Biodiversity crisis: Insect numbers collapse by 25 per cent around the world since 1990

Sign up to the Independent Climate email for the latest advice on saving the planet Get our free Climate email Get our free Climate email SIGN UP I would like to be emailed about offers, events and updates from The Independent. An international team of scientists collaborated to compile data from 166 long-term surveys performed at 1,676 sites worldwide, with data recorded between 1925 and 2018, and found that while some freshwater insect numbers were up, among terrestrial insects, which spend their entire lives on land, like butterflies, ants or grasshoppers, there was an average decrease of 0.92 per cent a year. First author Dr Roel van Klink, a scientist at the German Centre for Integrative Biodiversity Research and Leipzig University, said: “0.92 per cent may not sound like much, but in fact it means 24 per cent fewer insects in 30 years’ time and 50 per cent fewer over 75 years. However, the majority of insects are less conspicuous and live out of sight – in the soil, in tree canopies or in the water.” The research also acknowledged several recent studies which reported more drastic declines in insect abundance and species richness – with some global regions estimating biomass losses as high as 25 per cent per decade. The scientists said the average decline in terrestrial insect abundance they found – of roughly 9 per cent per decade – while lower than other published rates, confirms the general trend.