The Friends of Charles Darwin

…Charles Darwin, who was fascinated with flowers and the insects that pollinate them, first came across this orchid [Angraecum sesquipedale from Madagascar] in the middle of the 19th century and predicted that there would be a species of moth with a tongue long enough to reach down to the nectar. Sure enough, in 1903, after Darwin had died, entomologists found a moth on Madagascar that could unfurl a 16-inch tongue that was perfectly adapted to feed on the orchid's deep-seated nectar. They named it Xanthopan morgani praedicta - praedicta in honour of Darwin's prediction.

The point about the tale of the moth and the orchid is that it shows how each co-evolved for mutual advantage - of pollinating the flower in the case of the orchid, and of gaining the nectar in the case of the moth. Other cases of more cut-throat co-evolution between plants and insects, where one is trying to out-do the other, are now thought to have driven evolution to produce today's breathtaking biodiversity.