Cell Size: Does it matter?

Cell size is a highly heated and debated topic that I, as a former commercial beekeeper, did not know of until recently. As a commercial beekeeper, we would buy foundation in bulk, which had a “standard” cell size (5.2mm to 5.4mm). I had zero concept of small versus standard cell size, and I became curious about why beekeepers would use small cell instead of standard cell. So I did what any eager millennial would do- I googled it. I found Michael Bush’s (http://www.bushfarms.com/beesnaturalcell.htm)  and Randy Oliver’s post (http://scientificbeekeeping.com/trial-of-honeysupercell-small-cell-combs/) about small cell size (and I went down a few other rabbit holes), and I instantly became fascinated about small cell size. I hope you enjoy reading this blog as much as I enjoyed writing it.

In 1857, Johannes Mehring produced the first comb foundation (Graham, 1992). His goal was to provide bees with a template, which would encourage bees to build worker comb in the frames. From that day forward, artificial foundation became a part of beekeeping. However, beekeepers began to experiment with different cell sizes. In 1927, Baudoux hypothesized that larger cell sizes would produce larger bees, and based upon anecdotal evidence from his own colonies, he claimed larger bees produced higher yields of honey. Without scientific evidence, manufacturers in Belgium and France began to produce foundation with larger cells. These manufacturers asserted that bees raised in larger cells produced more honey and this concept took off (Grout, 1935). Those fallacies faded into history as cell size become standardized at 5.2mm-5.4mm.

Natural Worker Comb 4.6 mm to 5.1 mm
Dadant 4.9mm Small Cell  4.9 mm
Honey Super Cell  4.9 mm
Wax dipped PermaComb 4.9 mm
Mann Lake PF100 & PF120 4.94 mm
Dadant 5.1mm Small Cell 5.1 mm
Pierco foundation 5.2 mm
Pierco deep frames 5.25 mm
Pierco medium frames 5.35 mm
RiteCell 5.4 mm
Standard Worker Foundation 5.4 to 5.5mm
7/11 5.6 mm
HoneySuperCell Medium Frames 6.0 mm
Drone 6.4 to 6.6 mm

 

Natural Comb
Natural Comb

 

Rite Cell® 5.4 mm
Dadant Normal Brood 5.4 mm
Pierco Medium Sheet 5.2 mm
Pierco Deep Frame 5.25 mm
Mann Lake PF120 Medium Frame
Mann Lake PF100 Deep Frame
Dadant Small Cell 4.9 mm

I decided to see if scientific studies supported Baudoux’s 2 major claims: 1) larger cells=larger bees and 2) larger bees=higher honey yield.

 

Claim #1-Smaller cells= smaller bees

Honey bees raised in smaller cells did, in fact, become smaller. Apis mellifera mellifera raised in small-cell (5.08mm) comb versus standard-cell (5.48mm) comb became 1% smaller (McMullan & Brown, 2006). Moreover, bees raised in small-cells did have smaller thorax width and head width, morphometrics determined during development (Grout, 1935; Seeley, Griffin, Seeley, & Griffin, 2011). Yes, an 8% reduction in cell size only equated to a 1% reduction in size, and we do not know what these reductions mean on a colony level. However, these experiments show how the rearing environment impacts the individual, and not how it may have colony level impacts. I should note that body size is likely not only impacted by cell size, but also other environmental factors such temperature, nutrition, etc.

 

My Verdict: Yes, but only to a point

 

Claim #2-Larger bees=higher honey yield

Let us think about this: larger bees have bigger thoraxes, which possibly means a more profound locomotor function (simply, flight) ( Seeley, & Griffin, 2011). So, do larger bees produce more honey? Well we know that, of 62 bee species analyzed, body size was correlated with how far an insect forages (Greenleaf et al., 2007). For honey bees, worker weight does vary during the season (Levin & Haydak., 1951) so it is possible that larger workers can forage longer distance. But do larger bees produce more honey? The answer seems to be no. Obviously, more studies are needed to support this idea because honey production is dependent upon both genetic and environmental factors. Moreover, these studies did not scientifically compare honey production for colonies raised with small-cell comb (5.08mm) versus standard-comb (5.48mm). However, from what we know in the scientific literature, body size does not impact honey production.

