Starved for nutrition

Could a lack of Omega-3 be playing a role in the loss of bee colonies worldwide?

Bee [Illustrative] (photo credit: INGIMAGE)
Bee [Illustrative]
(photo credit: INGIMAGE)
USING AN impossibly small syringe and needle, Yael Arien, a doctoral student at the Hebrew University of Jerusalem’s Robert H. Smith Faculty of Agriculture, demonstrates how she fed bees in a series of recent experiments to test how Omega-3 affects cognitive function in honeybees. Her findings, it transpires, are perhaps crucial to understanding the mass die-offs of bee colonies around the world, which hit crisis proportions in 2006.
Hovering around a clear plastic entrance to the experimental hive, the tiny insects politely wait their turn to land on the tip of the needle and delicately sip a specially prepared sugar solution.
The learning experiments, conducted for Arien’s Master’s thesis, were carried out in collaboration with Entomology Prof.
Sharoni Shafir to learn more about the honey bee diet and how it can affect the whole process of honeymaking.
But for any experiment to work, the bees needed to collaborate, and if bees are not motivated they won’t cooperate.
“The key to learning is motivation, so if they are not motivated we can’t teach anything.
We have to keep them motivated and not stressed. They need to want to participate and eat the sugar, so we treat them gently,” says Shafir.
Working with honeybees means working with the whole colony ‒ about 20,000 workers and one queen ‒ in order to control their daily diet. Isolating each bee individually isn’t effective like it would be if you were doing a learning experiment with mice, he says.
For the experiments, the bees were put in big enclosures where they ate only food provided by the researchers. Then they were taken ‒ carefully, notes Arien ‒ one by one and harnessed by tiny straws so they could not fly and fed either a salty or sugar solution following a puff of one of two different odors.
“A bee needs to condition her brain between [the odor] and sugar and reward ‒ like the association my dog makes every time he sees me going to the fridge and he sits down, knowing that he may get a treat,” she explains.
The results of their research, published in the prestigious Proceedings of the National Academy of Sciences in 2016, focused on the importance of Omega-3 fatty acids rather than just the wider category of proteins in the bee diet.
Lack of Omega-3 in the human and mammalian diet has been connected to the brain’s cognitive function as well as to ADHD, depression, and learning and memory deficiencies, notes Arien.
Although at first thought bee nutrition may seem pretty basic: flowers with a little bit of nectar, which constitute the sugars for bees, and a little bit of pollen, which is the proteins for bees. But, like that for humans, Shafir says bee nutrition is complex and there has been a growing awareness over the last few years about the specific importance of proper pollen nutrition.
Indeed, in this first study of Omega-3 deficiency in invertebrates, the Israeli researchers discovered that bees fed solely an Omega-3 deficient diet were unable to distinguish which odor came before the sugar solution and which came before the salt solution, suggesting that lack of Omega-3 in their diet impairs cognition.
“The importance of proper nutrition is increasingly emerging as one of the main factors associated with declining honeybee populations because it is synergistic: if a healthy bee and a healthy colony is infected by a virus they can deal with it, and if there is a little bit of pesticides the colony can deal with it, but if on top of all that they are malnourished… all these stresses can kill [them],” said Shafir.
In nature, bees would not have difficulty balancing their diets but, because of increasing monoculture areas with large areas of one crop, bees are getting only one source of pollen for long periods, he says.
This fact is of great significance to the well-being of bees because the function and survival of bees and hives are highly dependent on the bees’ ability to learn and convey information.
“A BEE comes out [of the hive] and she is this small little creature and the world is huge and she can fly up to several kilometers… and this little insect has to navigate this huge area and orient herself to find flowers and find the hive,” says Shafir.
A bee also must memorize the landscape and build a cognitive map in her brain so she knows how to distinguish one place from another; she needs to evaluate the time she spends on each flower and what the risk is of being preyed upon. She needs to be able to convey all this information with a special “bee dance” to her fellow forager bees once she gets to the hive.
