Tuesday 10 November 2020

A no Diamond Diamond

 The last few night have been fascinating here in Longwick in not only the variety but the variability of moths attracted.

Whilst Sprawler, December Moth and Red-Green Carpet have been ever presents it is fascinating that one night provided Chestnut, Beaded chestnut and Dark Chestnut but the next night the chestnuts were gone  to be replaced by White-point and Double Striped Pug (possibly my latest ever?). Rusty Dot Pearl has appeared two nights in a row whilst the assumed Diamond-back arrived last night - it appears to be missing its Diamond!




9 comments:

  1. Hi Andrew,

    I think your Diamond-back is most likely something else, possibly the highly variable Ypsolopha ustella. Do you have any side-on pictures?

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  2. You may be right Dave - it seemed small though - but I have added another photograph just to confirm.

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  3. Thanks for adding the second picture. I'd say that was Ypsolopha ustella although it probably should be dissected to be absolutely sure.

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  4. This is Plutella xylostella. I have had 2 over the last 3 nights. Both were large females, the first was quite variegated had me wondering if I had caught an improbable Rhigognostis until I looked at it more closely. The second was very like Andrew's moth. P. xylostella is highly variable. Y. ustella is browner and has a broader forewing.

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  5. I've also had a non-diamond backed Plutella xylostella here in Herefordshire last night, which I did dissect and proved to be a female. Like Dave, I also thought initially it would prove to be ustella.

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  6. I saw a picture of a rather similar-looking dark, non-diamond-backed specimen on twitter this week: https://twitter.com/sambbryo/status/1323018141287485443. Interestingly, Steve Nash suggests in the discussion below the post that these forms are more frequent late in the season.

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  7. Interesting. As P. xylostella is such an abundant and widespread moth globally, its dynamics must be complex, but there may be something in this i.e. a trend to darker, less well-marked ones late in the year. I have also seen this with Lyonetia clerckella in Oct-Nov although this year it has been absent in the autumn. Our apple tree has been riddled with the mines but its parasitoids must have had a field day.

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  8. See also the 'sightings' page on the Sussex Moths blog.

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  9. Many thanks everyone - I had missed the fact that the discussion was continuing. It did instantly have the "jizz" for Plutella Xylostella and had a couple of white marks where the edge of the "diamond" might be. A useful learning experience!

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