Odd fritillary behaviour in Italy

[Simon-in-Kent]

Just something I observed last week: near Lake Maggiore, on the edge of a small town, I watched a female Valenzina Silver-washed Fritillary gliding about, obviously on an egg-laying mission. She flew right underneath a concrete bridge nearby, spending quite a few minutes in a rather dark space. Then she emerged, and paused at intervals on the "grass"....and I spotted that she was actually laying eggs on clover. This is rather different from the bark that is usually chosen in Britain...and there were no violets to be seen. So have I discovered a new foodplant for the SWF? Or is clover a known variant. Also, the butterfly's being at home in the dark corners under the bridge suggests that one "purpose" of this form is to lay eggs in darker places (eg in woods) - perhaps as an insurance policy in case more exposed areas dry out in hot weather (!). There's anecdotal evidence, isn't there, that Valenzinas do explore less sunlit parts of woods than their "normal" sisters do. Any thoughts welcome. No pic, unfortunately.