More than 40% of insect species could become extinct in the next few decades, according to the “Worldwide decline of the entomofauna: A review of its drivers” report, published in the journal Biological Conservation.
Insect biomass is declining by a staggering 2.5% a year, a rate that indicates widespread extinctions within a century, the report found.
In addition to the 40% at risk of dying out, a third of species are endangered — numbers that could cause the collapse of the planet’s ecosystems with a devastating impact on life on Earth.
The report, co-authored by scientists from the universities of Sydney and Queensland and the China Academy of Agricultural Sciences, looked at dozens of existing reports on insect decline published over the past three decades, and examined the reasons behind the falling numbers to produce the alarming global picture.
Its lead author, Francisco Sanchez-Bayo, of the School of Life and Environmental Sciences at the University of Sydney, called the study the first truly global examination of the issue.
While the focus in the past has been on the decline in vertebrate animal biodiversity, this study stressed the importance of insect life on interconnected ecosystems and the food chain. Bugs make up around 70% of all animal species.
The repercussions of insect extinction would be “catastrophic to say the least,” according to the report, as insects have been at “the structural and functional base of many of the world’s ecosystems since their rise … almost 400 million years ago.”
Key causes of the decline included “habitat loss and conversion to intensive agriculture and urbanization,” pollution, particularly from pesticides and fertilizers, as well as biological factors, such as “pathogens and introduced species” and climate change.
While large numbers of specialist insects, which fill a specific ecological niche, and general insects were declining, a small group of adaptable insects were seeing their numbers rise — but nowhere near enough to arrest the decline, the report found.
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