Edward O. Wilson, The Diversity of Life
(1992; rpt. New York: W.W. Norton & Company, 1993), pp. 210-211:
Entomologists are often asked whether insects will take over if the human race extinguishes itself. This is an example of a wrong question inviting an irrelevant answer: insects have already taken over. They originated on the land 400 million years ago. By Carboniferous times, 100 million years later, they had radiated into forms nearly as diverse as those existing today. They have dominated terrestrial and freshwater habitats around the world ever since. They easily survived the great extinction spasm at the end of the Paleozoic era, when life survived more than the equivalent of a total nuclear war. Today about a billion billion insects are alive at any given time around the world. At nearest order of magnitude, this amounts to a trillion kilograms of living matter, somewhat more than the weight of humanity. Their species, most of which lack a scientific name, number into the millions. The human race is a newcomer dwelling among the six-legged masses, less than two million years old, with a tenuous grip on the planet. Insects can thrive without us, but we and most other land organisms would perish without them.