Sentinel Apiary Monthly Memo: August Issue

We’re back again with another monthly update from the Sentinel Apiary Program! Let’s take a look at what’s been going on with mites, drones, honey, and more over the past month.

Throughout the month of July, Sentinel participants submitted 378 samples from 71 apiaries across 27 states! July finally showed us a big increase in mite loads, with the average Sentinel apiary now at the treatment threshold of 3 mites/100 bees. This July Sentinel apiary mite loads are higher than the historic national average, and much higher than the mite loads from last year’s Sentinel apiaries. This could mean we’re having especially high Varroa pressure this year, so if you have yet to check your colonies for mites, now is the time!

Monthly average mite loads for 2019 Sentinel apiaries compared to the historical national average, and 2018 Sentinel apiaries.

The state that had the lowest mite load in July was Colorado with an average of 0.22 mites/100 bees. Way to go Colorado! Over 50% (n=14) of states exceeded the 3 mites/100 bees threshold in July. The trend of higher mite loads in southern states is holding strong, with most southern states well past the threshold of 3 mites/100 bees. Northern states are also starting to creep up and will likely exceed that threshold in August. Check out our interactive Varroa map to see how your state is faring.


As for our July superlatives, congratulations to the following!

The state with the biggest bees: Illinois with 0.189 grams/bee.

The state with the most drones total: Michigan with 259 drones.

The state with the most drones per sample: New Jersey with 131 drones total, over 16 drones per sample!


University of Maryland apiary manager Andrew Garavito loads full honey supers onto our truck.

We also started to get Sentinel participants reporting honey harvested in July. A total of 12 beekeepers reported they harvested a total of 1,070 lbs of honey from Sentinel colonies. The state that reported the most honey harvested in July was Arizona. Let’s see if anyone can beat them in August!


That’s all for this month’s update. If you’re a Sentinel participant and have ideas about what you’d like to see in future updates, please let us know. We’ll be back next month to see how everyone looks as we approach fall!


Sentinel Apiary Monthly Memo: July Issue

We’re here to help you beat the heat with your second monthly Sentinel Monthly Memo of the year. It has been hotter than Hades out there, so hopefully you and your bees are keeping cool. We’re another month into the 2019 Sentinel Apiary Program, and here’s what we’re seeing.

In the month of June, we received a record 417 samples from 70 Sentinel Apiaries in 28 states. To put that into perspective, that’s over 125,000 bees, enough to comprise 2-3 full colonies. Our undergraduate lab technicians are certainly being put to good use!

Congratulations to the state with the lowest June mite load: New Hampshire with 0 mites! Mite loads continue to be higher in the South, with North Carolina, Georgia, Louisiana, Alabama, and Arizona above treatment threshold. Be sure to check out our interactive Varroa map to see mite loads at the county level. For the first two months of the program, Sentinel Apiaries have had lower average mite loads than the National Average (via APHIS NHBDS). We hope to continue this trend for the rest of the season!

Sentinel Apiary average mite loads (red) compared to the National Average (gray).

A couple of other fun superlatives we will begin awarding each month: the state with biggest bees was also New Hampshire with an average of 0.196 grams per bee. For context, the average bee weight was 0.173 grams.

The state that submitted the most samples was Michigan with a whopping 68 samples.

The state that submitted the most drones total was also Michigan with 369 drones. The state with the most drones per sample was New York with an average of 24 drones per sample. Sorry boys!

It’s also peak honey flow season, and we can’t wait to see how much sweet stuff our Sentinel participants pull in. Be sure to check out our hive scale map to see how your state is stacking up in honey production! And remember, as soon as you get those supers off you should monitor and apply a Varroa treatment if needed. Be careful to choose a treatment with a generous temperature threshold as it’s too hot for a few of the most popular chemicals. The Honey Bee Health Coalition has great resources to help you choose a safe product.

Check out our interactive hive scale map at

That’s all for this month, we’ll be back in August with another update. Stay cool out there and Happy Beekeeping!


Donate to BIP when you shop at Amazon!

