Sue Cobey
Carniolan Honey Bees
Carniolan bees, highly favored by beekeepers worldwide, are known for their calm temperament, Winter hardiness, rapid Spring buildup and productivity. The subspecies, Apis mellifera carnica, is indigenous to the European Alps, the highest and most extensive mountain range of Europe. Well adapted to the cold Winters, short Springs, and hot Summers, their home range includes the Danube Basin, Northern Balkans and into the Alpine region.
Behavioral and physiological traits distinguish Carniolan bees. Well adapted to a harsh cold climate, they tend to winter in smaller clusters and are frugal in consumption of Winter stores. Spring population growth is rapid in response to increasing day length and early pollen sources. Brother Adam called these the “ideal bee for early Spring flow.” If not given space and properly managed, they tend to swarm. Colonies are well-organized with a tight brood-nest, surrounded by rainbows of pollen and honey packed above. Highly responsive to the environment, in late season they cease brood production in response to limited resources and shortening days.
Cold climate adapted, Carniolan bees forage in cool, marginal weather and start at first light. A memorable demonstration of this was delivering NWC breeders to queen producers at a meeting. By lunchtime NWC foragers were returning with pollen to their five frames nuclei on my truck. Italian bees in two-story colonies in the nearby almond orchard were still confined by the spring drizzle.
Honey bee subspecies vary in communicating forging distances. The dance language dialect of Carniolan bees indicates a larger foraging range. Foragers transition between the round dance signaling nearby resources, the sickle dance signaling further distances and the waggle dance signaling more distant resources. Carniolan foragers perform the round dance at distances beyond 30m (98ft), do not display a definite sickle dance, and transition to waggle dances at distances beyond 60m (197ft) In contrast, Italian foragers transition from round to sickle dances at 20m and sickle to waggle dances at 40m (131ft).
These transition changes to different dance types indicate adaptations to the foraging range of the different subspecies. The waggle dance communicates complex information, the dialects vary in the dance tempo and duration of the waggle runs, The farther the resource, the longer the waggle phase. Carniolan bees have a longer dialect, performing the waggle dance after foraging a longer distance.
There is indication of assortative mating among subspecies. Carniolan mating flights tend to occur at higher elevations. A study in Austria reported differences in the vertical distribution of drones: Carniolan drones flew at 20m (66ft) and Italian drones flew at 4m (13ft). Progeny testing showed the tendency of queens to mate with drones of their own subspecies.
Carniolan bees are dark in color, the various ecotypes (geographical variants) vary in browns and grays, from uniformly dark to markings with brown rings and dark dots on the dorsal abdomen. Never yellow, as this is an indication hybridizing and mis-mating. Carniolan bees are large, slender in body shape and have a long proboscis, an advantage in foraging for diverse floral sources.
These traits and the genetic versatility of this subspecies afford high adaptability, and favorable response to selection. Breeding programs have resulted in larger winter clusters and negligible swarming. Widely distributed, Carniolan bees now exist on all continents except Antarctica. In Germany Carniolan breeding programs have largely replaced their native Dark bee, A.m.mellifera.
The New World Carniolan
The choice to work with Carniolans was to address the challenge of maintaining these bees among predominate Italian stocks. Italian drones flooded mating areas and isolated locations were difficult to find. Consequently, the Carniolan traits were diluted and often unrecognizable in U.S. stocks. The use of instrumental insemination provided a method of controlled mating to establish and maintain a Carniolan line.
Having the benefit of the best teachers and mentors, Dr. Harry Laidlaw introduced me to the technique of instrumental insemination, (II), at U.C., Davis and Dr. John Harbo refined my skills at the USDA Bee Lab in Baton Rouge. While at UCD, Dr. Harry Laidlaw and Dr. Rob Page developed their theory of the Closed Population Breeding Program (CPBP). This became the basis to establish and maintain the New World Carniolan (NWC).
The CPBP concept appeared practical and doable given the challenges of honey bee breeding: the random in flight, multiple mating of queens, the social and behavioral complexity of the hive and their sensitivity to inbreeding. Prior to the concept of the CPBP, the major breeding system used was the Four Way Hybrid Program of the Starline and Midnight lines. This system requires the cumbersome maintenance of inbred lines and crossing these to create hybrids, which are the final product. The CPBP supports the continuous selection of desirable traits within a large population, providing flexibility and longevity to a bee breeding program.
