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Bumble bee answers every beekeeper needs

Bumble bees are among the earliest bees of spring, so it won’t be long before beekeepers begin to hear the inevitable questions. Honey bee keepers, it seems, are expected to know all the answers, so here’s a short refresher to get you started.

Where do bumble bees go in winter?

Bumble bee colonies do not survive through the winter except in very warm climates. Normally, a colony begins to raise both queens and males in late summer. Once a virgin queen mates, she fattens up for the winter and seeks a sheltered place to hibernate until spring, much like a bear. She may burrow into the ground or, depending on the species, she may select a warm and secure above-ground cavity. The remainder of the colony dies, usually with the first hard freeze.

Do bumble bees live in hives?

Bumble bees do not live in man-made hives the way honey bees do. Most bumble bee species live in an underground cavity. Usually these holes were dug, and later abandoned, by a mammal such as a mouse. In early spring after the queens emerge from hibernation, you can often seem them scouring the ground, looking for the perfect nesting spot. Some species prefer above-ground accommodations, such as birdhouses, mailboxes, or slash piles. Occasionally, you can coax a queen to nest in a specially-designed bumble bee box, but it is difficult.

Do bumble bees swarm?

Although bumble bees live together in colonies headed by a queen, the colony does not divide and swarm the way a honey bee colony does. Instead, colony reproduction occurs in the fall when new queens are produced for the following year.

How long does a bumble bee live?

A queen bumble bee emerges in the fall, mates, hibernates, and raises a colony. The entire cycle lasts one year and then she dies. The other bees in the colony—the workers and the males—live much shorter lives. The workers can live perhaps two to three months, but the males die soon after mating.

What does a bumble bee eat?

Bumble bees are generalists when it comes to food, drinking nectar and collecting pollen from a wide variety of flowering plants. The nectar is consumed for energy, while the pollen is used as a protein source. Much like honey bees, the workers feed pollen mixed with glandular secretions to the young larvae.

Do bumble bees sting?

Female bumble bees, both queens and workers, can deliver a powerful sting. Unlike honey bees, the females can sting repeatedly. Their sharp, smooth stinger can easily slide back out of tough skin in preparation for delivering the next punch. Male bumble bees, just like all other male bees, cannot sting because they don’t have a stinger.

How do you collect their honey?

The queen bumble bee stores a small quantity of honey in wax pots that she builds inside the nest. She works hard to fill these pots with nectar so that when she starts to raise brood, she can stay in the nest until the first brood reaches maturity. Much like a broody hen, she careful tends her young family, keeping the developing bees warm with her body. The honey in the pots may be her entire food supply while she raises the first workers.

Unlike honey bees, bumble bees do not collect surplus nectar and have no need for a winter food supply. The small amount of nectar used by the queen is not enough to collect and, in any case, taking it might destroy the new colony.

Are bumble bees endangered?

All bee species are endangered to some extent, although some are more imperiled than others. Bumble bees have been particularly hard hit by habitat loss, pesticides, imported diseases, and a lack of forage. It is best not to kill any bumble bee, especially if you don’t know the species. A number of once-common bumble bees are now on the brink of extinction, so give them the benefit of the doubt and let them carry on.

Do bumble bees get colony collapse disorder?

Colony collapse disorder (CCD) is a term used to describe a honey bee problem. Because honey bees and bumble bees are so different, the term CCD does not apply to bumble bees. Most notably, bumble bee colonies do not overwinter so annual colony losses, as measured by beekeepers, do not occur.

However, some of the conditions thought to cause colony collapse, also affect bumble bees. Introduced diseases and parasites, lack of good-quality forage, loss of habitat, habitat fragmentation, pollution, climate change, and pesticides have all been suspects in colony decline and each of these affect bumble bees as well as honey bees.

Do bumble bees get Varroa mites?

Bumble bees are not bothered by Varroa destructor because the life styles and life cycles of these two species are very different. However, bumble bees have their own array of mites to contend with. Luckily, most of these mite species are relatively harmless to bumble bees. Although they latch on to bees for transportation to a new nest, they feed on bits of pollen and other nest debris instead of on the bees themselves.

