The world’s insects are heading towards a “catastrophic collapse” – and if the insects go, it’s bad news for the rest of us.

The worldwide decline of insects has been detailed in a major new meta-analysis published in the journal Biological Conservation that has reviewed 73 historical long-term reports of insect declines from across the globe, most of which happened to be carried out on populations in Europe and the US.

They concluded that up to 40 percent of the world's insect species could face extinction within the coming decades. This is especially jarring when you consider their essential role in the wider ecosystem as pollinators, let alone the fact they make up around two-thirds of all land-dwelling species on the planet.

“If insect species losses cannot be halted, this will have catastrophic consequences for both the planet’s ecosystems and for the survival of mankind,” study author Francisco Sánchez-Bayo, at the University of Sydney, Australia, told The Guardian, who first reported on the study.

With a 2.5 percent rate of annual loss of insects over the last 25-30 years, "In 10 years you will have a quarter less, in 50 years only half left and in 100 years you will have none,” he said.

The “root cause” of the problem is the intensification of agriculture over the past six decades. In turn, this leads to the worsening of other factors, such as pollution, the destruction of habitat, and the increasingly relentless use of synthetic pesticides. 

Once again, it appears that food production is the main culprit of the problem. As such, the researchers urge for a global “rethinking of current agricultural practices,” especially when it comes to the use of pesticides.

“The conclusion is clear: unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades,” the authors conclude in the study.

Climate change also stood out as a major driver of this extinction in almost 7 percent of the studies. The report notes how increasing global temperatures have already reduced the range of dragonflies, stoneflies, and bumblebees. As global temperatures continue to creep up, the problem is only likely to affect more and more species, especially those living in tropical regions.

All of these findings are particularly worrying because insects play a cornerstone role in their ecosystems. Butterflies and moths, which play a vital role in pollination and natural pest control, are among the worst affected of all. The researcher notes that out of 733 species of day-flying moths, up to 85 percent experienced significant declines since 1980.

Other vulnerable insects include numerous species of beetles and Hymenoptera, the order that contains wasps, bees, and ants. The global status of the world’s Hymenoptera is not crystal clear, however, numerous studies in Europe and the US have pointed to declines in certain populations of managed colonies of honey bees and wild bees, which carry out over 20 percent of agricultural pollination. 

“As insects comprise about two-thirds of all terrestrial species on Earth, the above trends confirm that the sixth major extinction event is profoundly impacting life forms on our planet,” the report concludes.

[H/T: The Guardian]