Support the Bee Informed Partnership through Amazon Smile

Today and tomorrow are Amazon Prime shopping days and if you have been waiting to purchase those early (or late) Christmas presents or treat yourself to some much needed items, it is easy to make supporting the Bee Informed Partnership part of all your Amazon shopping. Through Amazon Smile, you can build in a small donation to BIP every time you shop at no additional cost to yourself. With each purchase on Amazon Smile, 0.5% of the sale to a will go to an organization of your choice, and we hope that The Bee Informed Partnership is your non-profit of choice!

To add BIP as your selected charity:

  • Visit Amazon Smile at:
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  • Add us as your selected charitable organization
  • Start shopping!
  • Add a bookmark for to make it even easier to return and start your shopping at AmazonSmile
Select The Bee Informed Partnership as your charity

You must shop through Amazon Smile for a portion of proceeds to go to the charity of your choice.

When you’re buying an extra hive tool and dog bee suit this Amazon Prime Day (July 15th -16th), don’t forgot to add us as your charity of choice!

And, as always, you can give to us directly at our website:

We are thrilled to have your support and to know that you will be thinking of us when ordering that next shipment of paper towels, dried mealworms, and pool toys.


Empty Calories

Foragers gathering fresh sawdust. Photo: Mike Connor

Somewhere early on in a “Beekeeping 101” class you’ll learn that honey bees forage for 4 things: nectar, pollen, propolis, and water. The nectar and pollen become honey and bee bread to provide sustenance. Propolis is used as a structural component and also contributes to colony health through immunological activity. Previous blog posts about propolis here and here provide more information. Water is necessary for a variety of purposes including preparation of brood food and evaporative cooling. So in addition to water, bees need 3 substances produced by plants. But do they collect anything else? Of course they do. If you’ve ever seen open syrup feeding, it’s apparent that the bees will forego the flower visitation part of foraging when a sweet liquid is provided. Bees will also readily gather pollen substitute when bulk fed in powder form. While these nectar and pollen surrogates may not be as attractive or nutritious as the genuine articles they are intended to replicate, they can be important in getting colonies through lean times.

Flowers and their surrogates are what the bees should be getting into, but what are they actually getting into? Some beekeepers have a perception that if bees gather it they must need it, but in my time working in and around bees I’ve seen them get into a lot of different things that probably aren’t great for them. One summer we noticed a propolis traps in a yard were yielding a dark brown, almost black propolis with sharp plastic smell instead of the typical red/orange sweet smelling propolis for the area. When we  sat waiting for the construction worker with the Stop/Go sign to allow us through the roadworks where a new topcoat of asphalt was being applied, we noticed bees collecting road tar to use as propolis. This paper detected petroleum derived molecules that matched the chemistry of local asphalt in propolis from urban colonies, confirming that bees will gather sticky stuff other than plant resins. I’ve also seen bees appearing to collect silicon-based caulking product. I’ve often described the physical role of propolis in the colony as bee-glue or caulking, so seeing one bee resort to gathering our version shouldn’t come as a shock if actual resins aren’t available. Bees gather “real” propolis from a variety of botanical sources depending on geography and climate. Some of the most common propolis sources in temperate climates are members of the genus Populus which includes poplars, aspens, and cottonwoods. For more about the role of propolis in the colony and an overview of botanical sources around the world, check out this article.

It’s not just propolis collection where bees make mistakes, sometimes they get it wrong when seeking pollen too. While building woodware in the shop, I’ve seen bees take a lot of interest in the sawdust from both treated and untreated lumber. I’ve never actually seen a forager pack it onto her corbicula, but beekeepers report bees gathering a variety of powdery materials when pollen is scarce. An early study on pollen foraging noted this tendency,  “During periods of pollen scarcity bees are reported to seek substitutes, such as bran, sawdust, and coal dust, which are of no known value for brood rearing.

Just about any sweet liquid is going to get the attention of honey bees, and I’ve seen them investigate many kinds of sodas and juices. This tendency may be a little unnerving to picnickers, but it isn’t really a problem unless there is a more permanent stationary source of sugary liquid that the bees find. One such case happened when some urban bees in NYC found a bit of runoff syrup from a maraschino cherry factory which was only the beginning of the story.


