The hidden structure of unstructured citizen science insect monitoring

Insects are vastly under-represented in biodiversity monitoring, leading to uncertainties about their trends. Semi-structured monitoring, relying on protocol reporting than protocol standardization, has emerged as a promising and more flexible alternative to structured monitoring, retaining broad participation. We examined the potential opportunities and barriers for semi-structured monitoring of insects, using dragonfly monitoring in the UK as a case study. We found that many insect recorders already follow attributes of structured surveying, reporting complete species lists, collecting abundance data and revisiting the same sites. Most are also willing to report more comprehensive metadata, such as survey effort, but only a subset would follow a fully standardised protocol. We outline the key ecological and modelling opportunities if semi-structured monitoring were enhanced, but also identify the specific challenges for insects. Our findings highlight the overlooked structure within citizen science monitoring data that could be leveraged for more robust analyses of insect biodiversity change.