white letter hairstreaks in Northants

[brian laney]

Dear All,
While recording a 10km square given to me by Rob Wilson the Northants county recorder for plants for the Third Atlas of the British Flora, I have been keeping an eye out for any elms large enough that could support white letter hairstreaks. I have been lucky to see them at two sites so far, one on the west side of the M1 near the county boundary with Warwickshire and another site bordering an industrial estate by Daventry. At both sites there was two individuals I saw high up.
It would be nice to know from your experiences how often do they come down to nectar on bramble or thistles, is there any particular time of day and does this happen soon after they emerge or is it a bit later.
I have only ever seen one on ground level before and that was at Fermyn Woods back in 2011.
I will be keeping an eye out for more elms big enough to support this smart little butterfly.

Brian Laney, Northamptonshire county recorder for reptiles and amphibians.

[Tony Moore]

There is quite a big colony around Stafford near the M6 ; I easily find 30/40 eggs in the winter, always on flowering Elm, but often on small bushes. In 20 years I have only seen two adults! One flying along a stand of small Elms and one very worn one nectaring on thistle. I'm sure that this lovely butterfly is very much more common than generally thought.

Tony M.

[Trev Sawyer]

Hi Brian,
A few years ago, a large number of WLH were nectaring on thistle at Bedford Purleius - I counted more than 100 individuals along one particular ride and I've got a photo somewhere of 12 individuals on one thistle plant. I'm pretty sure that it was due to a spell of very wet weather which had washed all the honeydew from the tops of the trees and led to the butterflies searching lower down for their energy drink. The same thing seems to happen with Black Hairstreaks and they often spend much of the time out of reach in the treetops unless the aphids have received a good drenching with rainwater. With some of the heavy storms which have crossed the country over the last few days, I wonder if there's more of a chance of them coming down to feed on flowers a bit more at the moment? Not sure if this is typical, but the White Letters mentioned above came down during the morning and were at their most numerous in early afternoon, before retiring to the trees later on. Oddly, at Brampton Wood near me this year, the Black Hairstreaks were also coming down late in the afternoon and on into the evening.

Trev

[peterc]

Hi Brian,
A few years ago, a large number of WLH were nectaring on thistle at Bedford Purleius - I counted more than 100 individuals along one particular ride and I've got a photo somewhere of 12 individuals on one thistle plant. I'm pretty sure that it was due to a spell of very wet weather which had washed all the honeydew from the tops of the trees and led to the butterflies searching lower down for their energy drink. The same thing seems to happen with Black Hairstreaks and they often spend much of the time out of reach in the treetops unless the aphids have received a good drenching with rainwater. With some of the heavy storms which have crossed the country over the last few days, I wonder if there's more of a chance of them coming down to feed on flowers a bit more at the moment? Not sure if this is typical, but the White Letters mentioned above came down during the morning and were at their most numerous in early afternoon, before retiring to the trees later on. Oddly, at Brampton Wood near me this year, the Black Hairstreaks were also coming down late in the afternoon and on into the evening.

Trev

Interesting point you raised there, Trev. I have never seen WLHs low down although I have seen many high up on the elm tops. What you say about the WLHs coming down low after a spell of rain makes a lot of sense. Looking back at my records on one day in 2009 (July 10) I saw several Purple Hairstreaks (which also generally feed on honeydew) either on the ground or on thistles at Norton Green near Stevenage and after some heavy rain in the previous few days. I am pretty sure the same behaviour applies to WLHs too.

Peter

[MikeOxon]

A very interesting observation. I had a similar experience many years ago (1990) in woods at Clifton Heath (near Clifton Hampden, Oxon). As far as I recall, it had been raining and I was amazed to find several WLH nectaring along one of the rides.

It was the closest encounter I have had with this species, shown in my pre-digital photo:

Clifton Heath, Oxon - July 1990
Pentax K1000 with Tamron 90mm macro lens

Mike

[brian laney]

Thankyou for all the replies everyone and the excellent photograph there.Some very useful information. I will keep my eyes open next week especially after this rain. If I note anything I will report back.
Many thanks.
Brian Laney.

[brian laney]

Well I know Bedford Perlieus is in the modern county of Cambridgeshire but it still comes under the old vice county of Northamptonshire VC32. So I hope people don't mind me mentioning my sighting here. At last after 4 trys, at the 5th try at Bedford Perlieus I saw 4 white letters low down feeding on Marjoram at 5.20pm today. There was still one present at 6.37pm. It was great to catch up with this little smart butterfly however my pics will not be as excellent as your lot on this forum.
Many thanks everyone who helped me and directed me in the right direction.
Hopefully however, I still hope to come across some more unknown populations of the species during my botanical recording.

Brian Laney.