And not Cephus pygmaeus, as suspected.
No interactions present.
It is an ichneumon, certainly not a sawfly.
Specimens with a single broad yellow band at base of gaster are not Amblyteles armatorius, which has a series of narrow yellow bands in the female, e.g. http://www.ispot.org.uk/node/86404 and two irregular yellow bands in the male, e.g. http://www.ispot.org.uk/node/224563.
Lat/Lng: 54.649649041316, -1.3789408217417
OS grid ref: NZ401284