“If the bee disappeared off the face of the Earth, man would only have four years left to live.”
You’ve probably seen this quote, usually attributed to Albert Einstein, in connection with colony collapse disorder (CCD), a mysterious disease that is sweeping through US and European honeybee hives.
We are on the brink of ecological Armageddon, warn the people devising and sharing the meme, and they know who the guilty parties are even before the evidence is in – purveyors of neonicotinoid pesticides.
Don’t panic. The end is far from nigh.
“There’s absolutely no evidence that Einstein ever said that,” said Michael Pocock, an ecologist with the Centre for Ecology and Hydrology. “It does sound like the sort of thing he might have said, though.”
But even if the quote is misattributed, is it true?
Dr Pocock is an expert on bees – not honeybees, but bumblebees. It's an important distinction. CCD affects honeybees, but they are just one of more than 240 bee species. And wild bees are not being hit by CCD.
Plus, bees aren’t the only pollinators. Hover flies (which look a lot like bees to the untrained eye, but have only one pair of wings), butterflies, hummingbirds and even bats do it too.
The annual value of “pollination services” is usually estimated by working out the cost of having humans do the work, so the figures are debatable. Dr Pocock points to a study that pegs the figure for the US at $4.1bn to $6.7bn.
Of that, honey bees contribute about a fifth, Dr Pocock told Forbes.com at the British Science Festival.
Even if all the pollen-spreading insects did die out, it might lead to mass starvation on an unprecedented and unacceptable scale, but it probably wouldn’t be the end of mankind.
Many plants would survive, though in some cases the quality of their seeds would be lower. Corn, for example, is wind pollinated, while potatoes and carrots can be grown from tubers. Leafy vegetables, such as cabbage, also grow without the need for insects.
Melons, berries and fruits such as apples and pears, on the other hand, could conceivably be in trouble. Unless they get extra human help, that is. In the fruit orchards of southwest China, farmers and their children have to climb into the branches armed with pots of pollen and paintbrushes to individually pollinate each blossom because natural pollinators are rare, said Dr Pocock. This might be an impractical solution in more developed countries, which don’t have enough agricultural workers.
Honeybees do play an important role in mass flowering crops, those, such as blueberries that blossom at exactly the same time each year. If you grow such plants as a monoculture, there won’t be enough food to support wild pollinators year round. The only option then is to truck in honeybee hives, moving them northward with the season.
Pesticides, notably DDT, have been found to directly cause ecological damage in the past. But not all problems have a single cause. It is possible that neonicotinoids are one factor among many that are implicated in CCD.
“CCD is more serious for honeybees because they have hives that are permanent,” said Dr Pocock. Among social bumblebee species, the usual pattern is for the drones and workers to die off in the autumn, leaving the pregnant queens to hibernate alone.
But honeybees don’t die back in the winter. One advantage of this (from a human perspective) is that in preparing to survive the winter, they produce lots of surplus honey. The disadvantage is that they are vulnerable to parasites and infections. Varroa mites, another possible factor in CCD, can find hosts in the hive year-round, for example, which means they have a head start come spring.
In other words, risk factors can accumulate in the hive.
And there is evidence to suggest that even if neonicotinoids are involved in CCD, they’re not acting on their own.
A report to the Australian government in February found that, although the country had adopted neonicotinoids widely, its honeybees were not suffering from CCD, which suggests that it is not the sole cause of the problem.
That’s not to say that it is entirely benign. Recent studies have found that neonicotinoids cause a range of problems in insects, including making it harder for them to navigate.
But many of these studies have been done in laboratories, and may not be reproduced in the wild, Dr Pocock said. “Neonicotinoids are hugely controversial."
None of this means that we should be complacent. Although hard figures on populations are hard to come by, there is evidence that the diversity of pollinators has been declining, said Dr Pocock.
Bumblebee populations have been helped in the past quarter century by European farming policies that encourage the preservation of hedgerows, where bumblebees often establish nests in old mouse holes. Setting aside strips of wildflowers at the edges of fields also helps.
If neonicotinoids are implicated as a factor in CCD, the appropriate response might be to control when and where they are applied, rather than a blanket ban, as has been applied in the EU. Banning them pushes farmers to revert to older pesticides, some of which could be even more damaging to the environment.