Tiny cogs in a giant machine

If we woke up one day and there were no bees left, people would pay attention. Yet the steady eradication of our life-giving insects is no less horrifying, points out George McGavin

- George McGavin

PULL back the bark of a rotting log, examine a handful of soil or simply sit quietly and gaze at the comings and goings in a patch of wildflowers. Whatever you are looking at is not trivial it is a very important part of the biological mechanism of life on Earth. The small creatures you see scurrying and flitting about are the lifeblood of the landscape, the vital organisms that make the natural world work, and we would do well to pay them more attention. Insects first appeared on land more than 400 million years ago and, today, make up the vast majority of species on our planet. They are the creatures that do the ecological heavy lifting without insects, it would be hard to see how complex ecosystems could have evolved.

It may come as a surprise that all the herbivorous vertebrates on Earth are completely out-munched, perhaps by a factor of 10 to one, by myriad tiny mandibles and that insects consume many times more animal flesh than all the sharp-clawed and toothed vertebrate carnivores put together. Indeed, ants alone constitute the largest biomass of carnivorous animals in any habitat you care to name, whether it be the savannahs of Africa or your back garden. If any of this sounds implausible, consider that, although insects are individually small, there are an awful lot of them.

Insects also pollinate the vast majority of the world's quarter of a million or so species of flowering plants. This particular version of 'I'll scratch your back if you scratch mine' has been around for about 100 million years and has generated a rich diversity of species. Twenty thousand species of bee are, to a very large extent, responsible for the continued survival of flowering plant life, which includes a very long list of the things we eat-fruit and vegetables from pumpkins, plums and peas to cherries, cucumbers and cocoa.