Euroleon Esben-Petersen 1918

Euroleon Esben-Petersen, 1918

Diagnosis. Anterior margin of the clypeo-labrum slightly concave; mandibles with 3 equidistant teeth of which the apical tooth is slightly longer than the others; 1 seta after the apical tooth; external margin of the mandible with long setae; pronotum covered by sparse short setae; meso- and metathorax with sessile setiferous processes; VIII abdominal sternite with odontoid processes, posterior margin covered by long and thin setae; IX abdominal sternite equipped with an anterior row of digging setae and two short rastra each bearing 4 digging setae.

Examined species. E. nostras (Geoffroy in Fourcroy, 1785).

Comments. Euroleon is a small genus, closely related to Myrmeleon, comprising only 6 described species of exclusively Palaearctic distribution. The larval stages of the widespread European E. nostras were described numerous times since the XVIII century (see text), while those of eastern species, E. parvus Hölzel, 1972, E. polyspilus (Gerstaecker, 1885) and E. coreanus Okamoto, 1926 were treated only recently (Krivokhatsky 1994, 2011).

The morphological characters of Euroleon fall in the range of variability shown by the numerous species included in the closely related genus Myrmeleon. The larvae of Euroleon are differentiated by the hair-like setae covering the posterior margin of the VIII abdominal sternite, while at least in the European species of Myrmeleon the VIII abdominal sternite is equipped with short or spiniform setae.