Wild pollinators: the honey bee's allies the beekeeper forgets

Ask an average person about pollination and they will answer: bees. More precisely the honey bee, the one from the hive, the one that makes honey. That is a considerable oversimplification, one that does a disservice both to nature and to farming itself. Because alongside the honey bee works a whole army of wild pollinators few people remember, and which not rarely do the job better than it. In Poland alone there live over 450 species of wild bees, and by many accounts about 470, plus bumblebees, hoverflies, butterflies and beetles. The honey bee is the best known among them, but by no means the most important.

This text belongs to the category in which we look at beekeeping more broadly than through the hive entrance alone. After the piece on overcrowding, where the talk was of competition between the honey bee and wild pollinators, it is time for the other side of the coin: who these wild pollinators are, why they are so valuable, what threatens them, and what exactly a beekeeper can do for them without giving up their own bees. Because this is not a zero-sum game of hives versus wild insects. You can have both, and a wise beekeeper benefits from it.

Who the wild pollinators are

Let us start with the scale, because it surprises. In Poland alone over 450 species of wild bees, that is solitary bees, have been described, and by many accounts about 470, in the whole of Europe over two thousand, and worldwide over twenty thousand. The honey bee is one single species in that crowd. To this are added bumblebees, of which we have about thirty species in the country, and the whole rest of the pollinating company: hoverflies, including those disguised as wasps, butterflies, beetles and other insects.

Wild bees differ from the honey bee in almost everything. They do not make honey, do not form colonies of thousands, and mostly do not sting, because they have nothing to defend. A solitary bee, as the name says, lives alone: the female, after overwintering, builds a nest, provisions it with pollen, lays eggs and dies, never seeing her offspring. They nest in the most varied places, in hollow stems, cracks under bark, in walls, and most, of the order of seventy to eighty percent of species, dig them straight in the ground. That is why a bare, sandy bank can be more valuable to nature than a manicured lawn.

Bumblebees are a separate chapter. They are larger, densely furred, fly in cold, rain and wind when the honey bee sits in the hive, and can buzz-pollinate, that is shake pollen loose by vibrating their muscles. The latter is crucial for tomatoes, blueberries or peppers, which the honey bee cannot pollinate well. Without bumblebees a good part of modern greenhouse horticulture simply would not exist.

Why they are so valuable

Here we come to something hard to overrate. In our climate zone insects pollinate about 78 percent of angiosperm species, and it is estimated that close to 80 percent of crops in Poland depend on insect pollination. We are talking about oilseed rape, apples, pears, cherries, plums, raspberries, buckwheat, legumes and a whole mass of others. Without pollinators there is not only no honey, but not a fraction of what lands on our plates.

And now something that surprises many beekeepers: in many cases wild bees pollinate more effectively than the honey bee. There are several reasons. First, specialisation, because some species are closely matched to particular plants and pollinate them more precisely. Second, wild bees do not store reserves in a hive but gather pollen and nectar on the spot for their offspring, so they visit more flowers and are less choosy. Third, they fly in conditions the honey bee sits out, that is in cold and poorer weather, so pollination is more even across the whole season.

This is seen best in the red mason bee, a wild solitary now used in orchards on a large scale. It is so effective that, according to materials of the Institute of Horticulture, a small number of mason bees can replace the work of two honey bee colonies of tens of thousands of workers each. It starts in early spring, exactly when fruit trees flower, visits around a hundred and fifty plant species, does not sting and needs no hive. No wonder orchardists reach for it ever more readily.

What threatens them

The bad news is that wild pollinators are faring ever worse, and faster than the honey bee, which after all has a carer in the beekeeper. Global analyses speak plainly of an alarming decline in insect numbers, and a widely cited review by researchers from the University of Sydney from 2019 estimated that up to 41 percent of insect species are threatened with extinction. Wild bees, deprived of human care, are first on that front line.

There are several causes and we know them all. Intensive farming with huge monocultures turns the landscape into a green desert, where after the brief, violent flowering of oilseed rape nothing remains. Field margins, fallows, scrub and sandy banks in which wild bees nest disappear. Pesticides, especially those acting on the insect nervous system, hit pollinators directly. To this are added the concreting-over and mowing of everything to a lawn, and diseases with which, as we will see in a moment, too dense an apiary can also gift its wild relatives.

