Xeris spectrum is a kind of horntail or wood wasp, that lives in open pine forests. 
Both sexes are equal in length, between 12 and 28 millimetres.
The body is black or dark brown and shiny with white spots behind the eyes and on the sides of the prothorax.
Xeris spectrum's legs are orange-red. 
Males have brown rings around the leg.
Females have a very long ovipositor, almost as long as its body.
It is widespread and is found in large parts of Europe, Asia, Africa and North America.

The photo shows a female because she has a long ovipostor at the end of her abdomen .
Females drill their long ovipostor deeply into wood to deposit their eggs.

In my yard, Hilversum, The Netherlands, 24 June 2021