Rare swallowtail butterfly suffers worst summer since records began

An Old World swallowtail sips nectar from a flower. In the UK, this insect is only found in Norfolk. Photograph: Attila Kovács/EPA

The swallowtail, one of Britain’s rarest butterflies and also the largest, has suffered its worst summer since records began.

The butterfly is confined to the Broads in East Anglia, where its caterpillar’s food plant is found, and is now breeding on just 16 sites.