Sentinel Apiary Monthly Memo: June Issue


I don’t know about you, but my back hurts, which must mean the peak beekeeping season is officially well underway. The honey is flowing and supers are filling up. Do you know what your mite loads are? If not, Sentinel Apiaries are here to help. Sentinel Apiary participants sample 4 or 8 colonies for Varroa every month during the peak beekeeping season. This year marks the largest year of the Sentinel Apiary Program to date with 102 registered Sentinel Apiaries! If there’s a Sentinel Apiary near you, check their mite loads at This can help show you what mites are doing in your neighborhood.  Now that the first month of the program is complete, we’d like to begin a series of monthly Sentinel updates to share results with the BIP community.

Throughout the month of May, over 330 Sentinel Varroa and Nosema samples were processed by our diagnostics lab! Apiaries were sampled in 26 states across the country. Typically, the trend is that mite loads increase faster in the south than they do in the north. This makes sense because the warm southern climate allows colonies to brood up earlier, and mites depend on capped brood to reproduce. This year’s Sentinel Apiaries have shown just this, with May mite loads higher in the south than the north. So far, of the participating states, Arizona, Texas, Alabama, Georgia, Florida and North Carolina have exceeded an average of 2 mites/100 bees in Sentinel Apiaries.. So if you’re in the south, be sure to monitor next time your colonies are super free and get a treatment in if you need one.

Figure 1. Map of Sentinel mite loads available at Varroa loads are also displayed at the county level.

All other participating states are still well below threshold at an average of 0-2 mites. A big congratulations to Wisconsin for having this month’s lowest mite load at 0.09 mites/100 bees! This is great news for northern beekeepers, who have seen colder and wetter weather than typical, but be sure to still monitor if you’re planning on adding supers soon. It’s important to make sure your mite levels are as low as possible if it’s going to be a while before you get back down to the brood nest to sample. It’s only a matter of time until mite loads rise throughout the country.

Figure 2. University of Arkansas Apiculture Instructor Jon Zawislak prepares for flooding by propping colonies up on cinderblocks. Photo from University of Arkansas, Jon Zawislak.

Another observation from early Sentinel samples is that weather has been anything but normal. Sentinel participants report on whether their climate has been atypical, and many participants cite heavy rains and abnormal temperatures as negatively impacting their colonies. There has been substantial rain and flooding throughout much of the Midwest and plains regions. Beekeepers are having trouble getting queens well mated, as well as producing honey since there have been so few days with flyable weather. It’s been a rough start to the year for many, but everyone is hoping things will calm down soon in time for the last couple months of summer.

We’re just getting started and we would love to hear from you. As the season progresses, we’ll be sharing some interesting data in these monthly blogs and hope to have some Sentinel participants share how their monthly monitoring is changing how they manage their colonies. Get ready, hold on and take care of your back!



Latest Loss Survey Results 2018-19

Dear BIP Survey participants,


You might have been wondering when the preliminary results of the 2018/9 Bee Informed Partnership Colony Loss and Management Survey will be posted.

Well, today is the day. Thanks for your patience!

The “traditional” abstract is now posted on the BIP webpage here, while the Press Release issued by the University of Maryland can be read here.

We want to thank all of you – whether you are a long-term respondent or a new-Bee to the survey – for participating this year. The information you provided is critical to building a long-term data set that we can now use to develop regionally-specific management recommendations.

Please keep your eyes on our national colony loss map and our interactive management portal. In the coming weeks we will be publishing our 2018/19 state-specific results.

Please take care!




The Bee Informed Partnership


2019 California Spring Update

Many California beekeepers reported that the start of this year was the worst in 20+ years. Several factors contributed to this year’s issues, starting with the numerous fires last year causing nearly 3 months of smoke in the area.

A beekeepers yard in September showing smoke from fires in Northern California 2018.
Petal Fall in 2019 in almonds after heavy rain.

Once the days got longer, queens started laying but the temperatures dropped again and egg laying stopped once more resulting in smaller colonies after almonds. In fact, most colonies were 2-3 weeks or even a month behind, which delayed the start of queen production. Many producers had to source bulk bees from beekeepers further south to begin starters, builders and nucs.

