Bradycellus verbasci
There are fewer records of this species in Norfolk than Bradycellus harpalinus but verbasci is probably the beetle that I catch most often and certainly the beetle I catch in the largest numbers. That is in part because they are readily attracted to moth traps and when conditions are right they can arrive in their hundreds.
One of the key criteria for separating this species from Bradycellus distinctus (which may not occur in Norfolk?) is the presence of a small discal puncture about two thirds of the way down the third elytral interval, however I find this extremely hard - if not impossible - to see on many specimens.
My first experience of a mass emergence was on the night of 22nd August 2016. This was shortly before I had started to seriously look at beetles but every eggbox in the trap was was covered in beetles and they were piled up at the bottom edges of the trap - I conservatively estimated 1,500 beetles in the trap. I retained one which was later confirmed as Bradycellus verbasci and although I can't exclude the possibility (likelihood?) that there was the odd harpalinus among them I reckon the vast majority were verbasci.
many Bradycellus verbasci, North Elmham (Norfolk, UK), 22nd August 2016
Bradycellus verbasci, Wendling Beck Environment Project (Norfolk, UK), 20th August 2021
2x Bradycellus verbasci, North Elmham Cathedral Meadows (Norfolk, UK), 12th August 2018 (first two photos are the same beetle)
Bradycellus verbasci, North Elmham Cathedral Meadows (Norfolk, UK), 26th July 2019
Bradycellus verbasci, North Elmham Cathedral Meadows (Norfolk, UK), 31st July 2021
Bradycellus verbasci, North Elmham Cathedral Meadows (Norfolk, UK), 4th August 2019
Bradycellus verbasci, North Elmham (Norfolk, UK), 16th July 2020
2x Bradycellus verbasci, North Elmham Cathedral Meadows (Norfolk, UK), 8th September 2020
Bradycellus verbasci, North Elmham (Norfolk, UK), 13th August 2020
Bradycellus verbasci, North Elmham (Norfolk, UK), 16th July 2017
2x Bradycellus verbasci, North Elmham (Norfolk, UK), 17th July 2019
Bradycellus verbasci, North Elmham (Norfolk, UK), 18th July 2020
Bradycellus verbasci, North Elmham (Norfolk, UK), 19th July 2017
Bradycellus verbasci, North Elmham (Norfolk, UK), 22nd August 2017
Bradycellus verbasci, North Elmham (Norfolk, UK), 22nd July 2020
Bradycellus verbasci, North Elmham (Norfolk, UK), 23rd July 2020
Bradycellus verbasci, North Elmham (Norfolk, UK), 24th July 2021
Bradycellus verbasci, North Elmham (Norfolk, UK), 26th July 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 26th July 2019
Bradycellus verbasci, North Elmham (Norfolk, UK), 27th July 2019
2x Bradycellus verbasci, North Elmham (Norfolk, UK), 27th July 2018
2x Bradycellus verbasci, North Elmham (Norfolk, UK), 30th July 2020
Bradycellus verbasci, North Elmham (Norfolk, UK), 3rd August 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 30th July 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 30th July 2022
Bradycellus verbasci, North Elmham (Norfolk, UK), 4th August 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 4th August 2019
Bradycellus verbasci, North Elmham (Norfolk, UK), 5th August 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 6th August 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 7th August 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 7th August 2017
Bradycellus verbasci, North Elmham (Norfolk, UK), 26th July 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 12th August 2018
Bradycellus verbasci, North Elmham (Norfolk, UK), 15th August 2017
2x Bradycellus verbasci, North Elmham (Norfolk, UK), 14th August 2017
Bradycellus verbasci, North Elmham (Norfolk, UK), 12th September 2019