Insects have triumphed for hundreds of millions of years in every habitat but the ocean. Their success is unparalleled, which makes their disappearance all the more alarming
He calculated that as there are about 50,000 species of tropical tree, if that figure of 163 was typical for all the other trees, there would be more than eight million species, just of beetles, in the tropical rainforest canopy; and as beetles make up about 40% of all the arthropods, the grouping that contains the insects and the other creepy-crawlies from spiders to millipedes, the total number of such species in the canopy might be 20 million; and as he estimated the canopy fauna to be separate from, and twice as rich as, the forest floor, for the tropical forest as a whole the number of species might be 30 million.
Yes, 30 million. It was one of those extraordinary calculations, like Edwin Hubble’s of the true size of the universe, which sometimes stop us in our tracks.
Erwin reported that he was shocked by his conclusions and entomologists have argued over them ever since. But about insects, his findings make two things indisputably clear. One is that there are many, many more types than the million or so hitherto described by science, and probably many more than the 10m species sometimes postulated as an uppermost figure; and the second is that this is far and away the most successful group of creatures the Earth has ever seen.