In Part III of this series we described various iterations of the Farrar-system of two-queen hives, piggybacked single-queen colonies. Each brood chamber had its own entrance and honey supers. Early in the season the upper unit benefited from the resources of the brood box below during the establishment of a second queen while, as time passed, the whole colony benefited from the combined laying power of two queens. As with doubled hives, developed by Wells in the early 1890s and as Farrar established, the combined workforce not only operates cooperatively but also a proportionally larger number of bees harvest nectar more efficiently. So what further improvement could be made to systems with two queens.
Moelleri was the first researcher to recognise that complete separation of brood nests, each with its own queen, was quite unnecessary:
Most of the methods tend to emphasize separating brood nests, presumably to prevent queens from ‘fighting’ across the queen excluder. This is no longer considered critical. Some earlier methods are rather complex and unnecessarily involved. The two-queen system described here is simple and still uses the normal behavior patterns of bees.
This contradicted Farrar’s early assertionii that queens would always be lost if they were located in close proximity:
Two-queen colonies differ from multiple-queen colonies in that a second queen is introduced to another part of the hive for a portion of the season. Both queens produce eggs within their independent brood nests which must be separated from each other.
This was a critical inflection point in the long road to efficient contemporary two-queen hive operation.
The consolidated brood nest two-queen hive
With this growing understanding, Floyd Moelleriii operated two-queen colonies with queen excluders juxtaposing their brood nests. Moeller employed either standard full depth ten-frame gear or shallow twelve-frame gear throughout a six-year 1967-1974 study, shown here for his ten-frame operation (Figure 1).
To establish his two-queen hives, brood chambers were reversed from early spring to stimulate brood rearing. Once each colony grew to a strong double the colony was split and a caged queen was introduced to whichever portion of the split colony did not have fresh eggs after several days. This obviated the need to find the parent colony queen, an obvious advantage in any large commercial operation.
Initially a double screen was employed to separate the piggybacked splits, the upper colony benefitting directly from the rising warmth of the brood nest below. With this arrangement, and once well established, the two units could be united by the simple measure of replacing the double screen by an excluder.
Moeller’s system was very similar to that of Walton (see previous Part III) except in that ample space was always provided for brood rearing at all times, the upper queen only limited by her laying capacity.
Towards the end of the main flows, the colony was collapsed to a single queen hive – this time achieved by removing the excluder dividing the large brood nest. Here any effort to extend the capacity of the colony to raise more workers would be wasted and a drain on colony resources. Timing of colony building to coincide with major honey flows is important for any commercial operation but regulation of population size is more critical for two-queen-colonies.
Figure 1 Moeller system for operation of two-queen colonies, redrawn and modified to show operational detail: ds = double screen; x = excluder; e = entrance
(a) the process is started with a strong over wintered colony with an old queen (OQ);
(b) the colony is built to strong triple;
(c) the colony is split and a new queen is introduced above double screen and supered below the screen – as needed – to allow the lower unit to expand;
(d) the colony is further built with the double screen replaced by a queen excluder giving both queens given ample room to expand with simple top supering for the honey flow;
(e) the excluder is removed towards the end of the honey flow facilitating staged removal of honey supers. This also allows the top younger queen (NQ) to supersede the old parent hive queen (OQ); and
(f) the colony is further collapsed in preparation for overwintering (e → f→ a).
Moeller stated the obvious by noting that, under conditions where a single queen colony required a single honey super, a two-queen colony required at least two supers. In comparing his ten-frame full depth system with his twelve-frame shallow super operation, he observed that shallow supers were filled more quickly and were thus more easily removed and returned to the hive. Rapid honey removal is another key feature of any honey flow management program but is more critical for two-queen hive operation.
Moeller’s lasting contribution was the abandonment of the complex Farrar-style supering arrangements. All honey supers are operated on the single queen colony plan: all honey supers were located above the brood nest. Moeller later compared the single-queen and two-queen systems of management and concluded that well-run two-queen hives maximised honey productioniv.