The CPBP concept is intuitive and based upon what beekeepers have traditionally been doing – selecting and propagating the best colonies from large populations. Strengthening this process included working with a known breeding population, using scientific methods of selection, record keeping, and controlled mating, thus increasing the effectiveness and progress. The uniformity and consistency of desired traits in the breeding population increased and could be maintained over time.
In 1981, Susan Cobey and Timothy Lawrence established a beekeeping business, Vaca Valley Apiaries, in northern California and developed a Carniolan foundation population. Queens of mixed genetic backgrounds from across the U.S. and Canada were collected. Using instrumental insemination (II) and a system of selection and back-crossing, the breeding population increasingly expressed Carniolan traits within a few generations. The operation maintained 500 colonies for honey production and pollination services and 1000 mating nucleus to produce several thousand queens annually. Over half of the production colonies were headed by II queens to support the breeding program. It was essential to run II queens in full size colonies to provide income and evaluate these for field performance.
Five years into the NWC program, Dr. Harry Laidlaw brought his friend, visiting scientist Dr. Friedrich Ruttner, to see our project. A privilege, the renowned bee geneticist from Austria, who headed the Austrian Carnica Association at the time, offered his evaluation and advice. Samples were collected and tested using morphometrics (before molecular techniques were available). In his analysis, Dr. Ruttner described the NWC line as “the most Carniolan like bees” he had seen in the United States and Canada, although they did not meet the subspecies criteria for “pure” A.m.carnica. By appearance and behavior, the NWC expressed traditional Carniolan characteristics at this early stage of the program. Although, the mixed background of stock collected to establish the foundation population was evident in morphometric testing.
The NWC program was young and the dream to work with European A.m.carnica was not an option at the time. The Honey Bee Act of 1922 restricted importations to avoid the introduction of tracheal mites, Acarapis woodi. Subsequent amendments further restricted the importation of “undesirable germplasm” with concern of Africanized bees. We applied to obtain a permit for the importation of semen with the support of Dr. Laidlaw, Dr. Ruttner and Strachan Apiaries. Politics and concern over potential risks created unfavorable circumstances for importation. The award of a permit to import bee semen would take an additional 20 years.
Industry needs changed with the impact of parasitic mites, “Colony Collapse Disorder” and Africanized bees. The almond industry’s concern, if colony numbers would be sufficient for pollination needs, eased regulations. An estimated 105,000 package bees from Australia were imported between 2005 and 2010. However, increasing concern of risk management and the incursion of the Asian bee, Apis cerana, in Australia shut this down. These events opened the door to our request to import bee semen from Europe.
The NWC program moved from Vaca Valley Apiaries to several universities. The closure of the Canadian border eliminated a major queen market for these cold climate adapted bees. Commercial queen sales had supported the breeding program. This event pushed the focus of NWC program to concentrate on breeding stock, within a university setting. The program was housed at the Ohio State University from 1990-2007, then moved to back to California to UC, Davis in 2007 and to Washington State University in 2012. The goal remained, to produce highly productive bees with traditional Carniolan characteristics.
NWC program continues to provide breeding stock; instrumentally inseminated breeder queens and bee semen, to queen producers. This resource supplies most of the Carniolan production queens used by pollinators and honey producers in the U.S. Drs. Page and Laidlaw state in their 1997 book, Queen Rearing and Bee Breeding, the New World Carniolan program is “perhaps the most successful” such breeding endeavor.
Page-Laidlaw Closed Population Breeding Program
A modified CPBP, as applied the NWC, is briefly described. The program is designed to allow progressive selection within a large breeding population, over time. An essential component is maintaining genetic diversity within the breeding population A key criterion is selection for solid brood patterns. This is especially important considering a mass selection system is used (see the Page-Laidlaw CPBP description).
The theoretical model of the Page-Laidlaw CPBP is based on a foundation population of 50 queen mothers with a predicted life of 20 generations. Over time, the process of selection narrows the gene pool and can result in inbreeding depression. The NWC program has passed this benchmark. To increase the longevity of the program, additional Carniolan sources have been added to enhancing genetic diversity and increase vigor. The addition of A.m. carnica from European sources has proven a major benefit.
The goal is to maintain selection pressure on the breeding population to increase the consistency and uniformity of desirable traits. To evaluate numerous colonies efficiently, the selection process must be simple yet effective. Selection is based upon evaluating several general traits quickly and simultaneously among numerous colonies. New traits can be added to the selection criteria as new challenges and methodologies are developed, as well as testing for tolerance/resistance to pests and disease. These specific tests are labor intensive, so as a result, they are performed on fewer colonies after some culling.
