I had thought that by this time I would be summarizing my building experience and what I learned along the way. But the floor is still waiting to be poured, meaning nothing has happened on the interior of my new honey house. That story will have to wait.

I was delivering some honey to a local hardware store a couple weeks ago and they had a sign up that went something like this: “If everyone in the area spent just one dollar at a local store instead of a large box store, it would pump three million dollars into the local economy.” That sign should resonate with all of us who sell local honey. Think about it, most of us who sell to retail stores are selling to small, local stores who support local businesses, or to restaurants who pride themselves on buying from local producers. They all have access to cheap honey, but they see the value in supporting local endeavors.

My experiences over the last year, as I transitioned to a full-time beekeeper and growing my business, has given me a great deal of respect for the local businessperson. I got a flavor of the risks these businesspeople take to start and run a business. When I worked as a scientist for a large corporation, I got a paycheck whether I succeeded or failed and whether the economy was good or bad. When business drops for a local shop, the owners don’t get a paycheck, and/or they can’t pay their employees, suppliers or rent. Gosh, the pressure must be incredible. It costs a lot of money to start and maintain a business. As a hobbyist, the costs were right there in front of me: bee equipment, food, medicine, jars, labels. As I expand, I’m learning that a lot of other costs come into play.

Here are some of my take-aways regarding the financial aspect of going into the bee business. This is not a guide, or how-to. Only my experience thus far and what I am learning from it.

Initial investments
The initial investments were the most obvious costs when I decided to grow my business. I knew I needed a building for storage and a truck for efficiency. These allow me to be a larger scale beekeeper. I’ve written about this in previous Bee Culture editions. I purchased two acres of land and am in the process of putting up a 40×48 honey-house/storage facility. I got a used F450 ambulance from my son-in-law and just recently picked it up after having a flat-bed and lift gate put on it (see picture 1). I am like a kid in a candy store with my new “toys.” Those costs were significant and I have to sell a lot of honey to pay for them. I reason they are long term investments and, when I retire, I will get my money back. I was able to plan for this and there are various loan programs to which you can apply for help.

Picture 1. My new bee truck. The heavy-duty truck will allow me to do large scale beekeeping more efficiently. The lift gate on the back will minimize heavy lifting.

There were also the investments associated with expanding the size of my operation. These shouldn’t come as a surprise for a beekeeper. If you go from 100 colonies to 200 colonies, you will need the woodenware for those extra 100 colonies. You can easily plan for that too. You need to make the decision for consistent equipment (i.e. pallets or bottom boards, single or double brood boxes, deeps and/or mediums, etc) and buy or build what you need. Don’t forget about the supers, the queen excluders, the feeders, etc. Also, don’t forget the extra costs associated with hive maintenance. These include medications, food, and even the gas, since you will be driving to a lot more out yards than you are used to.

The easy to forget investments
The saying goes, “the devil’s in the details.” That’s true for the cost of starting my business, too. In my last article I described my plans for the inside of the building. I want it to have a certifiable commercial kitchen. I have my plan, then I saw the cost of the supplies. More than I expected. For example, electrical wire is around $0.50 a foot and I need around 1000 feet. 2x4s needed for framing the wall are between six and seven dollars each and I am going to need 150 of them. Then, there is the drywall, etc. Plus, the cost of three sinks, a stove, a refrigerator, a washer/dryer, toilet, shower, dishwasher, heater and air conditioner.

The above expenses are not unexpected, just more than I thought. Another area of expenses is the equipment to handle materials. Honey supers are heavy, so is sugar or sugar syrup. Then there are pallets of materials as you start buying in bulk. How do you handle all this in a way that will prevent back injuries? I broke down material handling into two categories: in the field and in the honey house. Most commercial guys have forklifts, which can do double duty. However, I can’t tow a forklift into the field because my yards are too tight for a bee truck hauling a trailer. I decided instead to have a lift gate installed on my truck. That allows me to move supers and bees using a cart in the field. I can place them on a half pallet onto my truck, then use a short-forked pallet jack to maneuver on my truck. I already have the cart. I still need to build the pallets and I need and purchase the pallet jack. I also need to purchase several rachet straps to make sure everything is tied down. Then I need something to cover the load to keep bees out of supers. Except for the lift gate, everything is under $500. But, many items at $500 adds up.

Picture 2. My home-made gantry crane and a 2400-pound pallet of sugar. This will be used to get heavy pallets off my truck and onto the floor where I can move them with a pallet jack.

There is a lot to consider for handling material inside the building. The first is how to unload my truck. For loads under 2000 pounds, I can use my lift gate. To move heavy pallets off my truck, like the 2400 pound pallet of sugar I am picking up today, I figured I need a gantry crane. The ones for sale have an inside clearance of 7.5 feet. The truck bed is eight feet, so I built one using lumber, an ATV winch, and some heavy-duty pulleys (see picture 2). It allows me to lift pallets off the bed of the truck, move the truck, put the pallet on the ground and move it with a pallet jack. Maybe not the most efficient method, but I won’t have to do this often.

The main material I will be handling is honey. Extracting aside, I need to store it, liquify it, and bottle it. The obvious question when expanding is whether the current equipment can handle the expansion. I currently extract into five gallon buckets, and I have a system where I can liquify three buckets at a time. But when I bottle, I can go through five or more buckets at a time. I need to think about storage tanks, heating units to liquify what’s in the storage tanks and mechanisms to fill the storage tanks. At 60 pounds a bucket, I want to lift those as little as possible. I am looking into getting either a U-cart or a hydraulic lift cart (see picture 3) to move the five gallon buckets from the storage area to the kitchen. Both are roughly the same cost. An automatic bottler would facilitate the bottling step, and that comes with its own expenses. The bottom line is that I must plan and execute an efficient handling system that minimizes the amount of material that I physically lift. I still need to figure out how to store the honey. Heavy-duty shelving minimizes the footprint of the honey but requires a lot more lifting without a forklift. I’m still working on that.

Picture 3. Two options for moving buckets of honey from storage to the bottling area. On the top is a U-cart. Simple, but minimizes lifting. On the bottom is a lift cart, that raises the load, so I don’t need to bend over to lift it. (The picture is of a smaller lift cart on top of a larger lift cart. They were connected in the store so I couldn’t separate them.)

Then, there is the business side of things. There is a TV commercial for an accounting software that really hits home. I know a lot about bees, but very little about business. I’ve always done my taxes by myself. But now, I’m an S-corporation. I not only need to track sales and expenses but to classify them. I need to deal with sales tax. I need to think about commerce laws and labeling laws. Someday I may need to do payroll. I now have an accountant to help me out. I do my record-keeping on a spreadsheet but was informed by my accountant that it may be time to get that online accounting software. Not huge expenses, but they all add up.

The continued expenses
There are a series of other costs that I really didn’t think about. These are the maintenance costs of the operation. The things you are billed for on a regular basis. Because I bought the land for the honey house, there is property tax. I had liability insurance for the company, but now I need to insure the building and the truck. I will have electricity and sewer costs associated with the building. I don’t have the final numbers, but these will likely cost several thousand dollars a year. Again, I need to sell a lot of honey to pay for these expenses. This has a large impact on my business model. Last year, I shared how I was trying to figure out how big I want to get. As I grow bigger, so do my expenses. Where before, I didn’t have property tax, and bee truck insurance and maintenance costs; now I do. I may have forced myself to grow bigger just to cover these additional expenses.