In a major refinement of the ‘double brood nest approach’ to the operation two-queen colonies, Hoggv (reviewed elsewherevi) formulated sound theoretical principles – and a range of practical measures – for establishing a single consolidated brood nest (CBN) containing two or, in principle, many queensvii. He drew on both Moeller’s experience and on Langstroth’s observationviii:
The queen bee never stings unless she has such an advantage in the combat that she can curve her body under that of her rival in such a manner as to inflict a deadly wound without any risk of her being stung herself! The moment that the position of the two combatants is such that neither has the advantage, and that both are liable to perish, they not only only refuse to sting, but disengage themselves, and suspend their conflict for a short time!
Here, as conceptualised by Hogg, instead of independent brood chambers, queens share in the development of a single but extremely large brood nest. Pheromone signalling and brood raising are fully integrated lending intrinsic stability to a colony so large that, in the absence of a honey flow would be very swarm proneix. Since active brood nest temperatures hover around 35 0C, they mainly operate well above ambient air temperature. And since the thermal efficiency of a brood nest improves as the nest expands by a factor of 4/3 times the radius*, and the proportion forager bees in a population increases as the bee population expands, two-queen hives tend to be more efficient, bee-for-bee than much smaller single-queen hives. While two-queen hives may benefit from other economies of scale, such as more efficient scouting for nectar, pollen, propolis and water and distributed decision making may be improved, quantifying and pinpointing any single benefit is not known.
* A quick calculation shows that the volume to surface area ratio is four thirds times the radius assuming a spherical brood nest:
However the storage of honey in upper supers, a singular feature of efficient single-queen colony management, is returned to the two queen operation. The consolidated brood nest setup returns traditional supering and honey harvesting practice to hives and removes the complex manipulations required to remove honey in the Farrar top-and-bottom brood nest schemes. Hogg’s scheme is depicted in Figure 2.
The rationale and means of establishing and operating colonies with two queens in a single brood nest have been fully canvassed elsewherex. Hogg concluded that the new arrangement would provide the basis for new and less complicated two-queen management systems, especially applicable to comb honey productionxi. The resulting powerful colonies generate an estimated 25-50 % more bees than a strong single queen colony, while their low propensity to swarm can, in large measure, be attributed to double queen pheromone production.
Figure 2 John Hogg’s model for operation of two-queen colonies employing a consolidated brood nest (CBN): ds = double screen; x = excluder; e = entrance
(a) an over wintered colony with old queen (OQ) is built to a strong double in early spring;
(b) the colony is split using a double screen and is requeened; and, once well established, either:
(c) the double screen is replaced with a queen excluder (employing single 10 or 12 frame brood supers), and is supered for the flow [Figure 2c], or
(d) the double screen is replaced with a queen excluder, employing and expanded bottom brood chamber and a single upper brood chamber (for eight-frame operation) [Figure 2d], and supered for the flow; and
(e) the queen excluder is removed towards the end of the flow when the colony then reverts to a strong single-queen unit for overwintering.
In his later writings, Hogg contemplated the exigencies of two-queen hives that might either swarm or where supersedure might occur. In the process he posed questions about our understanding of the operation of colonies with more than a single queen:
When swarming occurs, will one or both queens go out with the swarm; and will queen succession occur accordingly to maintain double queen status? Also, will supersedure of one or both queens ever occur.
Interestingly Farrar xii touches on this issue in observations he made on supersedure in two-queen colonies noting that:
The problem of supersedure is no greater in two-queen than in single-queen colonies except that, when one queen is poor and queen cells are started, cells usually will be built in the other brood nest.
Dannielle Harden, also from Canberra Region Beekeepers, and I made the same observation recently. One queen from a two-queen hive was lost under then poor seasonal conditions of 2019-2020. This happened to a number of hives in the previous, also poor, season though we were able to restore their two-queen status by uniting spare nuclei to these hives. Queen cells appeared in the queenright portion of the hive in the same manner reported by Farrar. There was however no worker or drone brood of any age anywhere in the hive but, on a subsequent inspection four weeks later, a new supersedure queen was found to be laying well, the colony having benefited overall from two laying queens in the spring and early summer buildup phase.
