Variability of middle tibia spurs in Cremastinae (Hymenoptera, Ichneumonidae)

Abstract

As a general rule the Cremastinae have two spurs in both middle and hind tibiae, but just two genera, Eucremastus Szépligeti, 1905 and Noxocremastus Narolsky, 1990 are characterised by the presence of only one spur in the middle tibia (Townes, 1971; Narolsky, 1990; Kolarov, 1997). The presence of one or two spurs in the tibiae seems to be a very well fixed character and have been used as a diagnostic character for distinguishing several genera in other subfamilies as Sphinctus in Tryphoninae and Periope in Metopiinae. In a study carried out in a protected area of Spain, two specimens of Cremastinae with one spur in one middle tibia and two spurs in the other middle one have been found. With this morphology their taxonomical position in the subfamily is uncertain, as a consequence in this communication we analyze the repercussion of considering this diagnostic character as a variable feature for distinguishing Eucremastus and Noxocremastus from other Cremastinae genera.