Butterflies Concern as climate crisis brings species out early

Midsummer butterflies are on the wing this month after a sunny spring sparked one of the most advanced seasons for Britain's Lepidoptera on record.

- Patrick Barkham

The Lulworth skipper, which is usually found in June and July, is flying at Lulworth Cove in Dorset, the chequered skipper emerged in April rather than mid-May in Scotland and the first swallowtail, which is commonest in mid-June, was spotted in Norfolk on 1 May.

Tom Prescott, head of Butterfly Conservation Scotland, said: "The chequered skipper is a butterfly you can set your calendar by - it typically comes out 13-15 May. I was absolutely staggered when it was seen on 26 April."

Lepidopterists say the early emergences this year are caused by the prolonged sunny, dry spring but are also a dramatic sign of insects responding to global heating. While some species appear to be adapting their emergence to climatic changes, there are fears early emerging insects may fall out of sync with pathogens, predators or the availability of food for their caterpillars.