Let us jump from the brood nest to the honey super: can bees store more honey in standard-cell comb versus small-cell comb? From a pure speculative opinion, I would suspect bees would possibly store less (but probably not much less) honey in small-cell comb for 2 reasons: 1) frames would have more cells, but less honey storage/cell and 2) my guess is that colonies can draw out standard cells further than small-cell sized comb. Because of this, bees can store more honey per cell. Like I said, this is pure speculation, so if you have thoughts/experience, please comment below

My Verdict: No

Beekeepers began to implement small cell comb into their colonies as a possible non-chemical varroa mite control in the 1990’s. This hypotheses stemmed from observations of Africanized honey bees (bees that produce smaller cells sizes than European species) whom seemed less prone to becoming harmed from varroa; however, we also know that much of that reduced harm was from swarming when varroa mite levels became too high. While hygienic behavior was also known to explain low mite levels in Africanized honey bees, there was an idea that the smaller cell sizes could control varroa. I decided to see if studies have shown the efficacy of small cell size on varroamanagement

 

Claim #3-Can small cells actively control varroa

Medina & Martin (1999) hypothesized the use of smaller cell size as a varroa control because they believed smaller cell size inhibited movement of immature varroa, thus reducing the mites’ ability to feed. This idea was tested by Martin & Kryger (2002) whom found evidence for this hypothesis. These researchers reared a subspecies of European honey bees that are similar in size in small celled comb (4.6mm), and they found higher mother mite and male offspring mortality. They also observed the mother mites and male protonymphs appeared to get trapped in in the upper part of the cell, which inhibited their ability to reach feeding site on the developing bee. This evidence was exciting; an easily implement management strategy that could be used to control mites!! But good science required initial claims to be repeated and verified. So five separate studies conducted experiments to test whether small-cells can actively control mites (Berry, Owens, & Delaplane, 2010; Coffey, Breen, Brown, & McMullan, 2010; Ellis, Hayes, & Ellis, 2009; Seeley, & Griffin, 2011; Taylor, Goodwin, McBrydie, & Cox, 2008). These studies have not found evidence to support this point. In one of the studies, Dr. Tom Seeley compared mite loads and mite drops of bees reared in standard comb size (5.4mm) versus small cell size (4.8mm) and found no difference between groups (Seeley, & Griffin, 2011). Moreover, he noticed the volume of the cell filled by a larvae was only slightly larger for a small cell versus large cell. He suggested that Martin & Kryger (2002) possibly found significant differences between bees reared in different cell sizes because the largest subspecies (a non-European race), Apis mellifera capensis, was reared in the smallest possible cell size (4.6mm). Using European races, small cell size did not have a huge impact on colony mite levels.

Small cell size, I found from online forums and posts, is widely believed to actively control varroa. but based upon the literature, it seems small cell size comb cannot actively control for varroa.

 Verdict: No

If you have thoughts/experience, please comment below!  I attached links to Randy Oliver’s post about the topic:

http://scientificbeekeeping.com/trial-of-honeysupercell-small-cell-combs/

 

And like I linked before, Michael Bush has information in his post:

http://www.bushfarms.com/beesnaturalcell.htm

 

References

Berry, J. A., Owens, W. B., & Delaplane, K. S. (2010). Small-cell comb foundation does not impede Varroa mite population growth in honey bee colonies *. Apidologie41(1), 40–44.

Coffey, M. F., Breen, J., Brown, M. J. F., & McMullan, J. B. (2010). Brood-cell size has no influence on the population dynamics of Varroa destructor mites in the native western honey bee , Apis mellifera mellifera *. Apidologie41(5), 522–530.

Ellis, A. M., Hayes, G. W., & Ellis, J. D. (2009). The efficacy of small cell foundation as a varroa mite (Varroa destructor) control. Experimental and Applied Acarology, (47), 311–316. https://doi.org/10.1007/s10493-008-9221-3

Graham, J. M. (Ed.). (1992). The hive and the honey bee. Hamilton, IL: Dadant & Sons.

Greenleaf, S. S., Williams, N. M., Winfree, R., Kremen, C., Greenleaf, S. S., & Williams, N. M. (2007). Bee Foraging Ranges and Their Relationship to Body Size. International Association for Ecology153(3), 589–596. https://doi.org/10.1007/s00442-007

Grout, R. A. (1935). Influence of Size of Brood Cell upon Size and Variability of the Honeybee. American Association of Economic Entomologists, 345–354.

Levin, M. D., & Haydak., M. H. (1951). Seasonal Variation in Weight and Ovarian Development. Journal of Economic Entomology44(1), 54–57.

Martin, S. J., & Kryger, P. (2002). Reproduction of Varroa destructor in South African honey bees : does cell space influence Varroa male survivorship ? Apidologie33, 51–61. https://doi.org/10.1051/apido

McMullan, J. B., & Brown, M. J. F. (2006). The influence of small-cell brood combs on the morphometry of honeybees ( Apis mellifera )*. Apidologie37, 665–672.

Medina, L. M., & Martin, S. J. (1999). A comparative study of Varroa jacobsoni reproduction in worker cells of honey bees ( Apis mellifera ) in England and Africanized bees in Yucatan , Mexico, (September 1994), 659–667.

