This Gasteruption species belongs to the Ichneumonid wasp family which are parasitic wasps.
The family of Ichneumonidae consists of at least 25,000 species but this is likely to be a very low estimate.
Ichneumonid wasps, with very few exceptions, attack the immature stages of various insects and spiders, eventually killing their hosts.
Adult ichneumonid wasps superficially resemble other wasps. 
They have a slender waist, two pairs of wings, a pair of large compound eyes on the side of the head and three ocelli on top of the head. 
Their size varies considerably from a few millimetres to seven or more centimetres.
Ichneumonid wasps have long antennae (at least 16 segments) and live solitary.
Unfortunately, many species cannot be identified from a photo.

The body lenght of this Gasteruption species is 8-12 mm.
The colour of the abdomen is black, with reddish-orange rings.
The tibiae of the hind legs are club shaped.
This is probably Gasteruption assectator, but identification by photo is very difficult.

Pfänder Mountain, Bregenz, Vorarlberg, Austria, 12 July 2013