(CNN) Insect populations are declining precipitously worldwide due to pesticide use and other factors, with a potentially "catastrophic" effect on the planet, a study has warned.

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.

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