You can often see mites clinging to foraging bumble bees. Single mites, or sometimes whole groups, ride the bee. The mites then jump off onto a flower where they await the arrival of another bee to carry them to a new nest.

The flower becomes an airport, of sorts, where mites flip through their messages and impatiently wait for a connecting flight. Sometimes, though, a mite infestation can become so heavy that a bumble bee has trouble flying. This may be temporary until the mites jump off, but in the meantime, the flight-impaired bee may succumb to predators like birds or frogs, or it may weaken, unable to gather food.

I found a bumble bee that cannot fly. What should I do?

Usually, nothing can be done for a bumble bee in distress. Things we can’t see may be affecting her health, including diseases, internal parasites, or poisoning. If the bees’ wings are tattered or her hair is worn, she might be dying of old age.

Still, sometimes a bee is just momentarily stranded and a little TLC can get her going again. I’ve seen bees fly into windows like birds and remain stunned for many minutes before they fly off. Or, if a bee is grounded due to mites, you can gently brush them off. If it’s energy she needs, you can dissolve a spoonful of sugar into a couple spoonfuls of water and put some right in front of her.

How can I help bumble bees?

All bees need the same things: a continuous supply of flowers, water, nesting habitat, and nesting materials. So the best way to help bees is to make sure those things are available. Grow lots of different flowering plants, especially those native to your area. Make sure you have a source of water, even if it’s just a drippy hose or leaky faucet. Leave patches of landscape unmowed so bees can find safe places to live and grassy materials to use in their nest. Above all, stop the use of insecticides and herbicides: fewer chemicals in the environment make the planet better for everyone.

Now you are ready

Okay, beekeepers, now you are ready to go forth and answer questions about bumble bees. And for an excellent book about the these amazing creatures, I highly recommend A Sting in the Tale by Dave Goulson. The author is a world authority on bumble bees and an excellent writer. He makes everything about these bees fun to learn.

Honey Bee Suite

The two tan-colored objects on this bumble bee’s thorax are mites. Most bumble bee mites are harmless to the bee and actually eat nest debris. © Rusty Burlew.



How the honey bee uses invertase

Honey bees produce a number of different enzymes that are important to their survival. One of these is invertase, the very same enzyme that is used in the baking industry. So what is invertase and what does it do?

First, let’s define a few words. In biochemistry, an enzyme is a substance that helps a biological process along. It’s a helper of sorts. Usually, an enzyme speeds up a reaction, so we call it a catalyst.

When you see the letters “ase” at the end of the word, it often means the thing is an enzyme. Sometimes enzymes are named after the substance they help to break apart. For example, lactase and lipase break down lactose and lipids. But sometimes enzymes are named after the things they do. Invertase, for instance, is named for the process of inverting (or separating) sucrose back into its component parts.

No invertase = no chocolate cherries

Invertase is very common in the natural world, especially in plants and various microorganisms. Plants like Japanese pear fruit, the common garden pea, and cereal oats are good sources of invertase. But the most common source by far is Saccharomyces cerevisiae, also known as ale yeast, bread yeast, or wine yeast.

So why do we want it? Well, invertase it an important ingredient in the production of candies and frostings. When added to regular sugar syrup, it breaks down (or inverts) the disaccharide sucrose into two monosaccharides, glucose and fructose. The resulting mixture, called invert sugar or invert syrup, helps keep baked good soft and moist.

Invertase is also the magic ingredient in chocolate-covered liquid cherries. Cherries are covered in a fondant that has been treated with a small bit of invertase and then coated with chocolate. Slowly, in a process that spans several days, the invertase breaks down the sucrose into the transparent, sweet, syrupy confection that surrounds the cherry and fills the hard chocolate shell. Awesome!

Honey bees produce their own invertase

The other big producer of invertase is the honey bee. And for good reason. To store honey in its runny liquid form, the bees use invertase to break down the sucrose portion of nectar. Sucrose is a common ingredient of nectar, but after the bees add invertase, the nectar is inverted into its two main components.

In addition, the inverted product becomes acidic because the fructose donates a proton during the reaction, causing it to behave like an acid. That is part of the reason honey is so acidic. Acidity is also enhanced by other bee-produced enzymes including glucose oxidase, which forms gluconic acid (among other things).

