Catastrophic threat to world's ecosystems as farm pesticides 'driving insect extinction'

Danger: Bees are among the most threatened insect species. Stock picture
Danger: Bees are among the most threatened insect species. Stock picture

Emily Beament

Pesticide use is driving an "alarming" decline in the world's insects that could have a "catastrophic" impact on nature's ecosystems.

More than 40pc of insect species are at risk of extinction within decades, with climate change and pollution also to blame, according to a global scientific review.

Their numbers are plummeting so precipitously almost all insects could vanish within a century, the study found.

An overhaul of the agricultural industry is "urgently needed" to "allow the recovery of declining insect populations and safeguard the vital ecosystem services they provide," wrote co-authors from Sydney and Queensland universities.

The biologists conducted a systematic review of 73 historic reports of insect declines across the world.

Ten per cent of known species are already extinct, compared to 1pc of vertebrates, they found. Of the insects that remain, 41pc are in decline.

Over the past 30 years, the total mass of all insects dropped an average of 2.5pc annually. The "dramatic" fall suggests none will be left in 100 years, warned Francisco Sanchez-Bayo, of the University of Sydney's School of Life and Environmental Sciences.

"The rate of decline is really huge," he told BBC Radio 4's 'Today' programme.

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Butterflies and moths are among the worst affected, along with bees and dung beetles. Researchers said "a considerable proportion" of aquatic fly species had also been lost.

The review highlighted four key drivers of extinction: habitat loss caused by agriculture, urbanisation and deforestation; pollution; biological factors such as invasive species and diseases; and climate change.

Agriculture was the "main culprit" in 40pc of the studies, with researchers highlighting "the way we apply pesticides".

"We have been doing agriculture for thousands of years and we have never seen these declines," said Dr Sanchez-Bayo. "The introduction of systemic insecticides has been in a big change in the way we do agriculture these days."

The review, published in the journal 'Biological Conservation', said: "Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades. The repercussions this will have for the planet's ecosystems are catastrophic to say the least."

It added dwindling insect populations were further evidence of a sixth mass extinction under way among animal and plant species worldwide.

Irish Independent

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