One of the most attractive of our high summer butterflies is the marbled white,having a checkerboard wing pattern of black and white (see photo).

A butterfly of chalk downland and grassy meadows,until quite recently it has been a rather sedentary species,seemingly reluctant to fly far.There are instances where for decades,the marbled white has been abundant in one field yet never ventured into an adjoining one despite the fact that its caterpillar foodplants of grasses were present and to us,both meadows look identical.

However,all seems to be changing and the butterfly is now turning up in all manner of grassy locations,many quite isolated and far from any other colony.

So,how it arrives in its new sites is something of a mystery.The most likely explanation is that where possible,the butterfly follows a green corridor or railway embankment linking one habitat with another.It has even reached Brompton cemetery in West London.

The name Marbled White is a bit of a misnomer because in reality it is a member of the 'brown'family,which includes the familiar meadow brown.Oddly,the butterfly does not lay eggs directly onto the caterpillar foodplant but scatters them while in flight,leaving the hatching larvae to find their own chosen grass species.

This time last year white butterflies were enjoying a bumper season but not so far this season although there is still time for them to make a late appearance.A few weeks ago I ventured to suggest that their scarcity is probably due to the wet winter which is far less beneficial than cold frosty conditions.

Yet the marbled white,like its brown relatives is faring very well this year.