ventral side of the head capsule without pale stripes (Figs. 10,11,13–15).......................................... 4

3 Dorsal side of the head with yellow markings; thorax and its scolus-like processes yellowish; legs with yellowish femora and tibiae; IX abdominal sternite yellowish (Fig. 16)...................................................... L. siculus

- Dorsal side of the head brown; thorax and its scolus-like processes grey; legs with brown femora and tibiae; IX abdominal sternite with contrasting dark markings (Fig. 12)...................................................... L. longicornis

4 IX abdominal sternite with contrasting dark markings (Figs. 10–13).............................................. 5

- IX abdominal sternite monochrome, without contrasting dark markings (Figs. 14, 15)............................... 7

5 Dorsal side of the head capsule pale brown with a median trapezoidal dark marking; IX abdominal sternite with two anterior dark spots; ventral side of abdominal scolus-like processes dark (Fig. 11).................................. L. latinus

- Dorsal side of the head capsule dark brown without a median marking; IX abdominal sternite without dark spots; ventral side of abdominal scolus-like processes pale (Figs. 10, 13)......................................................... 6

6 Odontoid processes of VIII abdominal sternite dark brown; no more than 3 (normally 1-2) pseudo-teeth between the basal and median teeth (Fig. 10).......................................................................... L. coccajus

- Odontoid processes of VIII abdominal sternite pale; at least 4 pseudo-teeth between the basal and median teeth (Fig. 13)............................................................................................ .. L. macaronius

7 General colouring of the body, including the ventral side, dark brown; dorsal side of the head capsule with distinct dark spots at the base of the larger dolichasters (Fig. 15)........................................................ .. L. corsicus

- General colouring of the body pale; dorsal side of the head capsule without distinct dark spots at the base of dolichasters (Fig. 14)........................................................................................ .. L. ictericus