Thanks to our current agricultural practices, nearly half of all insect species are in rapid decline and a third could go the way of the dodo within the lifetimes of middle-aged people alive today, finds a new peer-reviewed study set for publication in Biological Conservation this April.
“Unless we change our way of producing food, insects as a whole will go down the path of extinction in a few decades,” concludes the paper.
According to the authors, we are currently undergoing the largest extinction event on Earth since the late Permian and Cretaceous periods, or the sixth mass extinction of the past half-billion years.
“We estimate the current proportion of insect species in decline – 41 per cent – to be twice as high as that of vertebrates,” said Francisco Sánchez-Bayo of the University of Sydney and Kris Wyckhuys of the University of Queensland in Australia.
Basing their conclusions on more than 73 historical datasets on insect decline from across the globe, some dating back more than a century, the researchers have found habitat change (via deforestations, urbanisation, and conversion of farmland) to be the biggest culprit.
Pollution (mainly that by synthetic pesticides and fertilisers) related to commercial agriculture ranked not too far behind and have, when taken together with habitat change, already caused the populations of flying insects to decline by a staggering 80 per cent in Europe alone.
While most warnings about the loss of biodiversity up till now have focused primarily on large mammals, birds and amphibians, about two-thirds of all terrestrial species are actually comprised of insects, who are crucial for the survival of countless vertebrates both on land and at sea.
Furthermore, about 75 per cent of the world’s top food crops depend on animals for pollination, which is not exactly good news considering that one in six species of bees have already gone regionally extinct.
Estimates show that if a pro-active approach is not taken to drastically reduce the deployment of pesticides and chemical fertiliser, the world is going to keep losing about 2.5 per cent of the insect biomass (i.e., the total weight of all insects in the world) every year.
Given the dire straits we find ourselves in, Sánchez-Bayo and Wyckhuys call for “a rethinking of current agricultural practices”, which includes replacing synthetic pesticides with more sustainable “ecologically-based” alternatives, and cleaning polluted waters in both agricultural and urban environments.