Seeley, T., Griffin, S., Seeley, T., & Griffin, S. (2011). Small-cell comb does not control Varroa mites in colonies of honeybees of European origin Small-cell comb does not control V arroa mites in colonies of honeybees of European origin. Apidologie, (42), 526–532. https://doi.org/10.1007/s13592-011-0054-4

Taylor, M. A., Goodwin, R. M., McBrydie, H. M., & Cox, H. M. (2008). The effect of honey bee worker brood cell size on Varroa destructor infestation and reproduction. Journal of Apicultural Research.

The signs of mite damage- How to identify progressed varroosis

Varroa infested colonies entered the United States in ~1987, and changed beekeeping forever. Beekeeping has always been time consuming, difficult and experience oriented; however, beekeeping became even more challenging when beekeepers were called to eradicate a bug on another bug. Since its introduction in the US, beekeepers have reported high annual colony losses due to mites. In fact, some beekeepers report 60% losses due to this troublesome pest. While beekeepers have faced devastating challenges before, including American Foulbrood, Varroa mites has presented damages never before seen.

Varroa have become more difficult to manage since their introduction. The mites are seemingly embedded within the honey bee industry reality as nearly, if not all, colonies have Varroa. Like many beekeepers say: ” all my colonies have mites, I just cannot see them”. Even if alcohol washes do not reveal mites, Varroa is present in the brood or will be present soon due to infestation from surrounding colonies. As mites have become more widespread, they became a vector for a variety of viruses. In fact, researchers are finding more and more variants of Deformed Wing Virus (DWV), a virus that affects the honey bee’s essential flight capabilities. Research has shown that DWV-B (Deformed Wing Virus variant B) can be responsible for high over-winter losses.

The point here is that Varroa devastates colonies.  It would also seem that Varroa are transmitting more virulent strains of viruses with each passing year. Because of this, I recommend to keep mite levels below 1 mite/ 100 bees in the spring and below 3 mites/100 bees in the fall. With Varroa loads any higher, beekeepers risk high colony losses.

Monitor, Monitor, Monitor

Beekeepers must consistently monitor mites if they expect to have strong and healthy colonies. Beekeepers can monitor their mites in various ways, but I recommend both of these two methods: perform an alcohol wash (or other monitoring method) and observe the overt signs of mite damage. It is ideal to perform monitoring methods once a month, but we realize this is not always possible. Because of this, combining both monitoring and observation methods are recommended. Ideally, mites should be monitored at least 4 times a year.  As seen in Figure 1: population increase, population peak, population decrease, and fall dormant; it is essential to understand the seasonal changes. For example, brood density varies throughout the year, so certain treatments can be less effective at different times. By understanding seasonal cycles, beekeepers can better manage their mites. I understand Figure 1 does not reflect the reality of every region but it gives a good overall general idea.  Some regions have multiple population peaks due to large honey flows, so you will need to understand the honey bee seasonal phases in your region. But essentially, as the bee and brood population increase, so do the mites.

Screen Shot 2018-05-07 at 9.08.00 PM.png
Figure 1: Honey bee seasonal phases from the honey bee health coalition- Beekeepers should monitor mites once a month, but this is often not possible. But mites should be monitored at least 4 times a year: late winter-early spring dormant, population increase, population peak, population decrease, and fall dormant. I recommend alcohol washes (or another method) during these periods. Photo courtesy of the Honey Bee Health Coalition

Mite Monitoring Techniques

I attached a chart outlining the 3 major mite monitoring techniques I recommend. Perform one of these techniques 4 times a year: Early spring, late spring, late summer and early fall. Each beekeeper has their preference, so use the method you feel the most comfortable with. I use alcohol washes, but I feel comfortable with sugar rolls or CO2 as well. As long as you monitor, there is not a wrong method!

Advantages  Disadvantages 
Sugar Rolls
  • Known research on accuracy
  • Common method
  • Does not kill bees
  • Messy
  • Hard to do on windy, rainy or humid days
  • More time consuming
Alcohol Wash
  • Known and common method
  • Quicker than sugar rolls
  • Can be more accurate than sugar roll
  • Can be messy
  • Kills bees
CO2
  • Quickest method
  • Easy to do with multiple colonies
  • Kills the bees (most likely)

When monitoring for mites, beekeepers should review mite thresholds. I outline my recommended thresholds for each monitoring method below. If your colony is above threshold, I recommend taking actions. Mite thresholds are not an exact science, even if you have levels below the threshold, it is no assurance that your colonies will be healthy and successful. For example, I have sampled many commercial beekeepers with mite levels <0.5 mites /100 bees in the spring, and they eventually had huge losses. I typically see mite levels spike in the late summer because: A) summer treatment with honey supers are limited, B) Mites are often lurking in the brood, and C) Mites from other beekeepers nearby can (re)infest colonies. Because of this, always monitor and monitor again. Once mite levels do spike, they may be difficult to bring down. Too often, when you notice, the mite damage is already done. I should note that I recommend alcohol washes, powdered sugar rolls or CO2 over a sticky board. Sticky boards are not nearly as accurate, because they do not quantify the level of infestation. If a sticky board is your only option, you can attest that you have some mites or more mites, but you are not able to assess the level of infestation (1, 2, 3 mites/100 bees). Use other monitoring method options for more accurate results and an infestation level to compare with suggested thresholds. *These thresholds may vary per US regions. These are the threshold I recommend in the Midwest (MN & ND)

