A Map in Summer Guise

This butterfly that landed on a linden tree in front of me yesterday is a map (Araschnia levana), landkaartje in Dutch:

These butterflies have two generations a year; the one in the photo above is from the summer generation; a bit early, I think, but there you have it.

Strangely, the spring generation looks totally different:

No wonder people thought for a long time these were two separate species.

Here's a photo from the side, for the curious:

Thanks for watching!