Wednesday, 13 November 2019

Three new moths for me?

I ran my trap in the garden last night as the weather forecast was relatively benign even if the full moon and relatively little cloud cover dampened my expectations.

I normally don't set up the trap until about 15 minutes after sunset, but last night I set it going about quarter of an hour before sunset, as that happened to be more convenient.  This may have had a bearing on what I caught.

I checked the trap at about 21:30 and found three moths on it or nearby (but none in it).  I potted these and then left it running until half an hour before sunrise this morning, when I found no moths at all in, on, or around the trap.  So the three moths from yesterday evening were a paltry catch, but turned out to be interesting nonetheless.

One is a Silver Y.  I've been mothing for about 18 months, and although it's a common species, this is the first Silver Y that I've caught: it's strange that I should catch it well past its peak period, even if it has been recorded in all months.  However, I note that the field guide says that it flies around sunset, before most other moths - and I wonder if the fact that I don't usually have the trap running before sunset is the reason that I've not caught one before.
Silver Y, Newton Longville  12th November

The second moth I have tentatively identified as Diurnea lipsiella, but I'd be grateful for confirmation  It's also the first time I've caught this moth, and it's also one that flies earlier in the day.
Diurnea lipsiella? Newton Longville 12th November

The third moth was puzzling me.  I initially wondered if it was a poorly-marked Diamond-back Moth (Plutella xylostella), but I decided that it requires too much imagination to see a diamond pattern.  It did have the same "jumpy" behaviour as other specimens of P. xylostella that I've caught previously.

However, then I saw Dave's post that included Ypsolopha ustella.  This seems to be a better match, though I'm not sure: it is a variable species.  If it's confirmed, it will have the remarkable result that out of a poor catch of only three moths, all of them were firsts for me - albeit unexceptional ones.
Ypsolopha ustella? Newton Longville 12th November
Here's a couple more photographs of it:

Tim Arnold
Newton Longville, Bucks
(Edited to correct a formatting error)


  1. Hello Tim,

    Silver Y can appear at any time of year and I'm surprised that this is the first you've caught in the trap, even if you have only been going for a year and a half. In the garden here it is almost always found inside the trap and daytime sightings are close to non-existent, although it is sometimes disturbed elsewhere when I'm walking through grassland.

    Your second image does indeed show Diurnea lipsiella and that is a very nice moth to get in the garden (it is usually a woodland species and nowhere near as common as its Spring relative, Diurnea fagella).

    The shape of your final specimen certainly looks more like Plutella xylostella than any of the Ypsolopha species. Do you have any other views of it?

  2. Unfortunately the additional pictures don't really help very much (a view from on top would have been better in this particular case). From those images I still think the general shape (especially the size of the fringe along the termen) and posture is closer to it being an odd-coloured xylostella, but if that isn't correct then Ypsolopha ustella is really the only other candidate. If you still have the moth then getting it dissected would be the ideal path to follow.

  3. Thanks, Dave. As you noticed, I managed to add the two photos last night, but for some reason, every time I tried to add a comment (mentioning that I didn't think they added much), the comment vanished when I clicked "Publish". So now I'm trying from my phone.
    The moth was very fidgety and while photographing it, I had to retrieve it 3 times from the nearest window! The fourth time, it disappeared. Hence I have no photo from above and no remaining moth.

    If you look closely, there are two or three vaguely angular pale patches on the dorsum which MAY be echoes of the normal zigzag pattern of P. xylostella.

  4. Commenting from my phone worked, but not from my PC: when I get to the comments screen, it seems to think I have signed out, even though I was signed in immediately before, and the Publish button doesn't give me the opportunity to change that.
    Anyway, I have updated the final pic to one with arrows indicating the paler patches.

  5. Others have very occasionally had trouble commenting and it sometimes seems to depend on your browser. I usually use the ancient Internet Explorer with no problem and I'm told that Firefox works fine too. This message has come via Google Chrome and that seems to work. Commenting from my iPhone (Safari) is a bit of a lottery though, and comments don't usually get through even though I'm obviously signed in.

  6. If this comment is visible, then I now know what the problem was. Your comment about using Internet Explorer was the clue. I've always used it in the past, but after a number of websites started to say that they no longer work with IE, I've switched to Microsoft Edge in the last couple of weeks, and that's what I was using when the comments didn't appear. On my phone I was using Chrome, and that worked.

    I have Microsoft Edge set to block third party cookies. On IE, it was set to allow all cookies after long-ago problems with another website. Sure enough, setting Edge to "Allow all cookies" seems to work: the "Comment as:" field below says "Tim Arnold (Google account)", whereas when I was having the problem, it was just saying "Google account".

  7. That's a plain Plutella xylostella


Note: only a member of this blog may post a comment.