www.ukbutterflies.co.uk

How long is their flight period?

I ask because I first went to a CHB site on 19 July and saw 4 freshly emerged specimens. I've been back today, a full 6 weeks later, and not only are there dozens of them about, a healthy number look immaculate as if they're not long out of the pupa.

At Denbies Hillside in Surrey, the first males I saw were flying on 3rd July. Visiting last week (22nd September) I saw one fairly fresh male probably only a few days old. The whole emergence must have covered 11 to 12 weeks by those dates.

Dave

Gosh! That is late for CH Blue. My, personal, latest record for Chalkhill in 2010 was 4 Sept, prior to that it was the 17th Sept in 1996 (transect data) but I would not be surprised if there was something a bit later if I searched through all my and my fathers records and other records.

I would expect their emergence is staggered.
Not sure how long an adult lives for but I would expect about two weeks at best - depending on conditions.
So, if your sightings

look immaculate as if they're not long out of the pupa

then I think you could be seeing some very late CH Blue.
Were they male or female or a mix?

Crispin

Hi
CHBs seem to have moved forwards in their emergence over the last few years. It was seen as an August butterfly; it is now at its peak in mid-July, as often as not, on our sites in Cambs. BC Branch records for 2009 show a wide emergence period and sightings from 21st June <-> 12th Sept; this year, the first sighting was on 5th July and last so far 1st Sept.....
I am sure there are specimens hanging-on until well into September on most sites.
N

Agreed.

My first Chalkhill this year was on the 25th June, unfortunately I don't think this lone males plan of "early bird gets the worm", worked out. As it was another 4 weeks before the first females emerged. We were still recording 20+ Chalkhills on the 9th September, including some good condition males.


Regards Gruditch

I remembered this thread following my trip to Burwell Cutting on 2nd October, where I saw a single aged Chalkhill Blue female... ..any advance on 2nd Oct?