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Switzerland, May 2016
Switzerland, May 2018
Switzerland, April 2011
Switzerland, April 2011
Hostplant growing by the roadside, Switzerland, May 2016
Rocky gully with scattered hostplant, Switzerland, May 2018
Switzerland, April 2011
Switzerland, May 2013
Switzerland, May 2013
Switzerland, May 2010
Switzerland, June 2006
Switzerland, June 2006
Simplon Pass, June 2003 - individual with greatly reduced
underside
markings.
Simplon Pass, June 2003
Freshly laid egg, Switzerland, June 2010
Older egg, Switzerland, May 2013
Hatched egg, Switzerland, April 2011
Distribution
This is one of a complex of four very similar butterflies
spread
over the southern half of Europe, the others being the western and
eastern dappled whites, Euchloe
crameri and E.
ausonia,
and the Corsican dappled white, E.
insularis.
It can be seen from May, or very occasionally April, through to July or
even August at altitude. Unlike the others, which put in two or three
broods in this time, the mountain dappled white flies in a single
brood. It favours sparsely vegetated, rocky gullies and slopes where
its foodplant (in my part of Switzerland, Erucastrum nasturtiifolium)
grows,
but can also be seen in lusher areas.
All four species are distinguished from the otherwise similar
Portuguese dappled white, E.
tagis,
by the costa of the hindwing, which is conspicuously angled in the
middle. It is harder to distinguish them from one another. This
species, the mountain dappled white, is best known by its habitat and
altitude but it is also useful to note that the black mark at the end
of the forewing cell usually bleeds a little along the costa. It does
not do this in the others.
At my local site, at relatively low atlitude, males may be
seen
roding in May and early June, following large circuits during which
they stop briefly on any foodplant - less often on other plants.
Females do not rode but are also most easily found by waiting at the
foodplants, which they will visit to nectar and lay eggs. These are
placed carefully on unopened flower buds. They are bright blue when
first laid, quickly turning to yellow. The caterpillars feed up on the
ripening flowers, and then the seed heads, before hibernating as a
pupa. It is said the pupae may wait two seasonal cycles before they
hatch.