Plunging insects numbers threaten to trigger a “catastrophic” global environmental collapse that could spell the end for humanity, a shocking study has found.
More than four in ten bug species could become extinct within the next century, with the total mass of insects on Earth already dropping by a staggering 2.5 percent every year.
Butterflies, bees, dragonflies and beetles are among the worst hit, with at least a third of species in each group in dangerous decline.
Overuse of pesticides, expanding cities and climate change are to blame, scientists said. The study was published in the journal Biological Conservation.
“If insect species losses cannot be halted, this will have catastrophic consequences for both the planet’s ecosystems and for the survival of mankind,” Dr. Francisco Sánchez-Bayo, at the University of Sydney, Australia, told the Guardian.
Insects are vital to global ecosystems as they pollinate plant life and provide food for birds, lizards and other animals.
Heavy insect losses could, therefore, cascade up global food chains, threatening hundreds of species that humans need to survive.
“If this food source is taken away, all these animals starve to death,” Sánchez-Bayo said.
Scientists at the universities of Sydney and Queensland and the China Academy of Agricultural Sciences led the research.
They combined 73 studies on insects populations carried out over the past 30 years in countries across the globe, including the UK and Europe.
Results showed that over the last three decades, the total mass of insects on Earth has slumped 2.5 percent every year.
In total, 41 percent of insect species are at risk of dying out in the next century, while a further third are endangered.
Figures show that an astonishing 53 percent of butterfly species have declined over the past decade, while 46 percent of bees species are threatened.
More than a third of dragonflies have seen a decline. The worst hit group is the caddisfly, of which 68 percent of species are in decline.
Branding the plummeting numbers “shocking,” Sánchez-Bayo said: “It is very rapid. In 10 years you will have a quarter less, in 50 years only half left and in 100 years you will have none.”
Most research into population drops has focussed on vertebrates – animals with spines – like birds, fish or mammals.
The new study reveals that insect numbers are also in freefall, threatening to cause an environmental collapse.
“From our compilation of published scientific reports, we estimate the current proportion of insect species in decline (41 percent) to be twice as high as that of vertebrates,” researchers wrote.
Scientists called for immediate action to fix the problem.
“Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades,” the report said.
“The repercussions this will have for the planet’s ecosystems are catastrophic, to say the least.”
Conservation experts warned that humanity needs to rethink how it uses pesticides and other chemicals.
“A rethinking of current agricultural practices, in particular, a serious reduction in pesticide usage and its substitution with more sustainable, ecologically-based practices, is urgently needed to slow or reverse current trends, allow the recovery of declining insect populations and safeguard the vital ecosystem services they provide,” the report said.
Commenting on the research, the WWF supported a call for action.
“This is not about a summer without the chirp of crickets – this is about the disappearance of the foundation of life on Earth.”
“The collapse of insect numbers is another sign that our planet is in crisis and we need urgent action, on a global scale, to protect nature. Our future depends on it.”