Monitoring Method # of mites in early-spring # of mites in mid-spring # of mites in late-spring # of mites in early-fall # of mites in late-fall
Alcohol Wash  

1 mite/100 bees

1 mite/100 bees 1 mite/100 bees 3 mite/100 bees 3 mite/100 bees
Powdered sugar roll 1 mite/100 bees 1 mite/100 bees 1 mite/100 bees 3 mite/100 bees 3 mite/100 bees
CO2 1 mite/100 bees 1 mite/100 bees 1 mite/100 bees 3 mite/100 bees 3 mite/100 bees
Sticky Board 9 mites/24 hours 9 mites/24 hours 9 mites/24 hours 12 mites/24 hours 12 mites/24 hours

Mite related Disease Progression 

I inspect and observe hundreds of colonies annually. When I enter a colony, I often immediately know whether it has (or did) have high mite levels simply by observing progressed signs of mite damage. Just observing progressed mite damage does not suffice, but it is a good start. By noting visual signs of Varroa, you will know just how important your mite levels are and the need for action. Monitoring is best but if you can recognize some of the visual signs, you will better understand the extend of the mite damage to your colony.

I outlined the 5 stages of mite damage, which I relay to my beekeepers. In the spring during population increase, I want to see colonies within the Stage 1- 2. While I hate to see mites in the spring, this is not always a bad sign. Even if I observe mites, the colony may be below the recommended threshold, so just continue to monitor that colony. During the late spring, summer and fall, I like to see colonies within Stage 1-3. Even if Chewed Down brood (CDB) (outlined below) and phoretic mites are seen, it does not mean that beekeepers have high levels. However, a combination of phoretic mites and CDB can signal worse mite issues. If these signs are seen, continue to monitor these colonies. As for Stage 4-5, I never want to see these stages, regardless of temporal period. Deformed Wing Virus (DWV) and Varroa Mite Syndrome (formerly Parasitic Mite Syndrome or PMS) can signify high mite levels.  Specifically for Varroa Mite Syndrome, it signifies very progressed mite damage, which often results in colony deterioration and eventual colony death. If colonies are in stage 4 or stage 5, monitor immediately to determine extent of damage. Action is often required, but may be too late.

 Stage Visual Signs Notes
Stage 1 Zero signs of mites, brood diseases or viruses
Stage 2 Visual signs of phoretic mites on either workers or drones.

 

This does not necessarily mean a mite issue exists, but if mites are seen, monitor to determine extent of varroosis.

 

Stage 3 Chewed Down Brood and/or phoretic mites

 

 
Stage 4 Deformed Wing Virus (DWV) and/or Chewed Down Brood and/or signs of phoretic mites. Visual signs of Deformed Wing Virus (DWV) can mean larger varroa issues. Obviously, this depends upon the number of bees with DWV and the number of phoretic mites seen, but mite monitoring is recommended to determined extent of varroosis. These signs signal a more progressed form of varroosis.
Stage 5 Parasitic Mite Syndrome (PMS) and/or Deformed Wing Virus (DWV) and/or Chewed Down Brood and/or Phoretic mites Visual signs of Parasitic Mite Syndrome usually signal extreme issues with varroosis. If Parasistic Mite Syndrome is seen, then mite levels are often a significant issue and has advanced to the most progressed stage of varroosis.

Visual signs

Phoretic Mite

Phoretic mites are Varroa mites seen on the abdomen of worker (or drone bees). Most phoretic mites, however, are found underneath the bee, more precisely tucked between the abdomen’s sclerites where they latch on and feed. Because of this, I typically inspect the ventral abdomen of several worker bees during inspections. This is why beekeepers “never see mites”, even if these beekeepers have higher mite levels. Visually inspect phoretic mites just on the workers, not the drones. If phoretic mites are seen on worker bees, then this represents a more progressed infestation of mites. Signs of phoretic mites indicate the colony is in Stage 2-5. Visually inspect other signs to further pinpoint extent of damage.

 

Screen Shot 2018-05-12 at 10.38.32 AM.png
Phoretic mite on the thorax of a worker bee. Photo Courtesy of Rob Snyder

Chewed Down Brood (CDB)

Bees can sense mites in the brood. If sensed, bees will uncap and cannibalize the pupae. If CDB is seen, then mites may be at a high level, especially within the brood. CDB can indicate progressed mite damage, so continue to monitor and assess colony health.

