All plants and animals carry a natural chemical signature shaped by the environment in which they grow and feed. This signature comes from stable isotopes – naturally occurring forms of elements that differ slightly in mass but do not decay over time. The relative abundance of these isotopes varies predictably with factors such as climate, geography, and diet. Stable Isotope Ratio Analysis (SIRA) is a powerful analytical technique based on this principle. It measures these subtle differences in isotope ratios, allowing samples to be “fingerprinted” according to their origin. Over the past several decades, SIRA has been widely used to trace the production and movement of biological materials. This presentation introduces the principles behind stable isotopes and SIRA, and explores how the technique can be applied to identify insect pest pathways. Case studies include house flies and wood-boring beetles, such as the invasive Asian longhorn beetle and Ips typographus.
Tag Archives: insect ecology
Changes in the UK Stag Beetle Population
The Stag Beetle – Lucanus cervus – is the UK’s largest beetle. Males can be up to 75 mm long, including their impressive antler-like mandibles which they use to battle each other for access to females during breeding season. It is a truly beautiful species, inspiring amazement in all who are lucky enough to see one. Sadly, evidence from Europe suggests that stag beetle populations are declining across much of their range. But how are they faring in the UK? The south of England was historically recognised as a hotspot for the species. Is it still? A team of researchers from the People’s Trust for Endangered Species (PTES), the Natural History Museum (NHM) and the University of Cambridge set out to find an answer. Distribution records of stag beetles from 1998 to 2022 were analysed and compared with historic museum records going back over a century. The core range was found to have changed little overall, but has declined in the south west of England. Counts of adult beetles recorded together, although not systematic, indicate a worrying decline in abundance across the range. Phenology was also investigated. This webinar will share the findings from this research project, and discuss what can be done to ensure the long-term survival of this charismatic species.
Biological Recording 