It seems not to have stopped raining since last month’s Butterflywatch but it has been quite warm and in the gaps between the deluges I’ve seen plenty of Britain’s largest butterfly, the swallowtail, in its Norfolk heartland.
I’ve also admired hundreds of migratory painted ladies, blown in on southerly winds, in what is the largest invasion for a decade but still well short of the epic painted lady summer of 2009.
But it is Britain’s smallest butterfly that has been making the most waves. The small blue has been discovered in Norfolk for the first time since 1910, more than 25 miles from its nearest known colony. This tiny, mostly brown-grey insect has also been spotted in other places where it has been absent for some years, including in Suffolk, Essex and Cambridgeshire, where it is breeding at a site close to a housing estate.
The small blue caterpillar’s food plant, kidney vetch, is relatively common and increasingly found on roadsides. Some suspicious lepidopterists believe the small blue’s sudden arrival in new sites means butterfly breeders are releasing it, but this tiny insect consistently amazes in its ability to disperse across inhospitable urban terrain, locate its food plant and set up home.
