Heron-head Mol Molophilus griseus

I've examined a few Molophilus but up until now they've all been females which were not possible to identify to species. This male proved slightly more problematic than the species is supposed to be. Firstly I examined it dry and thought the dorsal projection on the coxite was separate from the coxite, and hence thought the coxite lacked such a projection. Keying it as such led me to appendiculatus which seemed to be a feasible solution being quite a common species. I wasn't quite convinced that the genitalia perfectly matched the illustration though, and fortunately I had the good sense to clear the abdomen slightly in order to get a better view. Once I'd done that it was immediately clear that it was one of the species with a dorsal projection on the coxite. In perfect side view the inner process was pointed, not hooked at all, and as such it keyed to occultus. This is supposed to be a species associated with bogs, but I'd caught this in the middle of an arable field - it didn't seem likely! Eventually I realised that the inner processes were in fact hooked, but the hooks pointed directly inwards so were not visible from the side. This is different from all the images and diagrams of griseus genitalia that I could find, where the hook is clearly visible in side profile, but in other respects mine was a far better match for griseus. I think griseus is meant to be the commonest and most abundant Molophilus (or one of them if not).

male Heron-head Mol Molophilus griseus showing wing and genitalia (4 views), Wendling Beck Environment Project (Norfolk, UK), 13th May 2024