Northern Brown Argus in Smardale
Posted: Sat Jun 27, 2009 3:15 pm
Hello
Although I've been dipping into this site for a few years now, this is the first time I've been confused enough to ask a question!
I was in Smardale (East Cumbria) a few days ago for the Northern Brown Argus. I must have seen 100+ specimens and photographed perhaps 20 or so.
Although I'd never seen this butterfly before, I'd done quite a bit of reading up and I was pretty confident I knew what I was looking for. In particular I'd been led to believe that there were two spots on the leading edge of the underside of the rear wing forming a colon. The clearest example I managed to photograph is attached as photo 1. In most of the other specimens I saw the inner circle was generally smaller and lacked a black centre. As I've seen similar photos of NBAs elsewhere in this forum I guess this is nothing special.
However, I found several specimens in which the inner circle of the colon was missing (or perhaps displaced), as shown in photos 2 and 3.
When I got home and had a closer look through my books I found that this type of patterning was actually included in one of them and designated Fsa (Britain's Butterflies, Tomlinson and Still). Presumably this means a female of the salmacis race. Would it therefore be correct to infer that all salmacis females have this characteristic? There is no mention of this in the accompanying text as a means of telling the sexes apart though, and so perhaps it was just a coincidence.
Some clarification would be appreciated!
Thanks in anticipation.
Paul
Although I've been dipping into this site for a few years now, this is the first time I've been confused enough to ask a question!
I was in Smardale (East Cumbria) a few days ago for the Northern Brown Argus. I must have seen 100+ specimens and photographed perhaps 20 or so.
Although I'd never seen this butterfly before, I'd done quite a bit of reading up and I was pretty confident I knew what I was looking for. In particular I'd been led to believe that there were two spots on the leading edge of the underside of the rear wing forming a colon. The clearest example I managed to photograph is attached as photo 1. In most of the other specimens I saw the inner circle was generally smaller and lacked a black centre. As I've seen similar photos of NBAs elsewhere in this forum I guess this is nothing special.
However, I found several specimens in which the inner circle of the colon was missing (or perhaps displaced), as shown in photos 2 and 3.
When I got home and had a closer look through my books I found that this type of patterning was actually included in one of them and designated Fsa (Britain's Butterflies, Tomlinson and Still). Presumably this means a female of the salmacis race. Would it therefore be correct to infer that all salmacis females have this characteristic? There is no mention of this in the accompanying text as a means of telling the sexes apart though, and so perhaps it was just a coincidence.
Some clarification would be appreciated!
Thanks in anticipation.
Paul