Deformed Wing Virus (DWV)

Deformed Wing Virus (DWV) represents the next stage of varroosis progression. Bees with DWV are kicked out of the colony so if bees with DWV are seen than Varroa has become an issue. DWV does not signify un-manageable mite levels for the colony, but it is a more progressed sign of mite damage.

Screen Shot 2018-05-08 at 7.37.06 AM.png
The bottom right corner contains a cell with chewed brood. Bees begin chewing brood when they sense mites within the cell, so this can indicate larger mite issues. Photo by Rob Snyder

Deformed Wing Virus (DWV)

Deformed Wing Virus represents the next stage of varroosis progression. Bees with Deformed Wing Virus are kicked out of the colony so if bees with DWV are seen than Varroa has become an issue. Deformed Wing Virus does not signify un-manageable mite levels for the colony, but it is a more progressed sign of mite damage.

Picture1s
This bee has deformed wing virus, a debilitating virus than can easily deplete a colony. Oftentimes, bees with the virus are removed from the colony. So if bees with Deformed Wing Virus are seen, than this can indicate larger issues. Photo by Rob Snyder

Varroa Mite Syndrome (VMS)

A pathogen has not been identified for this diseased, however mites are always present when this disease is seen. This brood symptom looks similar to other brood diseases except the larvae do not rope like foulbrood. Larvae do appear sunken to the side of the cell. If Varroa Mite Syndrome is observed, then colony has likely dwindled and deteriorated. Varroa Mite Syndrome is the most progressed sign of mite damage, and truly at a stage of no return. Even if low phoretic mites are seen, Varroa mite syndrome often means an end to your colony, even if treatment is applied.

Symptoms
  • Spotty brood and Varroa present on adult
  • Mites may be present on brood
  • Mites seen on open brood cells
  • Small population size
  • No odor present, just sunken brood
Screen Shot 2018-05-08 at 7.36.32 AM.png
Parasitic mite syndrome is the most progressed sign of mite damage. If parasitic mite syndrome is seen, than the damage is done. These colonies will likely collapse, and there is nothing a beekeeper can really do. At this stage, the colony has already dwindled and deteriorated.

Summary

All beekeepers should consistently monitor mites throughout the year. Even if mite levels are low at one point, it does not mean they will stay low. Mite levels can easily spike, so always be aware and monitor and re-monitor. Beekeepers should learn how to monitor and visually inspect for mites. By doing so, varroa mites can effectively be managed. Varroa mites are the most challenging issue beekeepers face, so make sure you know where your colonies stand. If you don’t, then you risk losing your colonies.

Cheers!
Garett Slater

 

Why do modern colonies have removable frames?

 

Historically, comb management was virtually non-existent because pre-1850’s beekeeping because colonies did not have removable frames. Beekeepers kept colonies in makeshift enclosures, and oftentimes these colonies were made of local materials found in specific regions. These beekeepers built hives with 3 basic premises: 1) the colonies must be protected from extreme weather, 2) a flight entrance must be provided that is small enough for the colony to defend predators, and 3) the hive must contain an opening to remove honey (Graham,1992). Below are pictures of different colony enclosures:

Figure 1: The four hives in Figure 1-4 are made primarily of straw. Figure 3 is known as a skep, which is a basket placed on an open-ended bottom.  – These pictures are courtesy of University of Minnesota Bee Lab
Figure 2
Figure 3

 

Figure 4

 

Figure 5 :This hive is made primarily from clay-This picture is courtesy of the University of Minnesota Bee Lab

 

These hives protected bees well; however, these hives had one common problem: the comb needed to be cut and destroyed to harvest honey. Post-harvest, bees had to rebuild comb, an energy expensive task. Moreover, these hives offered other challenges, such as colonies were difficult to inspect and bees were easily angered. Lorenzo Lorraine Langstroth identified this problem in his 1851 diary entry:

“Pondering, as I had so often done before, how I could get rid of the disagreeable necessity of cutting the attachments of the combs from the walls of the hives, and rejecting, for obvious reasons the plan of uprights, close fitting(or nearly so) to these walls, the almost self-evident idea of using the same bee space as in the shallow combs came into my mind, and in a moment the suspended movable frames, kept at a suitable distance from each other and the case containing them, came into being. Seeing by intuition, as it were, the end from the beginning, I could scarcely refrain from shouting out my “Eureka!” in the open streets.”