“Every day is different and she has to learn very quickly. Bees are very smart. Cognitively, they are very sophisticated,” says Shafir.
“The fact that malnutrition affects their cognitive performance is very critical for the many tasks bees have to do. This finding that Omega-3 deficiency so strongly affects cognitive performance is very surprising for us and very, very exciting.”
Not only was the importance of Omega-3 to the bee diet unknown, so too its importance in the invertebrate world.
“That raises a lot of questions because the brain of the bee is so different from ours and, yet, we are finding this [similar] effect,” he says.
It adds one more piece to the puzzle of why bee colonies are in distress, he says.
SOMETIME AROUND the 1980s, the last of the feral Western honeybees essentially vanished from the face of the earth, most likely killed off by a combination of pesticides, disease, invasive insects and a changing landscape of growing urbanization and expanding stretches of monoculture agricultural concerns that limit the types of food sources available to the bees.
Today, there are some three million commercial colonies in the US, about 120,000 in Israel and approximately 620,000 in Europe.
Non-commercialized honeybees in the wild can only be found in limited areas of Asia and Africa.
In 2006, reports about mass die-offs of commercial colonies began to emerge from US beekeepers. According to Shafir, they reported strange symptoms, which, in addition to bee deaths, included their disappearance ‒ simply abandoning the hive while the queen bee is still there ‒ and exhibition of other confused behavior.
Researchers believe the cause of this alarming occurrence in the bee population is multifaceted, including increased use of harmful neonicotinoids, pesticides, fungicides and herbicides; a change in agricultural topography; and diseases, specifically one passed through the varro mite ‒ small ticks native to Asia that attach themselves to the bee weakening its immune system and transferring viruses, causing a 20-30 percent mortality rate among bees.
The disappearance of the Western honeybees ‒ one of 10 honeybee species ‒ is a grave concern because more than 90 commercial crops rely on them for pollination, including avocados, watermelons, melons and fruit trees such as peach, plum, almond and apple, with a total market value in the US of approximately $10 billion.
There has been a complete disappearance in Israel of the native Syrian honeybee, which beekeepers largely have replaced with the Italian bee.
“There is a positive aspect and a negative aspect to this,” says Guy Bloch, a Hebrew University professor of Ecology, Evolution and Behavior who has studied the bees’ internal biological clock. “They are less aggressive and produce more honey, but in terms of biological ability, they are weaker and less adaptable to nature.”
Still, bee colonies in Israel have not been as affected by the factors bees in the US are struggling with, which, in addition to the chemical agents used in farming and the growing monoculture, includes the stressful yearly spring transport of two-thirds of the bee colonies to California to pollinate vast expanses of almond orchards, he said.
“In Israel, we are fortunate because of the Israeli topography, where we have a lot of uncultivated areas other than the large agricultural areas in the Negev. In the US, everything is huge. Think of the corn belt ‒ that is basically a desert for bees,” says Bloch.
Shafir notes that colony losses have been reported around the world for a long time, and as agriculture and urbanization become more intensified and the use of pesticides more widespread the situation becomes more acute.
“There is less food for bees,” says Shafir.
Concurring with Bloch, he said corn and sunflowers ‒ which are planted in large monoculture areas in parts of the US ‒ are notably low in Omega-3 though high in Omega-6. Eucalyptus trees, which, in Israel, are considered a good source of forging pollen for bees so they can make greater amounts of honey, are low in Omega-3.
In fact, in the experiments, bees that were fed exclusively eucalyptus pollen looked fine but were unable to learn, he says.
“The area of eucalyptus [plantation] worldwide is growing. Australia is full of eucalyptus, and in many areas of the world they are planting more eucalyptus as a wood source and honey source,” he notes.Although he says eucalyptus is excellent as a pollen source for honey-making, “bees in Israel are starved for nutrition because there are increasingly fewer flowers and fewer and fewer open fields.”