You don’t need to invert sugar for bees

I mention the acidity piece of this process because many times you will hear beekeepers say that table sugar isn’t good for bees because the pH of sugar is neutral whereas honey is acidic. Others say you have to invert the sugar with vinegar or lemon juice before it can be palatable to bees.

In truth, as soon as honey bees begin to eat sugar, the invertase they secrete both inverts and acidifies the food. They don’t even have to think about it. Just in the last ten years, I’ve seen a large shift in practice. Many beekeepers have gone from feeding concoctions of cooked sugar with added acids to feeding plain refined sugar straight out of the bag.

Don’t increase HMF if you don’t have to

One of the arguments for feeding plain sugar is that both heat and acid increase the production of hydroxymethylfurfural (HMF), a substance that is poisonous to bees. With that in mind, if we must feed a supplement due to a poor honey year, we’re better off feeding plain sugar (dry or in syrup) than feeding sugar we’ve tried to “improve.”

Sucrose has a bad name, I think, because we tend to focus on the relative amounts of glucose and fructose in our honey. Meanwhile, we forget that, until the bees began processing it, the nectar they collected may have been up to 55% sucrose. Sucrose is not a bad word in the honey bee world; it’s just one we’re not used to hearing.

Honey Bee Suite

Chocolate-covered-cherries-are made with invertase.
Chocolate cherries are made with invertase which converts the sucrose into glucose and fructose, making a soft, runny, delicious mess. Pixabay public domain photo.

It’s not about mites any more

“If one more speaker starts yapping about Varroa mites, I’m gettin’ up and walkin’ out!” The grumbler sitting next to me in the audience didn’t know me and didn’t know I was the next speaker. And yap I did. My topic? Deformed wing virus.

Honestly, I can’t blame the guy for feeling that way. I too am tired of mites. But in spite of endless boring discussions, I think we are still missing the point when it comes to managing Varroa. Mites are nothing more than bad guys with hypodermic needles. The true demon, deformed wing virus (DWV), rarely gets a mention.

I should clarify by saying DWV rarely gets a mention outside of academic circles. Among scientists and researchers, DWV is demanding more attention and taking its rightful position as villain-in-chief. What I’ve learned has caused me to re-think the way I handle mites. By looking at Varroa-mediated collapse not as a mite problem but as a virus problem, I’ve been able to better manage my bees.

The dream team

Many researchers agree that the ultimate destroyer of honey bee colonies is DWV, not Varroa mites. Apparently, when the virus is not present, honey bee colonies can withstand fairly heavy mite loads over long periods of time. Of course, having mites is not an ideal situation because mites feed on bees, weakening them in the process. Still, quick and total loss of a colony is not the usual result from Varroa mites alone.

Likewise, a colony of honey bees without Varroa mites can harbor DWV without succumbing to the disease. It appears that healthy honey bees have a natural resistance to the virus when it spreads via normal channels. What is normal? Normal channels include vertical transmission from queen to egg, and horizontal transmission via trophallaxis from worker to worker or from worker to larva1.

However, when both Varroa mites and DWV are present at the same time, the virus is transmitted through the bite of the mite into the tissue of the bee. Compare this to other diseases. You can catch the flu by breathing air or eating food that is tainted with the germs, or you may be able to fight it off. However, if you are actually injected with the pathogen, you have a much greater chance of becoming sick.

Casual contact or injected dose

In a similar way, honey bees can get DWV from casual contact within the hive, or they can be injected with it, courtesy of the Varroa mite. You will sometimes see the term “vectored infection” when the writer is referring to pathogens transmitted by the mites. In biology, a vector is an organism that spreads a disease without contracting the disease itself. Just as an anopheles mosquito is a vector for malaria and a deer tick is a vector for lyme disease, a Varroa mite is a vector for deformed wing virus.

Another term you sometimes see is “covert infection.” Basically, covert means hidden. So, depending on the author, it may refer to an infection that travels from bee to bee without a vector (the infectious pathway is hidden) or it may refer to a type of infection that does not produce obvious symptoms (signs of the disease are hidden).

Timing can make a difference

As I understand it, when the virus is transmitted naturally within the hive—from bee to bee—it is less likely to produce deformed wings and shortened abdomens than when transmitted by a mite.

