www.ukbutterflies.co.uk

If anyone's interested, I have posted a video of a female Iolas blue laying eggs in the calyx of bladder senna at http://www.guypadfield.com/movies/iolas071.wmv.

I took the video yesterday (Sunday 20th May) in the Rhône Valley in Switzerland. It's not particularly sharp, but the behaviour is quite interesting to watch.

G

Quite nice guy. I think videos show things quite well, and studying them can show some thing you may never have seen at the time.

There was one thing I didn't like about the video...it wasn't long enough

Martin.

Good point! It was a bit short. You only see it happen for a second and then, it ends.

The food plant appears to be quite common in London, on old railway lines and brownfield sites, such as on the Isle of Dogs:

http://www.thewildflowersociety.com/wfs ... page_3.htm

It's a lovely plant and I look forward to seeing it next time I pass through London.

Although global warming would have to go into overdrive for Iolas blues to reach London, bladder senna is favoured by a number of other species, including long-tailed blues, green-underside blues, silver-studded blues (probably not the UK subspecies) holly blues and Lang's short-tailed blues. The first time I went looking for Iolas blues, holly blues and green-underside blues constantly caught my eye, hanging around the yellow flowers. But when I saw iolas there was no doubt as to its identity - it's huge and has seven-league wings!!

If climate change does allow some of the more southerly species to extend their range northwards, perhaps bladder senna is precisely the sort of plant British gardeners might think about encouraging.

Guy