They're out to bait the Purple Emperor, one of Britain's most elusive butterflies, whose beauty disguises some filthy feeding habits. You never forget your first time, says butterfly enthusiast ...

In just six generations of selection, they took a brown butterfly and shifted it to a rich, purple color. The species chosen for this work was Bicyclus anynana, an African species that also goes ...

Butterfly conservationist and Purple Emperor fan Neil Hulme explains the allure of the species.