Farmers and orchard growers rely on both honey bees and wild bees for pollination of their crops. The UK’s Department for Environment, Food and Rural Affairs (Defra) reports that 90% of the world’s food comes from 100 core crops, 70 of those pollinated by bees. Whilst all bees and insect pollinators are facing challenges to their health and survival, the numbers suggest managed honey bee colonies are actually thriving. Despite this, numerous artificial pollination solutions are being developed to address agriculture’s demand for crop pollination, rather unexpectedly they may well help to safeguard the future of wild pollinators.
Managed pollinators – the continued rise of the honey bee
Managed honey bee colonies are transported between agricultural locations to provide pollination services and increase crop yields. Whilst a number of challenges are making the life of the professional beekeeper much more difficult, this is an industry that does not appear to be under imminent threat despite some adversities. Indeed as demand for insect pollinated crops increases, so too does the number of hives:
- In the United States, managed honey bees pollinate an estimated US$15 billion worth of food crops each year (USDA). The US National Agriculture Statistics Service (NASS) shows that there were around 3 million hives in 2020, a colony number that has remained reasonably static since at least 1980.
- Canada’s AAFC estimates that the total annual economic contribution of honey bee pollination through direct additional harvest value is about CAD$2.57 billion. There are currently over 750,000 colonies of honey bees in Canada, an increase of 25% since 2010 (up from 600,000).
- In England managed beehives are also in ascendancy with 25,000 beekeepers now managing 120,000 colonies. This is up from 15,000 beekeepers and 80,000 colonies just over a decade ago – a rise in colonies of 50%. Pollination services are estimated to provide £440 million to UK agriculture in the form of increased yields – about 13% of UK income from farming.
A total of approximately 100 billion managed bees are currently helping to pollinate crops and provide food across the US, Canada and England, with no sign of any long term population decline in the honey bee.
The mysterious decline of wild pollinators
Typically pollinator decline coverage focuses on the honey bee as the poster boy (or girl) of ‘pollinators in peril’ but there are thousands of other wild insect species including solitary bees, bumblebees, butterflies, moths and hoverflies that play a significant role in pollinating plants. Indeed there are at least 1,500 species of insect pollinators in the UK alone, 270 of those are different species of bee.
Whilst honey bee numbers are increasing, native wild pollinator numbers are in decline and this is a cause for concern. It is difficult to establish exact numbers but an ongoing study of all insects in Germany found a seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over 27 years. A British study has also found widespread losses of pollinating insects.
In 2017 the US Center for Biological Diversity conducted a systematic review of the status of all 4,337 North American and Hawaiian native bees and found that among native bee species with sufficient data to assess (1,437), more than half (749) are declining.
Threats to the health of all insect pollinators
Some of the health challenges faced by wild insect pollinators are the same as those faced by, and arguably exacerbated by billions of honey bees. Colony Collapse Disorder (CCD) and Varroa mites (Varroa destructor) affect all bees, the prevalence of honey bees might be contributing to their spread amongst wild bee and insect populations. Several European studies have also found that neonicotinoid pesticides negatively affect the health of all pollinators (leading to a complete EU ban in 2018).
These problems are certainly making life difficult for beekeepers who report increasing levels of ill health among their honey bee hives. However these colonies do at least have beekeepers on hand to help combat the threats from pests and diseases and to ‘recondition’ colonies with new queens. Wild species don’t have that support. Honey bee numbers are up, wild bee numbers are down.
Competition between honey bees and wild pollinators
Competition for nectar between the two groups of pollinators is not well discussed. When introduced into a new area to pollinate a crop, honey bees have the potential to destabilise the natural ecosystem by competing with local wild pollinators. If combined with increasing losses of nectar-rich habitat it’s possibly too much for the wild pollinators to cope with, leading to population decline.
In 2019 a three year field study in Spain’s Canary Islands found that the introduction of managed honey bees had serious consequences for biodiversity: ‘results show that beekeeping reduces the diversity of wild pollinators and interaction links in the pollination networks. It disrupts their hierarchical structural organization causing the loss of interactions by generalist species, and also impairs pollination services by wild pollinators through reducing the reproductive success of those plant species highly visited by honey bees. High-density beekeeping in natural areas appears to have lasting, more serious negative impacts on biodiversity than was previously assumed.’
Sheila Colla, an assistant professor and conservation biologist at Toronto’s York University, Canada asserts that honey bees are an extreme generalist forager – a vacuum cleaner of pollinators. “People mistakenly think keeping honey bees, or helping honey bees, is somehow helping the native bees, which are at risk of extinction.” she told Scientific American, “Beekeeping is for people; it’s not a conservation practice”.
