Insects Could Be Gone in a Century; Catastrophic Collapse to Ensue

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Public Domain. Wenceslas Hollar Digital Collection

Is this really how it ends?

Last year I read research revealing the crazy alarming fact that insects in Puerto Rico had declined by shocking numbers, and it chilled me to the bone. "Our analyses provide strong support for the hypothesis that climate warming has been a major factor driving reductions in arthropod abundance," wrote the authors, "and that these declines have in turn precipitated decreases in forest insectivores in a classic bottom-up cascade." David Wagner, an expert in invertebrate conservation at the University of Connecticut, told the Washington Post, “This is one of the most disturbing articles I have ever read.”

I started writing about it but it seemed so dire I didn't really even know where to go with it and I put it on the back burner. But now that the first global scientific review on the global decline of entomofauna (the insects of an environment or region) has been published, there is no time to waste in ringing the alarm bells.

And I mean all the alarm bells. Because if we lose all the insects, then we lose everything that eats the insects, and then we lose everything that eats the things that eat the insects and so on. They are also essential for pollination and the recycling of nutrients. You can see where this is going: As the authors put it, a “catastrophic collapse of nature’s ecosystems.”

Damian Carrington writes in The Guardian reports:

More than 40% of insect species are declining and a third are endangered, the analysis found. The rate of extinction is eight times faster than that of mammals, birds and reptiles. The total mass of insects is falling by a precipitous 2.5% a year, according to the best data available, suggesting they could vanish within a century.

The review notes that the main drivers behind these precipitous declines seem to be (in order of importance):

1. Habitat loss and conversion to intensive agriculture and urbanization;
2. Pollution, mainly in the form of synthetic pesticides and fertilizers;
3. Biological factors like pathogens and invasive species;
4. Good old climate change.

Last year Ilana created an infographic showing the very depressing visual that puts factor #1 above in perspective. Where are all the insects supposed to live?

40 percent of land on earth is being used for farmland

© Ilana E. Strauss

“The main cause of the decline is agricultural intensification,” says Francisco Sánchez-Bayo from the University of Sydney, Australia, who co-authored the review with Kris Wyckhuys from Beijing's China Academy of Agricultural Sciences. He explains that the initial decline seems to have started in the early 20th century and ramped up in the 1950s and 1960s – and going into code-red territory in the last few decades. Neonicotinoids and fipronil, two classes of insecticides introduced in this recent timeframe have been especially damaging, he says. “They sterilise the soil, killing all the grubs.”

(And note to gardeners: Home garden products containing neonicotinoids can legally be applied in far greater concentrations in gardens than they can be on farms – sometimes at concentrations as much as 120 times. There are at least 68 garden pesticides to avoid in order to help the bees.)

Bayer, one of the largest manufacturers of neonicotinoids, denies claims that the insecticides, uhm, harm insects.

Meanwhile, we've been hearing for years that the planet is in the early throes of the sixth mass extinction – and a lot of us who have been paying attention cringe with each new announcement of a species dying out. That insects are the most plentiful animals on the planet – there are about 25 million metric tons of spiders alone – brings the gravity of the situation home.

“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 note. “The repercussions this will have for the planet’s ecosystems are catastrophic to say the least.”

The researchers note that organic farms were more inhabited with insects and that moderate pesticide use in the past was not nearly as devastating as what we are seeing now. “Industrial-scale, intensive agriculture is the one that is killing the ecosystems,” he said.

So while we may be having heartbreak over skinny polar bears and coming to fisticuffs over plastic straws, the insects are dying. While we are arguing about climate change and maligning organic produce as elitist, the birds, reptiles and fish that eat the insects are starting to suffer. What if in the end, what finally kills off mankind is that we weren't paying attention to the planet's smallest inhabitants? It would be a hubris-filled finale worthy of Shakespeare.

“If insect species losses cannot be halted, this will have catastrophic consequences for both the planet’s ecosystems and for the survival of mankind.” says Sánchez-Bayo. And at the rate things are going, he says, "In 10 years you will have a quarter less, in 50 years only half left and in 100 years you will have none.”

Via The Guardian