Among these threats is one a beekeeper must speak of honestly, because it concerns them: competition from the honey bee. In terrain poor in flowers and overcrowded, a large number of hives takes pollen and nectar from wild pollinators, as I wrote more fully under overcrowding. The science is cautious here and shows the effects are context-dependent, but in crowded, poor landscape competition can be real. It is uncomfortable but important, because it means the beekeeper is not only a defender of bees, they can also, unwittingly, be part of the problem.

What a beekeeper can do without giving up the apiary

And here the good news, because the interests of the honey bee and of wild pollinators largely overlap. Everything that improves the forage base for your bees helps the wild ones at the same time. You do not have to choose, you just have to act with your head.

Plant and sow with the whole season in mind. A wild pollinator needs flowers from early spring to late autumn, not only at the peak of the flow. Crocuses, lungwort, willows and fruit trees give early pollen in late winter and spring, phacelia, berry shrubs, clovers, borage and lime carry the season through summer, and goldenrod, heather and ivy close it in autumn. These are largely the same plants that build your bees' fat body, so you work on two fronts at once. Bet on native, pollen-rich species, not on exotic ornamentals, which can be useless or even toxic to insects.

Leave a piece of wildness. The simplest and cheapest thing, and often the hardest for an eye used to order. An unmown strip of meadow, a clump of nettles, a pile of branches, a bare sandy bank, dead wood, a wall full of holes, all of these are homes and canteens for wild bees. Most solitary bees, of the order of seventy to eighty percent, nest in the ground, so a patch of bare, sandy soil is worth more than many a little hotel. Mow less often and not all at once, and you will do more for pollinators than with many a gadget.

Hang an insect hotel, but with sense. A house of reed tubes or drilled blocks of wood is a fine nest for the mason bee and other solitaries that nest in channels. But it must be made properly: dry, in the sun, facing south, with smooth-bored tubes of varied diameter, sheltered from rain. A badly made hotel, damp and mouldy, does more harm than good, because it becomes a breeding ground for diseases and parasites. Once a year it is worth cleaning it or replacing the tubes.

Care for the health of your own apiary. This is a thread beekeepers rarely think of, and which is real: honey bee diseases and viruses, including those spread by varroa, can pass to bumblebees and wild bees through commonly visited flowers. A neglected, sick, varroa-ridden apiary is therefore a threat not only to itself but to its wild neighbours. By keeping varroa in check and treating in time, you protect not only your own hives.

Do not overcrowd the terrain. This ties in with the whole piece on overcrowding. A reasonable number of hives matched to the forage base is not only better yields for you, but a place at the table for wild pollinators. In poor terrain fewer hives can be better both for your bees and for nature.

Curiosities and controversies

The honey bee is not a synonym for pollination. In common awareness saving the bees equals setting up hives, whereas that is a considerable misunderstanding. The honey bee is one of over twenty thousand bee species and happens to be the one doing best, because a beekeeper looks after it. The real crisis concerns wild pollinators, and setting up more hives in a city or in flower-poor terrain not only does not help them but can harm.

Urban beekeeping can be a harmful fashion. City hives have become a fashionable eco-gesture, only often devoid of sense. A city rarely has enough valuable flowers to feed both honey bees and wild ones, and hives added to rooftops sharpen competition for the scant urban pollen. To help pollinators in the city, a flower meadow, a wild corner and plantings do more than another hive.

A handful of mason bees instead of two hives. The mason bee's effectiveness in an orchard is so great that, according to Institute of Horticulture materials, a small number of these solitaries can replace the work of two honey bee colonies of tens of thousands of workers each. It is a good illustration that in pollination what counts is not only the number of insects but how they work. A wild pollinator is sometimes simply the better craftsman.

A bumblebee opens the flower your bee then uses. A little-known phenomenon, and a heartening one for a beekeeper, because it shows that wild pollinators not only compete with the honey bee but also help it. It is called nectar robbing. A short-tongued bumblebee, the buff-tailed for instance, cannot reach the bottom of long-corolla flowers like comfrey, delphinium or honeysuckle, so with its strong mandibles it bites a hole at the base of the flower and drinks the nectar from the side. Most interestingly, other insects then use that ready-made hole, including the honey bee, which on its own would never reach that nectar. In other words, the bumblebee unlocks for your bees a forage that without it would be out of their reach.

