‘The little things that run the world’

Humans like to think we run the world, believing in our omnipotence. But while we shape and engineer — make, muddle and destroy — we are not, according to scientists, the world’s ultimate controllers. That role clearly falls to insects, “the little things that run the world,” as E.O. Wilson, the world’s pre-eminent entomologist, told us back in 1987.

Insects may be tiny, but they are mighty and superabundant. British entomologist and ecologist C.B. Williams once estimated a population of one million trillion insects on Earth at any given time. They are everywhere that there is land and sky — intimately involved with everything.

Insects tend to every square centimeter of living soil; they aerate and fertilize; they breakdown the billions of bits of organic debris and waste that other Earth residents produce, disposing of everything from leaf litter to elephant dung. Insects are the original recyclers, digesting dead wood and dead bodies. They also reside at the base of the food chain, feeding tens of thousands of birds, mammals, reptiles, amphibians, fish — and, by extension, us. More than 300,000 known plants are pollinated by animals, most of them insects.

It’s estimated that all the world’s arthropods, a group that includes insects, arachnids, millipedes, centipedes and crustaceans, weigh 17 times more than the planet’s 7.5 billion humans.

Take away this vast mass of crawling, fluttering, skittering insects — comprising maybe 90 percent of all animal species — and you’re truly staring planetwide ecological breakdown in the eye. Waste will pile up; soil will shed nutrients without replacement; animals will starve; and potentially hundreds of thousands of plant species will vanish. Extinction would stalk the land like a famished beast, and the future of humanity would be at stake.

“Think of a meal reduced to wind-pollinated crops — the bread will stay, [but] fruits and vegetables and most of the meat will be gone,” says Axel Ssymank an entomologist with the German Federal Agency for Nature Conservation, who pointed out, for example, that cocoa is “exclusively dependent on the pollination of small midges.” Imagine: a world without these unsung, unseen midges is a world without chocolate — forever.

“We may not always see or understand the intricate ways that [insects] pull and hold ecosystems together, but we know enough to understand that even if we don’t see those roles … they’re key,” says Michelle Trautwein, an expert on flies and assistant curator of entomology with the California Academy of Sciences.

“The Insect Apocalypse is Here,” declared a New York Times Magazine story by Brooke Jarvis at the end of 2018. That piece took a behind-the-scenes look at a study out of Germany that put concrete data behind something researchers had been reporting anecdotally for years. The groundbreaking research found that flying insects fell by 75 percent in just 27 years in 63 nature reserves all across Germany.

Let’s be clear: this wasn’t a story about colony collapse disorder, or pollinator decline, the diminishment or extinction of one particular species, or even a whole family of insects. The German research showed that the abundance of all flying insects — wasps, flies, butterflies, bees, dragonflies, beetles, etc., etc. — had plunged dramatically. Or maybe dramatically isn’t forceful enough: precipitously.

The study did not find a direct cause for why this happened, but scientists believe the drastic decline is linked to agriculture intensification (including a loss of wetlands, cover crops and hedgerows that once supported insects in European farming areas), along with habitat loss and pesticide use. The researchers didn’t point their finger at climate change, but others have, especially in the tropics.

What scientists do know is the urgency with which we need to respond to this new data. “We need to take action right away. A world without insects is unimaginable,” says study co-author Hans de Kroon, a plant ecologist with Radboud University in the Netherlands. “It is really not possible to sit back and say, ‘Well, you know, we need a little more information.’”

For years, entomologists have talked among themselves about strange goings-on: car windshields no longer covered with dead bugs, researchers’ insect traps catching fewer and fewer specimens, and, as Martins pointed out, dinners in the bush getting quieter.

“There is nothing new about [the decline],” says Daniel Janzen, who has been studying insects in the tropics since the 1960s with the University of Pennsylvania. “All that is new is today’s publicity hype and hand wringing.”

Janzen, now 80, could be called the Cassandra of Insect Decline; he’s been talking about this threat longer than pretty much anyone else, with few heeding his warnings.

But the study in Germany couldn’t be ignored, as it rested on meticulous surveys by amateur entomologists since 1989, providing the first hard data demonstrating a full-scale, across-the-board decline in insect abundance everywhere researchers looked.