For everyone out there thinking about growing their beekeeping operation, think about this. It can be done. But for every action you take, there is a reaction. Think hard about how much your expansion will cost. Both the obvious and the non-obvious expenses. Then, determine if you have the passion for and the belief in your success to make those investments. That’s what’s needed to create a successful business. That’s why I have developed such a deep respect for our local businesspeople. That’s why you should buy local…

Click here to go directly to Part 6 – Getting Ready to Build

Click here to go directly to Part 8 – What Have I Learned?

Ingredients
□ 2 cups oats
□ ½ cup honey
□ ½ teaspoon vanilla
□ ½ teaspoon cinnamon
□ Flax seed
□ Chia seed
□ Almonds
□ Walnuts
These are just what I used. You can add goji berries, sunflower seeds, hemp seeds, etc. I also eyeballed the amounts. So, put however many your heart (or stomach) desires.

Directions
Step 1
Combine all your ingredients into a mixing bowl, and stir.

Step 2
Place mixture onto a baking sheet.

Step 3
Bake for 20-25 minutes at 350°F.

Step 4
Place in an airtight container and use on acaì bowls, in smoothies, yogurt, or just by itself.

While big injuries, exposures and accidents are always a risk, it is more often an accumulation of small insults and decay that bring down honey bee colonies. Baffled by not being able to find a singular cause for Colony Collapse Disorder, we coined ‘pathogen webs’ ten years ago to describe what was actually seen in collapsed colonies (Robert Cornman and colleagues, Pathogen Webs in Collapsing Honey Bee Colonies, 2012, PLoS One, https://doi.org/10.1371/journal.pone.0043562). Troubled bees contained multitudes of microbes, but those multitudes were different from Bakersfield to Okeechobee and from Harrisburg to central Texas. We might have missed the forest for the trees, as I mused for Bee Culture in C-C-Decade, (2018, https://www.beeculture.com/found-in-translation-13/) but perhaps the multitudes would have given us better insights if we had just waited long enough.

Dr. Renata Borba, from Agriculture & Agri-Food Canada’s Beaverlodge Research Farm (and now with the Alberta Beekeepers Commission), led her Canadian colleagues in a tremendous project to identify web players and ultimately connect them with poor colony health. Their open-access study, Phenomic analysis of the honey bee pathogen-web and its dynamics on colony productivity, health and social immunity behaviors, (2022, PLoS One, https://doi.org/10.1371/journal.pone.0263273), one-ups, or rather three-ups, prior work. 1) They sampled far more extensively both at each sample point (hundreds of bees) and across the country, 2) they looked at other key colony traits, from behaviors to honey yield, and 3) they checked up on their patients, gleaning data from one season to the next, important for assessing what really matters in sustainable beekeeping.

With over 1500 bee colonies, mostly started from packages, they had many opportunities to see how bee traits, management, and bad luck could lead to colony losses and honey production. You should read and discuss the paper to get more of their insights, but here are a few that stood out.

First, hygienic behavior really works: Colonies that scored high for a freeze-killed brood assay or for signs of grooming (in the form of mangled mites on the bottom board or in the sheer number of mites dropping over three days) showed lower mite growth rates, lower virus levels, and generally fared better. In fact, in the first year of the study, when 1000 colonies were vetted, 14/16 negative traits, from virus loads to mite numbers in multiple seasons, decreased significantly as hygiene scores (freeze-killed brood assay) increased, and the other two traits were non-significant but trending negative. The two other signals of grooming were not significantly tied to as many traits, although this might reflect the difficulty in quantifying these traits more than their importance as a form of social defenses against mites. In fact, in the second year the grooming ‘mite-damage’ score was a better correlate with decreased disease risk. This is comforting news and rare data for the colony level.

The study also quantified the importance of mite control on bee health. Mite numbers (as measured by alcohol washes) were positively tied to viral and nosema disease, and negatively tied to cluster size at both the time of measurement and the start of the next Spring. Several mite-transmitted viruses also showed predictive value for the state of colonies in current as well as subsequent seasons. Since there are not yet direct controls for viruses, the authors recommend effective mite controls coupled with selection for hygienic traits as the best way to decrease this threat. Interestingly, ‘total mite count’ in colonies was positively tied to sealed brood, in large part because of the ample mites found reproducing in sealed brood. This measurement was made by longterm exposure of colonies to amitraz while collecting fallen mites via sticky boards and is not normalized by the net amount of bees or brood. Results showing that mite control improve colony odds are not new, but the consistency of this work across Canada when compared to longterm studies in the U.S. and Europe suggests that Varroa and its viral partners remain the biggest drain on honey bees in most places. Another 2022 study, by Julie Hernandez and colleagues in Switzerland, showed 25-fold higher colony survival rates when beekeepers followed recommended mite treatments (Compliance with recommended Varroa destructor treatment regimens improves the survival of honey bee colonies over Winter, 2022, Research in Veterinary Science, https://doi.org/10.1016/j.rvsc.2021.12.025). The Borba study from Canada gives hope that some of the treatment burden, at least, can be reduced via good genetics.

Borba and colleagues refine additional yardsticks beekeepers might use to predict colony health and treatment regimes. While the results are confined to the eight populations studied, the authors argue that Spring colony weight is a poor predictor of current or future health, in large part because of greater honey stores in declining or lost colonies when compared to colonies that were ready to really take off. This is most evident in the first Spring cohort. Conversely, Fall colony weight does seem to predict disease load and, by correlation, colony health status in the Spring. Worker bee cluster size was a robust predictor of mite and disease status in both fall and spring, and this measurement is preferred.

The authors will report separately on the impacts of different management schemes (mite regulation and indoor versus outdoor storage) that varied across beeyards in this immense experiment. Integrating genes, behaviors (human and bee) and climate across a wide country is sure to give helpful insights for beekeepers everywhere, so keep an eye out for that study. In the meantime, mind the web and beat the mites.

We have all come to rely on science. It is responsible for most of the technologies we use daily and we rely on it to guide our decision making. As a writer for Bee Culture, I certainly rely on scientific articles to justify and provide credibility for the challenges I highlight that are facing our bees, ranging from pesticides and climate destabilization to electromagnetic radiation. I also use some scientific methods in my beekeeping. For example, I keep a journal to record data and observations, and I will try different honey bee management techniques by experimenting with them on a few hives before I commit to using them on my entire operation. However, while science is helpful, it isn’t the be-all and end-all that it is often made out to be.

What is Science?
Science (sometimes referred to as the scientific method) is the process of asking questions (creating a hypothesis) and then using experimentation and observation to test the veracity of the hypothesis. When science has established a fact, we tend to take it as the absolute truth. In reality, we can’t prove anything in science. What scientists do is gather observational evidence that support some theories and refute others. Over time, the accumulated evidence becomes overwhelmingly convincing, so we can say with a high level of confidence (but never 100%) that one theory is likely a good approximation of the “truth,” while the competing theories are very likely wrong. Thus, a single study on its own does not prove anything much without replication. This process has been the bedrock of the esteem in which science has been held, as an honest and impartial source of evidence-based knowledge that not only advances the frontiers of science but also informs the public and political leaders and aids in decision-making.
Ultimately, science is the best guess we are able to make about the reality of the world based upon what we know, and since what we know is always changing, the determination of what is scientifically “true” is always changing.

