ID Help - Empis sp.

Hi,

Just been keying out a box of Empids, one is causing a bit of difficulty. I'm using Mike Hackston's key, which is essentially an update of Collin (https://sites.google.com/view/mikes-insect-keys/mikes-insect-keys/keys-for-the-identification-of-british-true-flies-diptera/keys-for-the-identification-of-british-empididae).

This one keys out as Empis tumida, and the male genitalia is a perfect match for this species. Females caught at the same site on the same date also key out as E. tumida. The habitat is species-rich limestone grassland/downland near Bath, which sounds good for this species. However, the date is not - these were all taken on 7 June 2024, which is a few weeks too early for E. tumida. Have I gone wrong somewhere, or was E. tumida just out exceptionally early last year?

Any thoughts or help appreciated.