At least part of the reason may be timing. If a bee contracts the disease as an adult, she will not get deformed wings and a shortened abdomen because those parts are already fully formed. Other aspects of the disease will still result, including a weakened immune system and a shortened lifespan.

In practical terms, bees can be infected with DWV without showing obvious signs of the disease, even if the disease was transmitted by mites. I’ve heard beekeepers say they saw no sign of deformed wings in their colony, therefore it wasn’t DWV that killed them. We need to remember that when and how the bee contracted the disease affects the visible symptoms, so a bee may die of the disease without having obvious physical deformities.

Is the DWV getting worse?

Many beekeepers are finding that to keep their colonies alive, mites have to be treated more often than they used to be. Some who used to treat once a year are now treating two and three times a year. This increase appears to be related not to stronger mites, but to increased virulence of the DWV. In other words, the virus seems to have increased in potency such that a colony cannot withstand as many mites as it used to. Since a colony can succumb to DWV with a just a small number of mites, it becomes necessary to keep the number of mites per hive at a very low level, much lower than in the past.

Why this is happening is unclear, but it may simply be a matter of numbers. As the virus spreads, more individuals exist and a new opportunity for mutation occurs with each replication. So, basically, with more individuals you have more chance for change. Some of these mutations could have increased the virulence of the disease to its host, the honey bee.

Another cause could be migratory colonies. If you have a chance mutation in, let’s say Florida, and another in California, instead of those being local problems, they are soon continental problems as we—human beings—assist the DWV in spreading the mutations to more and more bees.

Varroa and DWV working together

Of course, there are most likely other explanations as well, but the fact remains that the disease appears to be getting more deadly. Right now, the only way we have of slowing the disease is controlling the mites that carry it, so we are in something of a bind since controlling the mites hasn’t gotten any easier. Worse, some research has shown that the Varroa mites actually do better in the presence of high viral loads, because the disease keeps the bees weaker and less likely to defend against the mites2.

Management choices

In my own apiary, I stopped thinking about managing mites and began to think about managing virus. This has helped me, especially with the timing of control measures. It also reminds me that killing the mites doesn’t kill the virus.

The most obvious case is the classic fall management conundrum. Most of us don’t want to treat colonies in August. Depending on where we live, it may be too hot, honey supers may be in place, winter is far off, the colony is huge and healthy, you’re hoping to pick up the fall flow, or you’re going on vacation. All of these reasons, and more, interfere with treating mites at the right time.

Instead of thinking about mites, think of DWV. Remember that here in North America, your long-lived winter bees will begin emerging in September and October. If they have deformed wing virus, they will not be able to care for the winter colony and, even if some survive the winter, they will pass the virus on to the early spring brood. So reducing the amount of deformed-wing pathogen must be completed by the end of August. Killing mites late in the year after the bees have already contracted deformed-wing virus, doesn’t help. By that time, the bees will succumb to the virus whether mites are present or not.

High winter losses

The scuttlebutt I’m hearing from beekeepers across the country is that pockets of high colony loss, up to 80 or 90%, are occurring in some areas. These losses are affecting commercial beekeepers, hobbyists, conventional, and natural beekeepers across the board. In other areas, sometimes relatively close by, losses are apparently at normal levels. What is going on? My own guess is that the heavily hit areas are hosting more virulent strains of DWV. I have no proof of this, but it will be interesting to see what happens next. Will these hard-hit areas recede and disappear, or will they expand?

As with many aspects of beekeeping, it is difficult to discern cause and effect. So when other factors come into play—exogenous variables like bad weather and poor forage—it is easy to assign colony loss to them. But throughout history, honey bees have shown amazing resilience when it comes to harsh environmental conditions like cold, snow, rain, heat, drought, wind, lack of forage, predation, and even viruses. But injected viruses? I just don’t know.

But even the classic signs of collapse by Varroa make more sense when you think of them as signs of collapse by virus. When a large colony collapses quickly in the fall or winter with plenty of food, a small and spotty nest, and practically no dead bees, it sounds more like disease than parasite.