Limitations of Science
Because science seeks to be objective, there are large areas of human existence that are outside the bounds of scientific discovery. Science requires the collection of hard data (measurements of some kind) in order to extrapolate patterns and use scientific outcomes to help describe or predict real world experience. However, when it comes to something that cannot be weighed or measured objectively, science becomes useless and things like love do not exist according to science.
Science is also slow, takes a lot of work and is often costly. The time and money required to carry out research severely limits the speed with which new knowledge can be disseminated to the public. The high price of subscriptions to scientific publications and the many publications that exist behind paywalls, along with the often highly technical language scientists use, can further limit access to scientific information.

Problems with Science
One problem with delays in the dissemination of new scientific information is that it can provide a small group of people with inside information that they can act upon, long before it gets out to a wider audience. This creates an uneven playing field in the development of new technologies.
Science has also evolved to exhibit numerous problems and complications that have degraded its integrity. These problems can be categorized into two basic groups: honest mistakes and dishonest mistakes.
Honest mistakes occur when researchers create poorly designed studies or make errors in carrying out their research. Researchers may also allow bias to creep into the process which can unduly influence the questions that are asked, and how questions are investigated. Such errors made following the scientific method have the potential to be fixed and leave room for improvement. At its best, the use of the lengthy peer review process, where fellow researchers unrelated to the study review it, can ask questions and seek revisions in order to validate the legitimacy of the conclusions prior to them being made publicly available, catches many honest mistakes and errors. The peer review process however is not without its own potential pitfalls. Scientific work can so challenge the established dogma that even carefully conducted science can be rejected in what some have referred to as a “political review” process.
Meanwhile, since money is required to fund scientific work researchers often gravitate toward outcome driven science that has the potential for patents and marketable products or systems. This comes at the expense of curiosity driven science that lays down the basic research that can lead to future discoveries and inventions.
Unfortunately basic research, especially that conducted by PhD candidates, is not followed up upon often enough. If there was some process that would guarantee a progressive path that would shepherd basic research projects from one level to the next until it either totally fails and the data can be used to inform future projects, or it produces something of value, scientists would be less likely to shun basic research and such research would become useful faster.

Scientific Integrity
Sometimes scientists appear to get so wrapped up in their work, they succumb to a kind of tunnel vision that causes the researcher to lose sight of moral and ethical standards as they focus on getting their data and finishing their experiment. This can lead to some truly horrific things being done in the name of science such as experiments on Jews by the Nazis, and the United States Public Health Service Syphilis Study at Tuskegee (originally called the “Tuskegee study of untreated syphilis in the negro male”). Honey bee researchers may be falling into this trap with the current research into genetically engineered bees. Scientists are far from fully understanding the full impacts to an organism when they change or modify one or more genes and if changes that are harmful get released into the global population of bees, honey bee bioengineering could cause more harm than good.
In many ways, today’s scientific community has even greater challenges conducting quality science that won’t get twisted in a dark way as they navigate more and more ethical questions and conflicts.

The poster child for the ‘political review process’ is the Italian astronomer Galileo (widely considered the father of the scientific method) whose support for the theory that the earth revolves around the sun, and not the other way around, was so opposed by the Roman Catholic Church that he was forccd to recant and spent his final years under house arrest for this heretical stance. Painting by Cristiano Banti (1857) Galileo facing the Roman inquisition: Soucre Wikipedia

Corruption of Science
Science can obviously be helpful, but it can also be misleading or even harmful when manipulated for personal gain (profit, power, or prestige) rather than the sincere search for truth about the nature of reality. Due primarily to the corrupting influence of money, over the years there has been a growth in the amount of intentional mistakes, omissions, oversights, fraudulent work and censorship being made in the realm of science.
Some of the problem can be traced to administrators who have a profound influence on science. Since they hire and fire individual researchers in their departments or organizations they can have significant influence over which studies get carried out and which don’t. In honey bee research this issue is most likely to emerge within regulatory agencies like the U.S. Environmental Protection Agency (EPA) or university settings.
Unfortunately when a scientist’s research suggests a result that large donors are not happy with, administrators have been known to censor scientific work preventing it from being published and have even prohibited researchers from discussing their work publicly. Should a scientist blow the whistle on such actions, administrators are not above personal attacks or other forms of retribution designed to punish the whistle blower and discourage others in the organization from following a similar path (Lerner 2021a, 2021b). Unfortunately, the agency responsible for protecting bees and other pollinators from dangerous pesticides and other pollutants (U.S. EPA) has a long history of employees stepping forward as whistleblowers and then being retaliated against despite laws that are supposed to prevent such retaliation.

Pseudo-Science
Some companies market their products as “clinically proven” which sounds scientific but is often not the case. Even when a company actually conducts research it is typically not published in a peer-reviewed journal. Companies claim the additional time and expense of the peer review process is prohibitive, or that their research is proprietary information, when the real reason is because the “science” does not meet accepted scientific standards and/or is not reproducible.
Meanwhile, it has been estimated that there are hundreds of journals that lack ethical practices in carrying out the peer-review process and have extremely low standards. When such journals publish something, the information then becomes fodder for unknowing researchers and scientists who are duped into believing it’s true. Given the immense amount of pressure on academics to publish, some become desperate enough to— either unintentionally or sometimes intentionally—engage with such predatory journals.
The importance of getting one’s work published can impact scientific integrity due to the publication bias that is exerted within scientific circles. The more dramatic and surprising the study results, the more publishable the study is and researchers will sometimes sensationalize their findings, articles and publicity surrounding their research in order to help ensure publication and widespread dissemination.
As I have outlined above, many of the drivers of compromised science are systemic and embedded in the current scientific-process intended to gather and disseminate evidenced based knowledge. It is within this peer review process where we see the intersection of scientific advancement and reputational and financial rewards for scientists, publishers incentivized gaming to capture more eyeballs for the attention economy. Unfortunately there is another major factor that is at work in the realm of fraudulent science: big business. We will explore the corporate war on science and its potential impacts on honey bee science next month in part two of this series.

Author

Ross Conrad is the author of Natural Beekeeping: Organic approaches to modern apiculture, and co-author of The Land of Milk and Honey: A history of beekeeping in Vermont. He will be teaching an organic beekeeping for beginners two-day intensive class May 7-8th and an intermediate beekeeping class on May 21st in Vermont. For more information visit: www.dancingbeegardens.com/events.html

References:
Lerner, Sharon (2021a) Whistleblowers expose corruption in EPA chemical safety office, The Intercept.
Lerner, Sharon (2021b) EPA Officials exposed whistleblowers three minutes after receiving confidential complaint, The Intercept.

United States Honey Production Down 14 Percent in 2021
United States honey production in 2021 totaled 126 million pounds, down 14 percent from 2020. There were 2.7 million colonies producing honey in 2021, down slightly from 2020. Yield per colony averaged 46.9 pounds, down 14 percent from the 54.5 pounds in 2020. Colonies which produced honey in more than one State were counted in each State where the honey was produced. Therefore, at the United States level yield per colony may be understated, but total production would not be impacted. Colonies were not included if honey was not harvested. Producer honey stocks were 23.5 million pounds on December 15, 2021, down 41 percent from a year earlier. Stocks held by producers exclude those held under the commodity loan program.

