Rhône Valley, June 2006

Rhône Valley, June 2006

Simplon Pass, June 2003

Simplon Pass, June 2003. This and the picture below show a rather strange individual with greatly reduced underside markings. The typical underside is more similar to that of the eastern and western dappled whites.

Simplon Pass, June 2003

Rhône Valley, May 2003

The mountain dappled white is very similar to the Eastern and Western dappled whites, E. ausonia and E. crameri. The best distinction, apart from the fact that simplonia is a mountain butterfly with a rather restricted distribution, is the black mark near the front edge of the forewing. In simplonia this mark is outwardly curved and at the top runs along the costa of the forewing, whereas in E. ausonia it is squarer and stops short of the costa. This can be seen very well in the picture at the top of this page. The last picture is of a more worn individual showing white at the costa where the scales have rubbed off. If you have an old copy of Higgins and Riley, you will find they confused simplonia and ausonia (crameri hadn't been invented then). Like E. ausonia, the butterfly is generally to be found feeding or laying on yellow mustards.