L.L. Langstroth developed a hive with removable frames, which is called the Langstroth hive today. Frames were easily moved and designed so the frames were spaced properly to overcome bees tendency to propolize in smaller spaces. With the Langstroth colony, beekeepers could now easily inspect colonies for diseases, bees would be disturbed less often, colonies could be easily split, frames with honey could be easily removed without disturbing or destroying brood, and it became easier to compartmentalized queens using queen excluders (Graham,1992). The Langstroth hive changed beekeeping forever and influenced beekeeping today. But L.L. Langstroth’s invention did offer a new challenge: comb management.

Figure 6: Langstroth Hive-This picture is courtesy of Rob Snyder

L.L. Langstroths’s idea of a removable frame was not a novel idea. A blind beekeeper by the name of Francois Huber developed a leaf hive, the first colony with removable frames (Huber, 1821). The leaf hive consists of 12 vertical frames or boxes that are parallel to each other. It is evident that Huber influenced L.L. Langstroth’s idea. In “Langstroth on the hive and the honey bee” (1860), L.L. Langstroth stated:

“The use of the huber hive had satisfied me, that with proper precautions the comb might be removed without enraging the bees, and that these insects were capable of being tamed to a surprising degree. Without knowledge of these facts, I should have regarded a hive permitting the removal of the combs, as quite too dangerous for practical use.”

From this, L.L. Langstroth developed the hive equipment we see today.

Figure 7: Original drawing of the leaf hive (Huber,1921)

 

Figure 8: L.L. Langstroth’s patent for original Langstroth hive

 

Improvements have been made to the original Langstroth hive, but the overall idea remains the same. This invention was a major turning point for beekeeping because the Langstroth hives provided the impetus for contemporary beekeeping. Bees became easier to manage, and interest in beekeeping rose. But as beekeeping changed, so did management practices. Today, beekeepers manage comb differently than pre-1850’s beekeepers, and because of this, comb management has become an important management practice.

Cheers,
Garett Slater

 

Citations

Langstroth, L. L. (1859). Langstroth on the hive & honey bee. American bee journal.

Graham, J. M. (Ed.). (1992). The hive and the honey bee (No. 638.12 G7 1992). Hamilton, IL: Dadant & Sons.

Huber, F. (1821). New observations on the natural history of bees. W. & C. Tait, and Longman, Hurst, Rees, Orme, and Brown, London

ALL ABOUT SPLITS: THE 3 MAJOR TECHNIQUES FOR SPLITTING YOUR COLONIES

Whether you are a hobbyist, sideliner, or a commercial beekeeper, spring is a busy time for many beekeepers. Of all the spring tasks, splitting colonies may be the most crucial. Whether beekeepers split to expand their operation, to re-queen their colonies or control varroa, splitting is an important, yet time consuming task. In many ways, splitting is a right of passage for beekeepers.

Why Split?

In simplistic terms, splitting is the act of producing two colonies from one. As mentioned earlier, beekeepers want to do this for several reasons:

Expand their numbers

Are beekeepers ever happy with their numbers? As beekeepers gain experience and passion for beekeeping, they likely want to expand their numbers. This is not different for any level of beekeeping. However, bee colonies can be expensive. Splitting colonies is an inexpensive way to expand your numbers.

Maintain numbers

Many beekeepers are not interested in expanding, but they want to maintain the status quo. Whether these beekeepers are satisfied with their numbers or have little room to expand, splitting is an effective practice to maintain numbers. Beekeepers typically split colonies in the spring to replace summer and winter losses.

Control varroa

Beekeepers biggest challenge for beekeeping is not skill set or management, but controlling varroa. Varroa can devastate colonies and eventually destroy your entire operation. While beekeeper may not split specifically to control mites, splitting can do just this. Beekeepers introduce a brood break when they split, which means capped brood is not found within the colony. Many varroa treatments fail because these treatments are ineffective at killing mites under the brood. Thus, a brood break can improve treatment efficacy. Whether a brood break is introduced by re-queening or caging the old queen, beekeepers can better control varroa during splits.

Requeen

Older queens can place your colonies at risk for the upcoming season. Whether the queen is older than 1 year or 3 years, re-queening older queens must be considered. If not, these queens may eventually fail, begin producing male drone eggs, lose pheromone capacity, or become tormented by unhappy worker bees before they can replace her. Because of this risk, many beekeeper re-queen colonies with young, prolific queens annually. Benefits of re-queening include more honey production, larger population, more consistent brood pattern, increased foraging, and these are just to name a few.

Prevent swarms

Beekeepers can prevent warming by splitting large colonies into two smaller colonies. While many beekeepers add space to prevent swarming, splitting can be an effective swarm management practice. However, beekeepers must be aware about the stage of swarming. If large colonies have swarm queen cups WITHOUT eggs, these colonies are in the early stages of swarming, and can easily be split. But if these queen cups do contain eggs and the queen is getting smaller, then all queen cells and queen cups must be removed before splitting.

When Can I split?