Hoggs elegant and indeed very practical two-queen system culminated in the ingenious Juniper Hill Planxiii designed not only to minimise swarming and to increase honey production, but also to improve section comb honey production. The critical differences between single-queen and two-queen operation distils: (a) to the initial timing and establishment of a second queen, (b) to nuanced timing of end-of-season colony collapse to a single queen unit and, (c) to the challenges of maintaining and intervening in a poor season where one or both queens fail or a queen is lost to supersedure.
Recent applications of two-queen and doubled hive systems
All in all two-queen hive operation has been set on a very firm footing. While running successful two-queen demands intensive management, and a nuanced understanding of their operation, two-queen hives have also been used to address emerging problems of apiary operation such as declining floral resources and colony collapse disorder.
The alternative being proposed by Tom Seeley, is to return beekeeping to a much more natural wild hive condition where colonies are much smaller and the returns (honey and pollination service) are much reduced but where bees, with some modicum of swarm and disease control, will survive and still provide traditional products such as wax and a small honey crop.. In this context it is instructive to read the account of Eva Crane on the declining farming of traditional native stingless bees (Meliponini) in Mexicoxiv where they are maintained as a commercial source of honey.
In the early 1990s, Duff and Furgalaxv compared the performance of 500 two-queen units made up from same-season package colonies, overwintered colonies each hived with its division on the same stand and parent colonies and their divisions hived on separate stands evaluating their productivity and, mainly in terms of management effecting their profitability. This study provides some insight into the most appropriate system for establishment of two-queen colonies tailored to latitudinal and floral resource conditions. From around 2000, a number of North and Central American two-queen hives studies were undertaken to attempt to address the problems of local climatic extremes.
Figure 3 Duff and Furgala’s 1990 single and two-queen hive study
Villarroel, Rebolledo and Aguileraxvi employed doubled and tripled colonies (rather than two-queen or three-queen hives) to investigate problems of declining honey production on the Mexican High Plateau attendant to the arrival of Africanised bees and Varroa. These authors describe a 44% honey yield increase with two queens. In another study on the Mexican High Plateau, also undertaken to address problems associated with declining honey bee yields, Africanisation of local honey bees and the arrival of Varroa mite, Valle, Guzmán-Novoa, Benítez, and Rubioxvii experimented with the Moeller system. They employed new queens in colony splits, doubling honey yields.
Gutierrez and Rebolledoxviii compared the productivity of double queen and traditional single-queen systems in Ranquilco, Chile using fifteen standard Langstroth hives. Of these, six employed a horizontal doubled hive, side-by-side single-queen brood nest chambers supered above a shared excluder, six employed the traditional tower two-queen hive and three used the normal single-queen set up, where hives with two queens increased productivity.
Steve Victors xix employed cold-adapted Carniolan two-queen colonies built from package bees. The Alaskan beekeeping season is extremely short and it is challenging to build bees to fully exploit honey flows. Victors found that with package bees, headed by cold climate Carniolan stock, two-queen colonies achieved both more rapid colony buildup and doubled honey yields.
Two-queen hives in retrospect
In reviewing the history of development of two-queen hives, we have seen that the many challenges attendant to establishing and operating them have been largely overcome. They are far more productive than comparable single-queen colonies employing the same amount of equipment.
Operating two-queen hives optimally requires some skill, particularly in respect of timing of operations and in their initial setup. They can only be operated during the main spring buildup through to near the end of major honey flows and are prone to failure in any time of dearth.
Well set up, however, they can be operated in much the same way as single-queen hives except in that honey must be removed promptly if their productive potential is to be realised. Unlike single queen hive systems all must employ at least one queen excluder to ensure that the queens are kept apart and colonies need always to be managed to minimise the risk of the colony reverting back to the natural single queen condition.
Hive design requirements
There is also a clear recognition that two-queen hives can be configured vertically or horizontally while honey supers and barriers can be deployed in many arrays. Overall the brood nest arrangement is either a top-bottom (or a side-by-side) arrangement, where there are two discrete brood nests, or a more sophisticated juxtaposition of brood where a single large brood nest (the consolidated brood nest or CBN) is divided only by a single excluder (Figure 4).
