Name: Why insects are so crucial to life on Earth | BBC Ideas
Uploaded: 2025-07-24T17:52:27.000Z
Duration: 5 min
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They make up around 70% of all known species on the earth and their combined biomass is 16 times that of humans.

300 million years ago giant dragonflies with wingspans of 75 centimetres soared amongst the tree ferns.

Nowadays, insects are extraordinarily diverse, existing in a bewildering array of colours, shapes and sizes,

and they play a crucial role in life on Earth.

They're food for a great many animals including most birds, bats, lizards, amphibians and freshwater fish.

80% of the world's wild plant species depend on insects to pollinate them, as do three quarters of the plants we grow for food.

It's no exaggeration to say that without insects, many of us would starve.

But many types of insects around the world are in big trouble.

Although measuring insect populations is complex there are worrying signs.

A major 2020 study estimated that globally land-dwelling insects are declining by about 9% per decade.

A German study found that the biomass of flying insects on nature reserves fell by an alarming 76% between 1989 and 2016.

In the United States, populations of the monarch butterfly are down 80% this century.

Some species, such as the Comerun speckled wood butterflies in the UK are bucking the trend, but the overall geographic range of butterflies in the UK has contracted on average by 42% since 1976.

Rats ate the St. Helena giant earwig to extinction and have nearly exterminated the giant wetter of New Zealand.

Light pollution also lures moths to bash themselves to death and disrupts the timing of insect life cycles.

It also disorients some dung beetles who navigate using the light of the Milky Way.

On top of all this, insects now have to cope with climate change.

Some adaptable insects such as mosquitoes, cockroaches and houseflies will benefit from warmer temperatures and more rain.

Bumblebees are disappearing from the southern edges of their range overheating in their furry coats as the climate warms.

Droughts, floods and forest fires will ravage already depleted insect populations.

In 1962, American biologist Rachel Carson wrote Silent Spring warning that we were doing terrible damage to our planet.

She wrote, "Man is a part of nature and his war against nature is inevitably a war against himself."

But what she witnessed was just the beginning.

Since then, insect rich wildlife habitats have been destroyed on a vast scale.

Soils have been degraded and rivers choked with silt polluted or drained dry.

Farming so reliant on insects for pollination is responsible for a large part of their decline.

An estimated 4 million tons of pesticides are released into the global environment every year.

So what can we do if we want to protect our insects?

The obvious place to start is by rewilding our gardens and balconies.

Inviting insects in by planting wildflowers and native shrubs.

Reducing lawn mowing and finding alternatives to pesticides.

Imagine green cities filled with trees, vegetable gardens, ponds and unmown verges.

All free from pesticides and buzzing with life.

A movement towards insect and nature-friendly sustainable farming is growing but it needs much more support.

Most threatened insect species have not yet gone extinct and could quickly recover if protected.

American biologist Paul Ehrlich likened the loss of species to randomly popping out rivets from the wing of an aeroplane.

Remove one or two and the plane will probably be fine.

Remove 10 or 20 or 50 and at some point there will be a catastrophic failure and the plane will fall from the sky.

Insects are the rivets that keep the planet running.

How many can be safely removed from the plane before it crashes?

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