It should be remembered that in the United States none of the 90 billion managed honey bees are native to the continent. Their ancestors were introduced from Italy during the mid to late 19th century as a solution to increasing pollination and crop yields. Concern about bee decline is misguided when focused on the honey bee, instead it should be directed to losses in native wild pollinators.
Farmers and growers can and do help boost native pollinator species by planting nectar rich wild flowers in buffer strips on arable land etc. but could it be that reducing the number of managed honey bee hives would boost population numbers in native pollinator species? Could that be done whilst also increasing pollination levels to feed a growing world population?
Modern pollination technology could reduce our honey bee dependency
US based start-up Dropcopter uses custom drones equipped with state of the art software and patented pollinator delivery systems. The Dropcopter already pollinates apples, almonds, cherries and pears in the US, it can pollinate 20 acres per hour, per drone. The company reports that the average pollination cost across the board is approximately $300 per acre (which includes two applications).
Cofounder of DropCopter, Matt Koball told Food and Farming Technology that the goal of their technology is not to replace pollinators but to augment what the bees do.
“We can provide the correct pollen at the correct time in the field to increase the opportunity for optimum crop set.” he says “Most of our trials have been done with hives in the fields and we have seen an increased crop set that typically outperforms bee-only pollination by 10 to 35% (each year and each field site is different).”
“We have been contacted by apiaries with the idea of making their hives more efficient and therefore being able to deploy fewer hives per acre and augmenting what they do. This would allow the limited number of hives available to be better utilized during pollination season as they are struggling to keep up with the demand.”
Fewer hives deployed per acre would be also good news for wild pollinators searching for nectar outside of the target crop zone since there would be a reduction in nectar competition.
In 2020 Washington State University scientists received a $1 million grant from the U.S. Department of Agriculture (through the Washington State Department of Agriculture) for a new project to develop robotic crop pollination technology. Again in the long term a robotic solution could potentially reduce honey bee hive dependency.
The team is led by Manoj Karkee, an associate professor in WSU’s Department of Biological Systems Engineering and Center for Precision and Automated Agricultural Systems (CPAAS). They have been working on robotics in agriculture for a decade and already have robotic systems that detect flowers for a robotic thinning system.
WSU’s new pollination project involves three steps:
- Camera and machine learning systems. The research team must teach machines to detect and locate flower blossoms on trees in an orchard to target what needs to be pollinated.
- Looking at models for blossom development. Researchers need to determine the best stage to pollinate a given crop.
- Developing a robotic hand and arm to spread pollen that will work with step one and will be tested in a lab and in the field.
The overall goal of the new project is to demonstrate capability for robotics to do this work, not build a full-scale machine.
“We plan to integrate components into a working research prototype. If that prototype is successfully tested in orchards to find and locate flower clusters and apply some pollens directly targeted to the centre of individual flower clusters, we will achieve our goal. Developing full scale machines with multiple arms is out of scope.” Karkee told Food and Farming Technology.
“Our hypothesis, based on the preliminary results, is that we will be as good as or better than natural pollination processes in achieving target crop yield and quality.
Another benefit will be that overall crop load management activities will be much reduced as we pollinate only target flowers thus minimizing the needs for flower and green fruit thinning.”
The three-year grant also includes scientists from Penn State University.
The folks at Walmart believe that flying robotic pollinators could be the future, in 2018 they filed a patent covering unmanned airborne pollinators, what one might describe as ‘robotic bees’. Back in 2013 the Wyss Institute for Biologically Inspired Engineering at Harvard University developed a ‘RoboBee’. Their flying insect-inspired robots measured about half the size of a paper clip, weighed less that one-tenth of a gram, and flew using “artificial muscles” comprised of materials that contract when a voltage is applied.
There are no signs of a swarm of tiny robotic bees coming to an orchard near you soon just yet, indeed Brownell added “More recent iterations of the RoboBee can transition between swimming and flying, or ‘perch’ on surfaces before taking off again.”
These tiny little micro robots won’t be taking over the job of the honey bee just yet.
The future of crop pollination
Globally there are a growing number of companies in the automated pollination space as well as several ongoing academic research projects. From soap bubble pollen delivery to autonomous pollen spreaders and the methods described above, some solutions are already proving successful. There will be more in the years ahead.
If through our ingenuity humans are able to develop effective crop pollination solutions, this will reduce our centuries-old dependence on honey bees and make us more sustainable as we reduce their numbers. That will be to the benefit of thousands of other insect pollinators including several hundred other species of bee. Indeed it’s entirely possible that modern pollination technology might just save the bee from itself.
