The Insect Problem


Illustration by Marco Oggian
Words by Channa Brunt

The windshield phenomenon: a shorthand used by entomologists to describe the observation people make of having fewer insects stuck to their windshield after a drive, of seeing fewer insects flying about under streetlights at night, of swallowing less insects while making a summer bike ride.

Insect groups are struggling. In Germany, scientists reported a decline in the biomass of flying insects by 75% in only 27 years. In Puerto Rico’s Luquillo rainforest, researchers repeated a study on insect populations conducted in the 70s, leading them to conclude that the dry weight biomass of arthropods captured in sweep samples declined by 4 to 8 times, and in sticky traps, the decline was up to 30 to 60 times.

Most recent to have ringed the alarm bell is a group of scientists who analyzed 73 scientific reports on the decline of insect population that have appeared in the past 40 years (though to note a point of criticism: they left out studies on population increases or stability). In Biological Conservation, they write:

Our work reveals dramatic rates of decline that may lead to the extinction of 40% of the world’s insect species over the next few decades.
— Francisco Sánchez-Bayo and Kris A.G.Wyckhuys, Researchers

What comes next isn’t of much surprise. According to the report, the main drivers behind the fallback are habitat change (mostly due to agriculture, urbanization and deforestation); pollution (pesticides and fertilisers, and to a lesser extent industrial and urban pollution); biological factors (parasites and pathogens); and, of course, climate change.

Overwhelming, habitat change accounts for almost 50% of insect declines. With 12% of all global land area currently being used for the cultivation of agricultural crops, this goes hand-in-hand with the fact that pollution  – and agricultural pesticides – is responsible for over 25%. There’s a big chance pollution has made it into your kitchen already: in 2017, scientists found traces of pesticides in 75% of the 198 honey samples they collected worldwide. What does that tell you about our bees?

There’s been particular talk about the consequences of losing a certain group of insects: the pollinators, and what it will mean for our food security. 3 out of 4 crops producing fruit or seeds for human use, are at least in part dependent on pollinators.

And there’s more. Take the insects cleaning up the environment – eating carcasses, dead plants, our waste even. Take the insects keeping the ecosystem in balance when hunting other insects and keeping their numbers regulated. In the very least, there is the role they take in the food chain. Think of the many birds, amphibians, and mammals even, that have a diet made up out of insects. Is the alarming rate in which Europe is losing its birds partially caused by the staggering drop in insects? And if we crawl up the food chain, after the insects, birds and amphibians are gone, what happens next?

Professors and biologists Jelle Reumer describes what comes next as ‘zombie nature’: when you look around and it all seems green and happy, but upon looking and listening more closely, you’ll notice all the insects, birds, mammals and flowers have disappeared. It might not be a world you want your kids to live in.