Overview
- A peer-reviewed paper published June 29 in PNAS estimates between 14 million and 20 million insect species worldwide, a much higher lower-bound than the long-used ~6 million figure.
- The authors built the estimate from more than 1.6 million insects sampled in Costa Rica’s Área de Conservación Guanacaste, where DNA barcoding identified roughly 54,000 species in Malaise-trap catches.
- Researchers used highly sampled parasitoid wasps (Microgastrinae) as an ecological yardstick and applied capture–recapture style estimators from epidemiology to infer many species missed by traps and rearing studies.
- The team scaled the ACG baseline (about 333,000 inferred insect species) to the globe by comparing local tree-species richness (≈1,200–1,500 species) to a global tree total (≈73,300), producing the 14–20 million range.
- The study highlights a severe taxonomic gap—only about 1.0–1.5 million insect species are described—so most diversity may be undocumented and could vanish before scientists can name, study, or protect it.