Netelia inedita

Using Gavin Broad's key to nocturnal Ichneumonidae I tentatively keyed this to Netelia inedita, but I wasn't wholly convinced. I'd had to choose whether the stemmaticum was the "same colour as rest of head, testaceous or dull yellow" or "darker than rest of head, dark brown or black" - in reality there were patches of dark on a testaceous background. The genitalia looked distinctive but aren't illustrated for this species so I didn't know if they fitted inedita or not.

An update to the Netelia section of this key helped solve it. This didn't require a decision on the stemmaticum colour and led more straightforwardly to inedita, and also added that the pad has conspicuous striation. I assume that's referring to the comb of cornuti-like structures in the genitalia which certainly looked like a distinctive feature. The occipital carina was quite indistinct at the sides and missing centrally. The forewing was 8.6mm long, so not a particularly large ichneumon.

male Netelia inedita showing face and mandibles, head from above, occipital carina, scutellum, propodeum, abdomen from side, wings, close-up of forewing veins cu-a and Rs+M and genitalia with close up of apex, Wendling Beck Environment Project (Norfolk, UK), 21st August 2023

It was easier second time around, and this keyed pretty quickly to inedita. I wasn't completely sure at one or two points but the striations on the pad clinched it.

male Netelia inedita showing mandibles, head from above (2 focuses), scutellum, forewing and genitalia, Wendling Beck Environment Project (Norfolk, UK), 8th September 2023