Annually, a foundation population of about 30-60 breeders are selected. From these, virgin queens and drones are reared. Drones are collected from all breeder colonies and the pool of semen is inseminated to the virgins. A test population of 200 to 250 colonies, headed by II queens, is established. These test colonies are evaluated in the field and the top third selected. Of the selected colonies, these are tested for more specific traits and the top scoring breeders selected and propagated. This cycle is repeated annually.
The selection process consists of scanning and comparing colonies, using a two-step process. Step one, the pre-selection process evaluates established young queens. Several general traits are observed simultaneously in each colony. These traits include brood viability, temperament, colony buildup, the incidence of pests and diseases and color. Each trait is given a point value and performance of each colony ranked. Of these, less than average colonies are culled.
Selected colonies are allowed to build up over the season. In step two, colonies are evaluated for honey production, based on a weight gain during the flow, and for overwintering ability, based on early Spring frame counts. Of these, colonies scoring above average are selected and tested for tolerance/resistance to pests and diseases. Monitoring Varroa levels and testing hygienic behavior are performed on fewer, select colonies. Of these, the top tier colonies are chosen as breeders to propagate the next generation and the cycle is repeated. Culled colonies are split and requeened.
Importations A.m. carnica from European Sources
Genetic diversity, the raw tools of selection, is known to improve colony health, fitness, productivity and reduce the incidence of pests and disease. The historical introduction of honey bees into North America, before the 1922 restrictive importation law, was limited to small samplings of European sources. Over time, the U.S. honey bee gene pool has been reduced by several “bottleneck” events. These include natural genetic drift and the practice of consolidating and reducing breeding populations for commercial queen production. In addition, the syngenetic effects of parasites, pathogens, pesticides, and malnutrition contribute to loss of colonies.
The need to strengthen selection programs of commercial breeding stocks is increasingly recognized. Ensuring importations are safe and effective is essential. Limiting importations to semen only, and to proven, established breeding programs reduces risks and ensures future benefits.
In 2006, a USDA-APHIS, United States Department of Agriculture – Animal Plant Health Inspection Service, permit was issued to Ohio State University to import A.m. carnica semen from the Austrian Carnica Association to augment the NWC program. In partnership with Dr. Steve Sheppard, additional permits were awarded to Washington State University. A.m. carnica semen was imported from Germany and from Slovenia. With the incorporation of these European sources into the NWC program, beekeeping customers anecdotally reported increased vigor.
To minimize risk and in compliance with the APHIS permit, samples of the imported semen are tested for viruses by the USDA Beltsville Lab. The colonies resulting from queens inseminated to the imported semen are placed in an isolated quarantine station in eastern Washington. Colony inspections and progeny testing are conducted, and USDA-APHIS approval is required for release.
The imported semen of A.m. carnica stocks were sourced from Europe breeding programs with a long tradition of maintaining, preserving, and improving this subspecies. Beekeepers, with the support of government institutions and beekeeping associations, coordinate selection programs based upon performance tests, statistical data analysis, and controlled mating. Today, these programs utilize a modified BLUP (Best Linear Unbiased Prediction) animal model program, adapted for honey bees to estimate breeding values. More recently a European-wide project initiated as part of the COLOSS project (http://coloss.org) estimates Varroa resistance and vitality of various European bee strains.
We sourced A.m. carnica stocks from the Austrian and German Carnica Associations, breeding programs initiated by Dr. Ruttner dating back to the 1950s. Bee semen was obtained in 2006 from the Lunz Bee Institute in Austria headed by Dr. Hermann Pechhacker. In 2008 and 2009 stock was sourced from the Bee Institute in Kirchhain, Germany with the support of the Director, Dr. Ralph Büchler.
Additionally, A.m. carnica stocks were sourced from Slovenia in 2011 and 2017. With a long history and tradition of beekeeping dating back over 300 years, Carniolan bees are highly valued and important to the national identity and heritage of Slovenia. Every village has traditional bee houses, beekeeping shops offering local honeys and bee products, and often a museum displaying the local beekeeping history.
A small country of diverse climates, landscapes, and flora, Slovenia supports several ecotypes of Carniolan bees adapted to the different geographical areas. Preserving these ecotypes and their individual characteristics is highly valued. The Slovenian Beekeepers’ Association ensures the status and protection of their native bees through the Pure-Line Carniolan Bee Breeding Register.
The calmness and elegance of these bees is impressive; when working the local bees our bee veils remained unused. Dr. Aleš Gregorc from the Agricultural Institute of Slovenia hosted our collection trips. The Agricultural Institute, Slovenian Beekeepers’ Association and Ministry of Agriculture work together to protect and conserve the purity, improve the quality of A.m. carnica throughout Slovenia.