Let me emphasize that much of this post is pure speculation on my part based on journal articles I’ve read and loss reports I’ve studied. You may come to different conclusions. Still, I think looking at the entire mite problem as actually a virus problem may help some beekeepers modify their management strategy. It’s time we evaluate the disease, not just the vector. After all, it was never about the mites.

1 Deformed wing virus and honey bee queens

2 Varroa, Honey Bees and Deformed Wing Virus – A Parasite-Pathogen Partnership

Honey Bee Suite

Honey bee with deformed wing virus by Xolani90 - Own work, CC BY-SA 3.0,
Honey bee suffering from deformed wing virus. Photo by Xolani90 – Own work, CC BY-SA 3.0,







Is cannabis honey really a thing?

Chicken soup is made by dragging a dead chicken through a pot of boiling water. At least, that’s what my father concluded after eating a particularly watered-down version. From what I understand, cannabis honey results from a similar process. After flying over a cannabis plant, honey bees make cannabis honey, right? Close encounters of the THC kind.

Cannabis honey seems to be a hot topic these days. But seriously, does such a thing even exist? In fact, cannabis is a wind-pollinated plant. Most wind-pollinated species do not produce nectar simply because they don’t need to. Nectar production is an energy-expensive adaptation that lures pollinators, but if you don’t need pollinators, nectar production is pointless.

The power of a trade name

However, honey bees can collect pollen from cannabis, and some of that pollen can easily find its way into a batch of honey. I suppose someone could conclude that honey containing cannabis pollen is cannabis honey. Following that philosophy, honey containing corn pollen could be called corn honey.

Many people call their marijuana products cannahoney, but CannaHoney is a US registered trademark. Much to the company’s credit, they describe their product like this, “CannaHoney is all-natural, unprocessed wildflower honey made by honey bees who have collected nectar from various “wild” flowers.” How can you argue with that?

The resin collectors

Claims by others are a little more difficult to swallow. The most famous proponent lives in France and claims to have trained his bees to “collect the psychoactive resin from pot plants” and he shows a video of honey bees madly collecting something from a cannabis flower. (Sorry, the article “Marijuana Laced-Honey: The Bees Don’t Catch a Buzz, but Can You?” is not linked here.)

My questions are twofold. First, why does he think the bees are collecting resin and not pollen? And second, even if they are collecting resin, why does he think they will put it in honey? Bees use resin to make propolis, not honey. In any case, the FDA defines honey as being made from the nectar of flowers, not the resin.

What does “all natural” really mean?

Every now and again someone writes to me wanting to know the proper pheromone to use for attracting honey bees to pot plants. Now, if this is how they get all those frantic workers to poke at a pot flower, no wonder the videos are so compelling. Worse, the proponents of cannabis honey call it an “all natural” product. I fail to see which part of training bees or luring them with pheromone is all natural.

In truth, I have nothing against marijuana. In fact, I don’t believe the government has any business regulating the ownership of plants. On the other hand, I don’t believe in forcing unnatural processes. If honey bees are not interested in your stupid pot plants, then leave them alone. Enough already.

Honey Bee Suite

Does cannabis honey come from cannabis flowers?
A cannabis flower produces no nectar. Pixabay public domain photo.

Bad news on the bee front

Feeling discouraged about the bee thing? You are not alone. Haunted by losses, Bill Castro, a thirty-year beekeeper from Maryland, shared the details of his disastrous 2016 bee season. The numbers are scary.

My apiary is experiencing the highest losses I have seen in my 30 years with bees. Drought, high pesticide load from yards, unprecedented amounts of mosquito spraying, and a severe lack of nectar and pollen have contributed to this in a spectacular way. 2016 proved to be disastrous for an ever-increasing number of beekeepers including myself. Our honey crop was cut in half from 2014 and 2015, even though I had more productive colonies. Sadly, I don’t know what my next moves may be with honey bees, but I will forever be haunted by the results 2016 brought me and my apiary.

Abysmal losses

A frustrating year for Maryland beekeepers
Last year was an extremely challenging for our managed honey bee colonies here in Maryland. According to the Bee Informed Partnership (BIP), 2016 is the year that losses exceeded 56%, and over a 3 year average, Maryland beekeepers have lost 54% of their total colonies. Maryland has approximately 14,000+ registered honey bee colonies according to Maryland State Agricultural statistics. The average replacement costs per colony is $150, replacement colonies range from $100/package to $200/nuc. This means that beekeepers in Maryland spend over $1.13 million every year to replace approximately 7,600 lost registered honey bee colonies.

