Hi there,
I'm not aware of ever having Dark Chestnut in my trap near Chesham, but I'm wondering about this one. Can someone help, please? Either way, is Dark Chestnut frequent in Bucks?
Many thanks
David
A Blog for moth recorders in Bucks, Berks and Oxon
Hello David. Hopefully, someone far more knowledgeable than me will give a definitive answer. Dave Wilton posted a good side-by-side photo and description here: https://upperthamesmoths.blogspot.com/2019/10/westcott-bucks_11.html (sorry - Blogger comments don't do hyperlinks, so you'll have to copy and paste this into your address bar).
ReplyDeleteI've struggled with this before, but based on what Dave wrote last year, here is how I now evaluate the moths that I catch, in case it helps you.
I look mainly at two things: the first of these is the forewing tips. On a Dark Chestnut, they're really sharp, like the blade tip of a Stanley knife, whereas the Chestnut's tip is blunt. On this basis, I think your photo shows a Chestnut. Another factor I look at is its sheen: if the angle of light is right, a Dark Chestnut shines like dark polished wood. This second factor is only useful as a positive indicator and with a live specimen: unless the camera and light are exactly right, a moth that is shining in your hand can look dull in a photo.
Both of these factors are easier to spot in a fresh moth than in a worn one. You could also notice that the Chestnut has a slightly rounded outer edge (as here) whereas the Dark Chestnut is essentially straight, but personally I sometimes find this hard to distinguish.
I'm in North Bucks (Newton Longville), and I've been catching somewhat more Dark Chestnut than Chestnut, but I gather that it's usually the other way around.
Hope this helps. Tim
Many thanks, Tim - I didn't know about the 'sheen' and will look out for it. So this specimen is Chestnut, as I suspected, but I'm still unsure as to why the Dark beast never seems to turn up round here! I will keep trying. Best wishes, David
ReplyDeleteI'm sure Dark Chestnut will turn up, David. They're both common, Dark Chestnut perhaps less so in woodland which is where Chestnut is particularly common, but in gardens they're often around in similar numbers. Both hibernate but can be tempted out on warmer nights even in January and February.
ReplyDelete