During our collection trips, fresh imported semen is inseminated to virgin queens supplied by cooperating NWC producers. The resulting queens are established in nucleus colonies and placed in quarantine, until release. Bee semen can be held at room temperature with good viability for over two weeks, time enough for collection and transport. We also cryopreserved some of the collected bee semen in liquid nitrogen for future use. Several lines of Slovenian A.m. carnica are maintained in the WSU germplasm repository and will be utilized to support the future of the NWC program.
Certified NWC Producer Partnership Established
The NWC is the major Carniolan stock used in the U.S. and serves as an industry standard. Now in its 40th generation, the goal is to transition the program into the future. A Certified NWC Producer Partnership has been established with the expertise of two, well respected, multi-generational queen producing operations, Strachan Apiaries and Buzz’s Bees.
Based in northern California, Buzz’s Bees and Strachan Apiaries will maintain the NWC breeding population and provide instrumentally inseminated breeder queens, in addition to production queens to the industry. Washington State University will continue to provide technical support. Part 2 of this article will feature Strachan Apiaries and Buzz’s Bees.
References & Additional Information
Bienefeld,K., Ehrhardt,K.., Reinhardt, F. 2007. Genetic evaluation in the honey bee considering queen and worker effects – A BLUP-Animal Model approach. Apidologie 38 (1), pp.77-85
Buzz’s Bees https://www.buzzsbees.com
Cobey S., Lawrence, T. 1988. Commercial Application and Practical Use of The Page-Laidlaw Closed Population Breeding Program. American Bee Journal, Vol. 128, Vol. 5, pp. 341-344
Hopkins, B.K., Herr, C.,Walter S. Sheppard W.S 2012. Sequential generations of honey bee (Apis mellifera) queens produced using cryopreserved semen. Reproduction, Fertility and Development 24(8) 1079-1083
COLOSS Honey Bee Research Association https://coloss.org
Johnson, R.N., Oldroyd, B.P., Barron, A.B., Crozier. R.H. 2002. Genetic Control of the Honey Bee (Apis mellifera) Dance Language: Segregating Dance Forms in a Backcrossed Colony. Journal of Heredity, 93: 3: 170-173. https://doi.org/10.1093/jhered/93.3.170
Koeniger,G., Koeniger,N., Pechhacker,H., Ruttner,F., Berg,S. 1989. Assortative Mating in a mixed population of European honey bees, A.m.ligustica and A.m.carnica. Insect. Soc.36, 129-138.
Laidlaw H.H. Page R.E., 1997. Queen Rearing and Bee Breeding. Wicwas Press.
Page R.E., Laidlaw H.H. 1982. Closed population honeybee breeding. 1. Population genetics of sex determination. J. Apic. Res. 21, 30-37.
Page R.E., Laidlaw H.H. 1982. Closed population honeybee breeding. 2. Comparative methods of stock maintenance and selective breeding, J. Apic. Res. 21, 38–44.
Page R.E., Laidlaw H.H., Erickson, E.H., 1983. Closed population honeybee breeding. 3. The distribution of sex alleles with gyne supersedure. J. Apic. Res. 22, 184-190.
Page R.E., Laidlaw H.H. 1985. Closed Population Honey Bee Breeding Program. Bee World, Vol. 66, pp. 63-72.
Rinderer TE and Beaman LD, 1995. Genic control of honey bee dance language dialect. Theor Appl Genet 91:727–732.
Nowottnick, K. 2012. The Carniolan Bee. The Beekeepers Quarterly No 107. pg 43
Ruttner, F. 1988. Breeding Techniques & Selection for Breeding the Honey Bee. British Isles Bee Breeders Assoc.
Sheppard, WS. 1989. A history of the introduction of honey bee races into the United States, I and II. Amer. Bee J. 129: 617-619, 130: 664-667.
Slovenian Bee breeding http://apis-mellifera-carnica.eu/en/
Strachan Apiaries https://strachanbees.com
Tarpy D.R. 2003. Genetic diversity within honeybee colonies prevents severe infections and promotes colony growth. Proceedings of the Royal Society of London Series B-Biological Sciences 270(1510), 99-103.
Tarpy D.R., T.D. Seeley. 2006. Lower disease infections in honeybee (Apis mellifera) colonies headed by polyandrous vs monandrous queens. Naturwissenschaften 93(4), 195-199.
