The Permian–Triassic extinction event saw the greatest level of insect extinction, with the Cretaceous–Paleogene being the second highest. Insect diversity has recovered after past mass extinctions, due to periods where new species originate with increased frequency, though the recovery can take millions of years.
In the Permian–Triassic and Cretaceous–Paleogene periods, there were major declines in insect populations. Despite these losses, insect diversity has since recovered as new species have emerged more frequently over extended periods, though full recovery often takes millions of years.