Honey Prices Up 21 Percent in 2021
United States honey prices increased 21 percent during 2021 to $2.54 per pound, compared to $2.10 per pound in 2020. United States and State level prices reflect the portions of honey sold through cooperatives, private, and retail channels. Prices for each color class are derived by weighing the quantities sold for each marketing channel. Prices for the 2020 crop reflect honey sold in 2020 and 2021. Some 2020 crop honey was sold in 2021, which caused some revisions to the 2020 crop prices.

Price Paid per Queen was 20 Dollars in 2021
The average prices paid in 2021 for honey bee queens, packages, and nucs were $20, $91, and $125 respectively. Pollination income for 2021 was $269 million, up six percent from 2020. Other income from honey bees in 2021 was $102 million, up 82 percent from 2020.

Released August 2, 2021, by the National Agricultural Statistics Service (NASS), Agricultural Statistics Board, United States Department of Agriculture (USDA).

January 1, 2020 – Some History
Honey Bee colonies Up Two Percent for Operations with Five or More colonies
Honey bee colonies for operations with five or more colonies in the United States on January 1, 2021 totaled 2.92 million colonies, up two percent from January 1, 2020. The number of colonies in the United States on April 1, 2021 was 2.86 million colonies. During 2020, honey bee colonies on January 1, April 1, July 1, and October 1 were 2.88 million, 2.97 million, 3.18 million, and 3.14 million colonies, respectively.
Honey bee colonies lost for operations with five or more colonies from January through March 2021, was 372,630 colonies, or 13 percent. The number of colonies lost during the quarter of April through June 2021 was 255,860 colonies, or nine percent. During the quarter of October through December 2020, colonies lost totaled 484,920 colonies, or 15 percent, the highest number lost of any quarter surveyed in 2020. The quarter surveyed in 2020 with the lowest number of colonies lost was April through June, with 300,990 colonies lost, or 10 percent.

Honey bee colonies added for operations with five or more colonies from January through March 2021 was 308,530 colonies. The number of colonies added during the quarter of April through June 2021 was 677,690. During the quarter of April through June 2020, the number of colonies added were 536,170 colonies, the highest number of honey bee colonies added for any quarter surveyed in 2020.
The quarter of October through December 2020 added 271,500 colonies, the least number of honey bee colonies added for any quarter surveyed in 2020. Honey bee colonies renovated for operations with five or more colonies from January through March 2021 was 156,270 colonies, or five percent. During the quarter of April through June 2021, the number of colonies renovated were 480,380 colonies, or 17 percent. The quarter surveyed in 2020 with the highest number of colonies renovated was April through June with 626,870 colonies renovated, or 21 percent. The quarter surveyed in 2020 with the lowest number of colonies renovated was October through December 2020, with 128,990, or four percent. Renovated colonies are those that were requeened or received new honey bees through a nuc or package.

Varroa Mites Top Colony Stressor for Operations with Five or More colonies
Varroa mites were the number one stressor for operations with five or more colonies during all quarters surveyed in 2020. The period with the highest percentage of colonies reported to be affected by varroa mites was July through September 2020 at 55.7 percent. The percent of colonies reported to be affected by varroa mites during January through March 2021 and April through June 2021 are 31.3 percent and 48.7 percent, respectively.

Colonies Lost with Colony Collapse Disorder Symptoms Down 27 Percent for Operations with Five or More colonies
Honey bee colonies lost with Colony Collapse Disorder symptoms on operations with five or more colonies was 76,930 colonies from January through March 2021. This represents a 27 percent decrease from the same quarter in 2020.

Per Capita Consumption, 2021
We calculate this figure each year using data from USDA ERS, NASS, ERS, FARM SERVICE and the U.S. Census Bureau. From these sources we determine how much honey entered the system, how much honey left the system, how much was used, how much wasn’t used and the population on July 1, 2021. These figures include U.S. production, U.S. exports, honey put under and taken out of the loan program and honey remaining in storage, plus how much was imported from off shore. Essentially it’s a measure of honey in minus honey out. The resultant figure, divided by how many people were here on that particular date results in how much honey was consumed by each and every individual in the US last year. And yes, you are correct, not every person eats honey, but by producing this figure on an annual basis, we are able to compare apples to apples each year in honey consumption.
The chart below compares these figures for the previous 12 years. We’ve included the USDA’s price of all honey for comparison too.

Honey Into The U.S., 2020
U.S. beekeepers with more than five colonies in 2020 produced, according to USDA, 147.6 million pounds of honey. The Honey Board calculates that an additional eight million pounds or so were produced by those with fewer than five colonies for a total production of 155 million pounds. Additional honey in figures include 40.9 million pounds taken out of warehouses from last year, 4.8 million pounds taken out from last year’s loan program, and a whopping 134.5 million pounds imported for a rough total of 513 million pounds of honey in, during 2021. This honey sold, on average, wholesale, retail and speciality honey for $2.41/pound, according to USDA figures. Commercial beekeepers in the U.S. will tell you to make a living, this price should be about the same price as diesel fuel. Take a look next time you are at the gas station.

Honey Out Of The U.S., 2020
For the honey out figure, we exported nearly 10.7 million pounds to other countries, have nearly 40 million pounds still sitting in warehouses and put just under five million under loan, for a total of about 58 million pounds of honey produced in 2021 that were moved out of the U.S. figures for 2021.
The July 1, 2021 population was right at 332 million people in the U.S. So, to calculate per capita consumption, subtract honey out (put under loan, exported or still in warehouses) from honey in (honey produced this year, left over from last, or imported) and divide by 332 million, for a total of 477 million pounds consumed in the U.S. last year. Divide this by 332 million people which gives you about 1.4 pounds of honey consumed by each and every person in the U.S. during 2021, the lowest since 2012.

These figures represent the various categories of honey imported, how much of each and the value. The price of comb honey to sell directly retail is the closest to the U.S. price, while extra light amber, a very common honey, is very low. Basically, U.S. honey producers are at $2.54/lb, while imports are at $2.41. Elsewhere, you’ll see income issues for U.S. beekeepers, and here is one good reason.

Top 10 Producing States
The places that yield the most honey every year are pretty much determined by the climate, the soil, agriculture and politics. The crops grown, or not grown in a region certainly play a role in what can be found relative to nectar, pesticides and regulations relative to how many colonies can you put on any given acre that won’t starve after a couple of months. Of course, government conservation programs lend a hand here too.
We’ve been curious about this for the last eight years or so, just because it’s interesting to see what changes, and what doesn’t. The Dakotas, California, Montana, Florida, Minnesota, Michigan and Texas are almost always in the top eight, with the last two changing occasionally: New York, Louisiana, Georgia, Idaho, Michigan and perhaps a few others round out these performers.
This year provided few surprises in who is on the list, and the totals for the top 10 this year were essentially where they always are relative to the number of colonies counted in these states and the amount of honey produced. Again, these states produced 71% of all of the honey produced in the U.S., and had 72% of all the colonies in the U.S. sitting somewhere within their borders. It’s pretty clear that what happens in these few states is going to determine the U.S. crop.
But, just because we can, this year we looked at the contributions of the top three states, for almost every year, the Dakotas and California. Combined, they held on to 40% of the colonies used last year and produced just short of 40% of all the honey U.S. beekeepers made last year. This means, of course, that 60% of the colonies, and 60% of the U.S. honey crop is spread out over the remaining 47 states. You can see this comes to just under 1%/state. That sort of puts us in our place, doesn’t it? This extreme unbalanced situation commands notice, then, as to what will happen when climate change erodes, or doesn’t, weather patterns in these three states including rainfall, Summer and Winter temperatures, farming practices and conservation practices.
Already, drought in the western third of the U.S. is having an effect, not only on the bees, but their forage and the crops they pollinate as well. Like it or not, we are at the mercy of big weather – call it climate change or whatever – it’s dry out there!

