The first creatures to evolve on land, insects have a crucial presence on Earth. Their passing presages our own doom.
Insects are not only a critical food source for numerous vertebrates, they also serve as essential pollinators to flowering plants, including many crops which feed humanity.
Deforestation and other disturbances have decimated insect populations worldwide in the past century. “The main cause of the decline is agricultural intensification,” said ecologist Francisco Sánchez-Bayo. “That means the elimination of all trees and shrubs that normally surround the fields, so there are plain, bare fields that are treated with synthetic fertilisers and pesticides.”
There has been a synchronous decline in the amphibians, reptiles, birds, and bats that eat arthropods. “It’s death by a thousand cuts,” lamented ecologist David Wagner.
Among the thousand cuts is heat. As ectotherms, insects rely upon a limited temperature range to live. Overheating threatens both insect reproductivity and their very survival. Global warming is happening faster than can be met by adaptation. “If we don’t stop it, entire ecosystems will collapse due to starvation,” Sánchez-Bayo concludes.
The mass die-off of insects at the present rate is unprecedented in geological history. The mass extinction that did in the dinosaurs 66 million years did not dent insects nearly as grievously as now. Insects got past the Great Dying – the worst mass extinction on Earth – better than presently.
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