The bumblebee works while the bee sleeps. Bumblebees fly in cold, wind and drizzle, in temperatures at which the honey bee will not stir from the hive. So in a capricious spring, when fruit trees flower and the weather is unkind, it is often the bumblebee, not the honey bee, that saves the orchard's pollination. In a cold climate their role can be irreplaceable.

There is a bee that cuts perfect circles from leaves. The leafcutter bee, with its mandibles, cuts neat oval and round pieces from the leaves of roses, lilac or other shrubs, and lines and partitions the cells of its nest with them. If you have seen in the garden a leaf that looks as if someone ran a hole-punch over it, that is its work. A single female can cut several thousand such pieces in her lifetime, and it does the plant no harm.

Solitary bees carry pollen on the belly, not the legs. The honey bee, bumblebees and many others gather pollen into baskets on the hind legs. But leafcutters and mason bees, of the Megachilidae family, have a dense brush of hairs on the underside of the abdomen and carry pollen on the belly. The effect is that such a bee loses more of it along the way than the honey bee, which makes it a more effective pollinator, because it scatters pollen around the flowers more generously.

From a pinhead to almost four centimetres. Under the label wild bee hides an enormous range. The smallest solitaries are barely two or three millimetres and are easily taken for gnats, while the largest bees in the world reach almost four centimetres. It shows how narrow a slice of this richness the honey bee everyone knows really is.

Male solitary bees sleep in flowers. In solitary bees the males have no nest or store, so they sleep wherever dusk finds them, often clamped by their mandibles onto a stem or curled up inside a flower. Sometimes in the morning you will find in a bellflower or a poppy a sleeping bumblebee or solitary, waiting out the cold of night. It is one of those little things that make a meadow full of wild bees more interesting than it seems.

Two myths

Myth one: to save the bees you have to set up a hive. This is the commonest misunderstanding on the topic. The honey bee is a managed species under human care and is not threatened with extinction. It is wild pollinators that need saving, and you help them not with a hive but with flowers, wild corners and nesting sites. Another hive in crowded terrain can even harm them.

Myth two: wild bees are dangerous, because they are bees after all. The opposite. Solitary bees mostly do not sting at all, because they have no colony or store to defend, and even if they have a sting, they are completely harmless to people, children and animals. A mason bee hotel on the house wall is not a threat, but a free crew pollinating your garden.

Most common mistakes

Equating pollination with the honey bee. This narrows the thinking and leads to setting up hives where flowers and wild corners are needed instead. Pollination is the work of a whole army of species, not one.

Perfect order in the yard. A lawn mown short, tidied branches and concreted banks are a desert for wild bees. A bit of controlled mess, an unmown strip and bare ground give them a home.

Exotic ornamentals instead of native plants. Fashionable ornamentals can be worthless or toxic to pollinators. Native, pollen-rich species feed, ornamentals often only please the eye.

A badly made insect hotel. A damp, mouldy hotel in the shade and never cleaned becomes a breeding ground for parasites. Better no hotel than a bad hotel.

A neglected apiary next to the wild ones. A sick, varroa-ridden apiary infects wild pollinators too through shared flowers. Caring for the health of the hives is also protection of the wild neighbours.

Sources and further reading

• Teper D., Borański M. Rearing solitary bees as a way to make up pollinator shortfalls. Institute of Horticulture. On the red mason bee and the use of solitaries in pollination.

• Madej D. (2022). The red mason bee, an alternative pollinator in plant growing. MODR Karniowice. Practical basics of mason bee rearing.

• Materials on wild pollinators in Poland (among others Witryna Wiejska, nature portals) on the number of solitary species, their biology and nesting habits.

• Fürst M. A. et al. (2014). Disease associations between honeybees and bumblebees as a threat to wild pollinators. Nature 506: 364-366. On the transfer of honey bee viruses to bumblebees via shared flowers.

• Sánchez-Bayo F., Wyckhuys K. A. G. (2019). Worldwide decline of the entomofauna. Biological Conservation (University of Sydney review). Source of the estimate of the share of insects threatened with extinction.

• Leadbeater E., Chittka L. (2008). Social transmission of nectar-robbing behaviour in bumble-bees. Proceedings of the Royal Society B. On nectar robbing and secondary robbing, in which the honey bee uses holes made by bumblebees.

• Mallinger R. E., Gaines-Day H. R., Gratton C. (2017). Do managed bees have negative effects on wild bees? PLoS ONE. Context for the competition of the honey bee with wild pollinators.