Your photo is of a giant ichneumon wasp. This family of wasps are beneficial insects.
The long tail like appendage at the end of the wasp is the ovipositor. This is what the female uses to lay its eggs. This long ovipositor is needed to insert through the bark of dead deciduous trees to lay eggs in the tunnels of the pigeon tremex another wasp larva. Larvae crawl along the tunnel until encountering a host larvae on which they feed.
Adult wasps often feed on body juices of hosts while the larvae feed in on immature stages.
Neat and unusual looking wasps!