A wasp mimic fly. ID suggested by people far more learned than I but as I don't have books for this group I've left it as less than certain.
No interactions present.
It may not look like it at first glance, but it's a cranefly.
This is listed as a Red Data Book species, and it is certainly not one that is seen very often, although it does seem to be recorded a bit more frequently in recent years. Its larvae develop in the decaying wood of large trees. I've never seen it myself, although quite a few people have sent me photos of it over the years, and I get increasingly jealous each time ... !
Entomologist and biological recorder
Listed as 'Vulnerable' - it requires ancient woodland and probably requires large dead wood. With forestry/woodland management practice (finally) moving away from the recently-acquired tendency for tidying, and back to leaving more dead wood in situ, I wonder if this is already starting to have a beneficial effect?
Fortunately two of its known sites are in parts of the New Forest I get to reasonably often, so have seen a few, though still not often,
Lat/Lng: 51.0, -1.0
OS grid ref: SU7431