Italian Queen selected for hygienic testing.
Carniolan Queen selected for hygienic testing in 2019.

Once queen producers started generating nucs, the weather conditions were still challenging enough that the windows of opportunities for queens to mate were narrow at best. However, many queen producers found the first round of catching queens resulted in better than expected mating percentages, allowing them to somewhat catch up on orders and start replacing their own queens. Around this time beekeepers were treating with terramycin to combat European foulbrood (EFB). Some beekeepers believe as I do, that fungicides play a roll in colonies being more susceptible to brood diseases especially EFB. I do think that some of the EFB outbreaks we see are due to the way commercial beekeepers and queen producers manipulate colonies to shake bulk bees.

Early EFB symptoms, orange arrows indicate larvae I would select for testing, red arrows indicate old larvae I would not test


If you are seeing this or lots of Deformed Wing Virus (DWV) it will be really hard to nurse colonies back to health. This is what happens if you neglect to treat or manipulate colonies to impact mite levels. Red arrows point to varroa mite in or on open brood.

Currently queen producers are re-queening and treating their colonies before shipping off to summer honey and pollination locations. The late spring has provided more rain than the past 8 years and many beekeepers say that rain in May increases the star thistle crop. We are hopeful this year will be a great star thistle honey crop, helping to restore lost colonies and recover some of the income lost due to the late start on queen production.


Honey Bee Caste Systems: Part 2 – How Genetics and the Environment Shape Honey Bee Workers and Queens

Author: Garett Slater, Former Midwest Tech Transfer Team

In part 1 of my blog series, I wrote about how genetics can shape reproductive males (drones) and both reproductive (queens) and non-reproductive (workers) females within a colony. However, genetics only explains part of the story. I will describe why that is in the second installment of my 3-part series:

  • Part 1: The Genetic Book of Life-The basics to honey bee genetics (for Part 1 click here)
  • Part 2: How Genetics and the Environment Shape Honey Bee Workers and Queens
  • Part 3: The Differences Between Queens and Workers
Figure 1: Queen and Worker honey bees. As you can see, there are clear anatomical differences between these castes despite genetic similarities.

Queen determination has always fascinated researchers and beekeepers. This is unsurprising considering queens and workers are genetically similar yet have distinct anatomical and physiological features (Figure 1). In fact, queens are highly fertile and lay more than 2000 eggs per day whereas workers have anatomical structures specialized for foraging, nursing and other colony tasks. So how does a colony produce either a fertile queen or a sterile, highly specialized worker, even if they have the same genetics?

Most beekeepers and queen producer know nutrition determines whether a fertilized larva develops into a queen or worker. Just place a 1-3-day old larvae into a queenless colony and watch as they develop a queen from a previously worker-destined larvae (Figure 2). However, how this nutrition determines queens has historically perplexed researchers. Since the 1890’s, diet quality has been thought to determine queen-worker castes in honey bees through a “biological active substance” found only in royal jelly. This quality hypothesis arose from early observations of queen and worker larvae receiving different proportions of water-clear and milky-white secretions from nurse bee glands. The milk-white secretion fed to queen-destined larvae was termed royal jelly whereas the water-clear secretion was termed worker jelly (Figure 3). Since then, royal jelly was thought to contain the major dietary components necessary for queen development.

Figure 2: Queen producers make queens by transferring worker-destined larvae into queen cells of breeder colonies.
Figure 3: Royal jelly (left) is fed to queen-destined larvae and worker jelly (right) is fed to worker-destined larvae.









The first person to empirically test differences between royal and worker jelly was Dr. Adolf van Planta in 1888 (Table 1). He concluded the food composition fed to workers changed drastically after the age of 4 days, which is when worker larvae cannot develop into a queen naturally in a colony. While the food fed to workers and queens seem striking, royal jelly content was only quantified for 1 day. However, once this study was published, researchers began to search for the substance in royal jelly that determines caste. In fact, the only other study after Dr. von Planta’s publication to compare differences between royal and worker jelly was Wang et al. 2016.

