A good record as this is a bit of a rarity according to the Natural History Museum expert who identified it for me.
No information on the Ichneumonidae.
Length: 15 to 22 mm. Ophion obscuratus is identified by pale corners of the ‘stigma’ (the dark mark on the leading edge of the forewing) and the distinctive pale marks on the top of the thorax. Many species of Ophion genera look similar therefore field identification is difficult. When viewed dorsally they have a long narrow reddish brown body but from a side view, the thin curved waist broadens out to a deep abdominal region
When to see it
April – October
Females lay their eggs in the caterpillars of various noctuid moths. Because of this, they have no need of the long (sting like) ovipositors which many of the other ichneumons need to reach deep seated wood boring larvae.
A fairly common species in Britain… Nature spot