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: invasive species
Antarctic Invertebrates: Diversity and Threats
Antarctica’s terrestrial biodiversity is restricted to tiny islands of ice-free habitat surrounded by vast expanses of inhospitable ice or ocean. Today it is dominated by microarthropods and other microinvertebrates, although that has not always been the case. Antarctica’s largest invertebrates are two chironomid midges and a small number of freshwater crustaceans Evolution in isolation, long-term persistence and regionalisation typify this fauna. This has important implications for understanding the geological and glaciological history of the Antarctic region, and of the climatic and oceanographic processes influencing it. Antarctica’s terrestrial biodiversity now faces considerable challenges from growing human activity and impacts, including considerable regional climate change.
An ‘Alien’ in Antarctica
A tiny flightless midge, Eretmoptera murphyi, accidentally introduced to Antarctica in the 1960s, has spread across Signy Island and now dominates the soil ecosystem. Its larvae feed on dead plant material, enriching the soil with nitrogen and changing conditions in ways that could help other species invade. Octavia’s research reveals these midge-altered soils also release more greenhouse gases, meaning this small insect could be quietly accelerating climate change in one of the planet’s most fragile environments.
Biological Recording 