Royal jelly was then deemed special and necessary for queen development. In fact, royal jelly has been thought to contain a “pure determining substance” not found in worker jelly ever since. This has pushed scientists to find this active substance so we can truly understand how queens develop.  Researchers have tested nearly every major component in royal jelly on caste determination. In fact, most studies found positive results. They found lipids, proteins, carbohydrates, water, pantothenic acid (vitamins) and even p-coumaric acid (chemical in pollen) all contribute to queen development in honey bees under some experimental conditions. Despite positive results, how does every single macronutrient and micronutrient in royal jelly determine caste? This question perplexed me.

Table 1: Comparison between Royal and Worker jelly.







As I began researching royal jelly and queen development, I realized none of these studies controlled for diet quantity. This is surprising because queens are obviously fed more food than workers during development. In fact, queen-destined larvae are fed an excess of 300mg of diet and are fed 1400 times more frequently by nurse bees than worker-destined larvae. As I did a literature search, I couldn’t believe the impact of quantity on honey bee caste determination has not been formally tested.


Figure 4: 48 well plate I use for rearing honey bee larvae on an artificial diet


I decided to pursue this question during my masters. I used in vitro rearing techniques to test whether diet quantity causes queen development (Figure 4). In vitro rearing is a useful tool because I can become a “nurse” bee and control the food larvae receive. In fact, I can change the type of food and the amount of food larvae receive and see how that impacts development. So, I tested the relative contributions of diet quantity and quality by rearing honey bee larvae on diets that altered both quality and quantity.


Figure 5: The range of sizes I produced by changing diet quantity. I produced small workers, workers, intercastes, and queens.

A wide range of individuals were raised from my artificial diets. Not only were queens and workers reared, but also intercaste bees (part worker-part queen), or what I call them, princess bees (Figure 5). I have never seen intercaste bees in a natural hive setting nor have I seen miniature workers half the size of normal workers. Thus, it seems bees have the ability to develop into a wide range of body sizes. These results indicate 2 conclusions: 1) nutrition during development is extremely important for both workers and queens, and 2) colonies impressively control queen versus worker development. More importantly, it seems diet quantity plays a larger role in caste determination than expected.

Caste determination is fascinating and I truly enjoyed studying it, but why should the average beekeeper care? The main reason is queens are an integral component of a colony however we have little understanding about how a queen develops and which factors make a high-quality queen. This is important to improve queen quality and manifest important queen traits through breeding, selection, and alternative management practices.

Honey bee queen determination is an intersection between genetics and the environment. I hope you enjoyed reading this post and keep an eye out for the next installment on the key differences between queens and workers.


von Planta, A. (1888). Ueber den Futtersaft der Bienen. Zeitschrift für physiologische Chemie12(4), 327-354.

Wang, Y., Ma, L., Zhang, W., Cui, X., Wang, H., & Xu, B. (2016). Comparison of the nutrient composition of royal jelly and worker jelly of honey bees (Apis mellifera). Apidologie47(1), 48-56.


Flame in the Bee Yard: Relighting a Smoker the Easy Way

The Scenario

We’ve all experienced a smoker going out just when we need it. Sometimes we may simply forget to pump the bellows for too long while we are getting some other things ready; sometimes we may make the mistake of stuffing the fire chamber too tightly with fuel before the fire has a good chance to catch. At other times our smoker may go out during travel between bee yards. Any of these scenarios sound familiar?

The Traditional Method

So, when your smoker goes out for the umpteenth time, what do you typically do? You could re-open the smoker, dig in there, take out some fuel, burn your fingers in the process of making room for a flame, light the fuel from the bottom and cross your fingers so it stays lit this time? Let me save you the embarrassment, there is a lazy way to re-light it!

A smoker holds up after numerous external lightings

The Tried and True Easy (Lazy) Method

First, if you do not already own a propane blow torch, it is well-worth your time, energy and money (~$40) to procure yourself one. Once you have a propane blow torch, you can simply blast the flame at the outside of the metal smoker while pumping the bellows, and voilà! The heat transfer through the metal will re-light most smoker fuels. Don’t be afraid to heat the metal red-hot: smokers are seemingly built to withstand such high heat for long periods of time. For example, commercial beekeepers will keep their smoker lit for a long time while loading a semi truckload of bees or working colonies in a big bee yard. If you are concerned about wear and tear, I can report that after a year of relighting my smoker with a torch, the metal on one part of the fire chamber is a little bumpy, but otherwise totally fine.



