Attactagenus plumbeus

The only British species in the genus.

This keyed to Attactagenus smoothly but given that it's a fairly scarce species (and this one seems to be darker than usual) I did double-check. Marram Weevil Philopedon plagiatum (which I don't suppose would be much more likely at this location) differs in having a more obviously expanded apex to the fore tibia. Other similar species differ in other ways, such as having a broader base to the elytra.

Attactagenus plumbeus showing fore tibia, Wendling Beck Environment Project (Norfolk, UK), 30th April 2023

I had a little more difficulty with keying this one to genus. I went wrong at Duff's key to tribes of Entiminae as I determined that my specimen had a weak median longitudinal keel through the pronotum. Although I wasn't convinced the rostrum was long enough, the keel seemed to be clear enough to leave little room for doubt that this must be tribe Tropophorini. The problem was, if it was in Tropophorini, it keyed to Tropiphorus obtusus, a species that has not been recorded in Norfolk and is decidedly rare in most of England. At first, going through descriptions of Tropiphorus obtusus and comparing it to photos of that species, nothing immediately jumped out at me as being inconsistent. But looking closer, especially after finding Mark Gurney's high res photo on Flickr, it became clear that there were some problems. There were a lot of similarities but as well as having a longer rostrum, Tropiphorus had more elongate scales on the elytra.

I then worked through Mark Gurney's weevil guide and realised that Attactagenus plumbeus was a pretty strong contender, so went back to Duff to see why I'd not keyed it that way. That was where I realised that it was the couplet dealing with the keel on the pronotum. Mine definitely does have some kind of line down the centre of the pronotum, shiny and bare in places, and I'm pretty sure this is very slightly raised above the level of the surrounding disc (i.e. is a keel), or at least it's angled. Given that Duff says the keel on Tropiphorini can be weak, I don't think it was unreasonable to conclude that this was the keel I should be looking for. Anyway, the rostrum isn't 1.5x as long as wide, so that really should have stopped me I suppose. Once I realised it wasn't Trophiphorini it keyed easily to tribe Cneorhinini and then to Attactagenus plumbeus. Not as exceptional as Tropiphorus obtusus would have been but still a scarce species so pretty good to have found two of these within the space of a month. This one was 7.5mm long excluding the rostrum.

Attactagenus plumbeus showing fore tibia (2 angles), pronotum (2 angles), elytral scales (2 views) and rostrum from side/above, Snake Wood (Norfolk, UK), 27th May 2023