www.ukbutterflies.co.uk

Whilst at Hills and Holes at the weekend I observed a Brown Argus that clearly showed white within the upperwing spots reminiscent of Castle Eden. They were not pure white, but I was still surprised to see this - how common a feature is this on Brown Argus?

Thanks.

Hi Lawts,

Where abouts is Hills and Holes..?

Felix.

Hi Felix,
I think it's near Peterborough.
Neil

Yes, it's not far from Peterborough - it's in the village of Barnack. A lovely reserve built on a medieval quarry. Good for Chalkhill Blue.

Hi Lawts,

The butterfly you saw was a Brown Argus 'aberration' called snelleni. This aberration is conveyed genetically and can be found regularly at some sites. There are a couple of localities in Somerset (where I gre up) that 'threw it out' with regularity. Although it has been some years since I last found one.

Good spot Lawts, it's certainly worth looking out for again at Hills and Holes.

Felix.

Hi Felix, what do you mean by "threw it out" - you mean record rejected?

I think this is Snelleni ter HAAR. I saw it on my local patch in Bedford last year and managed to grab this record shot before it disappeared.
Alex

Other than the difference in flight periods, it does make you wonder why they are split. Was this prior to dna analysis?

Lawts wrote:Hi Felix, what do you mean by "threw it out" - you mean record rejected?

I think he means that it was an abberation which was common in that particular colony - so thrown out by random chance (well not quite).

Bill

Hi Alex,

Yes you're 'spot on' (I'm too funny). Thanks for posting this photo as it illustrates the thread perfectly.

Lawts: is this what you saw? By the way, Bill is right; sorry to mislead you. By "a couple of sites which threw it out" I meant a couple of sites where the aberration occurred.

Felix.

Yes, that's what I saw.

The first Brown Argus I saw this afternoon at Mumbles Hill, Swansea was exactly like this. All the others I examined just had the usual black forewing spot but this one stood out a mile.

Interesting Dave that the orange on the upperwing also fades out towards the top and isn't striking. I've got shots of Northern Brown from Bishop Middleham earlier this year with less white on the two spots, and much more striking orange.

Should be fun if/when these two ever overlap.

Lawts wrote:Interesting Dave that the orange on the upperwing also fades out towards the top and isn't striking. I've got shots of Northern Brown from Bishop Middleham earlier this year with less white on the two spots, and much more striking orange.

Should be fun if/when these two ever overlap.

Are they approaching each other in terms of range?

Sorry for late reply - been on holiday. No. Bishop Middleham is some distance from the range of Brown, and all butt's. at this site are regarded as Northern.

Barnack H&H: TF074047

I was there a few weeks ago and was impressed by the large size of the abundant Chalkhill Blues

Jack

I live at the top end of Yorkshire ~ 20 miles from Bishop Middleham, and we had agestis here a few years ago.... they are within just a few miles now

Hi Felix,

How about a white dot on one wing only? Although to be fair, it's hard to see if this is a wing marking or a just a nick.
Cheers

Lee

This was the original butterfly in question. This was seen at Bishop Middleham, County Durham. I've treated as Northern Brown Argus, (Castle Eden). However note how strong the orange is on the upperwing all the way to the top.

Does anyone believe this to be a Brown Argus? Interesting position for the site if it is.

Here is a different butterfly - same location, same day. The fading out of the orange suggests this is a more typical Northern Brown, (Castle Eden). There were also some classic white-spotted individuals as well.