Keep the flame away from the bellow and its air valve


Even though it is shielded by metal on most models, be aware that there is an air valve on the back side of the bellows that could be damaged by flame or heat. The same goes for fingers…

The Lazy Man is a Safe Man

You read that right – this lazy method has an upside beyond convenience. At times and places with an elevated wildfire risk, this method may be a safer way to play with fire in the bee yard. Since it doesn’t require you to pull out the contents of the smoker, which often are still smoldering a little and with a slight breeze can blow sparks across a dry field, you too can prevent wildfires!



Lazy bees?

The parliamentary building in Victoria, British Columbia features many stained glass windows celebrating the arts and sciences. A colony of honey bees was chosen to represent industria (latin for industry).

Honey bees have long been admired by humankind for their industriousness. The beehive has served as a symbol of organization and hard work throughout history, and common sayings like “busy as a bee” that persist today indicate we still perceive bees to be hard workers. The state of Utah has been particularly fond of the beehive analogy. It officially adopted the beehive as the state emblem in 1959, although it featured the beehive on its seal as early as  the 1850s when it was still a territory.  The city of Manchester, England adopted the worker bee as an emblem during the industrial revolution, and a traditional skep is featured prominently in the stained glass of parliamentary building of British Columbia in Canada.

Temporal polytheism, the process by which individual bees transition through different “jobs” over the course of their lifetime, means that bees complete a diversity of tasks. But are all  bees busy all of the time? The younger bees in a colony typically do the work inside the colony, including rearing brood and curing honey. Open up the colony and remove a frame, and you’ll see a lot of the house bees doing various tasks as well as many that are just kind of hanging out. Stand at the entrance of a colony on a sunny day, and you’ll certainly witness a lot of activity from the older bees in the hive. When conditions are suitable the foragers fly hard, covering many miles to accumulate nectar, pollen, water, and propolis for the colony.

At different times of the year, colony growth and contraction dynamics will be such that the number of bees available for particular tasks may exceed the number needed. Thus, some bees will be underutilized. Queen events or seasonal brood dynamics in the colony can lead to situations where there is an abundance of young bees but not a lot of brood to tend to. Foragers work very hard when resources are abundant and weather conditions are favorable, but they essentially take cold, wet, and windy days off and are also largely idle overnight  in the hive.

This study used RFID tags on individual bees to track their location and monitor the foraging activity of colonies. One of their findings was that approximately 50% of the foraging activity was accomplished by only about 20% of the foragers. Their study demonstrates that the foraging effort is not evenly distributed, and some bees clearly worked harder than others. Even more interesting is that when the researchers removed the hardest working foragers from the colony, the other, previously lower workload bees increased their activity to compensate. This finding is fascinating in that it demonstrates that the flexibility of individuals allows the needs of the colony to be met even when a group of high performing individuals are removed. This research suggests that some of the bees may be holding back a little in foraging effort, thus prolonging their lifespan which may provide a measure of redundancy to the colony which could help overcome a sudden loss of foragers.

By holding some foragers in reserve, the colony could be protecting itself against an acute event causing the loss of foragers that could otherwise lead to precocious foraging, which is the premature transition of young bees into foragers. A different study demonstrated that precocious foragers performed poorly, leading to feedback loops where even more of the young bees attempted to forage, eventually depleting the colony of young bees and leading to a rapid decline in colony condition.

The settlers of Utah thought enough of the honey bee work ethic to include a traditional skep style hive on their state seal

It may not be fair to try to anthropomorphize a colony of insects by applying terms like “lazy” or “industrious,” but it does seem like healthy bees demonstrate a capacity for both traits. Making honey when the sun shines, while also holding a little bit in reserve as a buffer against acutely stressful events allows colonies to be both productive and resilient.



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