This magic number was stated in that flawed entomofauna paper, without any explanation of how this number was calculated – see why that paper is flawed here.
Since then, it has been stated regularly in popular media, scientific papers and technical reports, often without citation, just a number pulled out of the air and presented as fact.
Globally, there are about 5 million estimated insect species in total. Only 1 million species have scientific names. So, conservatively, the 40% claim suggests that at least 400,000 species are threatened with extinction.
So is it an accurate prediction? No. Here’s why: Continue reading