HYMENOPTERA > APOCRITA | Parasitica > Ichneumonidae > Tryphoninae > Tryphonini

This subfamily is represented in Britain by just over 180 species that are placed in 30 or so genera, and separated into six tribes. They have a wide variety of body forms and, typically, are not easily recognisable as Tryphoninae.

They are the largest group of ichneumonid koinobiont ectoparasitoids with the majority of species anchoring their eggs into the skin of the host larvae, which do not hatch until the host has prepared a pupation site - see Netelia fuscicornis for further detail. Although that species targets a particular type of moth, the majority of tryphonine genera are parasitoids of sawfly larvae (Hymenoptera > Symphyta), particularly species from certain families of the Tenthredinoidea.   

The individual featured here is Acrotomus sp., and very possibly Acrotomus lucidulus, although that tentative suggestion can't be confirmed without proper examination as there are two very similar species; Acrotomus lucidulus and Acrotomus succinctus. They are very poorly recorded - just 32 records in total on the NBN Atlas when I last looked, 23 for succinctus, and just 9 for lucidulus. Only three from the south, and only one of those is within a hundred miles or more from when I live. It was Acrotomus lucidulus, the only confirmed plausible sighting in recent years and, coincidently, was rather local, just a few miles down the road.

Updated, March 25 (v.2)