Beekeeping is exactly like crypto-currency: it’s one of those topics that you have to think twice about bringing up in conversation, depending on how many questions you’re in the mood to answer. Sometimes you wish you’d printed out a fact sheet to answer all the trivia (What do you mean a divide? What’s blockchain? Is it true that queens fight each other? What is a cryptokitty dragon and why does my son want one? Should I get some?).

But within the beekeeping community, when the language is shared, the topic is always beekeeping, and it never gets old. We can oscillate between discussing the mundane (how do you get the bees out of your supers before pulling them?) and the sublime (was Zeus’ mom a honey bee or what?) Then there are those science-y questions, which are the ones we truly love best. For example: haplodiploidy. Don your nerd glasses, dear reader!

Sex determination is important in honey bees, and not just for making jokes about how drones sit around eating all day while the females work. Honey bees are “haplodiploid,” a chromosome condition in common with all members of the insect Order Hymenoptera (think ants and wasps as well as bees). A simple way to explain honey bee haplodiploidy is that workers and queens are female, have two sets of chromosomes (diploid) and develop from a fertilized egg. Drones, or males, have only one set of chromosomes (haploid) and develop from an unfertilized egg. This chromosomal setup makes our already impressive honey beasts even more fascinating. Haplodiploidy is a part of the behind-the-scenes science of two common (and commonly confused) beekeeping management issues: drone layers and laying workers.

In the honey bee haplodiploid system, sex is usually determined by whether the egg is diploid (female destined) or haploid (male destined). Also important in sex determination is the alleles, or different forms of the same gene, and the locus (position) along the chromosome. Diploid females are heterozygous (have two different alleles) at the sex determining locus (see Figure 1). Normal haploid males have only one set of chromosomes, so can’t be heterozygous at the sex allele. However in some freak cases, a diploid egg can develop into a male called a diploid drone. This can happen if there is homozygosity (similar alleles) at the sex-determining locus on one set of chromosomes. Diploid drones are a sign of inbreeding, which is extremely rare in honey bees because the queen mates with multiple drones. Plus, you will not see diploid drones develop in the colony because workers cannibalize diploid drone larvae as soon as they hatch from the egg.

Figure 1: Examples of heterozygous gene
inheritance. Honey bee workers and queens
are diploid (two sets of chromosomes) and
heterozygous (have two different alleles) at
the sex determining locus.
Photo credit: https://commons.wikimedia.org/wiki/File:Heterozygous.jpg

Drone Layers
Drone production in a honey bee colony is seasonal. When floral resources are plentiful, drones are produced. When food gathering and temperatures decrease, drone production ceases. The colony controls the rearing of drones; choosing to feed drone larvae or not depending on the resources available. But sometimes, a queen runs out of sperm and that’s when the boys get out of control. Without viable sperm, the queen can only lay unfertilized eggs and therefore can produce only new males. It is relatively easy to spot a drone layer queen, as we can rely on the appearance of puffy, capped drone brood in worker cells within central brood nest areas where there should be worker brood. Queens can become drone layers for many reasons that include mating issues due to weather, running out of their stored sperm, extreme productivity, or relative old age. It is also possible for some of the sperm stored in the queen’s spermatheca to die due to temperature stress or pesticides and therefore not be able to fertilize eggs as effectively (Amiri et al. 2017). The drone layer queen issue is easy to fix if you can remove the dowager in question and introduce a new queen. With limited availability of mated queens, both early Spring and late Fall are difficult times to requeen colonies headed by drone layers.

Laying Workers
Although workers do not mate, they can lay eggs in particular situations, albeit only unfertilized, haploid (aka male) ones. In a functioning colony, worker ovaries are suppressed by queen and brood pheromone (Ronai et al. 2016, Winston, 1987). If the queen dies, is removed, or is pheromonally not vital, and there is little or no open brood (larvae), worker egg production is not suppressed, and some bees in a colony will progress to become laying workers, which is difficult to reverse (Winston, 1987).

Figure 2: Worker eggs are not fertilized, so they
are haploid (one set of chromosomes) and become drones. Workers also lack the elongated abdomen
that enables efficient and accurate egg laying in
cells. Instead of laying one egg per cell in a uniform pattern, workers will often deposit multiple eggs haphazardly into the cells.
Photo credit: Katie Lee, PhD

Figure 3: Here you can see multiple eggs in single cells, eggs laid on top of larvae, and two drones developing in a single cell: signs of a laying worker.
Photo credit: Katie Lee, PhD

Workers only have three to 26 ovarioles per ovary compared to the range of 100-180 in a queen ovary (Snodgrass 2018, Jackson et al. 2011). So one could be forgiven for assuming they therefore leave the egg laying to Mom. But why? Was it due to a cryptic fortune cookie prophecy like in Freaky Friday? Most likely not. This is actually the superorganism’s or worker’s last ditch effort to get their genetics out there.

Laying workers aren’t very good at egg laying (about as good as the first time you tried grafting) and the end result is far from the machine-like precision patterns of a queen (see Figures 2 and 3). When laying workers take over, you will see eggs on the side of the cells and often multiple eggs in each cell. We like an Australian study that quantified the impact those worker-produced drones might have in mating. Based on the smaller size of worker-produced drones, they measured their percentage in a drone congregation area at 0.23% (Utaipanon et al. 2019). While smaller than another study that estimated a 9% contribution of drones with worker moms (Berg 1991), the authors acknowledge that even at the less-than 1% contribution, it is a reproductive strategy that can move the colony’s genes into the next generation.

You can’t just requeen a colony that has laying workers. They will kill the new queen. Fixing a laying worker colony is more of a mad science experiment than a sound management decision. It requires you to move frames of open brood from a healthy colony to the laying worker colony over time until the brood pheromone odor begins suppressing the ovaries of the laying workers. You can introduce a queen cell along with the open brood and hope she emerges and mates. Meanwhile, you have been weakening the brood donor with the resource movement and wasting quite a bit of time. It is fun to do, but never officially recommended (like most fun things).

We hope you have a new or renewed appreciation of your bees’ chromosomes, egg production and your diploid bees. At the very least, if you find a drone layer or laying workers this Summer, remember that your bee problems are less complicated than your crypto-currency opportunities.

References
Amiri, E, Strand, M., Rueppell, O, & Tarpy, D (2017). Queen Quality and the Impact of Honey Bee Diseases on Queen Health: Potential for Interactions between Two Major Threats to Colony Health. Insects, 8(2), 48. MDPI AG. Retrieved from http://dx.doi.org/10.3390/insects80200
Berg S (1991) Investigation on the rates of large and small drones at a drone congregation area. Apidologie 22:437–438
Jackson, JT, Tarpy, DR, Fahrbach, SE (2011) Histological estimates of ovariole number in honey bee queens, Apis mellifera, reveal lack of correlation with other queen quality measures Journal of Insect Science, Volume 11, Issue 1, 82.
Ronai, I, Oldroyd, BP and Vergoz, V (2016), Queen pheromone regulates programmed cell death in the honey bee worker ovary. Insect Mol Biol, 25: 646-652.
Utaipanon, P, Holmes, MJ and Oldroyd, BP (2019) Queenless colonies contribute to the male breeding population at honey bee drone congregation areas. Insectes Sociaux volume 66, 593–599.
Winston, ML (1987). The Biology of the Honey Bee.