Figure 4 Basic architecture of two-queen hives depicting brood-chamber alignment for the ideal CBN setup: (a) tiered (vertical); and (b) side-by-side (horizontal) arrangements; x = excluder
While the principle purpose of operating two-queen colonies units has been to vastly improve honey production, their potential for use as powerful pollinators – with minimal supering to facilitate their ready movement – would appear to have been overlooked. Two-queen hives have been adopted for other purposes, notably as means to requeen colonies, as efficient producers of section comb honey, to reduce swarming, to accelerate development of nuclei and – with special measures – to overwinter an additional queen.
Horrxx has deftly dissected the advantages and disadvantages of operating two-queen hives. Systems such as the Hesbach-Nabors-Heuvel horizontal doubled hive may have appeal to the backyard hobbyist keen to hone beekeeping skills for managing large hives without a requirement to fully comprehend the complex dynamics of two queens operating in a single brood nest.
Lessons from history necessary for successful operation of two-queen hives can be distilled as the need:
- to understand the special conditions required for acceptance of two queens in the initial setup;
- to routinely check for the presence of two queens and that they remain reasonably matched in terms of their age and provenance;
- to aggressively super and remove honey during flows;
- to time set up so that peak colony population coincides with anticipated honey flows; and
- to collapse colony to single queen status well before conclusion of main honey flow.
I would like to thank Liz Miller at the CSIRO Black Mountain Herbarium, Anne-Marie Slattery, Josie Braddick and William Hastie at the CSIRO Black Mountain Library and Michael Herlihy from the Australian National Library for their assistance in locating publications.
iMoeller, F.E. (1976). p.5. Two queen system of honeybee colony management. Production Research Report 161, Agricultural Research Service, United States Department of Agriculture, 15pp., Washington DC 20402. http://naldc.nal.usda.gov/download/CAT87210713/PDF
iiFarrar, C.L. (1953). Two-queen colony management. American Bee Journal 93(3):108-110, 117 reprinted as Farrar, C.L. (1953). Two-queen colony management. Bee World 34(10):189-194. p.189. https://doi.org/10.1080/0005772X.1953.11094821
iiiMoeller, F.E. (1961). The relationship between colony populations and honey production as affected by honey bee stock lines. p.8. US Department of Agriculture, Agricultural Research Service, Production Research Report 55, 24pp. https://babel.hathitrust.org/cgi/pt?id=uc1.aa0001977776;view=1up;seq=2
Moeller, F.E. and Harp, E.R. (1965). The two-queen system simplified. Gleanings in Bee Culture 93(11):679-682, 698.
Moeller, F.E. (April 1976). loc. cit.
ivMoeller, F.E. (1980a). Managing colonies for high honey yields. Beekeeping in the United States Apiculture Handbook Number 335, 64-72. US Department of Agriculture. Revised October 1980. http://beesource.com/resources/usda/managing-colonies-for-high-honey-yields/ originally published in 1971 at: https://thebeeyard.org/wp-content/uploads/2014/02/Beekeeping.in_.the_.United.States.pdf
Also found online as Moeller, F.E. as Managing colonies for high honey yields at pages 23-30 in Agricultural Research Service, United States Department of Agriculture (August 1967, revised June 1971) Agriculture Handbook No. 335. Beekeeping in the United States. 148 pp. https://babel.hathitrust.org/cgi/pt?id=uva.x030492509&view=1up&seq=6
Moeller, F.E. (1980b). Queens, two queen system of honey production. ABC and XYZ of Bee Culture, pp.555-556. AI Root Co., Medina, Ohio.
