Butterfly Conservation (UK)'s 8th International Symposium was held at the University of Southampton between the 6th and 8th April 2018, Butterfly Conservations 50th anniversary year. Over 200 delegates listened to 78 talks and read 46 posters from 24 countries across the world.This was Butterfly Conservation's second symposium entitled "The Ecology and Conservation of Butterflies and Moths", the title being deliberately broad to encourage as many scientists and conservation practitioners from a diverse range of disciplines from around the world to gather and share their research and conservation action with a global community of Lepidopterists (Dover et al. 2015). The 18 papers published in this special issue of the Journal of Insect Conservation reflect the broad theme of the symposium.Much of this special volume is concerned about the status, ecology and conservation actions needed for rare and threatened species and their habitats at a range of scales (