Insects are underrepresented across red lists of threatened biodiversity in the Neotropics

Insects are critical to the sustainability and productivity of ecosystems worldwide, yet up to 40 % of insects may face extinction in coming decades. Globally, Brazil is a major producer of agricultural commodities, but we lack robust studies to investigate policy gaps and biases that may threaten the sustainability of insect ecosystem services in this biodiversity-rich region. Our previous work in the UK and Ireland showed that conservation policies informed by species' red lists consistently underrepresent insect biodiversity. However, we still do not know whether similar patterns are present in biodiversity hotspots like Brazil, that rely proportionally more on insect ecosystem services for socioeconomic wealth. Here, we analyzed Brazil's three major red lists which influence national conservation policies: the IUCN Red List (2024), the Ministry of the Environment's official list (2022), and the Chico Mendes Institute's Red Book (2018). Nearly all insect orders are significantly underrepresented, except for Odonata. In contrast, vertebrate groups are consistently well-represented, underscoring a taxon-specific disparity rather than inherent limitations among all three lists. These findings highlight a key barrier to insect conservation in Brazil, where conservation biases threaten not only local biodiversity but also global food security. We argue for better methodologies and funding for more robust biodiversity assessments in underrepresented regions, such as Brazil. This is crucial for strengthening conservation policies to safeguard both ecological and socioeconomic systems against mounting anthropogenic pressures. • Brazil is arguably the most biodiverse country in the world. • Red lists underpin conservation actions. • Insects are significantly underrepresented in all three red lists underpinning conservation. • Paleopterans are the only insects well-represented. • This likely represent a global gap in red lists and conservation actions.