New research estimates around 20 million insect species on Earth — doubling those facing extinction

A focus-stacked image of the Aeshna affinis dragonfly found in southern Europe and Asia. (Wikimedia Commons/Sven Damerow), CC BY-SA New research estimates around 20 million insect species on Earth — doubling those facing extinction Published: August 9, 2026 8.48am EDT Share article Print article The dragonfly that perches delicately on your foot as you drift on the lake. The mosquito you swat at around the campfire. The ants that march your cracker crumbs away. The bees that produced your delicious wildflower honey. We are surrounded by thousands of insects every day, some of them buzzing in our face, others almost invisible to our eyes. They come in a wild variety of shapes, sizes and colours. And they perform a diversity of jobs, many of them essential to the sustainability of our ecosystem — from pollinating flowers to controlling garden pests, aerating soil and decomposing waste. Taxonomists have discovered and described about one million insect species so far. Until now, the general consensus was that there must be around five to six million insect species in total on Earth, with some entomologists criticizing this number as too low. Our new research reveals that this number was a vast underestimation. There are in fact anywhere between 13.3 million and 24.7 million insect species on Earth. The challenge of estimation In 1735, Carl Linneaus established a system of ranked biological classification that has become the foundation of modern taxonomy — the scientific study of naming and classifying groups of biological organisms based on shared characteristics. Some 1.9 million species have been discovered and described since then, but a big question remains — how many species does our planet have? We don’t have a definite answer but one of the most widely cited estimates, calculated back in 2011, is around 8.7 million species. Estimating the number of insect species on Earth is especially challenging, due to their diversity, small size and frequent inaccessibility. Seven-spot ladybird (Coccinella septempunctata), photographed in Viernheimer Waldheide Special Area of Conservation, Germany. (Wikimedia Commons/Stephan Sprinz), CC BY Learning from parasitic wasps To obtain an improved estimate, my colleagues and I borrowed our study methodology from statistical epidemiology. The first step was to test how well previous survey work had captured the diversity of parasitic wasps called Micrograstrinae in a particular species living in the Área…