vHogg, J.A. (1981). The consolidated two-queen brood nest and queen behavior: Queens co-exist in contact through an excluder. American Bee Journal 121(1):36-42. http://www.twilightmd.com/Samples/Hogg/Hogg_Halfcomb___Publications/ABJ_1981_January.pdf
Hogg, J.A. (1983a). Methods for double queening the consolidated broodnest hive: The fundamentals of queen introduction, Part I. American Bee Journal 123(5):383-388. http://www.twilightmd.com/Samples/Hogg/Hogg_Halfcomb___Publications/ABJ_1983_1May.pdf
Hogg, J.A. (1983b). Methods for double queening the consolidated broodnest hive: The fundamentals of queen introduction. The fundamentals of queen introduction, Part II: Conclusion. American Bee Journal 123(6):450-454. http://www.twilightmd.com/Samples/Hogg/Hogg_Halfcomb___Publications/ABJ_1983_2June.pdf
Hogg, J.A. (2000). The Juniper Hill split for comb honey production. American Bee Journal 140(5):368-369. http://www.twilightmd.com/Samples/Hogg/Hogg_Halfcomb___Publications/ABJ_2000_May.pdf
Hogg, J.A. (2003). The Juniper Hill plan for comb honey production. American Bee Journal 143(4):285-288. http://www.twilightmd.com/Samples/Hogg/Hogg_Halfcomb___Publications/ABJ_2003_April.pdf
Hogg, J.A. (2005). The Juniper Hill plan for comb honey production, improved two-queen system. American Bee Journal 145(2):138-141. http://www.twilightmd.com/Samples/Hogg/Hogg_Halfcomb___Publications/ABJ_2005_February.pdf
viWade, A. (2019a). Establishing two queens instead of one queen in a honey bee colony Part II. Setting up two-queen colonies. The Australasian Beekeeper 120(9):16-21.
viiWade, A. (2019b). Establishing two queens instead of one queen in a honey bee colony Part III. Operating two-queen colonies. The Australasian Beekeeper 120(10):22-25.
viiiLangstroth, L.L. (1853). The Hive and the Honey-Bee: A beekeeper’s manual, 404pp. Northampton, Bridgman & Company. p.234. https://babel.hathitrust.org/cgi/pt?id=ncs1.ark:/13960/t5w671f5m&view=1up&seq=11
ixLynne, J. (1957). The two-queen system is an aid in swarm control. Gleanings in Bee Culture 85(4):213, 215.
xWade, A. (2019c). Establishing two queens instead of one queen in a honey bee colony Part I. Principles of introducing and running two-queen colonies. The Australasian Beekeeper 120(8):18-21.
xiFarrar (1953). loc. cit.
xiiFarrar (1946). Two-queen colony management. United States Department of Agriculture. Agricultural Research Administration, Bureau of Entomology and Plant Quarantine, 14pp. http://ufdc.ufl.edu/AA00026061/00001/14j
xiiiHogg, J.A. (1980). A new comb honey concept. American Bee Journal 120(5):357-362.
Betterbee (Northeast Center for Beekeeping, LLC) [US] (March 2015). Juniper Hill split. https://www.betterbee.com/images/Juniper%20Hill%20Split.pdf
Parsons, W. (1997). Using the Juniper Hill plan for comb honey production.American Bee Journal 137(9):627-628.
