No interactions present.
Is a head on or profile view what is needed to make the differentiation?
Im pretty sure its the original ID as I see many of these moths, BUT if they are as similar as you say then there is always the chance that I have made an assumption without double checking.
Im not sure the Langmaids Yellow Underwing is actually present here in N. Ireland, is it known by any other English names? I cant see it on the list, you werent to know where this moth was recorded if this is the case, my fault for not making the location clear!
The extent of black on the hindwing is the usual (non-dissection) feature for separating those two. Some authorities would require dissection. Other authorities would dispute whether these are two good species but just variation within a species.
I think most confirmed records of Langmaid's have been from the southern coast of England but the split is recent and determination is not trivial so I suspect distributions are not well know. So the absence from a N Ireland list will not necessarily mean it does not occur there.
Thanks David, I might have a look at afew hindwings come the summer, if I can manage it without causing injury? Could be difficult as Douglas describes.
If you check the earliest ones you'd be much more likely to find Langmaid's, they generally appear earlier in the season that LBBYU.
I don't think it causes too much damage, especially if you're careful, they just lose a few scales.
I've only found one (but I've only been checking this past year) and I'm relatively northern (mid-Wales), so who knows!
it is important to retain the specimen to prove the record. Also worth getting the new edition of Skinner "Colour Identification Guide to Moths of the British Isles" if you have not got it as it has some helpful comparisons.
Thanks for this recommendation David, I must get that guide and if I think I find a Langmaid's YU I will retain the specimen.
It probably is present in NI but may not have been found yet (it is a migrant only (relatively) recently confirmed in the UK), but due to people not checking I think these are far more common than records suggest.
To tell you need to look at the hindwing and underside of wing to be 100%, they're very slippery so it's quite tricky to do!
This is good to know, Ive just been looking at other images Ive recorded, some of them are possibly the Langmaid's, a moth which I hadnt even heard of before this evening.
Mentioning Skinner made me look up this pair again. It also illustrates the forewing differences, which are subtle. N. janthe typically has finger like projections on the outer edge of the dark area of the forewing.
NB the text in Skinner has an error at this point and says the opposite. But the correct situation (as I describe it here) was confirmed by John Langmaid on the UKmoths group last year.
From this photo I'm not confident to say whether that feature shows or not, it is pretty subtle so would need a very high res image (and possibly not be safe to do even from that). And to be honest only having seen a few Langmaid's at entomological exhibtions I'd not be confident anyway.
Just found your comments David while trying to check another candidate Langmaid's YU. I think I'm right in saying that the finger-like projections are on the underside of the forewing, so again not easy to see in most photos.
Entomologist and biological recorder
The text in Skinner is ambiguous - I'd managed to convince myself I could see the finger like projections on the upperside of the comparative figures in there. But on closer examination it seems I was wrong.
Lat/Lng: 55.078, -6.06
OS grid ref: NW409834