Beekeepers can split whenever queens are available. Typically, commercial queens become available around April-May, so this is when beekeepers usually split. Furthermore, April-May is before many major honey flows, which can help splits become established. However, I do not want to discourage you from making splits later in the season. If you have queens readily available and a major fall honey flow, than late season splitting can be successful. But if a major fall honey flow does not occur, especially in northern climates, fall splitting may do more harm than good.

I should also mention that you can only split larger colonies. If you split weak colonies, these are less likely to succeed because weaker colonies produce weaker splits. Even if a beekeeper wants to split, they must consider their colony size, brood availability, and number of nurse bees. Typically, you want a strong, double deep colony with at least 9 frames of brood, 6 at a minimum.

How many times can I split?

Beekeepers can split colonies multiple times, but this can depend upon the strength of the colonies and the degree of the honey flow. I have heard reports of beekeepers splitting colonies +5 times, but these colonies were strong and were in an area of a great honey flow. Also, the more times beekeepers split, the less honey they will produce. If I were to provide a guide, have AT LEAST 6 frames of brood before you split. 9 is ideal, but 6 is necessary.

Can splitting help control mites?

Beekeepers can better control mites by splitting their colonies. Certain splitting practices elicit a brood break, which make mite treatments more effective. Moreover, brood breaks make organic treatments, such as oxalic acid, formic acid, and apiguard more effective. If you want to initiate a brood break, you have 3 options:

  1. Requeen both the parent and daughter colony

Splits require requeening just the daughter colony (the split). However, both the parent colony (the colony being split) and the daughter colony can both be requeened at the same time. If you requeen with cells, you will have nearly a 2 week broodless period by the time the queen mates, begins laying eggs, and these juveniles become capped. If inserting cells, this window is shorter (few days if the colony contains open brood), but still long enough to apply an effective treatment.

2. Requeen the daughter colony and cage the parent colonies queen

If you want to keep the queen from the parent colony, you can cage her for 1-2 weeks in order to initiate the same brood break. Queens placed into a queen cage and inserted in a colony are fine 1-2 weeks in a colony. Even though caging the queen can impact colony size, growth and honey production, this can be an effective mite management strategy.

3. Requeen the daughter colony and just pay closer attention to parent colonies. 

The parent colony does not necessarily need to be requeened or have its queen caged. If you know which are the parent colonies, you can easily monitor these colonies throughout the year. These colonies will likely have higher mite levels throughout the year because they did not receive this brood break, but you can manage accordingly.

How far should I move the split?

You can choose to move your splits 4 feet or 4 miles, it does not really matter. You do not need to move the splits to new a new yard miles away, so do not feel the need to. But if you do keep colonies within the same yard, move the daughter colony at least 4 feet away from the parent colony, and make sure the entrance facing a different direction.

How to split?

I will talk about 3 methods for splitting, but please remember that every person has their own method of splitting. I am sure you can find variations of the methods I present below, but these are the methods I typically use. I did not chat about producing nucs, even though nuc production is a form of splitting. I plan to write about producing nucs in a seperate post, so please bear with me!

Method 1:

 

Advantages Disadvantages
Easy to gauge number of bees transferred between colonies Queen needs to be found
The method requires only 1 day Can be time consuming
No extra equipment needed, other than  the split

1. Finding queen and cage her

Method 1 may be the most time consuming because the method requires finding the queen. For inexperienced beekeepers, this can seem like a daunting task. However, finding the queen is an essential aspect of beekeeping. In order to easily find queens: 1)split double deep colonies before queen inspection so the queen does not run between boxes and 2) limit colony agitation by carefully inspecting frames. Once found, gently grab the queen by the wings or thorax, and place her into a queen cage. Queens are delicate insects, so they should be treated with care. Typically, beekeepers place caged queens next to the colony under shade or in another safe, shaded area.

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2. Add 2-3 frames of capped brood to split

Once queen is caged, you can begin adding frames to the split. You will want to add at least 2-3 frames of brood, preferably 2 frames of capped/emerging brood and 1 frame of open brood such as eggs, young larvae, or older larvae. The new split needs capped/emerging brood  because the capped brood will hatch soon. These newly emerged bees will both repopulate the colony and accept the queen more readily than older bees.

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3. Shake a minimum of 3 brood frames into split

New splits need bees so the capped brood is properly warmed and tended to. I recommend shaking at least 3 brood frames into the split. Shake only brood frames because the new splits will need young, nurse bees to tend the brood. Beekeepers typically shake only 3 frames, but you can can add more depending upon the parent colonies strength and impending recovery.

