Friday, 1 July 2022

Moths to check

Dave reported that he had more than 100 species on the night of the 29th.  I didn't manage that many, but I still ended up with about 89 species.  I haven't run a trap for about three weeks - mainly as a result of being abroad for a fortnight - which meant that about about half of these were new-for-the season.  Having so many moths with which to re-familiarise myself (and to photograph) meant it took me a long time to work my way through the catch.

I have a few to check, of which I think the first is probably a Small Wainscot rather than a Concolorous.  It lacks the central dark streak that I have seen with previous Small Wainscots, but the outer ends of the veins are dark and I can find no examples of Concolorous like that.  I have added a photo that shows just a tiny bit of its hindwings, just in case.  I am clumsy and have a slight tremor, so getting it to show its hindwings was a struggle and both the moth and the human were getting a little fractious, so a photo taken with the moth in a pot and its wings only very slightly open is the best I could do.

Version with grossly exaggerated contrast
to show kidney mark with dark corner

Next is what I think is a heavily-marked example of Oidaematophorus lithodactyla, the Dusky Plume.  The tibia of the mid-leg is thickened with scales as described in the field guide, but the brown banding above the joints on the hindleg is at best subtle.

Possible Oidaematophorus lithodactyla
Newton Longville, 29th June 2022

My last moth for checking is at the opposite end of the scale of marking.  I originally wrote down Grey Birch, then I dallied with Engrailed, but after looking at the photo, I think the posture and general shape better fits (female) Willow Beauty or Mottled Beauty.

Finally, I reviewed the photos for my previous session of 6th June which I hadn't had time to label, and realised that Gypsonoma oppressana was a nice catch.  It came from the trap which I set directly between two Lombardy-style Black Poplars, so I hope it's resident in the garden.
Gypsonoma oppressana
Newton Longville, 6th June 2022

Tim Arnold
Newton Longville, Bucks


  1. Hello Tim,
    89 species isn't to be sniffed at and isn't all that far from 100! I think you are correct with the first in that it must be Small Wainscot even though it is a bit tatty for a moth which has only just started flying. Concolorous would have been nice but is very unlikely to have wandered quite that far south! I'll reserve judgement on the plume as these are not easy from photos - if it is lithodactyla then it would be good to get it dissected because there are only three previous records of that species from Bucks and the furthest north in the county is from Ivinghoe Beacon. The other macro has the shape of a male Brown Scallop or Dark Umber and I'd suggest that it must be Brown Scallop which often ends up almost scale-less like this one! The final picture I'd agree is Gypsonoma oppressana which, although described as "very local" in the field guide, is actually quite common in our area wherever there are poplars.

  2. Thanks, Dave. I'm certainly not regretting "only" 89 species as it's still heavy going to work my way through them (I reckon about eight hours of work). It's my third-highest species count ever.

    I am regretting two silly slips. The second slip was in not recognising the Brown Scallop even as a candidate, especially because I now see that I recorded one in only slightly better condition in the garden on 8th July last year!

    I have no idea how the first slip occurred, but it resulted in the retention of the wrong moth. If I have some that I'm not sure about, I keep them until either (a) I have satisfied myself, or (b) I've posted them here and seen a reply. Somehow, I managed to release the plume and retain a pot containing ... an absolutely 100% normal Common Footman! (One of 33 from that night, of which 32 were released immediately and one kept for photography as the first of the season). I don't know quite how I then managed to release the plume and retain the footman after photography.

  3. Hi Tim, on the Plume moth, you could send the photo to Colin Hart (of the 'British Plume Moths' book); on Dave's advice I did this for an unusual Plume I found a couple of years ago and he confirmed the species. Having said that, the markings on your Plume could also fit to a heavily-marked Common Plume.

    1. Hi John, as it happens I've already asked Martin A to do that so we live in hope...

  4. Regarding the Wainscot (and the tattiness), as a relatively inexperienced recorder, what are the features which would rule out Mere Wainscot?

  5. Good point, Keith. On reflection I think Tim's photos may in fact show Mere Wainscot because if you squint hard enough you can just about make out a paler area where the kidney mark would be as well as the vaguest hint of a lighter outer cross-line. The quite variable Mere Wainscot is generally longer-winged than the very stubby Small Wainscot but sometimes they can be fairly similar in size and shape. Small Wainscot generally has nothing in the way of markings apart from the darkened veins, with occasionally the hint of a row of black spots at about two-thirds (much more obvious in Concolorous).

  6. Let's hope that Colin Hart can make something of the plume. I did consider Common Plume (Emmelina monodactyla): the spots at 1/3 and before the forewing cleft are compatible with that - and now I also recognise the dots in the dorsal margin of the dorsal lobe, which I failed to consider at the time. However, I couldn't find an example with as much dark thickening before the midleg joints. I did find one example on with similar heavy markings. On a subsequent closer study of photos of O. lithodactyla on many sites, I have realised that the spot at 1/3 is absent on most individuals. Also, the patterning on heavily-marked moths is rather different than on the one that I caught. I am now leaning towards E. monodactyla.

    Others more experienced than I can answer better about the Mere Wainscot as I've never seen it (nor Concolorous). I excluded it on the basis (a) that the hindwing does not appear to be grey - hence my wrestling match to look at it, (b) the row of dots is almost invisible (OK, it's a worn moth) and (c) the almost complete absence of any darkening in the trailing corner of the kidney, though when I grossly exaggerate the contrast, I can see a faint mark. Looking at the atlas, its also at the start of the season for Mere, as it is for Smaller Wainscot, which Dave pointed out.

  7. OK, well Dave typed faster than I did! I'll add my contrast-exaggerated photo that makes the kidney mark easier to see.

    1. Thanks for adding the extra picture - that must be Mere Wainscot.


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