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 (Ellis et al. 2019; Maes et al. 2019a; Middlebrook et al. 2019; Nowicki et al. 2019; Vrabec et al. 2019). While concerns about widespread species and how to conserve them are also reflected (Dennis et al. 2019; Geest et al. 2019). Detailed, autecological studies have always been and continue to be the backbone of butterfly conservation and several authors have added to this body of work (Cini et al. 2019; Marschalek et al. 2019). In an increasingly globalised world, the risks from non-native pests and pathogens is also increasing, which is the subject of a paper from America from Gezon et al. (2019) and Paradiso et al. (2019) from Europe helping to demonstrate the global nature of this threat to our wildlife.

Research on butterfly populations, particularly on meta-population structure and habitat quality has led to the development and delivery of landscape scale conservation and urban butterfly ecology initiatives. This broad tradition is maintained in this volume with several papers in this field (Münsch et al. 2019; Sielezniew et al. 2019; Topp and Loos 2019; Viljur et al. 2019; León-Cortés et al. 2019).

Setting conservation priorities is crucial if resources are to be spent wisely and two papers demonstrate both the usefulness of IUCN Red Lists and how to use and improve them for short-lived invertebrates (Fox et al. 2019; Maes et al. 2019b).

We would like to thank all the authors that submitted such an interesting and broad array of papers. At a time of Insectageddon (Thomas et al. 2019), robust data and rigorous analyses have never been more important for the conservation of butterflies, moths and their habitats.