Over 40 percent of insect species could go extinct soon

More than 40 percent of insect species could go extinct in the next few decades, a new study has warned.

"Worldwide decline of the entomofauna: A review of its drivers", written by Francisco Sanchez-Bayo at the University of Sydney and Kris Wyckhuys at the China Academy of Agricultural Sciences, revealed that one-third of insect species were under threat and a decline in their numbers could have a "catastrophic" effect on Earth.

The study -- published in the journal Biological Conservation -- said insects' rate of extinction is 2.5 percent a year, suggesting they could vanish within a century.

The scientists warned that loss of natural habitats, use of pesticides and fertilizers on farms and emissions from factories and cities are the "main drivers" of the decline, while invasive species and climate change are additional causes.

The report said insects' rate of extinction is eight times faster than that of birds, mammals and reptiles, adding that Lepidoptera, an order of insects that includes butterflies and moths, Hymenoptera, which includes sawflies, wasps, bees and ants, and Coleoptera, which includes dung beetles, are the most affected.

Insects, a food source for many other species such as birds and mammals, are of key importance to the earth's ecosystems and wildlife circles.

The scientists called for quick action to prevent this mass extinction from occurring.