Acknowledgement
The authors would like to thank Dr. Marla Spivak for helpful edits and suggestions in our navigation of haplodiploidy.

If you want to learn to be a good beekeeper, it is extremely important to learn about Varroa mites. You don’t have Varroa mites because you’re a bad beekeeper; you have Varroa mites because you are a beekeeper! Whether you’re a multi-generational beekeeper or a beginner, commercial manager or hobbyist, use “conventional” or “natural/organic” methods, Varroa will find a way to wreak havoc on your bees. There are few things more disheartening than seeing a strong honey bee colony wither and die because of uncontrolled Varroa populations.

Often times, miticides are used as the primary tool to manage Varroa populations, mostly due to their ease of use and effectiveness. It is easy to get into the routine of using the same miticide every year because “It worked in the past so it should keep working this year” and “If a little bit works, then a little more should work better.” However, this kind of approach to miticide use creates conditions that can lead to miticide resistance. In fact, that is exactly what happened with Apistan® (tau-fluvalinate) and CheckmiteTM (coumaphos) and why they are not widely used any more(1,2).

The development of miticide resistance is the expected evolutionary outcome of a selection event (miticide application) that leads to differential reproduction (dead Varroa don’t reproduce) in which their offspring possess the means for survival (miticide-resistance genes). Miticide resistance in Varroa is not unique or unusual as resistance to a diverse array of pesticides is very common in many arthropods(3).

Amitraz resistance in Varroa was first reported in the United States more than 20 years ago(4). Despite widespread amitraz use since then, there have been few reports of resistance in the USA in the scientific literature(5) and amitraz-control failures were mostly rare and anecdotal. It is our hypothesis that it is due to a few factors. Amitraz and its toxic breakdown product, N-(2,4-dimethylphenyl)-N-methylformamidine (DMPF), does not accumulate to extremely high concentration and prevalence in the wax in the manner that tau-fluvalinate and coumaphos do(6,7). The high concentration of tau-fluvalinate and coumaphos in wax provide constant conditions for strong selection of resistance. Amitraz tends to reach high concentration in the colony when the strips are applied and declines rapidly after they are removed. Under this scenario, amitraz does not continuously select for resistance. However, constant amitraz application where strips are removed and immediately replaced throughout the year may provide adequate conditions to select for amitraz resistance. It is possible that widespread amitraz resistance has not developed because there may be a trade-off or a fitness cost to amitraz resistance, especially in the absence of amitraz exposure. Fitness costs can manifest in lower reproduction, reduced survivorship, altered behavior, or a variety of other detrimental conditions. Fitness costs have been observed in amitraz-resistant cattle ticks(8), so a similar condition in amitraz-resistant Varroa is plausible. These statements are still just hypotheses and current and future research will provide much needed answers to the how and why of amitraz resistance.

Our interest in amitraz resistance in Varroa began about five years ago after having many conversations with beekeepers who had the same recurring experience that amitraz did not provide adequate Varroa control as it used to. There were a number of explanations about why amitraz was becoming ineffective, but the only consistent explanation was that amitraz resistance was developing in Varroa. Amitraz resistance was first reported in the USA more than 20 years ago(4) so it is likely becoming more widespread after years of use.

Beginning in the Spring of 2019, two different approaches were used to detect amitraz resistance. The first approach was to test for amitraz toxicity using pure amitraz in the glass-vial bioassay(4). Small jars (20 mL) were treated with different concentrations of pure amitraz to determine the LC50 (the concentration that is lethal to 50 percent of the population or the concentration that has a 50/50 chance of killing an individual Varroa mite). This approach allowed for toxicological comparison between Varroa populations. The second approach was to perform the Apivar® efficacy test in which a sample of bees are exposed to a square of Apivar® in a plastic container and the number of Varroa on those bees that survive the treatment indicates if those Varroa are resistant or susceptible(9). By using these two complimentary methods, we determined that reduced Apivar® efficacy was due to reduced amitraz sensitivity as determined from the glass-vial bioassay, thus confirming that reduced Apivar® efficacy is due to amitraz resistance(10). This is an important observation because it demonstrates that resistance is due to the active ingredient of pure amitraz, so it is unlikely that product formulation is a factor. In that first year of limited sampling, we found that most beekeeping operations had low to moderate amitraz resistance and only one operation was experiencing a bona fide control amitraz failure at the colony level.

Amitraz resistance monitoring was a large part of our research efforts in 2020 and 2021. While restrictions on research travel during the COVID-19 pandemic may have dampened our research efforts, it was an opportunity for innovation which dramatically improved the scope of our monitoring efforts. Amitraz resistance monitoring kits were shipped free of charge to beekeepers, apiary inspectors, and scientists who were interested in performing the test. The results and Varroa samples were sent back in the mail. We were able to double the number of apiaries and colonies sampled each year so that after three years of monitoring, we have worked with 44 beekeepers in 62 apiaries for a total of 674 colonies sampled. Work will continue with this expanded amitraz-resistance monitoring network in 2022 and our goals are to cooperate with 50 beekeepers across 70 apiaries and sample 1,000 colonies. It’s an ambitious goal but entirely feasible with external cooperators performing resistance monitoring with kits we will provide in concert with on-site sampling. With this abundance of data, we can start to make well-supported trends and observations that we hope to publish in the Summer of 2022.

Despite a number of alternative explanations for why amitraz applications fail to control Varroa, amitraz resistance is the most consistent factor in Varroa control failures. In nearly every instance of where beekeepers reported that amitraz application failed to control Varroa, the Varroa from those apiaries showed low levels of Apivar® efficacy.

Another interesting observation is that amitraz resistance varies from colony to colony within an apiary. For example, out of a sample of 10 colonies within an apiary, five may have no amitraz resistance (i.e., 100% Apivar® efficacy), three may have low levels of resistance, and two may have high levels of resistance. This is mostly consistent with a common anecdote from beekeepers where they said, “The treatment worked in most colonies, but there were a few where it didn’t work at all.” These “islands of resistance” may be due to 1) founder effect where the Varroa population within the colony is derived from a small initial Varroa population which included a few amitraz-resistant individuals, or 2) mutations that confer amitraz resistance arise spontaneously and independently in Varroa populations in each colony.
We hope to provide answers to these questions through a collaboration with Arian Avalos, who is the geneticist at our lab. We are sequencing nearly 500 individual Varroa genomes to identify DNA markers and determine the population genetics of amitraz-resistant Varroa. We hope this research will be published later in 2022. Some beekeepers ascribe the colony-to-colony variation in amitraz resistance to application error. While application error tends to be very infrequent, it is possible. In our experience, the most common miticide misuse is using only one strip per colony and making efficacy observations before the treatment is completed. It is understandable that application costs may result in only one strip used per colony, but it’s a much better economic strategy to invest in a proper treatment program than replacing a colony that was lost due to high Varroa infestation. Amitraz does not act instantaneously upon exposure at the colony level, and it takes a few brood cycles to control emerging Varroa that were under capped brood when strips were first applied. It is important to wait until the end of the treatment period to make a final assessment about treatment efficacy. Your patience will be rewarded!

