The hunt for glow-in-the-dark caterpillars

A new and exciting technique is being introduced to help find glow-in-the-dark caterpillars. This method uses ultraviolet light, which allows volunteers to see these special caterpillars at night. Two wildlife charities are looking for volunteers to assist in this important project. The goal is to make it easier to survey butterflies and moths, while also uncovering more about their behavior and evolution. The surveys will take place in areas such as Bernwood Forest, the River Ray, and the Otmoor Basin, all located near Oxford. Steven Lofting, a conservation manager for Butterfly Conservation, expressed his enthusiasm for this new method, stating, 'It has the potential to change our understanding of their biology, distribution, abundance, and ecology. It's really exciting. ' One of the main focuses of this project is the black hairstreak caterpillar, which is currently classified as an endangered species in the UK. This caterpillar glows a bright yellow-green and can be seen resting on a leaf that appears purple against a dark background. The training for volunteers is part of a larger project led by the Berkshire, Buckinghamshire & Oxfordshire Wildlife Trust (BBOWT), which has received £512,182 from The National Lottery Heritage Fund to support their efforts. The first group of volunteers was trained at the Trust's Finemere Wood nature reserve, located between Bicester and Aylesbury. They were tasked with searching for caterpillars from the UK's five hairstreak butterfly species. The black hairstreak is endangered, while the brown hairstreak and white-letter hairstreak are considered vulnerable. Additionally, the green hairstreak and purple hairstreak have also seen a decline in their populations since the 1970s. The initial training session for volunteers took place at BBOWT's Finemere Wood nature reserve, where participants were equipped with high-visibility vests and instructed on how to search for the caterpillars. The volunteers are crucial to the success of this project, as the data they collect will help the organizations develop strategies to increase the abundance and range of hairstreak butterflies through habitat creation and restoration. The black hairstreak butterfly is typically found in thickets of blackthorn in woodlands between Oxford and Peterborough. This butterfly has brown wings with an orange band and black spots, making it a striking sight. Butterfly Conservation and BBOWT have been studying hairstreak butterflies for decades, but the methods used have often been slow and labor-intensive. For instance, to find brown hairstreak eggs, volunteers must venture out in the middle of winter to search for tiny eggs on twigs using magnifying glasses. Mr. Lofting noted, 'If we can just shine a light in the bushes and these caterpillars suddenly glow at us like an electric lightbulb, it could make it so much easier and quicker to do surveys of these species. ' The ultraviolet light causes the luminous caterpillars to shine as if they are producing their own light, a phenomenon known as photoluminescence. Surveys of butterflies are essential for conservation efforts because they are considered indicator species. This means that changes in their populations can provide valuable insights into the health of the broader ecosystem. According to official figures from the UK Butterfly Monitoring Scheme, more than half of the UK's butterfly species have experienced long-term population declines since the scheme began in 1976. The volunteers' efforts will be vital in helping to protect these beautiful creatures and their habitats, ensuring that future generations can enjoy the wonders of nature.