It cannot be said the eucalyptus are bad for bees, but, according to Arien, feeding exclusively from those trees as their only source of pollen, is. The key to proper bee nutrition ‒ as in human nutrition ‒ she says, is variety.
SIGNIFICANTLY FOR the American beekeeping community, also low on the list of Omega-3-rich crops are the high-commercial value crops of fruit trees, such as peach, plum and apple, as well as almond trees, which depend solely on bees for pollination.
In early spring, 2 million of the 3 million bee colonies in the US are packed up and transported to the huge almond orchards in southern California to pollinate them.
“It’s a huge industry… the area of almonds is growing. There are more and more almonds, oceans of almonds, in all of southern California,” says Shafir.
Although there have already been recommendations for almond farmers to plant wildflowers throughout their orchards, Arien and Shafir hope that with their new study farmers will consider planting specific wildflowers for their pollen value with a favorable ratio of Omega-3 to Omega-6, such as globe thistle, wild radish, blue lupin, glaucous star thistle, white mustard and passionfruit. They caution, however, that the list is only in terms of the value of that specific component of the pollen and does not refer to the nectar needs of bees, which is a completely different matter.
“The crisis of 2006 taught us a lot about the problems bees are facing and the difficulties they are having,” says Victoria Soroker of the Volcani Center Department of Entomology who collects and analyzes data on bee colonies.
“Colony losses in the US vary in different states. In some states, there are very high winter losses, in others, they have low losses.
We can’t say the losses in Israel are like the high losses, but we have losses similar to what Europe is experiencing in winter, although our major losses are during the summer.”
Bees commonly carry viruses, but they are asymptomatic, says Soroker, noting that modern agricultural conditions have created a situation in which bees have become more susceptible to these viruses.
She adds that, although chemical treatments exist for the varro mite virus, the treatment also affects the bees so it is not a foolproof solution.
Biodynamic beekeepers, which represent only about 1 percent of beekeepers worldwide, blame much of the bees’ woes on commercialization, claiming it has destroyed the natural makeup of the hive by inserting artificially raised queen bees.
Biodynamic beekeepers raise bees naturally, with little human intervention, maintaining that this makes for stronger bee colonies that are able to stave off pests, diseases and the effects of pesticides.
“The root of the problem is the manipulation of putting in a queen bee, which is not part of the hive,” says Hilmar Kuhnemann, who studied the biodynamic method in Europe and has been raising bees biodynamically and teaching the method in the Jerusalem area for 15 years.
Citing a 2016 joint Swiss-Dutch study, Kuhnemann said commercialized beekeeping tries to override the power of natural selection of the queen bee.
“In the end, you get a queen that looks like a queen bee but is not really a queen bee. An artificial queen bee can live one to two years ‒ if she is lucky, three. A natural queen bee can live up to seven years,” he says.
At Volcani, Soroker opposes the biodynamic assertions as too simple, saying commercial queen bees are produced in the strongest colonies to provide the strongest queen for colonies.
“We are in quite challenging times, facing a worldwide food crisis and if you want to have vegetables and fruits you need bees ‒ especially honeybees ‒ and you need to cultivate them.
“Should beekeeping be done more sustainably? Yes. Give bees more sustainable treatments? Yes. Leave them more honey? Yes. I am also for the use of less chemicals and antibiotics, but we have to help bees confront their pests and pathogens. We cannot leave them on their own because the ecosystem has changed,” says Soroker.
While the alarm has been raised over the troubles bees are facing, people should also be concerned about the difficulties faced by beekeepers, she says.
“We also have to look at the problems beekeepers are having now. Keeping bees in good condition is problematic,” she says. “Beekeepers need to invest a lot of time and money to keep their bees alive and it is becoming less profitable. We are now importing lots of honey and the price is going down.”
For Israel Honey Board director Avidor, bees are like the “canary in the coal mine.”
“Bees are telling us that something is not right here [that] ‘If it is difficult for me, you, too, will be affected.’”