Saturday, 23 July 2011

Light Emerald

Light Emerald moth, Campaea margaritata.  Flew across Saville Row on the morning of 20 July 2011.
Light Emerald moth, Campaea margaritata.  Flew across Saville Row on the morning of 20 July 2011.
This moth flew across my path in the early morning and landed on a laurel leaf, where it rested while I photographed it with my Ixus 100, staying put even though I put my hand right next to it to pull a leaf out of the way. Aha, I thought. I have the books now, so I should be able to identify this one without assistance.

I wasn't sure I could, though. I can see the signs of my inexperience. I have failed to identify several moths that I have good clear photos of.

When I was writing machine code for the ZX Spectrum, if a sequence failed to work as expected it was very tempting to say that there was an error in the manual, or an undocumented effect. But there never was. It was always an error in my code or my understanding of it. In the same way, it is tempting to say that all those moths I can't identify must be micromoths, and therefore not in my book, which doesn't cover those. And some of them might be, but I am pretty sure that others are actually in there somewhere, as yet unrecognised by me.

I thought I recognised this one as one of the "Waves" but when I looked them up, the banding on their wings was darker than the background, not lighter. But on the same page was a Light Emerald.  This moth does have a slight greenish tint, which I thought at first was because of the green leaves it is resting among. The Light Emerald's description says "fading to whitish" and as this specimen is damaged, it could well be old. And the Light Emerald, I suddenly realised, has one fewer wing band than the Waves, and so does my specimen.

The diagram in my book, the widely used "Concise Guide to the Moths of Great Britain and Northern Ireland," shows the Light Emerald's bands as having both a light and a dark component. My specimen does not show that.  The lower band on the forewing should match up with the single band on the hindwing.  On this one, it does not. And the description on the UKmoths site mentions a blood-red tip to the forewing, which mine does not seem to have either. But moths do vary a lot; the experts say they haven't read the books.

I could still be wrong, of course. I don't yet now which features are critical and don't change, and which are mutable, either generally or with age. Moths are tricky.


  1. Indeed. I believe you. The book doesn't say how many hundred specimens they looked at.
    Cameras are tricky, too. Bravo to the Ixus. Did you use its flash? The surface of the leaf suggests that perhaps you did.

  2. It looks like a Light Emerald to me, Bill. Green moths fade in colour very quickly.

    I remember being caught out by a Green Carpet moth the first time I trapped on Farthing Downs. The pattern was distinctive but I couldn't match the yellowy colour with anything. Finally, a helpful piece of text in Chinnery informed me that the green quickly faded to yellow! Mystery solved and an important lesson learned...

    BY the way, I have just found my way into your monochrome photos & really enjoyed them. I've only started doing monochromes this year, but I really enjoy it (although not great for natural history).


  3. Thanks! A lot of the stuff on Picasa is quite old; scanned negatives. My cameras are all electronic now and to make them produce monochrome seems artificial. And a lot of the photos on my blog are the best I could get of a particular specimen, rather than super pictures.

    Are any of yours on line? Monochrome stuff? You can email me at