This does not include lost revenue, lost labor, or losses in potential business growth that would otherwise be possible by splitting healthy colonies. There are multiple complex reasons for these losses including, but not limited to, the following:

Forage is the basis of a healthy colony’s immune system. Yet, most areas of the state saw very low levels of natural forage and rainfall this year, adversely affecting the colonies’ immunity. Thus, colonies with compromised immune systems succumb to the ravages of mites, viruses, and bacterial infections. To add to this, many beekeepers have seen an increase in pesticide use in the form of lawn and yard spraying, compounded by municipal and private responses to Zika virus in the form of broad spectrum mosquito spraying. Moreover, summer queen failures have become a chronic problem in Maryland, even including queen failures that occur within the first summer after a colony is established, which, historically, would be considered a rarity. Furthermore, the translocation of honey bee colonies is highly problematic as colonies are unable to easily or fully integrate into the environment into which they have been transported.

If managed honey bee losses are this high, how do we think that wild native bee populations are faring? Managed populations are the only populations to which beekeepers have regular access. If managed honey bees are facing the difficulties mentioned above, then it is reasonable to assume that wild native bee populations are suffering in the same ways.

Dr. David Goulson, Elizabeth Nicholls, Cristina Botías, and Ellen L. Rotheray published their research findings in their article, Bee Declines Driven by Combined Stress from Parasites, Pesticides, and Lack of Flowers, suggesting several possible ways to mitigate managed honey bee colony losses:

Bees are subject to numerous pressures in the modern world. The abundance and diversity of flowers has declined; bees are chronically exposed to cocktails of agrochemicals, and they are simultaneously exposed to novel parasites accidentally spread by humans. Climate change is likely to exacerbate these problems in the future. Stressors do not act in isolation; for example, pesticide exposure can impair both detoxification mechanisms and immune responses, rendering bees more susceptible to parasites. It seems certain that chronic exposure to multiple interacting stressors is driving honey bee colony losses and declines of wild pollinators, but such interactions are not addressed by current regulatory procedures, and studying these interactions experimentally poses a major challenge. In the meantime, taking steps to reduce stress on bees would seem prudent; incorporating flower-rich habitat into farmland, reducing pesticide use through adopting more sustainable farming methods, and enforcing effective quarantine measures on bee movements are all practical measures that should be adopted. Effective monitoring of wild pollinator populations is urgently needed to inform management strategies into the future.

Beekeepers here in Maryland have very tough decisions to make. Our current track record for managed honey bee losses is abysmal, in fact the entire Mid-Atlantic region is suffering from catastrophic honey bee losses in managed colonies. Do we make much needed corrections to our management of our colonies or pursue the “same ol’ same ol’” and continue to pay for replacement colonies, which in many cases only exacerbates the situation?

We can make things better for pollinators and give them the best possible chance for survival, but in order to do that, we must all act together to see those changes come to fruition.

Bill Castro

Update on the rusty-patched bumble bee

In related news, due to policy changes in Washington DC, the inclusion of the rusty-patched bumble bee on the EPA Endangered Species list was thwarted one day prior to taking effect. Regardless of the setback, we should not be discouraged. I’m of the belief that environmental protection is up to every individual. After all, the Earth is our home. Indeed, we shouldn’t let issues as important as species conservation be relegated to a government bureaucracy. Instead, each of us can help by caring for the patch we control, no matter how small it is.

Bumble bees, honey bees, and the tiniest sweat bees all need the same things: abundant flowers, clean water, and a safe place to call home. You have no excuse. Plant flowers and get rid of the pesticide. And don’t forget to raise local bees whenever possible: nothing spreads disease faster than shipping bees from place to place. That pertains not only to honey bees, but to all managed species including bumble bees, mason bees, and leafcutting bees. It is not up to the EPA or the Department of Agriculture to save the bees. It is up to us.

Honey Bee Suite

Haunted by losses. Honey bees at hive entrance.
All bees need flowers, water, and a pesticide-free environment. Pixabay public domain photo.