Preliminary results indicate that miticide rotations are another valuable strategy to impede or overcome miticide resistance. In 2020, we worked with a number of beekeepers who had amitraz-resistant Varroa. After discussing the results, many of them used oxalic acid vapor on their amitraz resistant Varroa and documented the treatments and efficacy. When we went back to those apiaries in 2021 in hopes of studying the amitraz-resistant Varroa populations, we were unable to identify any amitraz-resistant Varroa in nearly every instance. The theory behind this phenomenon is that the probability of developing resistance to any single miticide is very low (e.g., 0.001%). Therefore, the probability of developing resistance to two miticides is essentially zero (e.g., 0.001% x 0.001% = 0.000001%). In fact, large-scale multi-state beekeepers that utilize amitraz with an organic acid or thymol treatment experienced reduced colony losses(11). The effectiveness of miticide rotations is important to beekeepers who may have amitraz-resistant Varroa because a non-amitraz treatment may provide adequate control and allow the colony to survive rather than euthanizing the colony to prevent the spread of amitraz-resistant Varroa. However, much more work is needed in this area to make more confident recommendations.

Miticides should not be considered a silver bullet for all of your Varroa ailments. Rather, miticides should be used as part of a multifaceted Varroa management program. Using different approaches build redundancy in the system to ensure that if one strategy fails, another will be there to ensure efficacy. Selective breeding efforts and investigations of naturally surviving honey bee colonies have identified a number of hygienic behaviors honey bees may utilize to control Varroa(12). Overwintering of honey bees at indoor storage facilities can take advantage of the brood break that is induced by cold temperatures while modulating carbon dioxide levels and fumigating with formic acid or oxalic acid can further reduce Varroa levels(13). Caging queens or splitting colonies to induce brood breaks are effective strategies to slow down Varroa reproduction. Screened bottom boards and trapping Varroa in drone brood may also reduce Varroa populations.
To be good product stewards, it is imperative that miticides are used according to the labelled instructions to provide adequate control and reduce the probability of resistance development. In the case of Apivar®, that means one strip for every five frames covered with bees, strips placed in the brood area or cluster, and leave strips in for at least 42 days and no longer than 56 days. Refer to the label for more detailed instructions. Taking notes on Varroa infestation before and after treatment will document and quantify efficacy. The loss of miticide efficacy due to resistance is a squandering of technology for which our honey bees will suffer the consequences.

If you are interested in participating in the amitraz-resistance monitoring program in 2022, please contact me at Frank.Rinkevich@usda.gov with your contact information and the amount of supplies you are requesting. I will ship supplies, protocols, and datasheets for you to test colonies at your apiaries (10 colonies/apiary). At the end of the test, you simply mail me the datasheet and Varroa samples that you collected from the test in a prepaid mailer. We will go over the results with you by the next day and discuss the potential efficacy of amitraz treatments. I look forward to another year of amitraz-resistance monitoring and working with all of you in the effort.

Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.
USDA is an equal opportunity provider and employer.

References
1. S. J. Martin, Acaricide (pyrethroid) resistance in Varroa destructor. Bee World 85, 67-69 (2004).
2. J. S. Pettis, A scientific note on Varroa destructor resistance to coumaphos in the United States. Apidologie 35, 91-92 (2004).
3. M. Whalon, D. Mota-Sanchez, R. Hollingsworth, Global pesticide resistance in arthropods. (CABI, Cambridge, MA, 2008), pp. 166.
4. P. J. Elzen, J. R. Baxter, M. Spivak, W. T. Wilson, Control of Varroa jacobsoni Oud. resistant to fluvalinate and amitraz using coumaphos. Apidologie 31, 437-441 (2000).
5. D. Sammataro, P. Untalan, F. Guerrero, J. Finley, The resistance of varroa mites (Acari:Varroidae) to acaricides and the presense of esterase. Intl. J. Acaraol. 31, 67-74 (2005).
6. C. A. Mullin et al., High levels of miticides and agrochemicals in North American apiaries: implications for honey bee health. PLoS ONE 5, e9754 (2010).
7. K. S. Traynor et al., In-hive Pesticide Exposome: Assessing risks to migratory honey bees from in-hive pesticide contamination in the Eastern United States. Scientific Reports 6, 33207 (2016).
8. S. W. Corley et al., Mutation in the RmβAOR gene is associated with amitraz resistance in the cattle tick Rhipicephalus microplus. Proceedings of the National Academy of Sciences 110, 16772-16777 (2013).
9. P. D. Vu, L. C. Rault, L. J. Jenson, J. R. Bloomquist, T. D. Anderson, Voltage-gated chloride channel blocker DIDS as an acaricide for Varroa mites. Pestic. Biochem. Physiol. 167, 104603 (2020).
10. F. D. Rinkevich, Detection of amitraz resistance and reduced treatment efficacy in the Varroa Mite, Varroa destructor, within commercial beekeeping operations. Plos one 15, e0227264 (2020).
11. A. I. Haber, N. A. Steinhauer, D. vanEngelsdorp, Use of chemical and nonchemical methods for the control of Varroa destructor (Acari: Varroidae) and associated winter colony losses in US beekeeping operations. J. Econ. Entomol. 112, 1509-1525 (2019).
12. F. Mondet et al., Honey bee survival mechanisms against the parasite Varroa destructor: a systematic review of phenotypic and genomic research efforts. Int. J. Parasitol. 50, 433-447 (2020).
13. R. M. Underwood, R. W. Currie, Indoor winter fumigation of Apis mellifera (Hymenoptera: Apidae) colonies infested with Varroa destructor (Acari: Varroidae) with formic acid is a potential control alternative in northern climates. J. Econ. Entomol. 97, 177-186 (2004).

Apis mellifera lives in large communities with many little bodies confined in a nest (or hive) in an atmosphere which is both warm and fairly humid – ideal conditions for the multiplication and spread of pathogens. Notwithstanding varroa mites, how do most colonies manage to stay reasonably healthy most of the time? Keeping bees in hives is an artificial situation and can upset the balance that exists between bees, environment and pathogens. By what methods does the colony as a whole unit, and the individual bee, stay healthy? What factors can impact on this?

Colony-level immunity
Honey bees are very efficient at maintaining the colony in a fit condition providing certain requirements are met. Several factors are involved.

Cleanliness is very important in controlling the spread of pathogens, and honey bees are particularly clean animals. Everything in the hive is swabbed down with a salivary solution which contains small quantities of hydrogen peroxide, produced as a breakdown product of glucose, using the enzyme glucose oxidase. This is a mild disinfectant and bees pay particular attention to the cells where the queen is going to lay. Worker bees can use their tongues almost like mops in this process.

Breeding rates of bees can be very rapid, particularly in the early part of the season and a colony can often outbreed an infection such as nosema. At the same time that new bees are being produced, many are dying and, as a result, many pathogens are removed.

Thermoregulation can control some pathogens, particularly chalkbrood fungus (Ascosphaera apis) which needs a temperature of about 30oC for its spores to germinate. As the hive temperature is normally maintained at about 5oC above this, the fungus is unable to take over. Small or unbalanced colonies, particularly nuclei, are at risk as they are not always able to maintain a constant temperature.

