Global decline of insects may cause ‘plague of pests’

Cheryl Sanders
February 13, 2019

The review, which looked at 73 studies conducted around the world, claimed that more than 40 per cent of insect species are now declining, adding that the rate of extinction is about eight times faster than the respective rate for birds, mammals and reptiles. The heavy use of pesticides, climate change and invasive species were also pinpointed as significant causes.

"Unless we change our ways of producing food", the authors write, "insects as a whole will go down the path of extinction in a few decades".

"It's not just about bees, or even about pollination and feeding ourselves - the declines also include dung beetles that recycle waste and insects like dragonflies that start life in rivers and ponds", said Matt Shardlow from United Kingdom campaigners Buglife.

One of its authors, Francisco Sanchez-Bayo, from the University of Sydney, described the 2.5 per cent rate of annual loss over the past 25-30 years as "shocking". Lepidoptera, the order of insects that includes butterflies, which are often the canary in the coalmine for ecosystem problems, have declined by 53 percent. "Allowing the slow eradication of insect life to continue is not a rational option".

Various insects are also a common food source for larger animals. As explained, insects are responsible for pollinating 75 percent of the 115 most important food crops worldwide.

But where many die, others are expected to thrive, as "plagues of pests" may arise out of the loss of butterflies, bees, and dung beetles.

Prof Goulson said that some tough, adaptable, generalist species - like houseflies and cockroaches - seem to be able to live comfortably in a human-made environment and have evolved resistance to pesticides.

The total mass of insects - which now outweighs humanity by 17 times over - is falling by 2.5 percent a year, which suggests they could vanish altogether within the next century. Drastically reduce pesticide use and redesign agricultural systems to make them more insect-friendly.

While a number of factors have been attributed to the rapid decline, the researchers lay most of the blame on our methods of food production, saying that "intensive agriculture is the one that is killing the ecosystems".

Ten per cent of known species are already extinct, compared to 1pc of vertebrates, they found.

"Not much consolation for our children, I'm afraid". The views expressed therein are not necessarily those of, its sponsors or advertisers.

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