Thursday, 31 July 2014

Micros from Tuesday Night

I'm fairly confident that this one is Acrobasis/Trachycera advenella:


Following on from recent blogs concerning Small Ermines and Agriphila spp. I need to be sure that I've learned something from the discussions!


I think that this moth is a different species from the ones whose photos I posted on Saturday.  In his response to Isabel's blog last Friday, Sam described three sets of features: greyish with grey cilia, white with grey cilia, and white with white cilia.  Unless my grey/white perception is still off-mark, I would put this moth in the last category - which would make it a Spindle Ermine (Y. cagnagella)...I think!  However, if it is simply not possible for inexperienced operators like me, and with poor grey/white perception, reliably to separate the four species that don't have distinctive features like the more numerous spots of the Bird-cherry Ermine, (viz. padella, malinellus, cagnagella and rorrella), perhaps we should have the option of combining them in a single category for recording purposes, rather than risk making a mis-identification.

I had three Agriphila sp. individuals on Tuesday night:




In the first moth (in the box) the whiteish streak narrows sharply at about half way (= A. tristella) whereas I can see the 'cigar-shape' that Barry described, in his response to my previous blog, in the streaks on the other three (=A. selasella).  Hopefully I've got that right!

7 comments:

  1. I agree that looks White+White Chris, so would log it provisionally as cagnagella. Agriphila are making me feel more and more confused, as some of the 'cigar-shaped' A selasella appear to have a 'facial cone' above the palps. :-(

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  2. Re Yponomeuta I agree with Sam, quite different from your previous rorrella types. This excellent may prove useful... http://www.northumberlandmoths.org.uk/pdf/Provisional%20Yponomeuta%20Key.pdf
    With this taxon I think it's better to make some judgement rather than lump them.

    As for your Agriphila specimens, I agree with your ids. Sam, the facial cone is confusing and I misinterpreted it for years (I quickly chose to ignore this feature!). Even the author of the superb Nothumberland moth blog gets confused as you can see here, although the other characters given are very useful http://www.northumberlandmoths.org.uk/files/idtips/selasella%20-%20tristella%20ii.jpg

    As for 'the cone' It is more of a bump between the eyes on tristella, rather than the flat slope on selasella. Check out the hard anatomy on the previous link I posted then conpare this with photos/specimens. I think the confusion arises as in addition to the conspicuous long palps there is another triangular palpal process near the base which forms what I used to think was the facial cone - it's not - the facial cone is far more subtle than this.

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    1. facial cone explained here
      http://britishlepidoptera.weebly.com/agriphila-selasella-vs-tristella.html

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  3. Thank you both for your comments. Like all matters scientific, the more you delve into them the more complicated they become. I agree that if we can arrive at a species using a simple set of criteria and get it right most of the time, the outcome is likely to be more satisfactory than lumping several species together in a combined category. I shall endeavour to use this approach in the future. The websites Barry referredto seem very useful, particularly the British Lepidoptera one which contains a wealth of information, perhaps we should have a link to it on our blogsite, if that's permissable.

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  4. Chris - I suggest that you send Colin an email re your latter request, in case he does n`t see this comments section. Have been unable to trap due to heavy rain, and same tonight.

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    1. Thanks Ian, I have emailed the suggestion to Colin.

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