The loss of biodiversity is a global crisis with profound ecological and economic consequences1,2,3,4,5,6,7,8,9,10. Among the numerous threats to biodiversity, the rapid decline in insect populations is particularly concerning3,4,5,6, as around 65% of insect species could go extinct over the next one hundred years. This could have disastrous consequences, as insects play critical roles in pollination and nutrient cycling, and act as a food source for other species2,3,4. Hence, insect species abundance and diversity conservation are crucial to maintaining ecosystem stability2,3,4.Literature describing the dynamics of insect populations is growing, furthering our understanding of global biodiversity decline. Common drivers for the rapid decline in insect populations are habitat loss to agriculture and urbanization, water, air, and soil pollution including pesticides and fertilizers, pathogens and invasive species, and climate change5. Furthermore, ecological niche species are increasingly replaced by more generalist species, declining diversity while potentially stabilizing overall insect abundance11,12. While some drivers of decline might be localized, global drivers such as climate change will affect every ecosystem on the planet5,9. There is an ongoing discussion regarding the effect of climate change on insect populations in temperate regions of the globe, while for tropical regions there is a consensus that there will be large effects4,5,6,7,8,9,10,13.Challenges in insect conservation include accurate species identification, which is a very complex task considering the vast number of insect species1,14,15, the enormous lack of spatial and temporal data covering insect species populations1,16, and high uncertainty about species’ ability to adapt to changing climate conditions4,13. There is also plenty of evidence that conventional approaches are falling short in monitoring efforts, as manual classification requires extensive expertise and labor1,11.There are other concerns when it comes to the data utilized to describe the decline. For example, Crossley et al.12 report no net abundance and diversity declines in long-term ecological sites in the United States of America, while Welto et al.11 report that the lack of consistent sampling techniques across long-term monitoring sites has influenced those earlier findings11,12. Another confounding factor is the seasonality of insect abundance, complicating objective quantification of decline6. Furthermore, we know very little about how extreme weather events might cause mass insect death episodes, further affecting the diversity and abundance of insects6,13,17.More effective and standardized monitoring of important taxa will allow for improved scientific consensus and ideally inform actions by governments to protect insect abundance and biodiversity across climatic regions.
