When beekeepers from across the US drive millions of hives on trucks to pollinate California’s almond crops in January, there simply isn’t enough food for them to eat until the million-plus acres of almond trees start to bloom in early spring.
California’s booming almond industry has created a vast monoculture, with little natural forage. The honeybees need to be in place to raise their broods before the pollen comes into season, forcing beekeepers to use pollen patty substitutes to keep them alive.
After studying the honeybees used to pollinate almond trees for many years, Prof Geraldine Wright, a biologist at the University of Oxford, realised that unless this pollen substitute was actually tailored to the specific nutritional needs of a honeybee colony, colonies can fail altogether.
“Nobody had done a really careful study of bee nutrition and the qualities of pollen,” says Wright, who has spent the past decade engineering a new bee food based on her knowledge of the intricacies of the honeybee diet.
As pollinators, honeybees are fundamental to food systems and are considered a domesticated species. In that vein, Wright says they need their own bespoke feed.
Until now, pollen substitutes have been “a little substandard”, consisting of a mix of flour, sugar and fat that “looks like gloopy cookie dough”, Wright says. Livestock feed companies haven’t invested heavily in producing the perfect bee food, perhaps because honeybees are small and only represent a fraction of the market share compared with cows, pigs and sheep.
Domesticated honeybees face similar issues to any farmed animals, such as disease, but this is compounded by threats such as pesticide use, the climate crisis and loss of habitat. More than one-fifth of colonies were lost over the winter of 2019-2020 due to a variety of factors, including pathogens, pesticides and poor nutrition.
In the field, honeybees collect nectar that is transformed into honey and pollen which they convert into bee bread (a mixture of plant pollen and honey) that can be stored in the hive for later use. But with decreasing natural forage available, beekeepers try to maintain their colonies using foods that rely less on the landscape. Beekeepers can use a pollen substitute, try to find some other natural forage for their bees or buy honeybee-collected pollen from abroad – but that can vector disease.
When you’re trying to domesticate an animal, Wright says, you want to provide it with an optimal food source: “In the springtime it might be easier for honeybees to collect lots of different types of pollen so they probably get a good enough mix of nutrients, but in the autumn the food is much more limited to particular flowers and there’s less of it so the colony has to adapt to the changing nutritional landscape.”
In her research lab, Wright rears thousands of worker bees from May through to September. Four large incubators each contain 100 Perspex boxes with standardised conditions. In every box, 40 worker bees of the same age are given different fat-protein combinations to feed on. That is weighed regularly to monitor which food choices they select. Wright assesses how long they survive to calculate the optimum combinations of nutrients and refine her recipe for the pollen substitute.
While worker bees favour carbohydrates to fuel their flight, nurse bees need more fat and protein to make the royal jelly and feed the larvae. The extent to which honeybees might go out of balance when their diet changes intrigues Wright, so she’s also studying mini honeybee colonies within an enclosed glass house to assess how different foods affect brood production.
Bee nutrition is complex and dynamic. Wright says that nutritional needs may depend on the time of year or geographical area. “We’re looking at how seasonal variations in bee food could change the biology of the whole colony, plus we’re studying bees from across Europe and the US to explore how local flora affects their nutrition,” she says.
Josette Lewis, chief scientific officer for the Almond Board of California, says supplements are “particularly important during the winter months when there is little pollen available in the landscape”, but that farmers are working to “improve bee nutrition by planting on-farm pollinator habitat”.
As well as a supplementary feed for bees, Wright’s team are developing a honey substitute. “Honey is a valuable crop, especially in the UK and Europe, but when beekeepers take honey from the bees in the summertime to sell, the bees need to be given an additional sugary food source.” She says that the bees put a lot of “the good stuff” into the nutrient-dense honey themselves, so when honey is harvested, beekeepers are removing a nutritional resource from the hive.
“If we can produce a food for the bees that is valuable but less expensive than honey, then it becomes economically sensible to do that,” says Wright.
Chris Hiatt, vice-president of the American Honey Producers Association, welcomes Wright’s innovative bee food, saying it is vital for keeping bees healthy and reducing losses to disease. “If we didn’t feed 5-10 pounds of pollen each winter, we would lose more than the 40% national average we do now.”
Once she gets investment, Wright’s new bee food will be marketed to beekeepers around the world. While farmers in some regions may have plentiful pollen, potential markets include Australia, as well as areas farming cranberries and blueberries in North America.
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