4. Keep brood together, and replace frames taken away from the parent colony

Make sure the brood is kept together in the split because if not, the nurse bees begin stretching resources. For example, limited nurses can only focus their energy to warm, tend, and feed the brood in a certain area. If brood is spread apart, the nurse bees cannot easily tend all the brood properly. On either side of the brood, you can place honey frames, empty drawn comb frames or foundation frames. Just ensure that foundation frames are at least 1 frame from the edge or else the bees will not draw them out. Once the split is organized, the empty frames can be placed into the parent colony. Organize the parent the same as the split: brood in the middle.

5. Move the split

Move the split to a new location, preferably 4 feet away. Once moved, face the entrance opposite of the parent colony. I face the entrance in the opposite direction, even though it may not be necessary. I want to ensure arriving foragers orient to the parent colony, not the new split. Older foragers will not readily accept a new queen, so foragers can cause splits to fail. Other beekeepers reduce the entrance when they move their colonies. Splits are often weaker and more susceptible to robbers, so entrance reducers can limit robbers, especially during times of dearth.

6. Introduce mated queen or queen cell

Once splits are made, you can now insert the queen. Certain beekeepers wait 24 hours before introducing a mated queen or queen cell, but that is not necessary. I wait 24 hours because I want newly emerged bees to hatch, which may increase likelihood of queen acceptance. But in all reality, it likely does not matter. When introducing a queen cage, place the cage between brood frames and make sure the wire caged is NOT facing the comb.

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Method 2:

Advantages Disadvantages
Do not need to find queen 2 day process
Quick process, despite requiring 2 days Queen excluder needed
Easy to do a large number of colonies Cannot control number of bees transferred

1. Remove 4 frames from empty split

When setting up this split, remove 4 empty frames from the empty split. The empty split now has 4 openings, which is where bee free brood frames will be placed.

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This is how a parent and daughter colony should begin as. The parent colony should have at least 9 frames of brood, 6 at a minimum before splitting. Split strong colonies before a honey flow to ensure success.

2. Add 3 frames of brood and 1 honey frame for feed to the empty split

Similar to method 1, colonies will need 3-4 frames of brood for a successful split. But instead of moving both the frames and bees to split, these frames must be inspected for the queen and shaken before they are moved. This method requires shaking because bees will auto-populate the colony over the next 24 hours. Moreover, inspecting and shaking the colony ensures the split does not have the old queen. If the queen is placed in the split, this adds more work for the beekeeper.

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Add frames of brood to the daughter colony. Preferably, 2 frames of capped brood and at least 1 frame of open brood (eggs, young larvae, older larvae). If the parent colony is very strong, you can add 4 frames of brood.

3. Add queen excluder above parent colony

This method requires a queen excluder so the queen does not travel into the new split. As mentioned earlier, if the queen enters the split, this adds more work and risk for the beekeeper.

4. Place daughter (split) colony above queen excluder. 

The daughter colony should only contain brood, not bees. However, bees will travel to the daughter colony over the next 24 hours so these bees can tend and care for the unattended brood. The bees will control the daughter colonies population, which is an added benefit.

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Add a queen excluder above the parent colony and place daughter colony above queen excluder. The queen excluder ensures that the daughter colony will become populated with bees without the queen moving up.

5. Come 24 hours later and move colony to new location

After 24 hours, the colony should contain plenty of bees, all of which will be young, nurse bees. Move the colony to a new location, preferably 4 feet away as stated in method 1.

6. Requeen colony

After the daughter colony is moved, the queen can be inserted. Similar to method 1, queens can be inserted immediately or 24 hours later, it is really a personal preference.

 

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This is how the final colony should look (maybe not exactly). This method can be done with singles, but these singles must be strong, full of bees, and packed with brood.

Method 3:

Advantages Disadvantages
Easy to split a large number of colonies 7 day proces
Does not require finding the queen Extra queen excluders required
Hard to produce a quality split that has the appropriate amount and type of brood

1. Place excluder between brood boxes

Method 3 is relatively quick and easy, but far less common. Essentially, place a queen excluder between brood boxes. By doing this, it keeps the queen into either the top or bottom box, which limits the time and effort needed to find the queen.

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The daughter and parent colony can be reversed, but it depends upon where the queen is. With this method, you will not know for at least 7 days.

2. Come back in a week, and divide boxes

After a week, it is apparent which brood box contains the queen. Comb through the boxes, and find the frames with eggs. This brood box will contain the queen.

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Divide the colonies, and move daughter colony to new location. Depending upon the state of the daughter colony, you may want to move some brood around.

3. Split colony and move daughter colony to new location

The colony without the queen is the new daughter colony. Move this colony to a new location, preferably 4 feet away. As mentioned earlier in method 1 and 2, you can add an entrance excluder during times of dearth to limit robbing and/or move the entrance in a different direction to ensure foragers do not enter the split.

4. Requeen daughter colony

You can now requeen. Similar to method 1, queens can be inserted immediately or 24 hours later, it is really a personal preference.

Cheers,

Garett Slater