Crane, E. (1980). New concepts in comb honey. Bee World 61(4):129-130. https://www.evacranetrust.org/uploads/document/1f7cc447fc2d880ffa514507b99f2ab854543a75.pdf
xivCrane, E. (1957). Second American bee journey. Part III: Cuba and Mexico. Bee World 38(12):301-313. https://doi.org/10.1080/0005772X.1957.11095023 https://www.evacranetrust.org/uploads/document/d8eb6b8772f4008dafb2b505b88306e080b53250.pdf https://www.evacranetrust.org/uploads/document/63b51bdc9c2af302e23c42ae73bb5a9428e7f50a.pdf https://www.evacranetrust.org/uploads/document/955e5c71044ed246bf7ba39cb86243c891027f50.pdf
xvDuff, S.R. and Furgala, B. (1990a). A comparison of three non-migratory systems for managing honey bees (Apis mellifera L.) in Minnesota: Part I Management and productivity. American Bee Journal 130(1):44-48. http://garybees.cfans.umn.edu/sites/garybees.dl.umn.edu/files/comparison_i.pdf
Duff, S.R. and Furgala, B. (1990b). A comparison of three non-migratory systems for managing honey bees (Apis mellifera L.) in Minnesota: Part II Economic analysis. American Bee Journal 130(2):121-126. https://scholar.google.com.au/scholar?hl=en&as_sdt=0%2C5&q=+Duff%2C+S.R.+and+Furgala%2C+B.+%281990b%29.++A+comparison+of+three+non-migratory+systems+for+managing+honey+bees+%28Apis+mellifera+L.%29+in+Minnesota%2C+Part+II.+Economic+analysis&btnG=
xviVillarroel, D.T., Rebolledo, R.R. and Aguilera, A.P. (1998). Comparative study of honey production with one and two queens per hive in the area of Nueva Imperial, IX Region, Chile. [Estudio comparativo de producción de miel con una y dos reinas por colmena en la zona de Nueva Imperial, IX Región, Chile.] Agro Sur 26(2):121-126. http://revistas.uach.cl/html/agrosur/v26n2/body/art12.htm
Rebolledo, V.R.R., Guiñez, C.G., Araneda, D.X. and Aguilera P.A. (2008). Comparative study of honey bee production with one and three queens by beehive in Neuva Imperial, IX Region, Chile. [Estudio comparativo de producción de miel con una y tres reinas por colmena en la zona de Nueva Imperial, Chile.] Idesia 26(2):19-25. https://scielo.conicyt.cl/scielo.php?pid=S0718-34292008000200004&script=sci_arttext and https://www.researchgate.net/publication/297710235_Comparative_study_of_honey_bee_production_with_one_and_three_queens_by_beehive_in_nueva_imperial_IX_region_Chile
Rebolledo, R.R., Riquelme, M.C., Haiquil, S., Sepúlveda, G. and Aguilera, A.P. (2011). Comparative study of honey and pollen production in a double queen system versus one queen per hive in La Araucanía Region, Chile. [Estudio comparativo de la producción de polen y miel en un sistema de doble reina versus una por colmena en La Araucanía, Chile.] Idesia 29:139-144. http://www.idesia.cl/Vols/2011/29-2/art18.pdf and https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0718-34292011000200018&lng=en&nrm=iso&tlng=en
Cengiz, E.H., Genç, F. and Cengiz, M.M. (2019). The effect of the two-queen colony management practice on colony performance and Varroa (Varroa destructor Anderson&Trueman) infestation levels in honey bee (Apis mellifera L.) colonies. Uludag Bee Journal 19(1):1-11. https://dergipark.org.tr/en/download/issue-full-file/45334
xviiValle, A.G.G., Guzmán-Novoa, E., Benítez, A.C. and Rubio, J.A.Z. (2004). The effect of using two bee (Apis mellifera L.) queens on colony population, honey production, and profitability in the Mexican high plateau. Téc Pecu Méx 42(3):361-377. http://cienciaspecuarias.inifap.gob.mx/index.php/Pecuarias/article/viewFile/1404/1399
xviiiGutierrez, P.J. and Rebolledo, R.R. (2000). Comparison between a double queen and a traditional one queen system per beehive for honey production. Agro Sur 28(2):10-14. https://eurekamag.com/research/003/686/003686522.php
xixVictors, S. (2001). Two queen hive system from package bees. Alaska Wildflower Honey, 8pp. http://sababeekeepers.com/files/Two_Queen_Hive_System_From_Package_Bees.pdf
Winston, M. and Mitchell, M. (1986). Timing of package honey bee (Hymenoptera: Apidae) production and use of two-queen management in southwestern British Columbia, Canada. Journal of Economic Entomology 79(4):952-956. https://discovery.csiro.au/primo-explore/fulldisplay?docid=TN_proquest14497293&context=PC&vid=CSIRO&lang=en_US&search_scope=All&adaptor=primo_central_multiple_fe&tab=default&query=any,contains,Winston,%20M.%20and%20Mitchell,%20M.%20(1986).%20%20Timing%20of%20package%20honey%20bee&offset=0
xxHorr, B.Z. (1998). My intensive two-queen management system means bigger crops. American Bee Journal 138(7):507-510. https://americanbeejournal.com/my-new-two-queen-hive-design/