A research review into the decline of insect populations has revealed a catastrophic threat exists to 40 percent of species over the next 100 years, with butterflies, moths, dragonflies, bees, ants and dung beetles most at risk.

Author of the review, Dr Francisco Sanchez-Bayo, an honorary associate with the Sydney Institute of Agriculture in the School of Life and Environmental Sciences, said that habitat loss from intensive agriculture alongside agro-chemical pollutants, invasive species and climate change are the main drivers behind the collapse in insect populations.

“As insects comprise about two thirds of all terrestrial species on Earth, the trends confirm that the sixth major extinction event is profoundly impacting life forms on our planet,” write Dr Sanchez-Bayo and co-author Dr Kris Wyckhuys from the University of Queensland and the Institute of Plant Protection, China Academy of Agricultural Sciences, Beijing.

Their study was published this week in Biological Conservation. It involved a comprehensive review of 73 historical reports of insect declines from across the globe, systematically assessing the underlying drivers of the population declines.

“Because insects constitute the world's most abundant animal group and provide critical services within ecosystems, such an event cannot be ignored and should prompt decisive action to avert a catastrophic collapse of nature's ecosystems,” the report said.

'We are realists'