Removal of infection from the colony is achieved in several ways. Most foragers die in the field and there appears to be an altruistic effect so that sick bees may leave the colony. Any bees that die in the hive are removed by other worker bees. Changes in behaviour can also help: the sacbrood virus is carried in the hypopharyngeal (brood food) glands of adult bees and overwinters there. They exhibit no symptoms, but their development is accelerated so that they transition to foraging at a much younger age than normal and rarely collect pollen when they are foraging. Fewer bees can therefore pass the virus on to the larvae.

Barrier methods serve to keep some individuals separated from others. The obvious case example is the larvae, each of which is reared in an individual cell. There is normally some separation of adults: nurse bees and queen in the central part of the brood nest, older receiver bees and Foragers bringing in nectar do not enter the brood nest and those bringing in pollen drop it in cells adjacent to and near the brood. However, this pollen is processed by mixing gut contents with it, so rendering it safe by the time the nurse bees consume it and feed it to the larvae. Obviously, this is not a complete separation of bees in the nest but there is a gradual move from the centre outwards as a bee ages. Food coming in from outside, which may be contaminated with pathogens, tends to be kept away from brood and queen.

Each larva is kept separate from other larvae, so minimising spread of pathogens

Propolis is a valuable aid to combatting many micro-organisms

An intruder – a snail – being encased

Many bodies crammed together give ideal conditions for the spread of pathogens

The varroa mite affects the immunocompetence of bees in several ways

Hygienic behaviour in its simplest form involves grooming of nest mates by the bees. This can remove some ectoparasites. The true meaning of hygienic behaviours is applied to those bees that can detect dead or diseased larvae and pupae and remove them. This is not a simple process and is dependent on the sense of smell, which is better developed in some bees. Oleic acid, the ‘death pheromone’ given off by dead larvae/pupae, is undoubtedly a key trigger for hygienic behaviour, but it is not the only one.

Antimicrobial substances are produced by the microbiome, bacteria and fungi which live in the bee’s gut. These substances are added to bee bread (preserved pollen) and brood food and helps to protect the larvae.
Propolis is a substance which bees love and beekeepers hate. It is gathered by the bees from plants, which produce it to protect themselves from attack by micro-organisms. Because it comes from various plants its composition varies, but it consists of a number of resins and balsams together with essential and aromatic oils. A wild colony living in a tree will coat all the internal walls of its nest and around its entrance with propolis so that it forms an envelope and confers considerable protection. There is work being done, experimenting with using roughened wood on the insides of hive boxes, to induce the production of this envelope. Another use is to coat foreign objects which gain access to the hive and might decay, thereby causing problems. Mummified remains of mice and snails are sometimes found. In areas where the small hive beetle (Aethina tumida) is found the bees may imprison the beetles in a ‘cage’ made from propolis.

Individual immunity
One of the simplest ways to combat pathogens is to prevent them from gaining access to the body. The commonest ways in are through the body wall and from the gut.

The cuticle is the first line of defence. It is impermeable to water and is quite tough, providing that it is undamaged. The protection becomes compromised where there is damage to the cuticle from broken hairs or due to the damage caused by the varroa mite. The spiracles also provide openings. Mostly they have valves, which protect the openings, but the spiracle on the second thoracic segment (mesothorax) has no such protection and here we see that Acarapis woodii, the parasite that causes of acarine, can get into the breathing tubes (trachaea) causing disease.

The gut is an obvious means of entry and has several defence mechanisms. The proventriculus, the one-way valve which connects the crop and the ventriculus, is able to filter out many small spores and micro-organisms along with pollen grains. These are then passed into the ventriculus as a food bolus. This part of the gut is not a welcoming environment as it is acidic and contains digestive enzymes. It is lined with a single layer of cells, called an epithelium, which limits the passage of substances and micro-organisms through it into the surrounding haemolymph. This epithelium is the structure targeted by nosema, which damages it and makes it vulnerable to the passage of some viruses as well as affecting the production of enzymes and limiting the bee’s ability to digest pollen. Finally, the peritrophic membrane, which is secreted continuously along the whole length of the ventriculus and surrounds the food bolus, acts as a barrier to prevent some pathogens from passing through into the haemolymph. Unfortunately it takes a short time to develop in both the larva and the adult bee and this leaves a newly emerged larva vulnerable to attack by organisms such as Paenibacillus larvae, the bacterium causing American foulbrood.

The haemolymph circulates round the bee’s body and bathes all the internal organs. It is the site of a number of immune responses and these are triggered by the structural patterns on the outside of pathogens. These are recognised by proteins in the haemolymph and the binding of the two together triggers the various responses:

Plugging a wound by some of the haemocytes (blood cells), which migrate to the wound. Melanin is then produced to form a permanent repair. This is rather like a scab in us.
Phagocytosis effected by other haemocytes called granulocytes. These surround the invader, and the nodule which is formed by plasmatocytes is later melanised.

Production of phenoloxidase. This is an enzyme, which is essential in the formation of melanin and is produced in haemocytes which are circulating freely but is present in the inactive form of prophenoloxidase. Once an injury or invading pathogen triggers a response, a cascade begins to convert it to phenoloxidase.

All of these responses are not constant during the life of a bee. Granulocytes peak in eight-day old larvae but decrease in young adults up to about five days when they dropped still further. Plasmatocytes have not been observed in larvae and are most abundant in young adults. These also decline in older adults. Queens appear to retain these cells. Phenoloxidase, apparently, may increase with age.

Finally, and taking slightly longer, antimicrobial peptides are produced by the fat bodies in response to chemicals produced by the haemolymph. These are able to inactivate the pathogens and persist after the invaders have been defeated. There are several of these and they are not specific to a particular pathogen. They can be passed between bees and added to royal jelly.

Vitellogenin is a precursor of some yolk proteins and, although it has many other roles in the honey bee, this original function has been retained. If a queen has micro-organisms in her body, particles of these become attached to the vitellogenin molecule which will be incorporated into the yolk. This can induce an immune response in the larvae hatching from these eggs.

Finally, iRNA (interference ribonucleic acid) is the major method used to prevent viruses multiplying. This interrupts the mRNA (messenger RNA) which conveys the blueprint for more viruses from the virus to the nucleus of the cell it has attacked.

Problems which may arise
Clearly, although immune responses can be overwhelmed, the bee has quite sophisticated methods for dealing with pathogens. However, some external factors can have a big impact and all kinds of stress can give the pathogens the upper hand.

Nutrition and most importantly provision of pollen from mixed sources, is fundamental. Protein is a major constituent of pollen and is needed for the production of enzymes and antimicrobial peptides among other things. Pollen is also the source of lipids but the role of these in immunity is not well understood.

Varroa feeds on the bee’s fat bodies, thereby affecting their function, and inhibits some of the genes controlling immunity. Even very good feeding after emergence cannot replace protein lost during pupal life.

Chemicals used in agriculture, particularly some of the neonicotinoids, have been shown to lower the immunocompetence of honey bees. Neonicotinoid pesticides have been removed from general use in the UK, but it will be some time before they disappear completely from the environment and we are not clear on the effects of other chemicals.

To sum up, immunity in honey bees is a complex of interconnected processes combining both colony level protection as well as the innate system of the individual bee. Various and combined stresses, particularly resulting from nutrition and from varroa, can have adverse effects leading to even more problems. We should aim to reduce the stress on our bees as far as possible.

Celia F Davis NDB lives in Warwickshire and has had a lifelong interest in insects and gardening. She taught pure and applied biology and has written two acclaimed BeeCraft books: The Honey Bee Inside Out and The Honey Bee Around and About.

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