Bitter Keying

I spent much of today ripping up old carpets and underlay and checking beneath floorboards throughout the entire reception/lobby/bar area. Not a sniff of any beetles, bugs or flies. Not even a dead bluebottle. Hygiene levels are obviously set far too high in this hotel, dammit...

So I decided to have a trawl through the 'unidentified' section of my Skye storebox. Oooh look, some mystery beetles! Practice makes perfect (well, less awful) and all that. I grabbed a carabid that looked like an Amara to my untrained eye. 

Keying it through to family I was pleased to prove myself right, it was an Amara after all. Not an especially tricky family to recognise, to be fair. But a bit of an arse ache to get to species, by all accounts (not named Amara for nothing...) 

Undaunted, I hit the keys. Somehow I only went wrong a couple of times before everything slotted into place surprisingly well. 

Apologies for the pin, this was from way back in 2017!!!

Any thoughts yet? I'm sure some of you will have sussed it already, but I'm a numpty and don't know the shortcuts yet. Keying through went a little like this - 

So I'd already keyed to Amara and was happy with that. I then needed to check the apical spur (single rather than tri-lobed) and the antennae showed pale basal segments that abruptly changed to darker segments. That took me to Amara sensu stricto. Cool, I'm getting somewhere.

Running the key through all relevant couplets went as follows - 

1) Legs entirely pale (nope!)…..4

4) At least basal half of 3rd antennal segment pale (it was entirely pale, in fact)…..8

8) Length at least 6mm and scutellary stria present (definitely on both counts)…..9

9) Scutellary pore absent....14

14) complicated shizzle (deep breath...) 

So my blind spot has always been seeing the fovea. No, that's not right. I mean, I can see them, interpreting what I'm looking at is the issue I have. No matter how I angle the light source, or the beetle itself, I just cannot match what I'm seeing to the drawings in the keys. Ever. Which is a real pisser, because by this point I'd narrowed it down to just four species (and one of those doesn't occur in Scotland). 

So that just doesn't match anything for Amara! 

Seriously, I always fall down at this point. Crossed epipleurs not a problem. Dorsal punctures along the striae not a problem. Number of hairs on penultimate segments of labial palps, easy. Recurved striae fine. Fovea? Get lost!

So, back to 14)

14)  - elytral striae fine to elytral apex, where intervals are flat, inner pronotal fovea consisting of a short, deep streak
 - elytral striae deepened apically, where elytral intervals are convex, inner pronotal fovea shallow or more gradually defined

Oh bugger off. What kind of concrete features are those meant to be? Ok, so the intervals looked fairly flat but with possible convex curvature. And who even knows what the fovea looked like! These are subjective decisions to make, and the key requires a decisive yes or no to progress. I dunno, bit of both maybe? How flat? How deep? How fine? How short a streak? What classes as shallow in the world of fovea?

If I decided to plump for the former option it dropped me out to species. If.

If I decided the latter option worked best it led to a further three species. I continued onwards and it didn't work (pronotum wasn't punctured and elytral punctures weren't interrupted) which dropped out at a very rare species entirely unknown to Scotland. So, by backing up a little and choosing the former option the key drops out at a very common species which is already known from Skye.

Ok, former option it is then! Not an entirely satisfactory use of the keys, I have to admit. However, I did a lot of background reading regards the species it keyed through to. Everything looked fine but, as per usual, it was the fantastic Watford Coleoptera Group that provided the necessary confirmation.

First three and base of fourth antennal segment orange, seemingly a very good feature

The WCG add an awful lot of extra detail that isn't in the keys. Stuff like the edges of the pronotum being thickly bordered laterally but less so basally, that the basal pronotal setae is situated close to the hind corner which is almost right-angled, the presence of two preapical punctures on 7th striae and another at the tip of the 2nd striae. I checked my specimen, everything fitted beautifully. They also confirmed that it's a dirt common species.

So, after all that, what is it? Well, this is a male Amara aenea and a lifer for me. Nice, pity it took me nineteen whole months to get around to keying it through!

I have a bonus day off work tomorrow (we prepped everything for the builders in one day instead of the anticipated two) so I shall be out there again trying to find all things beetle, fly or bug orientated. Tune in later for more of the same!