The decline of bees has attracted media headlines and widespread public concern in recent decades, and rightly so. Three quarters of all the crops we grow benefit from insect pollination; many would produce little or nothing without pollinators. Imagine a world without tomatoes, strawberries, coffee or chocolate to name just a few of the many crops that rely upon them. We simply could not feed the growing human population without pollinators.

Photo by Hailey Moeller on Unsplash

Of course it is not just crops that require pollination - overall, about 87% of all plant species on Earth need some sort of animal pollinator – that is pretty much all of them aside from the wind-pollinated grasses (including cereal grains), and conifers. Without pollinators there would be no wild flowers, and the world would be an infinitely poorer place. Hence humankind should be deeply troubled by the ongoing declines in wild bee populations, and by rising mortality of domestic honey bee colonies.

Some bee species have undergone massive range declines; for example the rusty patched bumble bee (Bombus affinis) has vanished from 90% of its North American range in the last 25 years, while in the UK species such as the great yellow bumble bee (Bombus distinguendus) and the potter flower bee (Anthophora retusa) are now found at only a handful of sites, when once they were widespread.

A few have gone entirely extinct; for example Franklin’s bumble bee (Bombus franklini), a native of California and Oregon, has not been seen since 2006 and is almost certainly gone forever. The UK has had three bumble bee species go extinct, the apple bumble bee (Bombus pomorum), Cullum’s bumble bee (Bombus cullumanus), and the short-haired bumble bee (Bombus subterraneus).

Farming needs bees, but paradoxically it is one of the main contributors to their decline; industrial farming involving large monocultures of crops treated with perhaps twenty different pesticides per year has turned vast tracts of the globe into a hostile environment for wildlife of all sorts.

There are few flowers in modern farmland aside from the flowering crops themselves, and whatever flowers do manage to bloom are likely to be contaminated with mixtures of pesticides. Frequent tillage or disking also destroys nesting sites. Bees and other pollinators also face problems with non-native diseases that we have carelessly spread around the planet, and they are beginning to suffer from the effects of climate change. All in all, we have made life very hard for our poor pollinators.

Photo: Harvard Microrobotics Lab

However, we may not have to worry about the bees for much longer; help is at hand. They could soon be redundant, for there are plans to replace them - with robots. Teams of scientists from far flung places from Japan to Indonesia to the UK and United States are working on it as I write. There have been a number of scientific papers published discussing the possibility of building miniature flying robots to replace bees and pollinate our crops for us. Clumsy robobee prototypes have already been built and some seem to crudely work, although most still rely on a human to control them from a remote handset, while others seem more likely to chop flowers to pieces with their tiny rotor blades than to pollinate them.

Regardless of these shortcomings, it seems likely that the technological hurdles may one day be overcome, and we might well be able to build bee replacements. Media coverage has already heralded the imminent retirement of ‘the bee’ and a brave new world in which tiny metal and plastic drones buzz from flower to flower. If crops could be pollinated this way, farmers wouldn’t have to worry about harming bees with their insecticides. With wild bee populations in decline, perhaps these tiny automatons are the answer?

While I can understand the intellectual interest and challenge for a robotics engineer of trying to create robotic bees, I would argue that it is exceedingly unlikely that we could ever produce something as cheap (i.e. free) or as effective as bees themselves. Bees and other pollinators have been around and pollinating flowers for more than 100 million years; they have become exceedingly good at it. It is remarkable hubris to think that we can replicate or improve on them.

Photo: Yufeng Chen/Harvard SEAS

Consider just the numbers; there are roughly 80 million honey bee hives in the world, each containing perhaps 40,000 bees through the spring and summer. That adds up to 3.2 trillion bees, give or take. They feed themselves for free, breed for free, and even give us honey as a bonus. What would be the cost of replacing honey bees with robots? Even if the robots could be built, complete with charged power pack and control devices, for one cent each (which seems absurdly optimistic) it would cost $32 billion to build them.

And how long would they last? Some would malfunction, some would get caught out in the rain or get lost, some would be damaged by wind or spiders’ webs or curious bee-eaters. If we very optimistically calculate the lifespan of a robot bee at one year, that means spending £32 billion every year (and continually littering the environment with trillions of tiny robots, unless they could be made of biodegradable materials).

What about the environmental costs of manufacture and distribution? What resources would they require, what carbon footprint would they have, what energy source would power them? What would happen when terrorists or the Russians hacked into the robobee control system and turned them against us? Real bees avoid all of these issues; they are self-replicating, self-powering, essentially carbon neutral, and unlikely to be subject to mind control by Vladimir Putin any time soon.

Thus far I have glossed over a vital further point. Pollination is not all done by honey bees. Numerous other insects pollinate crops and wildflowers, including butterflies, beetles, moths, flies, wasps, sawflies, and many more. In more exotic climes hummingbirds, parrots and bats help out, and even occasionally lizards and marsupial mice. These pollinators come in all sorts of different shapes and sizes suited to different flowers.

Photo by Stephen on Unsplash

For example, honey bees are no good at pollinating tomatoes, the flowers of which need to be vibrated to extract the pollen. Bumble bees and some solitary bees are adept at this. Chocolate is pollinated by tiny midges, barely visible to the naked eye. Broad and runner beans are pollinated by long-tongued bumble bees.

Overall, it has been calculated that honey bees contribute at best one third of crop pollination in the UK, averaged across crops, and that we have in the region of 6,000 other species of pollinator. So we wouldn’t just need to replace the 3.2 trillion honey bees. We’d also need to replace countless trillions of other pollinators. All to substitute creatures that currently deliver pollination for free.

Declines of bees are symptomatic of larger issues. It is not just bees that are declining; almost all wildlife is declining in the face of massive habitat loss and pollution across the globe. Even supposing we could create robot bees cheaply enough for it to be viable, should we? If farmers no longer need to worry about harming bees, they could perhaps spray more pesticides.

There are many other beneficial creatures that live in farmland that would then be harmed; ladybugs, hoverflies and wasps that attack crop pests, worms, dung beetles and millipedes that help recycle nutrients and keep the soil healthy, and many more. Are we going to make robotic worms and ladybugs too? What kind of world would we end up with? Is this really the world that we wish to leave for our children?

Why do we have to always look for a technical solution to the problems that we create, when a simple, natural solution is staring us in the face? We have wonderfully efficient pollinators already, let’s look after them better, not plan for their demise.

Dave Goulson’s recent books, "Silent Earth" and "The Garden Jungle", provide advice on how we can all get involved in helping bees and other pollinators.