Holly blue butterfly makes a welcome UK comeback after years of scarcity

Azure butterfly bounces back from cyclical decline caused by parasitic wasps with numbers increasing by 151% on last years' annual Big Butterfly count

A butterfly locked in a cyclical struggle with a parasitic wasp has bounced back this summer after years of scarcity, according to the world's largest annual insect count.

The holly blue, the only blue butterfly regularly seen flying in gardens and city centres, increased by 151% on 2014 in Butterfly Conservation's Big Butterfly Count.