David Dodwell

Outside In | Why the insect apocalypse should concern us all

About three-quarters of all crop types must be pollinated, mostly by insects threatened by climate change and habitat loss. The implications are clear

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A red-base jezebel butterfly rests on a plant. A 2019 study that analysed 73 historical reports on insect population trends concluded that 40 per cent of insects were threatened with extinction. Photo: Martin Williams

David Dodwell

Published: 5:30am, 31 Aug 2024Updated: 5:52am, 31 Aug 2024

Are environmentalists onto something when they wring their hands over the looming insect apocalypse and warn that almost half the world’s insect species are rapidly declining, with one-third threatened with extinction?

David Goulson, professor of biology at the University of Sussex in Britain, warns: “Whether you call it an apocalypse, insectageddon or whatever, there is certainly a serious problem with our insect populations declining.”

In his book, Silent Earth: Averting the Insect Apocalypse, Goulson reminds us that three-quarters of all crop types on Earth need to be pollinated, mostly by insects. The food security implications of insect extinctions are clear.

In 2017, German researchers in Krefeld near Düsseldorf, poring over insect records back to 1905, reported that the insect population in one nature reserve was down 80 per cent from 1989. The Rothamsted Insect Survey reported a 33 per cent decline in larger moths caught in a light-trap network over the past 50 years.

In California’s Central Valley, 1.5 million beehives are ready to pollinate almond blossoms each spring. But the region is such a “toxic soup of pesticides”, according to the beekeepers, that they lose about a third of their bees every pollinating season.

But questions arise: if insect populations are in such sharp decline, how is it that huge locust swarms have swept so ruinously across East Africa in recent years? How is it that here in Hong Kong, jezebel butterflies have swarmed this year in such large numbers?